Abstract
Decreased heart rate variability (HRV) has been reported as prognostic predictor in
coronary artery disease population. The aim of the study was to assess the relationship
between cardiac autonomic tone disturbances and the degree of left ventricular dysfunction,
estimated by 2-dimensional and Doppler echocardiography, in patients with coronary
artery disease. Forty patients with angiographically proven coronary artery disease
and 15 age-and sexmatched healthy subjects were included into the study (Group I and
II, respectively). Routine clinical examinations, electrocardiography, coronary angiography,
and 2-dimensional and Doppler echocardiography with assessment of LV systolic performance
were done in all the patients and control subjects. Cardiac autonomic function was
assessed by means of frequency-domain analysis of heart rate variability. The powers
of LF and HF bands (P1 and P2), their ratio (P1/P2), and the logarithmic expression
of powers were measured. The patients (Group I) had lower values of parasympathetic
band of HRV and higher sympathetic activity than the healthy population (Group II)
(p < 0.0002 for P2 and p < 0.04 for P1/P2 ratio). A positive significant correlation was seen between parasympathetic
band of HRV and ejection fraction (r=0.61,p < 0.0001), and mean acceleration of aortal flow (r=0.56,p < 0.0001), whereas P1/P2 ratio inversely and significantly correlated with the same
parameters (r= −0.46,p < 0.002 and r= −0.41,p < 0.008).
