Tissue Doppler-Derived Indices Predict Exercise Capacity in Patients With Apical Hypertrophic Cardiomyopathy.

The article presents a study conducted to determine the relationship between diastolic mitral annular velocities combined with conventional Doppler indexes and exercise capacity in patients with apical hypertrophic cardiomyopathy (ApHCM). Twenty-nine patients with ApHCM underwent supine bicycle exercise with simultaneous respiratory gas analysis and two-dimensional and Doppler echocardiographic study. The mitral inflow velocities were traced and measured. Early diastolic mitral annular velocity was measured at the septal corner of mitral annulus by Doppler tissue imaging (DTI) from the apical four-chamber view. It was seen that correlation exists between DTI-derived indexes, an estimate of myocardial relaxation and left ventricular filling pressures, and exercise capacity in patients with ApHCM, suggesting that abnormal diastolic function may be a factor limiting exercise capacity.