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[Apical mid-diastolic rumble in hypertrophic cardiomyopathy: a pulsed Doppler echocardiographic study]
Insights
This study investigated the mechanism of apical mid-diastolic rumbles in hypertrophic cardiomyopathy (HCM). Findings suggest these rumbles are linked to altered left ventricular (LV) filling dynamics and decreased LV dimensions in HCM patients.
Area of Science:
- Cardiology
- Echocardiography
- Cardiovascular Physiology
Context:
- Hypertrophic cardiomyopathy (HCM) is a complex cardiac condition.
- Apical mid-diastolic rumbles are an atypical auscultatory finding in some HCM patients.
- The precise mechanism underlying these rumbles remains incompletely understood.
Purpose:
- To elucidate the mechanism of apical mid-diastolic rumbles in hypertrophic cardiomyopathy (HCM).
- To analyze left ventricular (LV) inflow velocity patterns and hemodynamic parameters in HCM patients with and without rumbles.
- To compare these findings with normal subjects and patients with conduction abnormalities.
Summary:
- Patients with HCM and apical mid-diastolic rumbles exhibited shorter acceleration times and significantly shorter deceleration times of LV rapid filling compared to those without rumbles.
- HCM patients with rumbles showed significantly decreased LV dimensions and increased apexcardiogram A/H ratios compared to controls.
- The rumble coincided with the rapid filling phase of the left ventricle, suggesting a mechanical origin related to altered diastolic function and chamber geometry.
Impact:
- Provides insights into the pathophysiology of diastolic dysfunction in HCM.
- Highlights the utility of Doppler echocardiography and apexcardiography in characterizing complex HCM phenotypes.
- Contributes to a better understanding of the acoustic manifestations of HCM, potentially aiding in diagnosis and management.
Abstract:
To investigate the mechanism of an apical mid-diastolic rumble in hypertrophic cardiomyopathy (HCM), we recorded left ventricular (LV) inflow velocity patterns using pulsed Doppler echocardiography and apexcardiography for 10 HCM patients with rumble and 20 HCM patients without rumble. Controls consist of 17 normal subjects, three patients with complete atrioventricular block and two patients with artificial right ventricular pacemakers. The LV inflow velocity profiles were analyzed in terms of acceleration time (AT) and deceleration time (DT) of the rapid filling wave, and the ratio of peak velocity of the atrial contraction wave to that of the rapid filling wave (A/D ratio). The results were as follows: The apical mid-diastolic murmur in HCM had a crescendo-decrescendo character mainly of medium frequency, and increased in intensity after the inhalation of amyl nitrite. All patients with rumble had asymmetric septal hypertrophy and the five of these had LV outflow obstruction. In six of the 10 patients with rumble, mild mitral regurgitation was detected. In HCM with rumble, the AT tended to be shorter than that of HCM without rumble, but it was significantly longer than the AT of normal subjects. In HCM with rumble, the DT was significantly shorter than that of HCM without rumble, but it was significantly longer than the DT of normal subjects. There was no significant difference in the A/D ratio between the HCM with rumble and the normal subjects, but the A/H ratio of the apexcardiogram was significantly increased in HCM with rumble as compared with those of HCM without rumble and of the normal subjects. The LV dimension was significantly decreased in HCM with rumble as compared with those of HCM without rumble and the normal subjects. Peak negative VCF was significantly decreased in HCM with rumble as compared with that of HCM without rumble. But there was no significant difference in this parameter between HCM with rumble and the normal subjects. In simultaneous recordings of apical mid-diastolic rumble and LV inflow velocity patterns, the rumble appeared to start after the beginning of the diastolic rapid filling wave and to stop before or at the end of the diastolic rapid filling wave. In patients with complete atrioventricular block and with artificial right ventricular pacemakers, the apical mid-diastolic rumble appeared when the P wave was during the rapid filling phase of the left ventricle.(ABSTRACT TRUNCATED AT 400 WORDS)