Coronary microvascular dysfunction in hypertrophic cardiomyopathy: Pathophysiology, assessment, and clinical impact.

Myocardial ischemia constitutes one of the most important pathophysiological features in hypertrophic cardiomyopathy. Chronic and recurrent myocardial ischemia leads to fibrosis, which may culminate in myocardial dysfunction. Since the direct visualization of coronary microcirculation in vivo is not possible, its function must be studied indirectly. Invasive and noninvasive techniques allow microcirculatory dysfunction to be evaluated, including echocardiography, magnetic resonance, positron emission tomography, and cardiac catheterization. Blunted myocardial blood flow and coronary flow reserve have been suggested to associate with unfavorable prognosis. Microcirculatory dysfunction may be one additional important parameter to take into account for risk stratification beyond the conventional risk factors.