Name: catheter ablation in combination with left atrial appendage closure for atrial fibrillation
Uploaded: 2013-02-26T11:57:00
Duration: 28 min 13 s
Description: Watch this Scientific Journal Video about Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation at JoVE.com

The authors would like to thank Ted van de Beek of Boston Scientific for his support during the preparation of this manuscript.

1. Pre-procedure Preparation
<ol>
	<li>Prior to performing the procedure, discuss the risks and benefits of the procedure with the patient, and obtain a signed consent form. Adjust the patient's vitamin K antagonist dose to achieve an international normalized ratio of 2.0 to 3.0. Continue antiarrhythmic drug therapy up to the time of the procedure.</li>
	<li>Either the day before or the day of the procedure, perform a transesophageal echocardiogram (TEE) to document the absence of thrombi within the LAA, assess the features and type of the LAA, and to determine the appropriate WATCHMAN device size to implant (see the 2012 JoVE article by Mobius-Winkler and colleagues for more information)22.</li>
	<li>Perform the combined catheter ablation and WATCHMAN LAA Closure Device placement procedure in an electrophysiology lab with the appropriate diagnostic and imaging equipment for the procedure.</li>
	<li>With the patient in the supine position, administer anaesthesia according to institutional protocols.</li>
</ol>
2. Catheter Ablation
<ol>
	<li>Ensure that the electrophysiological recording system (Bard Inc., Lowell, MA) is using filter settings of 100 to 500 kHz and a signal amplification of 5,000.</li>
	<li>Once the patient is fully anesthetized, administer 20 ml of 1% lidocaine as a local anesthetic in the groin region. Immediately, clean and prep the inguinal region for cannulation.</li>
	<li>Locate the femoral vein, and insert a venous 8 French (8F) sheath. Introduce a quadripolar catheter into the coronary sinus for pacing purposes. Then, insert a long guidewire, and remove the sheath. Introduce a standard venous transseptal access sheath.</li>
	<li>Remove the long guidewire, and insert a Transseptal RF Brockenbrough needle (Baylis Medical Company Inc., Montreal, Quebec, Canada) with a 12.5F-outer-diameter/9.5F-inner-diameter steerable sheath (Channel, Bard, Lowell, MA) and perform a transseptal puncture.</li>
	<li>After crossing the interatrial septum, position a pigtail catheter in the center of the left atrium and perform a 3D rotational angiography.</li>
	<li>The Pulmonary Vein Ablation Catheter (PVAC: Medtronic/Ablation Frontiers, Inc., Carlsbad, CA) is a 9F, over-the-wire, circular, decapolar mapping and ablation catheter with a 25-mm-diameter array at the distal tip. No additional nonfluoroscopic guiding or steering systems were used. The PVAC has ten electrodes on a nitinol frame that enable mapping, ablation and verification of pulmonary vein isolation. Insert a 0.032-inch guidewire into the PVAC.</li>
	<li>Next, insert the whole system into the venous sheath. The information gathered by the PVAC is displayed on a monitor to generate a 3D image of the patient's heart with the catheter's location displayed.</li>
	<li>Deliver a bolus of 10.000IE heparin to prevent clotting as a result of the procedure. Position the wire in one of the branches of the pulmonary vein, then advance the PVAC into the pulmonary vein antrum.</li>
	<li>Use fluoroscopic guidance, electrograms, and 3D electric signal imaging (ESI) reconstruction to assess the position of the PVAC and adjust it to get the best contact with all of the electrodes.</li>
	<li>Once a satisfying catheter position is achieved, commence radio frequency (RF)-ablation by selecting the appropriate electrode pairs for delivery of RF energy.</li>
	<li>Set the generator to adjust the power to achieve a target temperature of 60 &deg;C for each electrode in the selected pairs. In most cases, all electrodes pairs will be activated during the first applications to create overlapping lesion rings.</li>
	<li>Ablate for 60 sec. Check the monitor for conditions during ablation. If the temperature does not rise above 50 &deg;C within 15 sec, discontinue the application, adjust the position of the electrodes and start again.</li>
	<li>Move and rotate the PVAC-catheter to create circumferential pulmonary vein lesions.</li>
	<li>Repeat this procedure for all pulmonary veins.</li>
	<li>After creating circumferential lesions for all pulmonary veins, restore sinus rhythm by direct current cardioversion (DCCV).</li>
	<li>Confirm isolation by checking the absence of local potentials (entrance and exit block) with PVAC mapping inside each vein combined with pacing maneuvers from the coronary sinus.</li>
	<li>For residual potentials on isolated electrode pairs, target ablation only on that and adjacent pairs to facilitate reaching target temperature.</li>
</ol>
3. Implantation of the WATCHMAN Device
<ol>
	<li>Once the catheter ablation procedure is complete, the WATCHMAN device is implanted.</li>
	<li>Advance a 0.035" stiff guidewire (e.g. Amplatz Super stiff 260 cm) into the PVAC and position the guidewire in the left upper pulmonary vein. Remove the PVAC while maintaining the position of the guidewire.</li>
	<li>If ablation was not performed prior to implantation, administer heparin at 100 IU/kg bodyweight to obtain an activated clotting time of 200-300 sec. Check the activated clotting time level to ensure that it is still 200-250 sec. Continue to monitor this every 30 min as needed.</li>
	<li>Remove the WATCHMAN Access System and dilator from the packaging under sterile conditions. Carefully inspect it for damage.</li>
	<li>Fill a 60CC syringe with saline and flush the side port of the WATCHMAN access sheath. Use the remaining saline to flush the dilator. Insert the dilator into the WATCHMAN access sheath.</li>
	<li>Advance the WATCHMAN access sheath and dilator over the guidewire into the left atrium. As the WATCHMAN access sheath nears the center of the left atrium, hold the dilator and advance the WATCHMAN access sheath to the initial position of the left atrium only.</li>
	<li>Remove the dilator and guidewire. Before tightening the hemostasis valve, allow back bleed to minimize the potential for introducing air. Flush WATCHMAN access sheath with saline.</li>
	<li>Tighten the valve on the access sheath.</li>
	<li>To confirm the LAA dimensions, use TEE to measure the maximum LAA dimensions in 4 views at 0 &deg;, 45 &deg;, 90 &deg; and 135 &deg;.</li>
	<li>Flush the pigtail catheter with saline and advance it over the wire and through the WATCHMAN access sheath. Then, remove the guidewire and connect a syringe with contrast dye to the pigtail.</li>
	<li>While viewing TEE, turn the WATCHMAN access sheath counterclockwise to align the sheath more anterior and advance the pigtail in the desired position in the distal portion of the LAA.</li>
	<li>Once the pigtail catheter has reached the LAA, obtain angiography at a right anterior oblique (RAO) of 20-30 &deg;, caudal 20-30 &deg;. Then perform TEE with a minimum of a 0-135 &deg; sweep. This is most important when the sheath is advanced near the wall or apex of the LAA and while advancing more distally in any anatomy.</li>
	<li>Carefully advance the access sheath over the pigtail catheter in the most superior lobe: in angiography this is the LAA-lobe situated around 2 o'clock at a right anterior oblique (RAO) of 20-30 &deg;, caudal 20-30 &deg;, in TEE it is the most right LAA-lobe at 135 &deg;.</li>
	<li>Under fluoroscopic guidance, advance the WATCHMAN access sheath to the desired depth in the LAA based on the marker band corresponding to the appropriate size.</li>
	<li>Once the pigtail is as distal as possible, inject the contrast dye.</li>
	<li>Select the appropriate WATCHMAN device size based on maximum LAA ostium dimensions and sizing 22.</li>
	<li>Under sterile conditions, remove the WATCHMAN device from the packaging inspect it for damage. To confirm the device is attached to the core wire, open the hemostatic valve and retract the device approximately 1 cm.</li>
	<li>Align the distal tip of the device with the marker band. The WATCHMAN device should not protrude.</li>
	<li>Attach a large 60 cc syringe containing saline. Flush the system several times to remove any air. Then, submerge the tip of the delivery catheter in saline and tap it to remove bubbles.</li>
	<li>Recheck the position of the access sheath by angiography. Loosen the access sheath valve and slowly remove the pigtail catheter from the sheath. Allow the sheath to back bleed.</li>
	<li>To avoid introducing air, inject saline through the flush port so that it drips from the delivery catheter, then, introduce the WATCHMAN device system.</li>
	<li>Under fluoroscopic guidance, slowly advance the delivery catheter into the access sheath until the most distal marker band on the access sheath lines up with the marker band on the delivery catheter and stabilize the delivery catheter.</li>
	<li>Retract the access sheath and snap it onto the delivery catheter. Using fluoroscopy, reconfirm position of the delivery catheter tip. Do not advance the access sheath once the delivery system has been snapped into it.</li>
	<li>If repositioning is required, remove the delivery system, reinsert the pigtail catheter and advance the access sheath into the proper position.</li>
	<li>Once the delivery system is positioned, loosen the valve on the WATCHMAN delivery catheter. Observe the distal end of device to ensure that no forward advancement or repositioning relative to ostium occurs.</li>
	<li>Then, to deploy the device, hold the deployment knob stationary and slowly retract the access sheath/delivery catheter assembly with a slow stable motion over a period of 3-5 sec.</li>
	<li>Withdraw the access sheath/delivery catheter assembly a few centimeters from the device to align it with the LAA, leaving the core wire attached.</li>
	<li>Once the device has been deployed, inject contrast again. Then, using fluoroscopy and TEE, confirm the Position, Anchor, Size and Seal (PASS) device release criteria have been met as follows:</li>
	<li>Position: Confirm the device is properly positioned by ensuring that the plane of maximum diameter of the device spans the LAA ostium and is at or just distal to the orifice of the LAA.</li>
	<li>Anchor: Confirm the device is anchored in place, by withdrawing the access sheath/delivery catheter assembly 1 - 2 cm from the face of the device then gently retracting and releasing the deployment knob. The LAA and device should move in unison.</li>
	<li>Size: Confirm that the device is appropriately sized by measuring the plane of the maximum diameter of the device using TEE in the standard 4 views 0 &deg;, 45 &deg;, 90 &deg;, and 135 &deg;, ensuring the threaded insert is visible. The device should be 80-92% of the original size.</li>
	<li>Seal: using color Doppler, ensure that all of the lobes distal to device are sealed. Color flow should not be detected near the device. If there is a gap or jet around the device that is larger than 5 mm, the device should be repositioned or fully recaptured and replaced.</li>
	<li>If all release criteria are met, move the access sheath/delivery catheter up to the face of the device and rotate the deployment knob 3-5 turns counterclockwise to release.</li>
	<li>After release, perform angiography with contrast dye to document that the device is still in place. Then, using TEE, recheck the size and seal. Remove the sheath assembly from the left atrium.</li>
	<li>If the device is too distal or proximal in the LAA or the device criteria are not met, it may be necessary to partially or fully recapture the device (for details please see the 2012 JoVE article by M&ouml;bius-Winkler and colleagues)22.</li>
</ol>
4. Post-procedure
<ol>
	<li>Once proper placement of the device has been confirmed, remove the sheath. The femoral vein should then be compressed for a few hours and the patient should be carefully monitored for at least 6 hr with blood pressure and heart rate monitoring.</li>
	<li>Check for hematoma and/or bleeding at regular intervals according to institutional guidelines. The patient should be administered antibiotic prophylaxis per the American Heart Association's guidelines. NOTE: Post procedure heparin is not recommended.</li>
	<li>Once the patient is awake, perform a neurological examination.</li>
	<li>The patient should remain on warfarin and 81 mg aspirin for a minimum of 45 days after the implant procedure (internal normalized ratio = 2.0-3.0).</li>
	<li>The patient should be hospitalized overnight and discharged the next day. A transthoracic echocardiogram (TTE) or chest x-ray may be performed to confirm the absence of pericardial effusion.</li>
	<li>At 45 days, assess the WATCHMAN device placement using TEE. Cessation of warfarin is at physician discretion, if the LAA is closed completely and thrombus on the device was ruled out. If flow is noted around the device greater than 5 mm, consideration should be given to keep the patient on warfarin until it has decreased to less than 5 mm.</li>
	<li>Patients ceasing warfarin should begin 75 mg clopidogrel daily through 6 months post-implant and continue taking aspirin daily indefinitely.</li>
	<li>Prescribe the appropriate endocarditis prophylaxis for 6 months following implantation. Continuing endocarditis prophylaxis beyond 6 months is at physician discretion.</li>
</ol>

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D. i., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Left+atrial+appendage:+an+underrecognized+trigger+site+of+atrial+fibrillation.">Left atrial appendage: an underrecognized trigger site of atrial fibrillation.</a> Circulation. 122, 109-118 (2010).</li></ol>

The Cardiology Department of St. Antonius Hospital (Nieuwegein, the Netherlands) receives proctoring fees for training/educational services from Atritech/Boston Scientific.
Production and Free Access to this article is sponsored by Boston Scientific.

The preceding text describes a procedure for combined catheter ablation and left atrial appendage occlusion as treatment for AF and prevention of associated thromboembolic events. Preliminary data indicate that this procedure can be safely performed in patients at high risk for stroke. No technical difficulties have been encountered in performing the combined procedure. While no improvement to either procedure can be expected since they do not influence each other, the combined procedure may offer several advantages over performing the procedures separately. The combined procedure enables simultaneous treatment of AF symptoms and reduction of stroke risk, improving quality of life for those affected by AF. It may also present drug refractory-patients a treatment option by allowing them to undergo implantation of the WATCHMAN device without subsequent warfarin treatment. Furthermore, the need for, and associated risk of, a repeated left atrial intervention and transseptal puncture is reduced should LAA closure become desirable during follow-up.
While CA is an established treatment for symptoms of AF, recent data suggest that it is also effective in reducing stroke. In a retrospective analysis of matched AF patient pairs, Reynolds and colleagues saw a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy 16. Data also indicates that amputation of the LAA or occlusion via surgical ligation or device placement effectively reduces embolic events. These methods appear promising: in a study of patients undergoing mitral valve replacement those that underwent surgical ligation had significantly fewer strokes (3 vs. 17%) 19, 23. A less invasive, thoracoscopic ligation using an loop snare procedure has been performed successfully in 14 of 15 patients with stroke occurring in 2 patients (4%) over the following 42 months 19,24.
Several percutaneous catheter LAA occlusion devices have been developed including the Amplatzer Cardiac Plug (AGA medical), the Transcatheter Patch (Custom Medical Devices), the percutaneous LAA Transcatheter occlusion (PLAATO) system, and the WATCHMAN LAA occlusion device. At present, clinical studies regarding safety and efficacy are published only for PLAATO (which is no longer available) and the WATCHMAN. The PLAATO demonstrated safety and efficacy and offers proof of concept for LAA closure using a nitinol filter-based device. The device was a self-expanding nitinol cage covered in polytetrafluoroethylene that prevented blood from entering the LAA 25. A non-randomized study of 64 patients with a CHADS2 of &gt;2 demonstrated complete occlusion in more than 98% of patients. After 5 years, the stroke/transient ischemic attack rate was reduced to 3.8% compared to the expected 6.6% in a population 26.
The data obtained from the PROTECT AF study 18, which compared the efficacy of the WATCHMAN device to treatment with warfarin further support a device-based approach of LAA occlusion. This randomized study showed that implantation WATCHMAN was found to be non-inferior in terms of all-cause stroke and all-cause mortality in OAC eligible patients, raising the possibility that the procedure could eventually be used as an alternative to chronic warfarin therapy in patients who are drug-refractive 18. In the study published in Netherlands Heart Journal in 2012 21, we successfully implanted the device in 10 patients, 9 of whom underwent concurrent CA. Note that although residual flow was seen in 3 cases at 45 days follow up, Viles-Gonzalez and colleagues have shown that this residual flow around the device is not associated with an increased risk of thromboembolic events 27.
While the available data support both CA and LAA occlusion using the WATCHMAN device as effective treatments for AF, both procedures are associated with complications. A worldwide survey of CA in 2010 showed that complications occur in 4.5% of patients 14. The most significant complications include: death, cerebral thromboembolic events, extrapericardial pulmonary vein perforation, tamponade, stenosis, and atypical flutter of new onset (iatrogenic) 14, 15, 28. Procedural complications that may result from WATCHMAN device placement procedure include serious pericardial effusion, device embolization, procedure-related stroke 18. In both cases, the incidence of complications has been found to depend on operator experience 15, 29.
In the 2012 study of the combined procedure, complications were limited to one device embolism. Half of the patients did not have documented recurrence of AF at 3-month follow-up. The other half of the patients required at least one direct current cardioversion. One patient underwent repeat ablation and it was successful 21. Though this study was of a small population and does not provide a direct comparison with other methods of treatment, studies of safety in each of the independent procedures 29, 30 suggest that the potential benefits of treatment offsets the increase in safety risk. Additional safety issues to consider are the longer procedural times, requirement for general anesthesia, and the increased risk of GI-tract bleeding with TEE monitoring, which must accompany WATCHMAN placement.
While the procedure described herein describes a combined procedure of WATCHMAN placement and PV CA, it is important to note that WATCHMAN placement does not preclude a strategy of electrical isolation of the LAA. A recent study by Di Biase and colleagues demonstrated that in a selected patient group with recurrent AF, 27% showed foci arising from the LAA after an initial ablation, which was optimally treated via complete circumferential LAA isolation31. This patient group might especially benefit from LAA closure because electrical isolation of the LAA could lead to LAA stasis even during sinus rhythm, making it more thrombogenic. In patients for whom AF ablation and LAA closure is considered, one could first perform an electrophysiological study with pharmacological challenges to detect and ablate possible LAA triggers before implantation of the WATCHMAN device 31.
Given the present study is not randomized, and is limited to a 45-day follow up with 10 high-risk patients, numerous questions remain to be addressed: Is the combined CA/WATCHMAN implantation procedure more effective in stroke prevention and relief of AF symptoms than either method alone? How do the benefits of the procedure compare if the order of the procedures is reversed, with LAA occlusion first? How does the safety of the procedure compare to either device implantation or CA alone? Is this effective in lower-risk patients? Is the need for future ablations affected by the combined procedure? Can the procedure be performed with equal success in patients not taking warfarin? Future studies will include a randomized control study to examine whether combining these techniques improves patient outcome and quality of life in these patients.
Note that when performing this procedure it is important to carefully evaluate the LAA anatomy when selecting the device size and to thoroughly check the placement of the device before releasing it. It is also very important to ensure that the depth of the landing zone for the device is equal or greater than the maximum width of the LAA ostium. These steps are critical for patient safety and effectiveness of the procedure.

catheter ablation in combination with left atrial appendage closure for atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope 4, 5. Patients with AF have a five-fold higher risk of stroke 6.
Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64% 7. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range 8-11. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug 8.
The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF 12,13, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers 4. CA is a well-established treatment for AF symptoms 14, 15, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy 16.
Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation 17, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN LAA closure device. The WATCHMAN device resembles a small parachute. It consists of a nitinol frame covered by fabric polyethyl terephthalate that prevents emboli, but not blood, from exiting during the healing process. Fixation anchors around the perimeter secure the device in the LAA (Figure 1). To date, the WATCHMAN is the only implanted percutaneous device for which a randomized clinical trial has been reported. In this study, implantation of the WATCHMAN was found to be at least as effective as warfarin in preventing stroke (all-causes) and death (all-causes) 18. This device received the Conformit&eacute; Europ&eacute;enne (CE) mark for use in the European Union for warfarin eligible patients and in those who have a contraindication to anticoagulation therapy 19.
Given the proven effectiveness of CA to alleviate AF symptoms and the promising data with regard to reduction of thromboembolic events with both CA and WATCHMAN implantation, combining the two procedures is hoped to further reduce the incidence of stroke in high-risk patients while simultaneously relieving symptoms. The combined procedure may eventually enable patients to undergo implantation of the WATCHMAN device without subsequent warfarin treatment, since the CA procedure itself reduces thromboembolic events. This would present an avenue of treatment previously unavailable to patients ineligible for warfarin treatment because of recurrent bleeding 20 or other warfarin-associated problems.
The combined procedure is performed under general anesthesia with biplane fluoroscopy and TEE guidance. Catheter ablation is followed by implantation of the WATCHMAN LAA closure device. Data from a non-randomized trial with 10 patients demonstrates that this procedure can be safely performed in patients with a CHADS2 score of greater than 1 21. Further studies to examine the effectiveness of the combined procedure in reducing symptoms from AF and associated stroke are therefore warranted.

In a preliminary study of WATCHMAN implantation in 10 patients that had a high risk of stroke and bleeding, 9 of the patients received the device after a catheter ablation. The data from this study is published in the Netherlands Heart Journal, and is presented here with permission 21. All patients included in the study were fully informed about the procedure and signed a consent form. The study was approved by the hospital's ethics committee and all procedures were performed in accordance with the hospital's ethics standards and the Helsinki Declaration of 1975 (revised in 2008).
The characteristics of these patients are summarized in Table 1. All patients had documented AF with a high stroke risk (CHADS2 &gt;1) and all but one of the patients had history of stroke. LAA closure was indicated as an alternative to OAC for the following reasons: stroke during OAC therapy (3/10), severe bleeding during OAC therapy (2/10) and patient preference (5/10). Prior to the procedure all patients were taking a vitamin K antagonist. The median CHADS2 score for this group was 3, with a median CHA2DS2-VASc score of 3.5 and a median HAS-BLED score of 1.5. Prior to the procedure, all patients underwent TEE to exclude LAA thrombus and to rule out structural cardiac abnormalities. Among patients, the average maximum LAA diameter was 20.2&plusmn;2.2 mm with an average depth of 27.9&plusmn;5.4 mm. 40% of the patients had a multi-lobular atrial appendage.
Table 2 outlines procedural characteristics. The WATCHMAN LAA closure device was successfully placed in all 10 patients. Based on patient anatomy determined during preliminary TEE, three different device sizes were used. The median total procedure time was 104 min (range 75-167 min), including a median 56 min (range 38-137 min) for LAA occlusion. During the procedure, an asymptomatic catheter thrombus occurred in one patient. The thrombus was aspirated and the patient received an extra bolus of heparin. Prolonged femoral vein bleeding in this patient necessitated a blood transfusion and extended hospitalization. All other patients were discharged from the hospital on the day following the procedure (Table 2). OAC was continued at least until TEE was performed at 45 days, at which point the device position and closure rate was assessed.
The findings at the 45-day patient follow-up are summarized Table 3. Successful device implantation was defined as long-term sealing of the LAA as measured by TEE 45 days after the procedure without major adverse events. Residual flow (&lt; 5 mm) around the device was allowed after the procedure (according to the PROTECT-AF study). Importantly, no thromboembolic cerebral events occurred. Minimal residual flow was observed in 3 patients. TEE revealed asymptomatic embolization of the device in one patient, and the device was percutaneously retrieved via the femoral vein. Thrombus was not seen on the device in any cases. One patient required a redo-ablation procedure 3 months after the initial procedure, in which pulmonary vein isolation was successful. The implanted LAA device was not affected by and did not interfere with the procedure. Three of the 10 patients were able to discontinue warfarin treatment at 45 days. In the PROTECT-AF18 and Continues Access Registry29 device embolization occurred in 3 patients out of the 1,002 patients implanted.
Figure 2 shows a TEE screen capture of the LAA in one example patient in which no residual flow is observed 45 days post-procedure. In contrast, flow around the device, as evidenced by color Doppler, is seen for another patient (Figure 3).
<table border="1">
	<tbody>
		<tr>
			<td colspan="2">Baseline Characteristics</td>
		</tr>
		<tr>
			<td>Number, n</td>
			<td>10</td>
		</tr>
		<tr>
			<td>Age (years)</td>
			<td>61.6 +/9.6</td>
		</tr>
		<tr>
			<td>Sex (%female)</td>
			<td>5 (50)</td>
		</tr>
		<tr>
			<td>Median CHADS2</td>
			<td>3 (2-4)</td>
		</tr>
		<tr>
			<td>2</td>
			<td>4 (40)</td>
		</tr>
		<tr>
			<td>3</td>
			<td>4 (40)</td>
		</tr>
		<tr>
			<td>4</td>
			<td>2 (20)</td>
		</tr>
		<tr>
			<td>CHA2DS2-VASc</td>
			<td>3.5 (2-6)</td>
		</tr>
		<tr>
			<td>HAS-BLED</td>
			<td>1.5 (1-4)</td>
		</tr>
		<tr>
			<td>Vitamin K antagonist, n(%)</td>
			<td>10 (100)</td>
		</tr>
		<tr>
			<td colspan="2">Indication, n(%)</td>
		</tr>
		<tr>
			<td>Bleeding with OAC</td>
			<td>2 (20)</td>
		</tr>
		<tr>
			<td>Stroke using OAC</td>
			<td>3 (30)</td>
		</tr>
		<tr>
			<td>Patient Preference</td>
			<td>5 (50)</td>
		</tr>
		<tr>
			<td colspan="2">LAA, mm</td>
		</tr>
		<tr>
			<td>LAA width</td>
			<td>20.2+/2.2</td>
		</tr>
		<tr>
			<td>LAA length</td>
			<td>27.9+/-5.4</td>
		</tr>
		<tr>
			<td>Multilobular</td>
			<td>4 (40)</td>
		</tr>
	</tbody>
</table>
Table 1. Baseline characteristics of patients enrolled in the study. Data reprinted with permission from the Netherlands Heart Journal 21. All data are presented as mean +/- standard deviation, as number with percentage (n(%)) or median with lower and upper range, N=number, mm=millimeters, OAC=oral anticoagulation, LAA=left atrial appendage.
<table border="1">
	<tbody>
		<tr>
			<td colspan="2">Procedural characteristics</td>
		</tr>
		<tr>
			<td>PVAC, n(%)</td>
			<td>9 (90)</td>
		</tr>
		<tr>
			<td>Size device (mm)</td>
			<td>24 (21-27)</td>
		</tr>
		<tr>
			<td>21</td>
			<td>1 (10)</td>
		</tr>
		<tr>
			<td>24</td>
			<td>8 (80)</td>
		</tr>
		<tr>
			<td>27</td>
			<td>1 (10)</td>
		</tr>
		<tr>
			<td>LAA Occlusion Time (min)</td>
			<td>56 (38-137)</td>
		</tr>
		<tr>
			<td>Total procedural time (min)</td>
			<td>104 (75-167)</td>
		</tr>
		<tr>
			<td>Devices, n</td>
			<td>2 (1-3)</td>
		</tr>
		<tr>
			<td colspan="2">Complications, n(%)</td>
		</tr>
		<tr>
			<td>Catheter thrombus</td>
			<td>1 (10)*</td>
		</tr>
		<tr>
			<td>Inguinal bleeding</td>
			<td>1 (10)*</td>
		</tr>
		<tr>
			<td>Pericardial effusion</td>
			<td>0 (0)*</td>
		</tr>
		<tr>
			<td colspan="2">TEE</td>
		</tr>
		<tr>
			<td>Successful implantation</td>
			<td>10 (100)</td>
		</tr>
		<tr>
			<td>Residual Flow</td>
			<td>1 (10)</td>
		</tr>
		<tr>
			<td>Hospitalization, days</td>
			<td>2 (2-7)</td>
		</tr>
	</tbody>
</table>
Table 2. Procedural characteristics. Data reprinted with permission from the Netherlands Heart Journal 21. All data are presented as mean +/- standard deviation, as number with percentage (n(%)) or median with lower and upper range, N=number, mm=millimeters, PVAC=pulmonary vein ablation catheter, TEE=Transesophageal echocardiography. *Both in the same patient.
<table border="1">
	<tbody>
		<tr>
			<td colspan="2">Follow-up characteristics at 45 days</td>
		</tr>
		<tr>
			<td>Number, n (%)</td>
			<td>10</td>
		</tr>
		<tr>
			<td>TEE, n (%)</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Residual flow</td>
			<td>3 (33)</td>
		</tr>
		<tr>
			<td>Device embolization</td>
			<td>1 (10)</td>
		</tr>
		<tr>
			<td>Thrombus on device</td>
			<td>0 (0)</td>
		</tr>
		<tr>
			<td>Vitamin K antagonist, n(%)</td>
			<td>6 (67)</td>
		</tr>
		<tr>
			<td colspan="2">Complications during follow-up, n(%)</td>
		</tr>
		<tr>
			<td>Death</td>
			<td>0 (0)</td>
		</tr>
		<tr>
			<td>Stroke or TIA</td>
			<td>0 (0)</td>
		</tr>
		<tr>
			<td>Bleeding</td>
			<td>1 (10)</td>
		</tr>
	</tbody>
</table>
Table 3. 45-day follow-up. Data reprinted with permission from Netherlands Heart Journal 21. All data are presented as mean +/- standard deviation, as number with percentage (n(%)) or median with lower and upper range, N=number, mm=millimeters, TEE=Transesophageal echocardiography, TIA=transient ischemic attack.
<img alt="Figure 1" src="/files/ftp_upload/3818/3818fig1.jpg" /> 
 Figure 1. The WATCHMAN Device. The WATCHMAN device is a nitinol cage covered with a Polyethyl terephthalate membrane. Fixation barbs around the perimeter secure the device in the LAA.
<img alt="Figure 2" src="/files/ftp_upload/3818/3818fig2.jpg" /> 
 Figure 2. A complete LAA isolation or occlusion. TEE with color Doppler demonstrating proper positioning and occlusion at 45 days post-procedure from different TEE-angulations in a single patient. As the TEE probe looks at the device between 0-180 &deg;, there is no flow in the appendage and that the device is appropriately placed in all views.
<img alt="Figure 3" src="/files/ftp_upload/3818/3818fig3.jpg" /> 
 Figure 3. An incomplete LAA occlusion. TEE with color Doppler 45 days post-procedure demonstrating flow (leak) around the device. As the TEE probe looks at the device between 0-180 &deg;, a small gap (&lt;5 mm) with color flow is seen around the device. These findings still can be qualified as successful sealing. Therefore OAC can be stopped. All images are from the same patient.

Watch this Scientific Journal Video about Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation at JoVE.com

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and ...

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High-Resolution Endocardial and Epicardial Optical Mapping in a Sheep Model of Stretch-Induced Atrial Fibrillation

Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance seen in clinical practice and its prevalence is expected to increase in the coming years.3 Increased intra-atrial pressure and dilatation have been long recognized to lead to AF,1,4 which highlights the relevance of using animal models and stretch to study AF dynamics. Understanding the mechanisms underlying AF requires visualization of the cardiac electrical waves with high spatial and temporal resolution. While high-temporal resolution can be achieved by conventional electrical mapping traditionally used in human electrophysiological studies, the small number of intra-atrial electrodes that can be used simultaneously limits the spatial resolution and precludes any detailed tracking of the electrical waves during the arrhythmia. The introduction of optical mapping in the early 90's enabled wide-field characterization of fibrillatory activity together with sub-millimeter spatial resolution in animal models5,6 and led to the identification of rapidly spinning electrical wave patterns (rotors) as the sources of the fibrillatory activity that may occur in the ventricles or the atria.7-9 Using combined time- and frequency-domain analyses of optical mapping it is possible to demonstrate discrete sites of high frequency periodic activity during AF, along with frequency gradients between left and right atrium. The region with fastest rotors activates at the highest frequency and drives the overall arrhythmia.10,11 The waves emanating from such rotor interact with either functional or anatomic obstacles in their path, resulting in the phenomenon of fibrillatory conduction.12 Mapping the endocardial surface of the posterior left atrium (PLA) allows the tracking of AF wave dynamics in the region with the highest rotor frequency. Importantly, the PLA is the region where intracavitary catheter-based ablative procedures are most successful terminating AF in patients,13 which underscores the relevance of studying AF dynamics from the interior of the left atrium. Here we describe a sheep model of acute stretch-induced AF, which resembles some of the characteristics of human paroxysmal AF. Epicardial mapping on the left atrium is complemented with endocardial mapping of the PLA using a dual-channel rigid borescope c-mounted to a CCD camera, which represents the most direct approach to visualize the patterns of activation in the most relevant region for AF maintenance.

This report provides a detailed description of the methodology and results of simultaneous endocardial and epicardial optical mapping of electrical excitation in the intact left atrium of a Langendorff-perfused sheep heart during stretch-induced atrial fibrillation.

 Atrial fibrillation (AF) is a complex cardiac arrhythmia with high morbidity and mortality.1,2 It is the most common sustained cardiac rhythm disturbance ...

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting an estimated 6 million people in the United States 1. Since AF affects primarily elderly people, its prevalence increases parallel with age. As such, it is expected that 15.9 million Americans will be affected by the year 2050 2. Ischemic stroke occurs in 5% of non-anticoagulated AF patients each year. Current treatments for AF include rate control, rhythm control and prevention of stroke 3.
The American College of Cardiology, American Heart Association, and European Society of Cardiology currently recommended rate control as the first course of therapy for AF 3. Rate control is achieved by administration of pharmacological agents, such as &beta;-blockers, that lower the heart rate until it reaches a less symptomatic state 3. Rhythm control aims to return the heart to its normal sinus rhythm and is typically achieved through administration of antiarrhythmic drugs such as amiodarone, electrical cardioversion or ablation therapy. Rhythm control methods, however, have not been demonstrated to be superior to rate-control methods 4-6. In fact, certain antiarrhythmic drugs have been shown to be associated with higher hospitalization rates, serious adverse effects 3, or even increases in mortality in patients with structural heart defects 7. Thus, treatment with antiarrhythmics is more often used when rate-control drugs are ineffective or contraindicated. Rate-control and antiarrhythmic agents relieve the symptoms of AF, including palpitations, shortness of breath, and fatigue 8, but don't reliably prevent thromboembolic events 6.
Treatment with the anticoagulant drug warfarin significantly reduces the rate of stroke or embolism 9,10. However, because of problems associated with its use, fewer than 50% of patients are treated with it. The therapeutic dose is affected by drug, dietary, and metabolic interactions, and thus requires detailed monitoring. In addition, warfarin has the potential to cause severe, sometimes lethal, bleeding 2. As an alternative, aspirin is commonly prescribed. While aspirin is typically well tolerated, it is far less effective at preventing stroke 10. Other alternatives to warfarin, such as dabigatran 11 or rivaroxaban 12 demonstrate non-inferiority to warfarin with respect to thromboembolic events (in fact, dabigatran given as a high dose of 150 mg twice a day has shown superiority). While these drugs have the advantage of eliminating dietary concerns and eliminating the need for regular blood monitoring, major bleeding and associated complications, while somewhat less so than with warfarin, remain an issue 13-15.
Since 90% of AF-associated strokes result from emboli that arise from the left atrial appendage (LAA) 2, one alternative approach to warfarin therapy has been to exclude the LAA using an implanted device to trap blood clots before they exit. Here, we demonstrate a procedure for implanting the WATCHMAN Left Atrial Appendage Closure Device. A transseptal cannula is inserted through the femoral vein, and under fluoroscopic guidance, inter-atrial septum is crossed. Once access to the left atrium has been achieved, a guidewire is placed in the upper pulmonary vein and the WATCHMAN Access Sheath and dilator are advanced over the wire into the left atrium. The guidewire is removed, and the access sheath is carefully advanced into the distal portion of the LAA over a pigtail catheter. The WATCHMAN Delivery System is prepped, inserted into the access sheath, and slowly advanced. The WATCHMAN device is then deployed into the LAA. The device release criteria are confirmed via fluoroscopy and transesophageal echocardiography (TEE) and the device is released.

The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke.

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting an estimated 6 million people in the United States 1. Since AF affects primarily ...

Robotic Ablation of Atrial Fibrillation

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between pulmonary vein (PV) and left atrium (LA) is created. This conduction block prevents AF, which is triggered by irregular electric activity originating from the PV. However, transmural atrial lesions are required which can be challenging. Re-conduction and AF recurrence occur in 20 - 40% of the cases. Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new remote catheter system (RCS), is presented. Objective of this article is to show feasibility of robotic AF ablation with a novel system. Materials and Methods: After interatrial trans-septal puncture is performed using a long sheath and needle under fluoroscopic guidance. The needle is removed and a guide wire is placed in the left superior PV. Then an ablation catheter is positioned in the LA, using the sheath and wire as guide to the LA. LA angiography is performed over the sheath. A circular mapping catheter is positioned via the long sheath into the LA and a three-dimensional (3-D) anatomical reconstruction of the LA is performed. The handle of the ablation catheter is positioned in the robotic arm of the Amigo system and the ablation procedure begins. During the ablation procedure, the operator manipulates the ablation catheter via the robotic arm with the use of a remote control. The ablation is performed by creating point-by-point lesions around the left and right PV ostia. Contact force is measured at the catheter tip to provide feedback of catheter-tissue contact. Conduction block is confirmed by recording the PV potentials on the circular mapping catheter and by pacing maneuvers. The operator stays out of the radiationfield during ablation. Conclusion: The novel catheter system allows ablation with high stability on low operator fluoroscopy exposure.

Pulmonary vein isolation (PVI) with an ablation catheter is a curative treatment for atrial fibrillation (AF). Robotic catheter systems aim to improve catheter steerability. Here, a procedure with a new robotic catheter system is presented. The goal of the procedure is electrical block between pulmonary vein and left atrium.

Background: Pulmonary vein isolation (PVI) is an established treatment for atrial fibrillation (AF). During PVI an electrical conduction block between ...

Reduction of Iatrogenic Atrial Septal Defects with an Anterior and Inferior Transseptal Puncture Site when Operating the Cryoballoon Ablation Catheter

The cryoballoon catheter ablates atrial fibrillation (AF) triggers in the left atrium (LA) and pulmonary veins (PVs) via transseptal access. The typical transseptal puncture site is the fossa ovalis (FO) &#8211; the atrial septum&#8217;s thinnest section. A potentially beneficial transseptal site, for the cryoballoon, is near the inferior limbus (IL). This study examines an alternative transseptal site near the IL, which may decrease the frequency of acute iatrogenic atrial septal defect (IASD). Also, the study evaluates the acute pulmonary vein isolation (PVI) success rate utilizing the IL location. 200 patients were evaluated by retrospective chart review for acute PVI success rate with an IL transseptal site. An additional 128 IL transseptal patients were compared to 45 FO transseptal patients by performing Doppler intracardiac echocardiography (ICE) post-ablation to assess transseptal flow after removal of the transseptal sheath. After sheath removal and by Doppler ICE imaging, 42 of 128 (33%) IL transseptal patients demonstrated acute transseptal flow, while 45 of 45 (100%) FO transseptal puncture patients had acute transseptal flow. The difference in acute transseptal flow detection between FO and IL sites was statistically significant (P &#60;0.0001). Furthermore, 186 of 200 patients (with an IL transseptal puncture) did not need additional ablation(s) and had achieved an acute PVI by a &#8220;cryoballoon only&#8221; technique. An IL transseptal puncture site for cryoballoon AF ablations is an effective location to mediate PVI at all four PVs. Additionally, an IL transseptal location can lower the incidence of acute transseptal flow by Doppler ICE when compared to the FO. Potentially, the IL transseptal site may reduce later IASD complications post-cryoballoon procedures.

The goal of this study is to demonstrate the preferential location of transseptal puncture during a cryoballoon catheter ablation procedure for the treatment of atrial fibrillation.

The cryoballoon catheter ablates atrial fibrillation (AF) triggers in the left atrium (LA) and pulmonary veins (PVs) via transseptal access. The typical ...

Cooling or Warming the Esophagus to Reduce Esophageal Injury During Left Atrial Ablation in the Treatment of Atrial Fibrillation

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most frequent type of cardiac ablation procedure performed. Although generally safe, collateral injury to surrounding structures, particularly the esophagus, remains a concern. Cooling or warming the esophagus to counteract the heat from RF ablation, or the cold from cryoablation, is a method that is used to reduce thermal esophageal injury, and there are increasing data to support this approach. This protocol describes the use of a commercially available esophageal temperature management device to cool or warm the esophagus to reduce esophageal injury during left atrial ablation. The temperature management device is powered by standard water-blanket heat exchangers, and is shaped like a standard orogastric tube placed for gastric suctioning and decompression. Water circulates through the device in a closed-loop circuit, transferring heat across the silicone walls of the device, through the esophageal wall. Placement of the device is analogous to the placement of a typical orogastric tube, and temperature is adjusted via the external heat-exchanger console.

The goal of this protocol is to describe the use of esophageal temperature modulation to counteract esophageal thermal injury from left atrial ablation for the treatment of atrial fibrillation.

Ablation of the left atrium using either radiofrequency (RF) or cryothermal energy is an effective treatment for atrial fibrillation (AF) and is the most ...

Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale (PFO) detection, for patient selection for transcatheter ASD/PFO closure,&#160;for intraoperative guidance and for long-term follow-up. The size, shape, location and the number of the atrial communications schould be determined. The accuracy of PFO detection can be improved by using agitated saline together with maneuvers to transiently increase the right atrial (RA) pressure. The appearance of microbubbles in the left atrium (LA) within 3 cardiac cycles after opacification of the RA is considered positive for the presence of an intracardiac shunt. Three dimensional TEE identifies further septal fenestrations and describes the dynamic morphology of ASD/PFO and atrial septal aneurysm. Follow-up evaluations with TTE is recommended at 1, 6, and 12 months after the procedure, with a subsequent evaluation every year. Previous studies showed an increased incidence of atrial arrhythmias early after device closure. Speckle tracking analysis may help to understand functional left atrial remodeling following percutaneous closure and its impact on atrial arrhythmias.

Transthoracic (TTE) and transesophageal (TEE) echocardiography represent the basic imaging tools for interatrial septum examination. Three dimensional (3D) TEE provides incremental information in the assessment of the interatrial septum. Further advanced echocardiography techniques using speckle tracking echocardiography are applied for sensitive volumetric and functional assessment of the heart chambers.&#160;

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale ...

Sterile Pericarditis in Aachener Minipigs As a Model for Atrial Myopathy and Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia caused by structural remodeling of the atria, also called atrial myopathy. Current therapies only target the electrical abnormalities and not the underlying atrial myopathy. For the development of novel therapies, a reproducible large animal model of atrial myopathy is necessary. This paper presents a model of sterile pericarditis-induced atrial myopathy in Aachener minipigs. Sterile pericarditis was induced by spraying sterile talcum and leaving a layer of sterile gauze over the atrial epicardial surface. This led to inflammation and fibrosis, two crucial components of the pathophysiology of atrial myopathy, making the atria susceptible to the induction of AF. Two pacemaker electrodes were positioned epicardially on each atrium and connected to two pacemakers from different manufacturers. This strategy allowed for repeated non-invasive atrial programmed stimulation to determine the inducibility of AF at specified time points after surgery. Different protocols to test AF inducibility were used. The advantages of this model are its clinical relevance, with AF inducibility and the rapid induction of inflammation and fibrosis-both present in atrial myopathy-and its reproducibility. The model will be useful in the development of novel therapies targeting atrial myopathy and AF.

We describe a sterile pericarditis model in minipigs to study atrial myopathy and atrial fibrillation (AF). We present surgical and anesthetic techniques, strategies for vascular access, and a protocol to study the inducibility of AF.

Atrial fibrillation (AF) is the most common arrhythmia caused by structural remodeling of the atria, also called atrial myopathy. Current therapies only ...

Transesophageal Atrial Burst Pacing for Atrial Fibrillation Induction in Rats

Animal studies have brought important insights into our understanding regarding atrial fibrillation (AF) pathophysiology and therapeutic management. Reentry, one of the main mechanisms involved in AF pathogenesis, requires a certain mass of myocardial tissue in order to occur. Due to the small size of the atria, rodents have long been considered 'resistant' to AF. Although spontaneous AF has been shown to occur in rats, long-term follow-up (up to 50 weeks) is required for the arrhythmia to occur in those models. The present work describes an experimental protocol of transesophageal atrial burst pacing for rapid and efficient induction of AF in rats. The protocol can be successfully used in rats with healthy or remodeled hearts, in the presence of a wide variety of risk factors, allowing the study of AF pathophysiology, identification of novel therapeutic targets, and evaluation of novel prophylactic and/or therapeutic strategies.

The present work describes an experimental protocol of transesophageal atrial burst pacing for efficient induction of atrial fibrillation (AF) in rats. The protocol can be used in rats with healthy or remodeled hearts, allowing the study of AF pathophysiology, identification of novel therapeutic targets, and evaluation of new therapeutic strategies.

Animal studies have brought important insights into our understanding regarding atrial fibrillation (AF) pathophysiology and therapeutic management. ...

Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation

Atrial fibrillation (AF) is the most common form of arrhythmia. Atrial remodeling is considered the most critical mechanism for the presence and development of atrial fibrillation. Also, atrial remodeling can lead to the enlargement and dysfunction of the left atrium (LA), resulting in thrombosis and heart failure. Functional changes in left atrial strain and strain rate occur before structural alterations and are closely associated with structural remodeling and left atrial fibrosis. These parameters are sensitive biomarkers for atrial function. Cardiac magnetic resonance feature tracking (CMR-FT) is a novel, non-invasive, post-processing technique that can evaluate left atrial strain and strain rate. The CMR-FT was utilized in this investigation to assess the bilateral atrium strain rate in individuals with paroxysmal AF. Modifications in each segmental strain were evaluated using segmental analysis. The CMR-FT is recommended for non-invasive evaluations in the clinical assessment of atrial strain among existing strain imaging techniques. Further, it is a flexible parameter measurement with good reproducibility, high soft-tissue resolution, and post-processing based on standard cine balanced steady-state free precision (bSSFP) long-axis images without requiring a new sequence acquisition.

The atrial function is associated with the strain and strain rate. The cardiac magnetic resonance feature tracking (CMR-FT) technique was used in this study to quantify left and right atrial global and segmental longitudinal strain and strain rate in individuals with paroxysmal atrial fibrillation.

Atrial fibrillation (AF) is the most common form of arrhythmia. Atrial remodeling is considered the most critical mechanism for the presence and ...

Reduced Procedure Time and Variability with Active Esophageal Cooling During Radiofrequency Ablation for Atrial Fibrillation

Various methods are utilized during radiofrequency (RF) pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF) to protect the esophagus from inadvertent thermal injury. Active esophageal cooling is increasingly being used over traditional luminal esophageal temperature (LET) monitoring, and each approach may influence procedure times and the variability around those times. The objective of this study is to measure the effects on procedure time and variability in procedure time of two different esophageal protection strategies utilizing advanced informatics techniques to facilitate data extraction. Trained clinical informaticists first performed a contextual inquiry in the catheterization laboratory to determine laboratory workflows and observe the documentation of procedural data within the electronic health record (EHR). These EHR data structures were then identified in the electronic health record reporting database, facilitating data extraction from the EHR. A manual chart review using a REDCap database created for the study was then performed to identify additional data elements, including the type of esophageal protection used. Procedure duration was then compared using summary statistics and standard measures of dispersion.&#160;A total of 164 patients underwent radiofrequency PVI over the study timeframe; 63 patients (38%) were treated with LET monitoring, and 101 patients (62%) were treated with active esophageal cooling. The mean procedure time was 176 min (SD of 52 min) in the LET monitoring group compared to 156 min (SD of 40 min) in the esophageal cooling group (P = 0.012). Thus, active esophageal cooling during PVI is associated with reduced procedure time and reduced variation in procedure time when compared to traditional LET monitoring.

This study utilized advanced informatics techniques to compare procedure duration in patients undergoing radiofrequency atrial ablation treated with active esophageal cooling to those treated with traditional luminal esophageal temperature monitoring. Contextual inquiry, workflow analysis, and data mapping were utilized. The findings demonstrated reduced procedure time and variability with active cooling.

Various methods are utilized during radiofrequency (RF) pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF) to protect the ...