The Combyn™ ECG: Adding haemodynamic and fluid leads for the ECG. Part II: Prediction of total body water (TBW), extracellular fluid (ECF), ECF overload, fat mass (FM) and “dry” appendicular muscle mass (AppMM)

• Published in: Medical engineering & physics Vol. 44; pp. 44 - 52
• Main Authors: Skrabal, Falko, Pichler, Georg P., Penatzer, Mathias, Steinbichl, Johannes, Hanserl, Anna-Katharina, Leis, Albrecht, Loibner, Herbert
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2017
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Body Composition; Body Water - metabolism; Case-Control Studies; Dry weight; Electric Impedance; Electrocardiography; Extracellular Fluid - metabolism; Female; Heart Failure - metabolism; Heart Failure - pathology; Heart Failure - physiopathology; Hemodynamics; Humans; Hydration; Male; Middle Aged; Muscles - anatomy & histology; Organ Size; Radiology; Signal Processing, Computer-Assisted; Sodium bromide; Whole body DXA; Young Adult; CHF; NYHA; Hydration; BNP; FM; ECG; TBW; AppMM; ECF; Sodium bromide; DXA; ICF; Dry weight; CRF; LBM; AT1 blocker; HD; ACE inhibitors; Whole body DXA; BMI; lean body mass; chronic renal failure; fat mass; brain natriuretic peptide; angiotensin-converting-enzyme inhibitor; dual energy X-ray absorptiometry; chronic heart failure; intracellular fluid; electrocardiogram; appendicular muscle mass; angiotensin-II-receptor-subtype-1 blocker; body mass index; extracellular fluid; haemodialysis; New York Heart Association classification; total body water
• ISSN: 1350-4533; 1873-4030; 1873-4030
• DOI: 10.1016/j.medengphy.2017.03.002

•Measurement of body compartments comparable in precision to whole body DXA in health and disease during the routine ECG.•Determination of ECF excess and “dry weight” in CHF and CRF during the routine ECG.•Determination of “dry” appendicular muscle mass corrected for ECF overload during the routine ECG – not being measurable by whole body DXA. Simultaneous with a 12 channel ECG, body composition was analysed by segmental multi-frequency impedance analysis in 101 healthy subjects and in 118 patients with chronic heart failure (CHF, n= 40), chronic renal failure with haemodialysis (HD, n= 20), and miscellaneous internal diseases (n= 58). Whole body DXA and sodium bromide dilution were used as reference methods for total body water (TBW), extracellular fluid (ECF), appendicular muscle mass (AppMM) and fat mass (FM). Empirical prediction equations were developed in a randomized evaluation sample and then evaluated in unknowns. TBW, ECF, AppMM and FM could be predicted with regression coefficients of 0.96, 0.90, 0.95 and 0.93, respectively, all with p< 0.001. Only segmental impedances and height, but not age, sex, weight and BMI contributed to the prediction of water compartments. About half the patients with CHF and half of those on HD showed increased ECF/ICF ratio in relation to % FM at the legs but not at the thorax. The predicted AppMM was additionally corrected for increased ECF to determine “dry AppMM”, which is markedly lower than the misleading reference DXA. This methodology shows promise as a combination of routine ECG with measurement of body composition, assessment of sarcopenia and detection of overhydration.