Autonomic functions in restrictive cardiomyopathy and constrictive pericarditis: A comparison

Abstract Background This study was undertaken to analyze autonomic functions in restrictive cardiomyopathies. Restrictive cardiomyopathies have clinical and hemodynamic similarity with chronic constrictive pericarditis. Autonomic dysfunction has been described in the latter. Methods and Results Autonomic function analysis has not been reported in restrictive cardiomyopathy. Six consecutive patients with restrictive cardiomyopathy were included in this study (5 men, 1 woman, mean age 35 ± 5.4 years). The tests performed were designed to test the sympathetic efferent pathway, that is, by cold hand immersion and loud noise tests, parasympathetic efferent pathway by Valsalva ratio and expiration/inspiration ratio and the baroreceptor function by testing their sensitivity slope. The results were compared with 20 patients with chronic constrictive pericarditis and with 10 healthy age- and sex-matched control subjects previously studied. The rise of systolic blood pressure after cold hand immersion and sudden loud noise was not significantly different compared with control subjects. The expiration/inspiration ratio was 1.1 ± 0.01 compared with 1.57 ± 0.1 in the control group ( p p p p = not significant). The baroreceptor sensitivity slope is normal in patients with restrictive cardiomyopathy as compared with significant depression seen in constrictive pericarditis ( p Conclusions Autonomic dysfunction is localized to parasympathetic efferent pathway. This is in comparison to constrictive pericarditis, in which severe autonomic dysfunction is a universal feature and includes all segments of autonomic nervous system. (Am Heart J 1998;136:443-8.)