An unusual cause of left ventricular outflow tract obstruction: the importance of a new systolic murmur with a large pleural effusion.

Background: Left ventricular outflow tract obstruction due to systolic anterior motion of the mitral valve occurs as a result of a dynamic interplay between the anatomy and mechanics of the heart. While systolic anterior motion and left ventricular outflow tract obstruction are well-recognized hallmarks of hypertrophic obstructive cardiomyopathy, several other specific etiologies have been described with similar pathophysiology.

Methods: We present a unique case of a middle-aged woman who developed acute dynamic left ventricular outflow tract obstruction due to systolic anterior motion of the mitral valve resulting from a large left-sided pleural effusion.

Conclusions: Dynamic outflow tract obstruction should be considered among the potential causes of a new systolic murmur in patients with large pleural effusions in the absence of valvular heart disease.