Doppler evaluation of left ventricular filling: effect of verapamil on non-obstructive hypertrophic cardiomyopathy

Impaired left ventricular (LV) filling is known to be a major determinant of non-obstructive hypertrophic cardiomyopathy (HCM). Seventeen patients with non-obstructive HCM (mean age 71 years) were investigated by Doppler echocardiography, before and after oral treatment with verapamil (mean daily doses: 335 mg). Diagnosis was based on clinical and echocardiographic data. Mitral regurgitation was absent or mild. Heart rate, PQ interval and mitral regurgitation did not change after treatment. All calculated values of Doppler LV filling improved significantly: corrected relaxation time, ratio of atrial to early velocity, EF slope and pressure half-time (P less than 0.005) showed more significant differences than more sophisticated indices using time-velocity integrals of Doppler LV filling flow (P less than 0.005). Results appear to reflect an effect of verapamil on LV relaxation; a slight effect of a modified load was nevertheless not excluded. We conclude that all parameters of Doppler LV filling show marked improvement in this elderly group with non-obstructive HCM, after oral verapamil. Doppler echocardiography is an easy and useful clinical method to assess the effect of a drug on ventricular relaxation of non-obstructive HCM.