Elsevier

American Heart Journal

Volume 136, Issue 6, December 1998, Pages 982-987
American Heart Journal

Effects of postural changes on left atrial function in patients with hypertrophic cardiomyopathy,☆☆,,★★

https://doi.org/10.1016/S0002-8703(98)70153-XGet rights and content

Abstract

Background We assessed left atrial function in normal subjects and in patients with hypertrophic cardiomyopathy (HCM) by using Doppler echocardiography at the supine position and after sudden standing. Methods and Results Twenty-seven patients with hypertrophic obstructive cardiomyopathy (HOCM), 17 patients with HCM, and 35 normal subjects were studied. From the transmitral Doppler flow velocities, peak early and late (E and A) waves, E/A ratio, and time velocity integrals (Ei and Ai) were calculated. Left atrial active contribution (LAAC) was assessed as the ratio Ei/(Ei + Ai). Furthermore, isovolumetric relaxation time (IVRT) was estimated by means of Doppler echocardiography. In the supine position, the E/A ratio was similar in the 3 groups. Conversely, LAAC was significantly higher in patients with HOCM (24.4 ± 2.0) and in patients with HCM (23.3 ± 3.3) compared with normal subjects (20.3 ± 2.3, P < .001 and P < .05, respectively). After sudden standing, LAAC increased significantly in normal subjects by 11%, in patients with HOCM by 24%, and in patients with HCM by 13% (P < .001). Similarly, IVRT increased significantly in all study groups (P < .001). By using stepwise forward multiple linear regression analysis, we found that LAAC was associated with age, IVRT, and body mass index in the supine position and with diastolic blood pressure and IVRT in the standing position. Conclusions Left atrial contribution to left ventricular filling was increased after sudden changes of posture in normal subjects and in patients with HOCM or HCM. (Am Heart J 1998;136:982-7.)

Section snippets

Study population

The study cohort consisted of 27 patients with typical echocardiographic Doppler findings8 of hypertrophic obstructive cardiomyopathy (HOCM). Inclusion criteria were (1) a hypertrophic nondilated left ventricle (ventricular septum thickness ≥13 mm), (2) a basal interventricular pressure gradient of 30 mm Hg recorded in the left ventricular outflow tract, (3) normal coronary arteries at angiography, and (4) no underlying cardiac or systemic disease.

A group of 17 patients with HCM were also

Baseline characterstics and echocardiographic data

There were no differences between the study groups with respect to age, sex, and body mass index (Table I). Left ventricular ejection fraction was significantly higher in patients with HOCM compared with normal subjects (P < .005). Normal subjects had a significantly thinner interventricular septum and a lower ventricular septum/posterior wall ratio (P < .001). Furthermore, normal subjects had a significantly increased left ventricular end-systolic volume index compared with patients with HOCM

Discussion

In this study, we estimated left atrial contribution to left ventricular filling by means of mitral flow velocity measured with Doppler echocardiography in normal subjects, patients with HOCM, and patients with HCM. Moreover, we examined the effects of postural changes on left atrial function in these patients. Similar studies have been reported,13, 14, 15 but the postural changes were not examined in these groups of patients. We assessed left atrial function by using Doppler echocardiography,

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From the Department of Cardiology, Hippokration Hospital, University of Athens.

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Supported by a grant from the Hellenic Heart Foundation.

Reprint requests: John Dernellis, MD, 61 Kousidou St, 15772 Zografou, Athens, Greece.

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