Systolic anterior movement of the mitral valve and the Venturi effect: an in vitro study.

We constructed two different "mitral valve" models in order to investigate the influence of the Venturi effect on SAM. According to our results, SAM can be caused as a result of a subvalvular obstruction. In this case, the valve itself does not contribute to the degree of outflow tract obstruction (first model). In the second model, the valve itself contributes to the degree of outflow tract obstruction. In both models only the Venturi effect is the cause of SAM. We conclude that different anatomic abnormalities causing a Venturi effect can induce SAM.