Long-term outcomes after radiofrequency catheter ablation of the atrioventricular node: The experience of a Portuguese tertiary center.

INTRODUCTION: In patients with supraventricular arrhythmias and high ventricular rate, unresponsive to rate and rhythm control therapy or catheter ablation, atrioventricular (AV) node ablation may be performed. OBJECTIVES: To assess long-term outcomes after AV node ablation and to analyze predictors of adverse events. METHODS: We performed a detailed retrospective analysis of all patients who underwent AV node ablation between February 1997 and February 2019, in a single Portuguese tertiary center. RESULTS: A total of 123 patients, mean age 69±9 years and 52% male, underwent AV node ablation. Most of them presented atrial fibrillation at baseline (65%). During a median follow-up of 8.5 years (interquartile range 3.8-11.8), patients improved heart failure (HF) functional class (NYHA class III-IV 46% versus 13%, p=0.001), and there were reductions in hospitalizations due to HF (0.98±1.3 versus 0.28±0.8, p=0.001) and emergency department (ED) visits (1.1±1 versus 0.17±0.7, p=0.0001). There were no device-related complications. Despite permanent pacemaker stimulation, left ventricular ejection fraction did not worsen (47±13% vs. 47%±12, p=0.63). Twenty-eight patients died (23%). The number of ED visits due to HF before AV node ablation was an independent predictor of the composite adverse outcome (OR 1.8, 95% CI 1.24-2.61, p=0.002). CONCLUSIONS: Despite pacemaker dependency, the clinical benefit of AV node ablation persisted at long-term follow-up. The number of ED visits due to HF before AV node ablation was an independent predictor of the composite adverse outcome. AV node ablation should probably be considered earlier in the treatment of patients with supraventricular arrhythmias and HF, especially in cases that are unsuitable for selective ablation of the specific arrhythmia.

Prevalence, multimodality imaging characterization, and mid-term prognosis of quadricuspid aortic valves: an analysis of eight cases, based on 160 004 exams performed during 12 years in a tertiary care hospital.

AIMS: Quadricuspid aortic valve (QAV) is a rare abnormality, which may cause aortic regurgitation (AR) requiring surgical intervention in some patients. The characteristics associated with aortic valve functional degeneration in patients with QAV are still unknown. The aim of this study is to describe QAV prevalence, characterize the disease by multimodality imaging, evaluate predictors of severe AR, and assess mid-term prognosis. METHODS AND RESULTS: Retrospective search in imaging exams database of one tertiary centre, for patients diagnosed with QAV between January 2007 and September 2019. QAV was characterized by cardiac computed tomography, transthoracic/transoesophageal echocardiography, and cardiac magnetic resonance. A total of 160 004 exams were reviewed and eight patients with QAV were identified (50% men, mean age 53.5 ± 10.7 years). The prevalence of QAV was 0.005%. During a median follow-up of 52 months (interquartile range 16-88), there were no deaths. Seven patients (88%) had pure AR (three severe, one moderate, and three mild) and one patient (12%) had moderate AR and moderate aortic stenosis. Three patients (38%) with severe AR underwent valve surgery (two replacements and one repair). Analysis of predictors of severe AR was not statistically significant. CONCLUSION: QAV is a rare congenital cardiac defect, with a prevalence of 0.005% in our study. Its predominant functional abnormality was regurgitation and about one-third of the patients required aortic valve surgery. Multimodality imaging may play a pivotal role in assessing patients with QAV with significant valve dysfunction or associated congenital heart disease and improve their treatment strategy.

The effects of transcatheter aortic valve implantation on cardiac electrical properties.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is associated with cardiac electrical disturbances. However, beyond the risks of pacemaker implantation, few studies have performed a detailed assessment of the effects of TAVI on several cardiac electrical properties. OBJECTIVES: To assess the frequency and type of electrocardiographic disturbances following TAVI, according to the type of prostheses and to assess predictors of these disturbances. METHODS: We performed a detailed retrospective analysis of all electrocardiograms in patients who underwent TAVI, before and after the procedure, at a tertiary center from August 2007 to October 2016. Patients with permanent pacemakers were excluded. RESULTS: We included 182 patients (78±8 years; 56% female) and self-expanding prostheses (SEP) were implanted in 54%. Most patients (80%) were in sinus rhythm at baseline. After TAVI, 21% of patients developed new-onset atrial fibrillation and there was a significant increase in PR interval at discharge (186±41 ms vs. 176±32; p=0.003), which was not maintained after at six-month follow-up (181±35 ms, p=0.06). There was also a significant increase in QRS duration at discharge (129±28 ms vs. 114±25 at baseline p<0.0001), which persisted at six-months (122±28 ms, p<0.0001). New-onset left-bundle branch block (LBBB) was observed in 25% of patients. The depth of valve implantation was a predictor of new LBBB at discharge after multivariate analysis (OR 37.6, 95% CI 14.6-65.2, p=0.001). CONCLUSIONS: The main electrocardiographic disturbances post TAVI were PR prolongation, increased QRS and new-onset LBBB. These disturbances were more pronounced in patients undergoing SEP implantation and tended to improve at six-month follow-up. The depth of valve implantation was a predictor of conduction disturbances.