Nistri S, Olivotto I, Maron MS, Grifoni C, Baldini K, Baldi M, Sgalambro A, Cecchi F, Maron BJ. Timing and significance of exercise-induced left ventricular outflow tract pressure gradients in hypertrophic cardiomyopathy. Am J Cardiol. 2010 Nov 01; 106(9):1301-6.