Assessment of left ventricular systolic function and diastolic time intervals by the bioimpedance...

In order to detect left ventricular systolic function and diastolic time intervals using a new improved bioimpedance polyrheocardiographic system (BPCS), 110 healthy subjects and 128 patients with myocardial infarction were examined. Twenty-four simultaneous measurements of cardiac output by thermodilution and BPCS were performed in 11 patients with complicated acute left ventricular failure. Studies demonstrated a high degree of correlation (r = 0.91, p < 0.001). The correlation between the methods of using signals of the second derivative and the subtracted first derivative waveform of BPCS and continuous-wave Doppler echocardiography of systolic and diastolic time intervals was studies in 51 patients. The methods were closely correlated, especially with respect to left ventricular ejection time (r = 0.95), isovolumic relaxation time (r = 0.85), time to peak filling (r = 0.90), and deceleration of rapid filling time (r = 0.91). New bioimpedance hemodynamic parameters such as peak volume acceleration of ejection (PVAE) and peak power ejection (PPE) in patients with heart failure (NYHA Class I-III) were studied. Significant reductions of PVAE and PPE in groups of patients with marked progression of heart failure were noted. These results have demonstrated that BPCS is a noninvasive, simple accurate method of assessment of left ventricular systolic function and diastolic time intervals.