Atrial tachycardia as a proarrhythmic effect of radiofrequency catheter ablation for atrioventricular nodal reentrant tachycardia.

Radiofrequency catheter ablation is now the first line treatment for atrioventricular nodal reentrant tachycardia. The success rate is high with a low incidence of complications. However, a possible proarrhythmic effect of radiofrequency energy has been rarely reported and no study has demonstrated a direct correlation between the anatomic site of the radiofrequency application and the origin of a new post-ablation arrhythmia. We present a case of a focal atrial tachycardia that occurred after slow pathway radiofrequency catheter ablation for atrial nodal reentrant tachycardia and originating close to the previous ablation site. This tachycardia was successfully treated with a second ablation session.

Morphologic analysis of left atrial anatomy by magnetic resonance angiography in patients with atrial fibrillation: a large single center experience.

UNLABELLED: LA and PV Anatomy in Patients With AF. INTRODUCTION: Although transcatheter atrial fibrillation (AF) ablation requires accurate anatomic knowledge, pulmonary vein (PV) anatomy has not been fully investigated. Aim of this study is to describe left atrium (LA) and PV anatomy by magnetic resonance angiography (MRA) in a large cohort of patients with AF. METHODS: MRA was performed in 473 patients preceding transcatheter AF ablation (paroxysmal 60.9%; persistent 39.1%). The Venice Chart classification was used to classify PV branching patterns. RESULTS: About 40% of the patients presented typical PV branching pattern (2 left and 2 right PVs). A representative number of patients presented a common left trunk (19.9% and 11.0% short and long, respectively). A right middle PV was described in 12.5% and 2 right middle PVs in 1.5% patients. The remaining patients presented other complex, previously unclassified patterns: 6.3% presented an accessory PV originating from LA areas not describable as right or "upper" and 8.7% a common left trunk plus right middle PV. Diameters and circumference of each PV, LA, and LA appendage volumes resulted larger in patients presenting persistent compared to paroxysmal AF (P < 0.001). CONCLUSION: This study highlights that "typical" PV branching pattern is not a common finding. That 25.6% of the patients present at least 1 accessory PV needs to be kept in careful consideration when planning and performing transcatheter AF ablation. In addition, not only LA volume, but also each PV ostia and LA appendage are significantly enlarged in patients with persistent compared to paroxysmal AF.

Pulmonary veins branching pattern, assessed by magnetic resonance, does not affect transcatheter atrial fibrillation ablation outcome.

AIM: The aim of the present study is to provide, in a large cohort of patients, a description of the left atrium (LA) and pulmonary veins (PV) anatomy in relation to ablation outcome. BACKGROUND: The role of LA imaging, assessed before transcatheter ablation of atrial fibrillation (AF), is unknown. METHODS: 330 patients referred for transcatheter ablation of AF (paroxysmal 62.7%; persistent 25.5%; long-standing 11.8%) underwent contrast-enhanced magnetic resonance imaging (MRI) before the procedure. Transcatheter ablation was performed aiming to AF interruption and/or absence of inducibility. Patients were followed clinically, by ECG, and 24-hour Holter ECG at 1-3-6-12-18-24 months. RESULTS: The MRI preceding the procedure depicted a typical PV branching pattern, two left and two right, in 130 (39.4%) patients; 117 (35.4%) presented common left trunk (short and long) and 75 (22.7%) at least one accessory PV. Mean atrial volume was 142.0 +/- 48.5 ml. The ablation procedure resulted successful, after 15.6 +/- 7.2 months follow-up, in 174 (52.7%) patients. PV branching pattern did not relate (P = 0.304) to ablation outcome. A multiple Cox proportional hazard model, adjusted for potential confounders, proved that only LA volume was independently related to ablation outcome (HR 1.007, 95% CI 1.003-1.011; P = 0.001). A LA cut-off volume of 135 ml emerged as a significant predictor of ablation failure (ROC curve area 0.651, 95% CI 0.591-0.710; P < 0.001). CONCLUSIONS: Less than half of the patients referred for transcatheter AF ablation present a typical PV branching pattern; the PV branching pattern, however, does not affect ablation outcome. LA volume strongly predicts AF ablation outcome.

Sirolimus-eluting stent implantation for bare-metal in-stent restenosis: is there any evidence for a late catch-up phenomenon?

OBJECTIVES: In-stent restenosis occurs not infrequently after intracoronary implantation of bare-metal stents. Many techniques have been proposed for the treatment of in-stent restenosis, but drug-eluting stents seem to provide the best early and mid-term results. We aimed to appraise whether the effectiveness of drug-eluting stents for in-stent restenosis is maintained even in the long term. METHODS: Participants in this prospective multicenter study were patients with in-stent restenosis treated with sirolimus-eluting stents. The primary endpoint was freedom from major adverse cardiovascular events (i.e. death, nonfatal myocardial infarction, target vessel revascularization, or stent thrombosis) in the long term (> or =24 months), with 6-month angiography planned for all patients. RESULTS: A total of 271 consecutive patients were enrolled (332 sirolimus-eluting stents). Procedural success was obtained in all patients, with no case of in-hospital death, acute/subacute stent thrombosis, stroke, or urgent coronary bypass. Survival free from major cardiovascular events decreased progressively from 98.8% at 1 month, to 95.7, 83.7, 75.4, and 65.8% at 6, 12, 24, and 30 months, respectively. A similar attrition in freedom from repeat target vessel was found from 97.6% at 6 months to 76.7% at 30 months. A total of four possible and one definite stent thromboses (2.6%) were noted, all occurring several months after clopidogrel discontinuation and in patients on life-long aspirin. CONCLUSION: The present study supports the mid-term safety and effectiveness of sirolimus-eluting stents for the treatment of in-stent restenosis in comparison with the other available treatments. Whether the late catch-up phenomenon observed in repeat target revascularization and stent thrombosis is an incidental finding deserves further rigorous scrutiny.

Sirolimus-eluting stents for the treatment of bare-metal in-stent restenosis: long-term clinical follow up.

BACKGROUND: Studies focusing on short- and mid-term follow up support the beneficial role of sirolimus-eluting stents (SES) in the treatment of in-stent restenosis (ISR), yet no long-term safety and/or efficacy data are available. METHODS: Patients with ISR following bare-metal stenting (BMS) and treated with SES were prospectively studied. Baseline, procedural, and in-hospital data were appraised. The primary endpoint was the rate of major cardiovascular events (MACE) at long-term follow up (>9 months). Secondary endpoints were the individual contributors to MACE. RESULTS: A total of 180 SES were implanted to treat 138 consecutive patients. Procedural success was achieved in all patients without in-hospital death, acute stent thrombosis, stroke, or urgent coronary artery bypass. During follow up, MACE occurred in 5.8% of patients at 6 months, 14.3% at 12 months, and 25% at 24 months. Specifically, all-cause mortality was 1.7% at 6 months, 3.5% at 12 months, and 4.8% at 24 months, for a total of 5 deaths. Target vessel revascularization occurred at 6, 12, and 24 months in 4.2%, 11.2%, and 15.9% of patients, respectively, while target lesion revascularization (TLR) alone accounted for 3.4% at 6 months, 9.6% at 12 months, and 11% at 24 months. Three case of myocardial infarction occurred during follow up (2.2%), without any surgical revascularization or stent thrombosis. CONCLUSIONS: Treatment of ISR with SES appears safe and effective, even if a 10% annual rate of MACE can be expected, with a sizable portion of these due to apparently nontarget lesion events.

Short- and long-term outcomes of percutaneous coronary interventions in patients with severe left ventricular dysfunction.

AIMS: Poor left ventricular function is considered a high risk condition for performing either percutaneous (PCI) or surgical revascularisation. The aim of this study was to evaluate immediate and long term results of PCI in patients with coronary artery disease (CAD) and severe left ventricular dysfunction (EF < 0.30). METHODS AND RESULTS: Seventy-eight consecutive patients with CAD and severe left ventricular dysfunction (EF < 30%) were selected. The majority of these patients (87%) had multivessel disease. Coronary angioplasty procedure was mainly motivated by angina associated with clinical manifestation of heart failure (54%). Total number of treated vessels was 181, and a total of 203 stents were implanted (2.6 stent/patient). Procedural success was achieved in 77 patients (97.8%). The total procedural and in-hospital adverse event rate was 7.8%. Mean follow-up period (FU) was 25+/-6 months. Event-free survival rate at the end of FU was 55%; repeat revascularisation was performed in 21 patients (27.6%). Female gender, diabetes, new acute myocardial infarction and number of treated vessels were independent predictors for death and combined mayor adverse cardiac events (MACE) during the follow-up. CONCLUSIONS: In symptomatic patients with CAD and severe left ventricular dysfunction, PCI can be performed with excellent procedural outcome and acceptable long-term morbidity and mortality.