Mutations In Beta Myosin Heavy Chain Gene Val606Met In Familial Hypertrophic Cardiomyopathy

Objective To study the disease-causing gene mutation in Chinese with hypertrophic cardiomyopathy(HCM), and to analyze the correlation between the genotype and phenotype. Methods Samples of peripheral blood were collected from three Chinese families with HCM in whose families at least two HCM patients existed. The exons in the functional regions of the beta myosin heavy chain gene(MYH7) were amplified with PCR and the products were sequenced. Results A Val606Met missen mutation was identified in the exon 16 of MYH7 gene in a Chinese family . One hundred and twenty patients as controls were normal in the genetic test. Conclusion The Val606Met missen mutation may be a benign mutation in Chinese HCM. In one family, the identical mutation has different phenotypes and prognoses. The heterogeneity of phenotype suggests that multiple factors might be involved in the pathogenesis. Object: Gauging the acute effect of Percutaneous transluminal septal myocardial ablation (PTSMA) as a treatment for hypertrophic obstructive cardiomyopathy (HOCM).Methods: PTSMA was performed in seventy -two patients with symptomatic HOCM. All patients had echocardiography performed before the procedure, three to seven days and six months after the procedure.Results: Procedure success was achieved in forty-one patients, success rate was 81.9%.The average left ventricular outflow tract (LVOT) gradient was 97.88±40.91 mmHg before the procedure, 50.96±37.92mmHg three to seven days post-PTSMA (p<0.001) and 41.35±29.97mmHg six month post-PTSMA(p<0.001). The thickness0 of inter ventricular septum (IVS) was 22.96±5.15 mm before the procedure, 20.73±4.53mm three to seven days post-PTSMA (p < 0.05) and 16.48±4.42mm six month post-PTSMA(p<0.05). The incidence of right bundle branch block development post-PTSMA was 19.4% (>48hour) , and one patient(1.38%) had complete heart block. Two patients died.Conclusions: PTSMA is an effective non-surgical procedure for symptomatic patients with HOCM because of its low risk and its significant hemodynamic and echocardiographic improvement. Objects 1.To evaluate the safety and efficiency of the dobutamine stressechocardiography in the patients with hypertrophic cardiomyopathy. 2.To estimate thedifference between provokable obstruction and resting obstruction.Methods Echocardiogarphy-Doppler ultrasound measurements in twenty-two patientswith HCM(LVOTPG<50mmHg at rest) studied at rest and at the end point ofdobutamine stress.Fifty-seven patients with HCM(LVOTPG>50mmHg at rest)werealso studied at rest.Results Sixteen patients had positive result at the end point of dobutamine stress.Themain difference between the provokable obstruction and resting obstruction was thatin provokable obstruction patients,the SAM positive patients were fewer and theproportion of Maronâ…¡patients was 50%.Conclusions Dobutamine stress echocardiography was a safe and sensitive way for the patients with hypertrophic cardiomyopathy. In provokable obstruction patients,the SAM positive patients are fewer and the proportion of Maronâ…¡patients was higher. Objective To evaluate the left ventricular function in patients with hypertrophic obstructive cardiomyopathy(HOCM) before and after the PTSMA procedure. Methods The velocity of mitral annulus was measured by Doppler tissue pulsed wave mode. Doppler tissue imaging(DTI)Was obtained from the apical window at 4-chamber,2-chamber, and long apical views to measure Ea, Aa, Sa,respectively. The DTI data of HOCM patients before the PTSMA procedure were compared with the data after the PTSMA procedure. Results There were differences in systolic myocardial velocities of mitral annulus(Sa) ,early diastolic myocardial velocities of mitral annulus(Ea) and late diastolic myocardial velocities of mitral annulus(Aa) before the PTSMA and after the PTSMA . Sa and Ea were higher before than those after the procedure. Conclusions Relaxation and systolic function of the left ventricle decrease in patients with HOCM who underwent PTSMA after several days. Objective To evaluate myocardial infarction induced by percutaneous transluminal septal myocardial ablation (PTSMA) in symptomatic patients with hypertrophic obstructive cardiomyopathy using contrast-enhanced (CE) magnetic resonance imaging (MRI).Methods Cine and CE MRI were performed before and three to seven days after PTSMA in thirty patients. Results Three to seven days after PTSMA, regional hyper enhancement was visualized in the basal interventricular septum in all patients. Mean infarction size was 35.1±18.04g. Volume of ethanol administered correlated well with infarction size(r=0.608, p=0.036) and peak creatine phosphokinase-MB (r=0.762 p=0.01). Conclusions Contrast-enhanced MRI can evaluate the size and location of septal myocardial infarction induced by PTSMA precisely. Infarction size correlated well with ethanol volume. Object: To evaluate myocardial perfusion and metabolism functions influenced byPTSMA.Methods: ⁹⁹Tc^mMIBI and ¹⁸F-FDG Images were performed in 31HCM patientsbefore and in 14 patients 3-7days after PTSMA. Analysis the images in different LVsegments by using scores.Results: In ⁹⁹Tc ^m MIBI images, uptake decreased at the septal regions in most of theHCM patients after PTSMA, ¹⁸F- FDG Images also showed decreased uptake at theseptal regions in most of the HCM patients after PTSMA.Conclusions: ⁹⁹Tc ^mMIBI images might be an important method to evaluate PTSMAresults, ¹⁸F-FDG images showed important value as reference. Object Assess the autonomic function in hypertrophic Obstructive cardiomyopathy(HOCM) patients who underwent PTSMA through heart rate variability (HRV).Methods HRV were performed in Seventy-two HOCM patients before PTSMA,three to seven days and 6 month after PTSMA. Six-two volunteers also underwentHRV test as controls. Time domain variables were obtained at daytime and nightrespectively.Results HRV was shown to be lower in HOCM patients before PTSMA, and becameeven lower three to seven days after PTSMA. Six month after PTSMA ,HRV inHOCM patients seemed recovered, analysis showed no difference between HOCMpatients and controls.Conclusions HRV showed its value on gauging autonomic stimulatic function in HCM patients who underwent PTSMA; no correlation was found between HRV and LVOTPG.