Noninvasive indexes of left atrial diastolic function in hypertrophic cardiomyopathy

Objectives: Our goal was to noninvasively assess left atrial diastolic func tion and its relation to the impaired left ventricular filling in patients with hypertrophic cardiomyopathy. Methods and Results: We studied 34 patients with hypertrophic cardiomyopath y, 26 patients with secondary forms of left ventricular hypertrophy (aortic stenosis, fixed subaortic stenosis, hypertension), and 21 control subjects . Left atrial diastolic function was assessed by measuring acceleration tim e (SAT), deceleration time (SDT), and the EF (mean deceleration rate) slope of the pulmonary venous how systolic wave (SW). Left ventricular diastolic function assessed by transmitral Doppler included peak early left ventricu lar and peak atrial filling velocities, the ratio of early-to-late peak vel ocities, isovolumic relaxation time, deceleration time, and EF slope. In pa tients with hypertrophic cardiomyopathy, acceleration time was significantl y reduced (P < .05), deceleration time was significantly prolonged (P < .00 01), and EF slope was significantly reduced (P < .01). These indexes were s imilar among the other two groups. No statistically significant difference existed between the subgroups of hypertrophic cardiomyopathy in the above i ndexes. Patients with hypertrophic cardiomyopathy and secondary forms of le ft ventricular hypertrophy had evidence of left ventricular diastolic dysfu nction. In patients with hypertrophic cardiomyopathy, no correlation existe d between left atrial and left ventricular diastolic function indexes (r = -0.26 to 0.33). Conclusions: Echocardiographic indexes of left atrial relaxation and fillin g are abnormal in patients with hypertrophic cardiomyopathy but not in seco ndary forms of left ventricular hypertrophy. These indexes are abnormal in all forms of hypertrophic cardiomyopathy irrespective of left ventricular o utflow tract obstruction and distribution of hypertrophy; they are not sole ly attributable to left ventricular diastolic dysfunction The above may imp ly that hypertrophic cardiomyopathy is a cardiac myopathic disease that inv olves the heart muscle as a whole, irrespective of distribution of hypertro phy and obstruction.