title: Quantitative and qualitative changes in the resting electrocardiograph after percutaneous transluminal septal myocardial ablation for the treatment of symptomatic obstructive hypertrophic cardiomyopathy.
abstract: Percutaneous Transluminal Septal Myocardial Ablation (PTSMA) may reduce symptoms in patients with obstructive hypertrophic cardiomyopathy. Limited quantitative and qualitative data exists on the effects of PTSMA on the resting electrocardiograph. We report repolarisation and conduction abnormalities and incidence of arrhythmia post-PTSMA. Twelve-lead electrocardiographs from subjects without pre-procedural pacemakers who underwent successful procedures (37 procedures, mean age 61+/-14 years) were analysed for rhythm, heart rate, PR and QTc intervals, QRS duration and left or right bundle branch block (RBBB, LBBB). Four subjects developed permanent complete AV block, 19 subjects developed new RBBB and two subjects developed new LBBB pre-discharge. At a median follow-up of 34 (range 1-84) months, no new AV block, ventricular arrhythmias or deaths occurred. Post-PTSMA PR, QRS and QTc intervals lengthened (PR 180+/-33 ms, 204+/-40 ms, QRS 105+/-20 ms, 132+/-27 ms and QTc 454+/-32 ms, 491+/-37 ms (pre- and post-PTSMA respectively, all p=0.001). Predictors of permanent complete AV block included female gender (p=0.013), older age (p=0.013) and pre-existing LBBB (p<0.001). Atrio-ventricular and intra-ventricular conduction disturbances are common post-PTSMA. A pre-existing LBBB is a risk factor for the development of complete AV block and may merit prophylactic pacemaker insertion.
authors.affiliation: Monash Cardiovascular Research Centre, MonashHeart, Southern Health, 246 Clayton Road, Clayton, Victoria 3168, Australia.
authors.forename: Wai-ee
authors.initials: WE
authors.lastname: Thai
authors.forename: Paul R
authors.initials: PR
authors.lastname: Antonis
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Hope
authors.forename: Ian T
authors.initials: IT
authors.lastname: Meredith
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002037:Bundle-Branch Block / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology*; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality / Q000628:therapy*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012307:Risk Factors; D012737:Sex Factors