Comparison of Echocardiographic Markers of Cardiac Dyssynchrony and Latest Left Ventricular Activation Site in Heart Failure Patients with and without Left Bundle Branch Block

Background: Several echocardiographic markers have been introduced to assess the left ventricular (LV) mechanical dyssynchrony. We studied dyssynchrony markers and the latest LV activation site in heart failure patients with and without left bundle branch block (LBBB). Methods: Conventional echocardiography and tissue velocity imaging were performed for 78 patients (LV ejection fraction ≤ 35%), who were divided into two groups: LBBB (n = 37) and non-LBBB (n = 41). Time-to-peak systolic velocity (Ts) was measured in 12 LV segments in the mid and basal levels. Seven dyssynchrony markers were defined: delay and standard deviation (SD) of Ts in all and basal segments, septal-lateral and anteroseptal-posterior wall delay (at the basal level), and interventricular mechanical delay (IVMD). Results: The LBBB patients had significantly higher QRS duration and IVMD. The posterior wall was the latest activated site in the LBBB and the inferior wall was the latest in the non-LBBB patients. The most common dyssynchrony marker in the LBBB group was the SD of Ts in all segments (73%), whereas it was Ts delay in the basal segments in the non-LBBB group (48.8%). Ts delay and SD of all LV segments, septal lateral delay, septal-to-posterior wall delay by M-mode, pre-ejection period of the aortic valve, and IVMD were significantly higher in the LBBB group than in the non-LBBB group. Also, 29.3% of the non-LBBB and 10.8% of the LBBB patients did not show dyssynchrony by any marker. The number of patients showing dyssynchrony by ≥ 3 markers was remarkably higher in the LBBB patients (73% vs. 43.9%, respectively; p value = 0.044). Conclusion: The LBBB patients presented with a higher prevalence of dyssynchrony according to the frequently used echocardiographic markers. The latest activation site was different between the groups

Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia: Success Rates and Complications during 14 Years of Experience

Background: Radiofrequency catheter ablation (RFCA) has been introduced as the treatment of choice for supraventricular tachycardia. The aim of this study was to evaluate the success rate as well as procedural and in-hospital complications of RFCA for the treatment of atrioventricular nodal reentrant tachycardia (AVNRT).Methods: Between March 1995 and February 2009, 544 patients (75.9% female, age: 48.89 ± 13.19 years) underwent 548 RFCAs for AVNRT in two large university hospitals. Echocardiography was performed for all the patients before and after the procedure. Electrocardiograms were recorded on digital multichannel systems (EP-Med) or Bard EP system. Anticoagulation was initiated during the procedure.Results: From the 548 patients, 36 had associated arrhythmias, atrial flutter (4%), atrial fibrillation (0.7%), concurrent atrial fibrillation and atrial flutter (0.7%), and concealed atrioventricular pathway (0.4%). The overall success rate was 99.6%. There were 21 (3.9%) transient III-degree AV blocks (up to a few seconds) and 4 (0.7%) prolonged II- or III-degree AV blocks, 2 (0.25%) of which required permanent pacemaker insertion, 3(0.5%) deep vein thrombosis, and one (0.2%) arteriovenous fistula following the procedure. No difference was observed in the echocardiography parameters before and after the ablation.Conclusion: RFCA had a high success rate. The complication rate was generally low and in the above-mentioned centers it was similar to those in other large centers worldwide. Echocardiography showed no difference before and after the ablation. The results from this study showed that the risk of permanent II or III-degree AV block in patients undergoing RFCA was low and deep vein thrombosis was the second important complication. There was no risk of life-threatening complications