CARDIAC AUTONOMIC MODULATION AND INCIDENCE OF LATE POTENTIALS IN ESSENTIAL-HYPERTENSION - ROLE OF AGE, SEX, VENTRICULAR MASS AND REMODELING

The influence of age, sex, left ventricular hypertrophy (LVH) and geom etry on the autonomic activity to the heart was investigated in 96 hyp ertensive out-patients (53 men, mean age 53 +/- 9 years) and 39 health y subjects (19 men, mean age 43 +/- 1 years). Using 24-h Holter record ings, time [the standard deviation of all RR intervals (SDNN) and the square root of the mean of the squared differences between adjacent no rmal RR intervals (RMSSD)] and power spectral analysis of RR intervals [Fast Fourier algorithm, low/high frequency (LF/HF) ratio] were calcu lated over 24 h, daytime (D) and night-time (N) periods in all subject s. Signal averaged electro-cardiogram was recorded in 50 patients to d etect late potentials. Stepwise multiple linear regression analysis sh owed that the 24-h LF/HF ratio was influenced by age and sex, D-LF/HF by age and N-LF/HF by sex, a higher LF/HF ratio being found in younger patients and in men. These data suggest a more prominent sympathetic modulation of cardiac activity in these groups. No differences in RR p eriod variations were observed between patients with or without LVH. L ate potentials were observed in 10 patients, and did not correlate wit h any of the measured parameters.