Safety and feasibility of combined atrial fibrillation ablation and left atrial appendage occlusion after left atrial appendage electrical isolation.

OBJECTIVE: To demonstrate the feasibility of combining left atrial appendage electrical isolation (LAAEI) with left atrial appendage occlusion (LAAO) to increase efficacy of persistent/longstanding atrial fibrillation (PLAF) catheter ablation (CA) while mitigating risk of left atrial appendage (LAA) thrombus. BACKGROUND: CA for atrial fibrillation (AF) plus LAAO is safe and feasible. LAAEI may improve freedom from recurrence in PLAF but may increase LAA thrombus. METHODS: We performed 42 concomitant procedures in patients with PLAF. After standard lesions, LAAEI was performed. LAAO immediately followed ablation. If 3-month transesophageal echocardiogram (TEE) was benign, oral anticoagulation (OAC) was transitioned to dual antiplatelet therapy for 3 more months. RESULTS: Patients were 71.1 ± 8.5 years old, with CHADS2-VASc of 3.3 ± 1.1 and HAS-BLED of 2.5 ± 1.4. Twenty-eight of 42 patients (66.7%) were completely AF free over an average follow-up of 18.6 ± 8.6 months. The AF-free survival estimate was 94.5% at 1 year. There was no thromboembolism (TE) during the follow-up. There were six non-significant leaks acutely and six non-significant leaks at 6 months. There were three device-related thrombi, although 2/3 stopped OAC prematurely. CONCLUSION: A combined procedure is feasible and effective in treating arrhythmia and stroke risk associated with PLAF. The risk of TE despite OAC after LAAEI supports simultaneous LAAO.

Single- and dual-site ventricular pacing entirely through the coronary sinus for patients with prior tricuspid valve surgery.

PURPOSE: Transvenous right ventricular pacing has traditionally been avoided after surgical tricuspid valve repair or replacement because of possible valvular dysfunction. Epicardial pacing has been used but it requires surgical thoracotomy and has higher lead failure rates when compared to transvenous pacing. We evaluated the lead stability and clinical outcomes in patients with isolated coronary sinus (CS) lead due to relative contraindication to transvenous pacing from prior tricuspid valve (TV) surgery. METHODS: We retrospectively examined a single-center cohort of 34 patients with TV disease and/or surgery who underwent permanent pacemaker implantation with a left ventricular CS lead as the only ventricular pacing lead (to avoid crossing the TV). The clinical outcome, echocardiographic data, and pacing thresholds were evaluated at follow-up. RESULTS: We implanted 19 patients with a single-CS lead and 15 patients with dual-CS leads. The average left ventricular ejection fraction was 56 ± 13% prior to lead implantation and remained stable at 2-year follow-up. The tricuspid regurgitation remained mild at follow-up. The average lead pacing threshold was 1.2 ± 0.6 V × ms at implant and 1.1 ± 0.4 V × ms at 2-year follow-up (P = 0.39). For patients with dual-CS leads, the pacing threshold was 1.2 ± 0.7 V × ms at implant and 1.1 ± 0.5 V × ms at 2-year follow-up (P = 0.52). CONCLUSIONS: The use of ventricular pacing entirely through the CS is an effective and minimally invasive method that provides stable pacing for patients with prior TV surgery in whom transvenous lead placement either is not possible or is relatively contraindicated.

Wireless Smartphone ECG Enables Large-Scale Screening in Diverse Populations.

BACKGROUND: The ubiquitous presence of internet-connected phones and tablets presents a new opportunity for cost-effective and efficient electrocardiogram (ECG) screening and on-demand diagnosis. Wireless, single-lead real-time ECG monitoring supported by iOS and android devices can be obtained quickly and on-demand. ECGs can be immediately downloaded and reviewed using any internet browser. OBJECTIVE: We compared the standard 12-lead ECG to the smartphone ECG in healthy young adults, elite athletes, and cardiology clinic patients. Accuracy for determining baseline ECG intervals and rate and rhythm was assessed. METHODS: In 381 participants, 30-second lead I ECG waveforms were obtained using an iPhone case or iPad. Standard 12-lead ECGs were acquired immediately after the smartphone tracing was obtained. De-identified ECGs were interpreted by automated algorithms and adjudicated by two board-certified electrophysiologists. RESULTS: Both smartphone and standard ECGs detected atrial rate and rhythm, AV block, and QRS delay with equal accuracy. Sensitivities ranged from 72% (QRS delay) to 94% (atrial fibrillation). Specificities were all above 94% for both modalities. CONCLUSION: Smartphone ECG accurately detects baseline intervals, atrial rate, and rhythm and enables screening in diverse populations. Efficient ECG analysis using automated discrimination and an enhanced smartphone application with notification capabilities are features that can be easily incorporated into the acquisition process.

Worldwide experience with the robotic navigation system in catheter ablation of atrial fibrillation: methodology, efficacy and safety.

INTRODUCTION: The Hansen Robotic system has been utilized in ablation procedures for atrial fibrillation (AF). However, because of the lack of tactile feedback and the rigidity of the robotic sheath, this approach could result in higher risk of complications. This worldwide survey reports a multicenter experience on the methodology, efficacy, and safety of the Hansen system in AF ablations. METHODS AND RESULTS: A questionnaire addressing questions on patient's demographics, procedural parameters, ablation success rate and safety information was sent to all centers where more than 50 robotic AF ablation cases have been performed. From June 2007 to December 2009, 1,728 procedures were performed at 12 centers utilizing the Hansen robotic navigation technology. The overall complication rate was 4.7% and the success rate was 67.1% after 18 ± 4 months of follow-up. In 5 low volume centers there appeared to be a learning curve of about 50 cases (complication rate 11.2% for the first 50 cases vs 3.7% for the 51-100 cases; P = 0.044) and a trend showing a decrease of complication rate with increasing case volume. However, in the remaining 7 centers no learning curve was present and the complication rate was stable over time (3.7% for the first 50 cases vs 3.6% for the 51st case thereafter; P = 0.942). CONCLUSION: The Hansen robotic system can be used for AF ablation safely. In low volume centers, there appeared to be a learning curve of the first 50 cases after which the complication rate decreased. With a higher case volume, the success rate increased.

Inductionless or limited shock testing is possible in most patients with implantable cardioverter- defibrillators/cardiac resynchronization therapy defibrillators: results of the multicenter ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations).

BACKGROUND: Implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators have relied on multiple ventricular fibrillation (VF) induction/defibrillation tests at implantation to ensure that the device can reliably sense, detect, and convert VF. The ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations) is the first large, multicenter, prospective trial comparing vulnerability safety margin testing versus defibrillation safety margin testing with a single VF induction/defibrillation. METHODS AND RESULTS: A total of 426 patients receiving an implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator underwent vulnerability safety margin or defibrillation safety margin screening at 14 J in a randomized order. After this, patients underwent confirmatory testing, which required 2 VF conversions without failure at < or = 21 J. Patients who passed their first 14-J and confirmatory tests, irrespective of the results of their second 14-J test, had their devices programmed to a 21-J shock for ventricular tachycardia (VT) or VF > or = 200 bpm and were followed up for 1 year. Of 420 patients who underwent 14-J vulnerability safety margin screening, 322 (76.7%) passed. Of these, 317 (98.4%) also passed 21-J confirmatory tests. Of 416 patients who underwent 14-J defibrillation safety margin screening, 343 (82.5%) passed, and 338 (98.5%) also passed 21-J confirmatory tests. Most clinical VT/VF episodes (32 of 37, or 86%) were terminated by the first shock, with no difference in first shock success. In all observed cases in which the first shock was unsuccessful, subsequent shocks terminated VT/VF without complication. CONCLUSIONS: Although spontaneous episodes of fast VT/VF were limited, there was no difference in the odds of first shock efficacy between groups. Screening with vulnerability safety margin or defibrillation safety margin may allow for inductionless or limited shock testing in most patients.

Simultaneous biatrial computerized mapping during permanent atrial fibrillation in patients with organic heart disease.

INTRODUCTION: Activation patterns during permanent atrial fibrillation (AF) in patients with organic heart diseases are unclear. METHODS AND RESULTS: We studied six patients with permanent AF and organic heart diseases undergoing surgery. The duration of AF averaged 4.9+/-7.6 years. Computerized epicardial mappings of the right atrial (RA) free wall and the left atrial (LA) posterior wall were simultaneously performed with 224 bipolar electrodes at 3-mm spatial resolution. In the RA, large wavefronts and conduction blocks were frequently observed. The lines of block correlated with the crista terminalis and large pectinate muscles. In contrast, the LA had rapid repetitive activities originated from corners of the electrode plaque, near the four pulmonary veins (PVs). On average, 2.8+/-1.2 sites of rapid repetitive activities were identified per patient. They activated continuously, intermittently, or alternately during AF. The mean activation cycle length in the RA (196+/-22 msec) was significantly longer than that in the LA (179+/-26 msec; P = 0.004). The maximum dominant frequency in the LA was higher than that in the RA (6.41+/-1.18 Hz vs 5.66+/-0.55 Hz; P = 0.049). The maximum dominant frequency was consistently located in areas with rapid repetitive activations near the PVs. CONCLUSION: During human permanent AF associated with organic heart diseases, the activation cycle length was shorter in the LA posterior wall than in the RA free wall. Rapid repetitive activities are consistently observed in the LA posterior wall, at or near the PVs.