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Improvement in left ventricular diastolic filling by septal myectomy in hypertrophic cardiomyopathy
T Masuyama1, U Nellessen, E B Stinson
1Division of Cardiology, Stanford University School of Medicine, CA 94305.
Insights
Septal myectomy improved diastolic filling in hypertrophic cardiomyopathy patients by shortening deceleration time. This suggests symptom relief may stem from enhanced left ventricular diastolic function post-surgery.
Area of Science:
- Cardiology
- Cardiovascular Surgery
- Echocardiography
Background:
- Left ventricular diastolic dysfunction is a key factor in hypertrophic cardiomyopathy symptoms.
- Septal myectomy is a surgical intervention for hypertrophic cardiomyopathy.
- The impact of septal myectomy on diastolic function requires further clarification.
Purpose of the Study:
- To evaluate the effect of septal myectomy on left ventricular diastolic filling abnormalities in hypertrophic cardiomyopathy patients.
- To assess changes in transmitral flow velocity patterns before and after surgery.
Main Methods:
- Pulsed Doppler echocardiography was used to study 13 hypertrophic cardiomyopathy patients pre- and post-septal myectomy.
- Key parameters measured included peak early diastolic filling velocity (E), E/A ratio, and deceleration time.
- Analysis considered potential confounding factors like heart rate and mitral regurgitation severity.
Main Results:
- Septal myectomy significantly shortened deceleration time (314 ms to 271 ms).
- Excluding patients with significant heart rate or mitral regurgitation changes revealed improvements in E and E/A ratio.
- These findings suggest an improvement in left ventricular diastolic filling post-surgery.
Conclusions:
- Septal myectomy can improve left ventricular diastolic filling in hypertrophic cardiomyopathy.
- The improvement in diastolic function may contribute to symptom relief after septal myectomy.
- Doppler echocardiography is valuable for assessing diastolic function changes after surgical intervention.
Abstract:
Abnormalities in left ventricular diastolic function or filling are considered to be responsible for some of the symptoms in patients with hypertrophic cardiomyopathy. To clarify whether the abnormalities in left ventricular diastolic filling are improved by septal myectomy, 13 patients with hypertrophic cardiomyopathy and intracavitary pressure gradient were studied preoperatively and postoperatively by use of pulsed Doppler echocardiography. Peak early diastolic filling velocity (E), the ratio of peak early diastolic filling to peak atrial filling velocities (E/A ratio), and deceleration time were measured from the transmitral flow velocity pattern before and after septal myectomy. Although E and E/A ratio did not change after septal myectomy, deceleration time significantly shortened from 314 +/- 72 to 271 +/- 53 milliseconds (n = 10; p less than 0.05). Further, if seven patients with significant changes in heart rate (greater than 30%) or in the Doppler-determined severity of mitral regurgitation (more than one degree) were excluded (because these parameters may effect E and E/A ratio), there were also significant changes in E (81 +/- 21 versus 98 +/- 25 cm/sec, p less than 0.05) and in E/A ratio (0.84 +/- 0.17 versus 1.14 +/- 0.33, p less than 0.05). Because left ventricular systolic function has been demonstrated to remain constant or to decrease by most measures after septal myectomy, relief of some symptoms may be largely the result of the improvement in diastolic filling suggested by these criteria.