Shortening baroreflex delay in hypertrophic cardiomyopathy patients – an unknown effect of β-blockers
Article first published online: 20 MAY 2013
© 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society
British Journal of Clinical Pharmacology
Volume 75, Issue 6, pages 1516–1524, June 2013
How to Cite
Katarzynska-Szymanska, A., Ochotny, R., Oko-Sarnowska, Z., Wachowiak-Baszynska, H., Krauze, T., Piskorski, J., Gwizdala, A., Mitkowski, P. and Guzik, P. (2013), Shortening baroreflex delay in hypertrophic cardiomyopathy patients – an unknown effect of β-blockers. British Journal of Clinical Pharmacology, 75: 1516–1524. doi: 10.1111/bcp.12027
- Issue published online: 20 MAY 2013
- Article first published online: 20 MAY 2013
- Accepted manuscript online: 6 NOV 2012 04:34AM EST
- Manuscript Accepted: 31 OCT 2012
- Manuscript Received: 23 JUL 2012
- Poznan University of Medical Sciences
- baroreflex delay;
- baroreflex sensitivity;
- heart rate variability;
- hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and impaired diastolic and systolic function. Abnormal sympathetic–parasympathetic balance is a potential stimulus for left ventricular hypertrophy in HCM patients. β-Blockers are routinely used in HCM for their strong negative inotropic effect; however, these drugs also influence the sympathetic–parasympathetic balance. This study aimed to determine the autonomic control of the cardiovascular system and the autonomic effects of β-blockers in HCM patients treated or untreated with β-blockers.
Among 51 HCM outpatients (18–70 years old; 29 men) there were 19 individuals with no medication and 32 subjects treated with a β-blocker. Fourteen age- and gender-matched (23–70 years old; nine men) healthy volunteers were enrolled in the control group. Continuous, non-invasive finger blood pressure was recorded during supine rest for 30 min. Autonomic regulation of the cardiovascular system was measured by heart rate variability and spontaneous baroreflex function (cross-correlation sequence method).
The mean pulse interval, time domain and spectral measures of heart rate variability and baroreflex sensitivity were comparable between HCM patients, treated or not with β-blockers, and the control group. However, the delay of the baroreflex was significantly longer in HCM patients who were not treated with β-blockers [2.0 (1.6–2.3) s] in comparison with HCM patients receiving β-blockers [1.4 (1.1–1.8) s; P = 0.0072] or control subjects [1.2 (0.8–1.8) s; P = 0.0025]. This delay did not differ between HCM patients treated with β-blockers and the control group.
Hypertrophic cardiomyopathy not treated with β-blockers is accompanied by prolonged baroreflex delay. The use of β-blockers normalizes this delay.