Historically, the role of exercise stress echocardiography in the management of hypertrophic cardiomyopathy has been neglected in clinical practice according to the analysis of the 2002 Guidelines of the American College of Cardiology/ American Heart Association, which recommended caution use of this methodology in patients with hypertrophic cardiomyopathy due to the risk of both cardiac arrhythmia and hemodynamic collapse on exertion. Exercise stress testing in patients with hypertrophic cardiomyopathy is currently part of the routine assessment of symptomatic patients with or without a resting left ventricular outflow tract gradient < 50 mmHg. For this group, it is a safe and reliable method for measuring the left ventricular outflow tract gradient during exertion and a solid differentiator of patients with nonobstructive hypertrophic cardiomyopathy (absent gradient, both at rest and on exertion) from those with labile gradients (absent gradient at rest and present on exertion). Therefore, in the assessment of hypertrophic cardiomyopathy, exercise stress is equally useful for quantifying the degree of mitral regurgitation and left ventricular segmental contractility changes as well as assessing left ventricular diastolic function on exertion and is able to predict the future development of heart failure symptoms. The method is also important for determining different treatment strategies for each patient, from surgical myomectomy or alcohol septal ablation for those with a labile gradient, limiting symptoms, and who refractory to drug treatment to heart transplantation for those without a gradient.
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