After myocardial infarction (MI), baroreflex function is impaired and heart rate (HR) variability is reduced. An impaired baroreflex has been observed also in coronary patients with no previous MI, leading to hypothesize alterations of HR variability also in these patients. The aim of the present work was, therefore, to study whether and to what extent cardiovascular variability is altered in coronary patients with no previous MI.
Thirty-two individuals were studied: eleven patients with coronary artery disease but no previous MI [coronary artery disease (CAD)], eleven patients with a reduced left ventricular ejection fraction [congestive heart failure (CHF)] and ten age-matched controls (CNT).
Overall HR variability was significantly and similarly reduced in CAD (630 ± 272 ms2) and CHF patients (594 ± 395 ms2) with respect to CNT (1405 ± 837 ms2), this being the case also for the low and high frequency spectral components. Low-frequency oscillations of blood pressure (BP) were also significantly and similarly less pronounced in CAD (0.7 ± 0.7 mmHg2) and CHF patients (0.7 ± 0.7 mmHg2) compared with CNT (1.8 ± 1.4 mmHg2). Moreover, both CAD and CHF patients showed a significantly reduced baroreflex function and an increased pulse-wave velocity with respect to CNT.
Our study shows that in coronary patients with no MI and no left ventricular dysfunction, there is a profound alteration of both HR and BP variability as in CHF patients, presumably because of a marked impairment of the autonomic modulation of the heart and blood vessels.