Tissue Doppler imaging for the evaluation of patients with hypertrophic cardiomyopathy.

Abstract

To discuss the role of tissue Doppler imaging for assessing regional myocardial function in patients with proven or suspected hypertrophic cardiomyopathy and review its application in clinical practice for diagnosis, estimation of filling pressures, and monitoring of treatment. Patients with hypertrophic cardiomyopathy have very abnormal systolic and diastolic myocardial function, even if global systolic function of the left ventricle appears normal. Regional function is most abnormal in walls that are markedly hypertrophied, but it is also abnormal in segments that are not affected by hypertrophy, and it is depressed in patients who have a mutation for hypertrophic cardiomyopathy but have not yet developed clear phenotypic changes. Genetic diagnosis remains difficult especially in sporadic cases, due to the very large number of mutations that have been identified; the hypertrophy may represent a nonspecific compensatory response to any mutation that impairs myofibrillar function. Subclinical changes especially affect long-axis ventricular function, and tissue Doppler imaging is the most sensitive test to identify reduced velocities of long-axis shortening and early diastolic lengthening of the left ventricle, prolonged contraction and relaxation times, and reduced strain in affected segments, both in patients with hypertrophy and in asymptomatic subjects with mutations. It can also discriminate well between hypertrophic cardiomyopathy and athlete's heart, and can be used with standard echocardiographic measurements to estimate left ventricular filling pressure or to monitor treatment. Tissue Doppler imaging can now be usefully incorporated into the routine echocardiographic study of patients with proven or suspected hypertrophic cardiomyopathy.