To investigate the relationship between diastolic abnormalities and left ventricular hypertrophy, 52 patients with hypertrophic cardiomyopathy (HCM) and 22 normal subjects were studied with digitized M mode echocardiography and two-dimensional echocardiography. Echocardiographic indexes of diastolic function were compared in patients with different extent of left ventricular hypertrophy. Time interval from minimum left ventricular internal dimension to mitral valve opening and time to peak rate of increase in left ventricular internal dimension were significantly prolonged (80 ± 31 and 100 ± 37 msec, respectively) in patients with HCM and the most extensive left ventricular hypertrophy compared with those in patients with mild left ventricular hypertrophy (59 ± 25 and 74 ± 34 msec, respectively; p <.01). Furthermore, peak rate of posterior wall diastolic excursion was significantly reduced in those patients with HCM and posterior wall hypertrophy (8.3 ± 4.0 cm/sec) compared with that in patients with HCM but normal posterior wall thickness (11.2 ± 3.4 cm/sec; p <.002). However, abnormal M mode echocardiographic indexes of diastolic function were also identified in a substantial proportion of patients (i.e., 73%) with HCM and only mild left ventricular hypertrophy. In these patients, time interval from minimum left ventricular internal dimension to mitral valve opening (59 ± 25 msec), peak rate (12 ± 4 cm/sec), and time to peak rate of increase in left ventricular internal dimension (74 ± 34 msec) were significantly different from normal (25 ± 12 msec, 21 ± 3 cm/sec, and 49 ± 12 msec, respectively; p <.01). Furthermore, in 32 patients with HCM who had normal posterior wall thickness, peak rate of posterior wall diastolic excursion was significantly reduced (11.2 ± 3.4 cm/sec) compared with normal (16.7 ± 2.4 cm/sec; p <.001). In conclusion, our findings show a relationship, in patients with HCM, between magnitude of left ventricular hypertrophy and extent of diastolic wall motion abnormalities. However, our results also show that diastolic wall motion abnormalities are common in patients with HCM and mild localized left ventricular hypertrophy and may even be identified in segments of the left ventricle that are of normal thickness. These data suggest that the primary cardiomyopathic process in HCM may not be limited to areas of gross wall thickening, and nonhypertrophied regions of the left ventricle may contribute to impairment of diastolic function in patients with this disease.
|Number of pages||7|
|Publication status||Published - 1985|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine