Study On Electrophysiologic Changes In Hypertrophic Obstructive Cardiomyopathy Patients With Percutaneous Transluminal Septal Myocardial Ablation

Objective: To investigate the electrophysiologic changes in HypertrophicObstructive Cardiomyopathy patients with Percutaneous Transluminal SeptalMyocardial Ablation, and discuss the clinical significance.Methods: We summarize60HOCM patients who were treated with PTSMA inour hospital from2008to2010. To collect pre-operative and post-operative ECG and24h ambulatory ECG monitoring of HOCM patients and measure QT interval、 QTdispersion、Tp-Te interval、Tp-Te/QT ratio and the indexes of heart rate variability. Tomeasure AH interval and HV interval during operation and post-operation.Results: Arrhythmia incidence in post-operation: transient right bundle branchblock is66.7%, permanent right bundle branch block is56.2%, transient left bundlebranch block is14.7%, permanent left bundle branch block is5.8%, transientfirst-degree atrioventricular block is19%, permanent first-degree atrioventricular blockis8.8%, transient third-degree atrioventricular block is24.2%, permanent third-degreeatrioventricular block requiring permanent pacemaker is3.5%.24h ambulatory ECGmonitoring result：SDNN:（118.2±26.5）pre-operation vs（108.5±35.2）post-operation，P<0.05. QT dispersion:（71±32） ms pre-operation,（74±19）ms post-operation，（68±30）ms6-month post-operation,（69±30）ms12-month post-operation, P>0.05.Tp-Te interval:（100.90±30.90）ms pre-operation，（87.61±26.25）ms post-operation，P=0.006；Tp-Te/QT ratio:（0.262±0.12）pre-operation，（0.205±0.05） post-operation，P=0.041. The AH interval was delayed (>120msec) in two of the15(13.3%) patients,the HV interval was delayed (>55msec) in four of the15(26.7%) patients inpre-operation; The AH interval was delayed (>120msec) in there of the15(20%) patients, the HV interval was delayed (>55msec) in six of the15(40%) patients inpost-operation.Conclusion: The most common arrhythmia of HOCM patients after PTSMA wasright bundle branch block. It is because the blood of right bundle branch is suppled byablated target vessel. The incidence of ventricular arrhythmia did not increase comparedwith pre-operation in Holter recordings. Because of sympathetic nerve exciting withseptal myocardial infarction, the SDNN decreased in peri-operation. Compared withpre-operation QTd and QTcd had no significant differences. Compared with averageperson the Tp-Te interval and Tp-Te/QT ratio of HOCM patients increased significantly.Compared with pre-operation the Tp-Te interval and Tp-Te/QT ratio after PTSMAdecreased significantly. Tp-Te interval is a new and powerful predictor of suddencardiac death. Tp-Te interval is a better predictor of high-risk patients with HOCM thanQTd and QTcd. PTSMA may decrease the incidence of sudden cardiac death withHOCM. The AH interval was delayed (>120msec) in two of the15(13.3%) patients,the HV interval was delayed (>55msec) in four of the15(26.7%) patients beforePTSMA; The new AH interval was delayed (>120msec) in one of the15patients, thenew HV interval was delayed (>55msec) in two of the15patients after PTSMA. Thetarget vessel of the one new HV interval delayed patient is second septal branch. Thealcohol volume of the AH interval or HV interval delayed patients is2-2.5ml.