Open AccessCircadian Rhythms of Heart Rate Variability in Hypertrophic Cardiomyopathy
Author(s) -
Guzzetti Stefano,
Choudhury Lubna,
Mezzetti Silvia,
Cogliati Chiara,
Camici Paolo G.,
Malliani Alberto
Publication year - 1996
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/j.1542-474x.1996.tb00289.x
Subject(s) - medicine , cardiology , hypertrophic cardiomyopathy , heart rate variability , heart failure , heart rate , diastole , myocardial infarction , circadian rhythm , autonomic function , cardiomyopathy , autonomic nervous system , sympathetic activity , blood pressure
Background: It has been hypothesized that an interaction between sympathetic nervous activity and an abnormal myocardium plays a role in the development and progression of hypertrophic cardiomyopathy (HCM). Methods: In the present study we investigated cardiac autonomic function by 24‐hour spectral analysis of heart rate variability (HRV) in 18 patients with HCM, without evidence of heart failure, and 18 controls of similar age. Results: We found a significant reduction of 24 hour variance in HCM patients relative to controls (15,000 ± 9480 ms 2 vs 24,720 ± 12,450 ms 2 respectively; p < 0.05). Moreover, a loss of the expected day‐night changes in the low frequency (LF) spectral component (expressed in normalized units), and LF/HF ratio (HF; high frequency component) were observed in HCM patients. Decreased day‐night changes in LF/HF ratio were previously reported in patients with mild hypertension, uncomplicated coronary disease, and after myocardial infarction, conditions in which it seems to exist a higher than normal sympathetic activity. No significant correlations were found between HRV indices and echocardiographic standard measures of systolic and diastolic function parameters. Conclusions: These data are consistent with the presence of an alteration in neural modulation of heart period in HCM patients, noninvasively detectable by continuous 24 hour HRV analysis.