Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test

Podsumowanie

Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test.

Streszczenie

Ischemic heart disease (IHD) represents a group of clinical syndromes characterized by myocardial ischemia, leading to an impairment in the myocardial blood supply and compromised perfusion. Several clinical variables assessed through a stress test, such as oxygen uptake (VO2) and heart rate oxygen pulse (HR/O2), have been attributed as cardiopulmonary prognostic factors in patients with IHD. However, other factors like hydration status (HS), potentially affecting the cardiopulmonary response, have been barely addressed. Unbalanced HS has a short-term effect on plasma volume and the sympathetic nervous system, which impacts blood volume, and lowers VO2 and HR/O2. Recently, bioelectrical impedance analysis (BIA), a method based on the opposition of body tissues (including fluid volume) to a low electrical current, has been widely used to assess HS by obtaining two components: resistance (R) and reactance (Xc) and using prediction formulas. However, several limitations as chronic illness or abnormal fluid status, may affect the results. In this sense, alternative BIA methods, such as bioelectrical impedance vector analysis (BIVA), have become relevant. R and Xc (adjusted by height) result in a vector plotted on the R/Xc graph, which allows interpreting the HS as normal or abnormal according to the distance of the mean vector. This study aims to describe how to determine HS by BIVA using a single-frequency device and compare the results with the cardiopulmonary response in patients with IHD.

Wprowadzenie

Ischemic heart disease (IHD) represents a group of clinical syndromes characterized by myocardial ischemia, a mismatch in the myocardial blood supply and demand. The underlying pathophysiological defect includes inadequate perfusion, mainly due to atherosclerotic disease of epicardial coronary arteries^1,2,3. In general, the presence of cardiovascular disease (CVD) is common, showing poor survival worldwide⁴. Particularly in 2015, IHD contributed to approximately 9 million deaths and more than 160 million disability-adjusted life years, and nowadays, IH....

Protokół

The Institutional Research Ethics Committee from Centro Médico Nacional "20 de Noviembre", ISSSTE, approved this protocol (ID 383.2019). All enrolled patients signed written informed consent.

1. Before bioelectrical impedance analysis (BIA) measurement

NOTE: The BIA protocol procedure is measured using a single-frequency bioelectrical impedance device (Table of Materials). This device provides two values (resistance and reactance) at 50 kHz. Also, the BIA protocol described here is specific according to the single-frequency bioelectrical impedance device used.

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Wyniki

First, R and Xc (both adjusted by patient´s height) data registered from the single frequency (SF-BIA) device was used to obtain the BIVA R/Xc graph. Second, we classified hydration status as euhydration, hyperhydration, and hypohydration. Representative hydration data from male patients plotted with circle and triangle, aged 66 years and 67 years, weighing 72.2 kg and 72.3 kg, height 169 cm and 163 cm, are shown (Figure 2). In addition, impedance data are shown R/H= 280.7, Xc/H= 23.6 &.......

Dyskusje

Although BIA is considered a safe, practical, and noninvasive method, which overcomes the limitations of other methods to measure body composition and body water^19,23, it is relevant to consider the potential bias occurring regarding the type of bioelectrical impedance (the method described here is specific for a single-frequency bioelectrical impedance device), or the variation in the steps and technique verification methods.

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Materiały

Name	Company	Catalog Number	Comments
BIVA Tolerance	BIVA SOFTWARE 2002		Piccoli A, Pastori G: BIVA software. Department of Medical and Surgical Sciences, University of Padova, Padova, Italy, 2002 (available at E-mail:apiccoli@unipd.it).
Cardiopoint ECG C600	BTL	407-80MANEN03100	ELECTROCARDIOGRAPH
Cardiopoint Trolley	BTL	40700B000240	TROLLEY
Portable Digital Flat Scale	SECA	813	DIGITAL FLAT SCALE
Portable Stadiometer	SECA	213	STADIOMETER
Quantum IV	RJL SYSTEMS	Q4B-2405	BIOELECTRIC IMPEDANCE ANALYZER
Treadmill Clinical	BTL	216A18	TREADMILL