Now you see me, now you don't: The case of a vanishing outflow gradient in a patient with hypertrophic cardiomyopathy.

Cardiogenic shock is well described in hypertrophic cardiomyopathy (HCM) as acute hemodynamic collapse can develop in the setting of acute worsening of left ventricular outflow tract (LVOT) obstruction. We present the case of a 60-year-old man with drug refractory LVOT obstruction due to hypertrophic cardiomyopathy. On the evening prior to planned alcohol septal ablation, the patient presented in cardiogenic shock. Interestingly, his previously recorded LVOT gradients of 50 mm Hg at rest and 118 mm Hg at peak exercise were absent. With recovery of left ventricular function, significant left ventricular outflow obstruction returned. The patient then underwent successful septal reduction therapy. © 2016 Wiley Periodicals, Inc.