Effects Of Diltiazemon Left Ventricular Early Diastolicflow Propagation Velocity In Patients With Hypertrophic Cardiomyopathy

Objective To investigate the change of the left ventricular early diastolic flowpropagation velocity (V_P) in patients with hypertrophic cardiomyopathy (HCM) by usingcolor M-mode Doppler before and after administration of diltiazem and to discussthe clinical application value of V_P in evaluating left ventricular diastolic function inpatients with hypertrophic cardiomyopathy. Methods We studied 21patients withnon-obstructive hypertrophic cardiomyopathy and 23healthy volunteers matchedwith age and sex. The left ventricular internal dimension at end diastole (LVIDd), Theleft ventricular internal dimension at end systole(LVIDs), interventricular septalthickness at end diastole (IVSd), left ventricular posterior wall thickness at enddiastole (LVPWd) ang The left atria internal dimension at end systolic(LA) weremeasured in the parasternal long axis view by transthoracic two-dimensionalechocardiography, and to calculate left ventricular ejection fraction (EF) withTeichholtz. From the apical four chamber view, the image of mitral inflow wasobtained and early diastolic peak flow velocity (E), late diastolic peak flow velocity(A), the ratio of E/A and deceleration time of E wave were measured. From the apicalfour chamber view, left ventricular early diastolic flow propagation velocity (V_P) wasmeasured by color M-mode echocardiography. Results IVSd and LA were larger(all P＜0.01) in hypertrophic cardiomyopathy than in control group while LVIDd, E/A andV_P were lower (all P＜0.05 or P＜0.01) in HCM group. There were no significantdifferences in LVPWd,EF,E,A and DT in tow groups. After administration ofdiltiazem, LA decreased (P＜0.05) and V_P increased (P＜0.01) while other parameterssuch as LVIDd, LVIDs, IVSd, LVPWd, EF, E, A, E/A and DT have no significantchange(all P＞0.05). There was no correlation between V_P and gender, age, heart rate,blood pressure, EF, IVSd, LVPWd and LVIDd. Conclusions Patients with HCMhave the abnormality of left ventricular in relaxation. V_P is a preload and aftefload-independent index in HCM patients. V_P can correctly assess left ventriculardiastolic function with HCM. Diltiazem can improve left ventricular relaxation andcontributes increased V_P.