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[SAM sound studied by pulsed Doppler echocardiography]
N Tanigawa1, Y Ozawa, M Nagasawa
1Second Department of Internal Medicine, Nihon University School of Medicine, Tokyo.
Journal of Cardiography
|December 1, 1986
Summary
The systolic anterior motion (SAM) sound in hypertrophic obstructive cardiomyopathy is linked to a sudden deceleration of blood flow within the left ventricle. This finding offers new insights into the mechanics of this cardiac condition.
Area of Science:
- Cardiology
- Echocardiography
- Cardiovascular Physiology
Background:
- The systolic anterior motion (SAM) sound in hypertrophic obstructive cardiomyopathy (HOCM) is a known phonocardiographic finding.
- It is associated with the abrupt cessation of mitral valve leaflet movement during systole.
Observation:
- A 58-year-old male HOCM patient presented with a fluctuating intensity SAM sound.
- Cardiac catheterization and advanced echocardiography (M-mode, 2D, Doppler) were used for evaluation.
- Asymmetric septal hypertrophy and midsystolic aortic valve closure were confirmed.
Findings:
- Two-dimensional Doppler revealed persistent systolic turbulent flow in the left ventricular outflow tract.
- Systolic laminar flow near the apex was interrupted during SAM sound presence, indicating flow deceleration.
- Diastolic inflow and absence of mitral regurgitation were noted.
Implications:
- The SAM sound is associated with sudden deceleration of left ventricular blood flow from apex to mid-ventricle.
- This provides a potential hemodynamic explanation for the SAM sound in HOCM.
- Further research may clarify the precise mechanism and clinical significance.