The Clinical Features, Electrocardiogram And Electrophysiological Characteristics Of Focal Ventricular Tachycardia And The Combination Of Internal And External Surgery

Part ⅠTachycardia-induced Cardiomyopathy Secondary to Focal Atrial Tachycardia:Role of Focal Atrial Tachycardia Originating from the Atrial AppendageAbstractOBJECTIVE Reports on tachycardia-induced cardiomyopathy (TCM) secondary to focal atrial tachycardia (AT) are scarce. We sought to investigate the clinical and electrophysiological characteristics of patients with focal AT and tried to figure out the incidence, the risk factors of TCM in patients with focal AT and its prognosis.METHODS We included 214 consecutive patients with focal ATs who were managed by radiofrequency catheter ablation (RFCA) at our center between August 2008 and February 2015. The origin of the ATs were confirmed by endocardial mapping. The diagnosis of TCM was established by Echocardiography before admission and during follow-up. We compared the differences of clinical features and electrophysiological characteristics between patients with and without TCM. We further utilized logistic regression model to search for the risk factors of TCM.RESULTS A total of 15 patients (7.0%) were complicated by TCM. The origins of AT were crita terminalis (1 case), perinodal area (1 case), ostium of coronary sinus (2 cases), septum (2 cases), pulmonary vein (1 case) and atrial appendage (8 cases). The incidence of TCM was highest in patients with focal AT originating from the atrial appendage (32.0%), which was followed by 18.2% in patients with focal AT originating from the septum. In comparison with patients without TCM, patients with TCM were younger (30±13 vs.43±18 years old,p=0.0047), and their ATs were more likely to have the clinical feature of frequent paroxysm, incessancy or persistency. In the logistic regression analysis, the clinical feature of frequent paroxysm, incessancy or persistency was the only independent risk factor for the development of TCM (odds ratio [OR] 44.037, confidence interval [CI] 5.644-343.609,p=0.0003). When taking the origin of focal AT alone into consideration, the origins at the atrial appendage and at the septum predicted greater risk of TCM (OR 19.097, CI 5.324-68.504, p<0.0001; OR 8.783, CI 1.418-54.387, p=0.0195, respectively). After successful RFCA (11 cases), minimally invasive atrial appendectomy (3 cases) and strict ventricular rate control (1 case), the left ventricular ejection fraction recovered from 31±10% before admission to 60±4% during follow-up.CONCLUSION The incidence of TCM in patients with focal AT was 7.0%. The clinical feature of frequent paroxysm, incessancy or persistency was the only independent risk factor for development of TCM. The focal ATs originating from the atrial appendage had the highest incidence of TCM. TCM was completely reversible after successful elimination of the focal ATs or ideal ventricular rate control.Part IIAlgorithms Combining Electrocardiographic P Wave Morphology and Clinical Features Can Help Differentiate Focal Atrial Tachycardias Originating from the Atrial Appendage from Those Originating from Adjacent StructuresAbstractOBJECTIVE By electrocardiogram (ECG) alone, it is difficult to differentiate focal atrial tachycardias (ATs) originating from the left and right atrial appendage (LAA and RAA) from ATs originating from adjacent structures, i.e., left superior pulmonary vein (LSPV) and superior tricuspid annulus (TA), respectively. We sought to investigate whether the clinical features of these ATs can help differentiate them.METHODS We included 216 consecutive patients with 223 focal ATs, who were managed by radiofrequency catheter ablation at our center between August 2008 and February 2015. The origin of the ATs were confirmed by endocardial mapping. Out of these patients,14 patients with 14 focal ATs originating from LAA,16 patients with 16 LSPV focal ATs,11 patients with 11 RAA focal ATs, and 7 patients with 7 superior TA focal ATs were analyzed. By comparison of ECG P wave morphology and clinical features of each individual patient, we established two new algorithms to differentiate the origins of ATs from adjacent structures and evaluated their accuracy in prediction.RESULTS LAA and LSPV focal ATs shared common P wave morphologies such as positive P wave in lead V1-V6, positive P wave in inferior leads, negative P wave in lead aVL, but had different P wave morphology in lead I. In our cases, all LAA focal ATs presented as negative P wave in lead I. However, only 7 (43.8%) of LSPV focal ATs presented as negative P wave in lead I, and the remaining 9 (56.2%) of LSPV focal ATs had either an isoelectric P wave or a positive/negative P wave in lead I. In comparison with the patients with LSPV focal ATs, the patients with LAA focal ATs were younger (26.1±12.6 vs.48.3±17.6 years old, P=0.0041), were less likely to have concomitant atrial fibrillation (0.0% vs.56.3%, P=0.0028), and had higher incidence of incessant/persistent nature (100.0% vs.12.5%, P<0.0001). An algorithm based on the difference of lead I P wave morphology and the presence or absence of incessant/persistent nature, predicted the origin of LAA with an accuracy of 99.6%, a sensitivity of 100.0% and a specificity of 99.5% and predicted the origin of LSPV with an accuracy of 96.4%, a sensitivity of 88.2% and a specificity of 97.1%. RAA focal ATs and superior TA focal ATs shared common P wave morphologies such as negative P wave in leads V1-V2 with precordial transition in leads V3 to V6, positive but low amplitude P wave in inferior leads and positive P wave in lead I. Due to the anatomical superiority, RAA focal ATs presented as all positive P waves in inferior leads, but none with biphasic P wave in these leads was observed. While superior TA focal ATs presented as biphasic P wave in inferior leads in 42.9% of patients (p=0.0386). The only difference of clinical features between RAA and superior TA focal ATs was the presence of incessant/persistent nature (100.0% vs.0.0%, P=0.0008). An algorithm based on P wave morphology and the presence or absence of incessant nature predicted the origin of RAA with an accuracy of 99.6%, a sensitivity of 85.7%, and a specificity of 97.7% and predicted the origin of superior TA with an accuracy of 97.3%, a sensitivity of 90.9% and a specificity of 100.0%.CONCLUSION In addition to ECG P wave morphology, the presence or absence of AT incessancy/persistency helped differentiate the LAA/RAA focal ATs from AT originating from adjacent structures with good accuracy.Part IIIManagement of Focal Atrial Tachycardias Originating from the Atrial Appendage with the Combination of Radiofrequency Catheter Ablation and Minimally Invasive Atrial AppendectomyAbstractOBJECTIVE Focal atrial tachycardias (ATs) originating from the left and right atrial appendage (AA) were the most difficult to eliminate. We sought to evaluate the safety and long-term efficacy of minimally invasive surgical atrial appendectomy in combination with radiofrequency catheter ablation (RFCA) in management of focal atrial appendage tachycardias (AATs).METHODS We included 46 consecutive patients with 46 AATs confirmed by activation mapping and contrast venography. Thirty-four of them were successfully managed with RFCA (RFCA-successful Group), while the remaining 12 finally resorted to video-assisted thoracoscopic (VAT) atrial appendectomy due to RFCA failure (Resort-to-surgery Group). We searched for predictors of RFCA failure and the need for surgery using a binomial logistic regression model.RESULTS In RFCA-successful Group,6 patients experienced recurrence and re-do ablation and 12 AATs (35.3%) originated from distal AAs. In Resort-to-surgery Group, the tachycardias involved exclusively distal AAs and required more RFCA attempts, compared with those of RFCA-successful Group (1.58±0.51 vs.1.21±0.41;p=0.0206). During atrial appendectomy, incessant ATs were terminated immediately after resection of the AA at the base. Long-term success was achieved in all 46 patients with 28.9±17.7 months follow-up. No complications occurred. Sixteen patients with tachycardia-induced cardiomyopathy fully recovered. We identified origin at distal AATs and longer time to tachycardia termination by ablation as predictors of RFCA failure and the need for surgical intervention.CONCLUSION ATs originating from the distal portion of AA were more refractory to RFCA. The combination of catheter ablation and VAT atrial appendectomy was an effective strategy to manage AATs.