Mauricio Scanavacca

Selective Atrial Vagal Denervation Guided by Evoked Vagal Reflex to Treat Patients With Paroxysmal Atrial Fibrillation

Background— The aim of this study was to evaluate whether selective radiofrequency (RF) catheter ablation of the atrial sites in which high-frequency stimulation induces vagal reflexes prevents paroxysmal atrial fibrillation (AF). Methods and Results— Ten patients with episodes suggestive of vagal-induced paroxysmal AF and no heart disease were selected for percutaneous epicardial and endocardial mapping of the atria to search for sites in which high-frequency transcatheter stimulation (20 Hz,) induced vagal reflexes. A vagal response defined as AV block of >2 seconds was elicited in 7 of 10 patients (70%) with an average of 5±2.4 (range, 2 to 9) sites per patient, and RF pulses (21.0±12.0 per patient) were applied at those sites to eliminate all evoked vagal reflexes. The 3 patients in whom evoked vagal reflexes were not obtained underwent circumferential pulmonary vein ablation with an average of 58.0±13.9 RF pulses per patient (P=0.022). Autonomic evaluation was performed before and 48 hours and 3 months after the procedure and was consistent with vagal withdrawal in all patients. Two of the 7 patients who underwent denervation remained asymptomatic without the use of antiarrhythmic medication at a mean follow-up of 8.3±2.8 months (range, 5 to 15 months); 4 had frequent recurrences and were referred for circumferential pulmonary vein ablation; and 1 had few AF episodes without antiarrhythmic medication. The 3 patients without evoked vagal reflexes who underwent circumferential pulmonary vein ablation remained asymptomatic without antiarrhythmic medication. One patient had acute delayed gastric emptying after atrial vagal denervation. Conclusions— RF catheter ablation of selected atrial sites in which high-frequency stimulation induced vagal reflexes may prevent AF recurrences in selected patients with apparently vagal-induced paroxysmal AF.

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation

During the past three decades, catheter and surgical ablation of atrial fibrillation (AF) have evolved from investigational procedures to their current role as effective treatment options for patients with AF. Surgical ablation of AF, using either standard, minimally invasive, or hybrid techniques, is available in most major hospitals throughout the world. Catheter ablation of AF is even more widely available, and is now the most commonly performed catheter ablation procedure. In 2007, an initial Consensus Statement on Catheter and Surgical AF Ablation was developed as a joint effort of the Heart Rhythm Society (HRS), the European Heart Rhythm Association (EHRA), and the European Cardiac Arrhythmia Society (ECAS).1 The 2007 document was also developed in collaboration with the Society of Thoracic Surgeons (STS) and the American College of Cardiology (ACC). This Consensus Statement on Catheter and Surgical AF Ablation was rewritten in 2012 to reflect the many advances in AF ablation that had occurred in the interim.2 The rate of advancement in the tools, techniques, and outcomes of AF ablation continue to increase as enormous research efforts are focused on the mechanisms, outcomes, and treatment of AF. For this reason, the HRS initiated an effort to rewrite and update this Consensus Statement. Reflecting both the worldwide importance of AF, as well as the worldwide performance of AF ablation, this document is the result of a joint partnership between the HRS, EHRA, ECAS, the Asia Pacific Heart Rhythm Society (APHRS), and the Latin American Society of Cardiac Stimulation and Electrophysiology (Sociedad Latinoamericana de Estimulacion Cardiaca y Electrofisiologia [SOLAECE]). The purpose of this 2017 Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF and to report the findings of a writing group, convened by these five international societies. The writing group is charged with defining the indications, techniques, and outcomes of AF ablation procedures. Included within this document are recommendations pertinent to the design of clinical trials in the field of AF ablation and the reporting of outcomes, including definitions relevant to this topic. The writing group is composed of 60 experts representing 11 organizations: HRS, EHRA, ECAS, APHRS, SOLAECE, STS, ACC, American Heart Association (AHA), Canadian Heart Rhythm Society (CHRS), Japanese Heart Rhythm Society (JHRS), and Brazilian Society of Cardiac Arrhythmias (Sociedade Brasileira de Arritmias Cardiacas [SOBRAC]). All the members of the writing group, as well as peer reviewers of the document, have provided disclosure statements for all relationships that might be perceived as real or potential conflicts of interest. All author and peer reviewer disclosure information is provided in Appendix A and Appendix B. In writing a consensus document, it is recognized that consensus does not mean that there was complete agreement among all the writing group members. Surveys of the entire writing group were used to identify areas of consensus concerning performance of AF ablation procedures and to develop recommendations concerning the indications for catheter and surgical AF ablation. These recommendations were systematically balloted by the 60 writing group members and were approved by a minimum of 80% of these members. The recommendations were also subject to a 1-month public comment period. Each partnering and collaborating organization then officially reviewed, commented on, edited, and endorsed the final document and recommendations. The grading system for indication of class of evidence level was adapted based on that used by the ACC and the AHA.3,4 It is important to state, however, that this document is not a guideline. The indications for catheter and surgical ablation of AF, as well as recommendations for procedure performance, are presented with a Class and Level of Evidence (LOE) to be consistent with what the reader is familiar with seeing in guideline statements. A Class I recommendation means that the benefits of the AF ablation procedure markedly exceed the risks, and that AF ablation should be performed; a Class IIa recommendation means that the benefits of an AF ablation procedure exceed the risks, and that it is reasonable to perform AF ablation; a Class IIb recommendation means that the benefit of AF ablation is greater or equal to the risks, and that AF ablation may be considered; and a Class III recommendation means that AF ablation is of no proven benefit and is not recommended. The writing group reviewed and ranked evidence supporting current recommendations with the weight of evidence ranked as Level A if the data were derived from high-quality evidence from more than one randomized clinical trial, meta-analyses of high-quality randomized clinical trials, or one or more randomized clinical trials corroborated by high-quality registry studies. The writing group ranked available evidence as Level B-R when there was moderate-quality evidence from one or more randomized clinical trials, or meta-analyses of moderate-quality randomized clinical trials. Level B-NR was used to denote moderate-quality evidence from one or more well-designed, well-executed nonrandomized studies, observational studies, or registry studies. This designation was also used to denote moderate-quality evidence from meta-analyses of such studies. Evidence was ranked as Level C-LD when the primary source of the recommendation was randomized or nonrandomized observational or registry studies with limitations of design or execution, meta-analyses of such studies, or physiological or mechanistic studies of human subjects. Level C-EO was defined as expert opinion based on the clinical experience of the writing group. Despite a large number of authors, the participation of several societies and professional organizations, and the attempts of the group to reflect the current knowledge in the field adequately, this document is not intended as a guideline. Rather, the group would like to refer to the current guidelines on AF management for the purpose of guiding overall AF management strategies.5,6 This consensus document is specifically focused on catheter and surgical ablation of AF, and summarizes the opinion of the writing group members based on an extensive literature review as well as their own experience. It is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are caring for patients who are undergoing, or are being considered for, catheter or surgical ablation procedures for AF, and those involved in research in the field of AF ablation. This statement is not intended to recommend or promote catheter or surgical ablation of AF. Rather, the ultimate judgment regarding care of a particular patient must be made by the health care provider and the patient in light of all the circumstances presented by that patient. The main objective of this document is to improve patient care by providing a foundation of knowledge for those involved with catheter ablation of AF. A second major objective is to provide recommendations for designing clinical trials and reporting outcomes of clinical trials of AF ablation. It is recognized that this field continues to evolve rapidly. As this document was being prepared, further clinical trials of catheter and surgical ablation of AF were under way.

Epicardial Mapping and Ablation Techniques to Control Ventricular Tachycardia

Mapping and ablation of ventricular tachycardia (VT), in any of its several forms of presentation, are still challenging. The presence of epicardial circuits has been considered one of the reasons for the failure of endocardial ablation, and these circuits have been described in several types of cardiac disease in which surgical and nonsurgical techniques have been used. The transseptal approach and coronary cusp approach can be useful for the mapping of specific forms of idiopathic VT originating in the left ventricular outflow tract. Coronary veins can be used to perform epicardial mapping, but the manipulation of the catheter is limited by the anatomical distribution of these vessels. To the best of our knowledge, the subxiphoid percutaneous approach to the epicardial space is the only technique currently available that allows an extensive and unrestricted mapping of the epicardial surface of both ventricles. Several papers from our group were published after the initial report in 1996.1-4 This procedure must be performed with the patient under general anesthesia, because of the high-risk nature of the patients and also because radiofrequency (RF) pulses applied in the epicardial surface are painful. The subxiphoid approach to the pericardial space is performed after positioning a multipolar catheter in the coronary sinus and a catheter in the right ventricular apex, through the femoral approach, and before starting the anticoagulation. The pericardial space is reached using a commercially available needle, originally developed to perform a spinal tap. The tip of these needles is shaped to reach a virtual space, without damaging the spinal cord. These needles can be found in two sizes (epidural needle: 17 Ga ×3–7/8′ (9.84 cm) and ×5′ (12.5 cm) TW with centimeter markings (Arrow International Inc., Reading, PA). The choice of which to use is based on the size of the thorax. Because of its shape, this type of needle is considered safer for the transthoracic epicardial approach. Other types of needles can be used; however, the operator must be aware of the higher risk of perforation of the heart. The puncture must be performed at the angle between the left border of the subxiphoid process and the lower left rib. The spatial orientation of the needle is an important step and it will determine what portion of the ventricles will be

Effectiveness of the Maze Procedure Using Cooled-Tip Radiofrequency Ablation in Patients With Permanent Atrial Fibrillation and Rheumatic Mitral Valve Disease

Background—Although the Cox-Maze III procedure is effective for treating permanent atrial fibrillation (AF), its high complexity limits its use. The Saline-Irrigated Cooled-tip Radiofrequency Ablation (SICTRA) System is an alternative source of energy used to ablate AF. The aim of this study was to evaluate the effectiveness of the SICTRA for the treatment of permanent AF in patients with rheumatic mitral valve (MV) disease. Methods and Results—Between February 2002 and April 2003, 70 patients with permanent AF and rheumatic MV disease were randomly assigned to undergo a modified Maze III procedure using SICTRA associated with MV surgery (group A) or MV surgery alone (group B). Groups A and B were similar in terms of baseline characteristics. The in-hospital mortality rate was 2.3% (1 death) in group A versus 0% (no deaths) in group B (P>0.99). The additional time required for the left-sided radiofrequency ablation in group A was 14.2±5.1 minutes and for right-sided ablation was 12.3±4.2 minutes. The mean postoperative follow-up periods were 13.8±3.4 and 11.5±7.3 months, respectively, in groups A and B. The overall mid-term survival rate was 95.1% in group A and 92.8% in group B (P>0.99). The cumulative rates of sinus rhythm were 79.4% in group A and 26.9% in group B (P=0.001). Doppler echocardiography documented biatrial transport function in 90.3% of group A patients in sinus rhythm. Conclusions—The SICTRA is effective for treating permanent AF associated with rheumatic MV disease.

Pulmonary vein stenosis complicating catheter ablation of focal atrial fibrillation.

Pulmonary Vein Stenosis. Introduction: A recently described focal origin of atrial fibrillation, mainly inside pulmonary veins, is creating new perspectives for radiofrequency catheter ablation. However, pulmonary venous stenosis may occur with uncertain clinical consequences. This report describes a veno‐occlusive syndrome secondary to left pulmonary vein stenosis after radiofrequency catheter ablation.

Venice Chart International Consensus Document on Ventricular Tachycardia/Ventricular Fibrillation Ablation

(J Cardiovasc Electrophysiol, Vol. 21, pp. 339–379, March 2010)

Nonsurgical Transthoracic Epicardial Approach in Patients with Ventricular Tachycardia and Previous Cardiac Surgery

AbstractIntroduction: The subxyphoid pericardial mapping approach can be used to facilitate catheter ablation of postmyocardial-infarction ventricular tachycardia (post-MI VT), but the presence of dense adhesions is thought to preclude this approach in patients who have previously undergone open-chest cardiac surgery. Aims of the Study: This study reports the first use of a nonsurgical transthoracic epicardial approach in patients with scar-related VT and previous cardiac surgery. Methods: Five patients with a mean age of 67 ± 10 years, left ventricular ejection fraction (LVEF) of 40 ± 4.3%) and recurrent VT occurring 7 months to 10 years after cardiac surgery underwent combined endocardial and epicardial mapping and ablation during the same session. Because pericardial adhesions were anticipated to be denser in the anterior wall, the nonsurgical transthoracic epicardial puncture was directed to the inferior wall of the left ventricle. Failure to interrupt VT with radio frequency (RF) energy pulses delivered at the best endocardial or epicardial site prompted changing from one approach to the other. Results: During the epicardial puncture procedure, the contrast medium accumulated in the inferior wall instead of spreading around the cardiac silhouette. The pericardial sac could be entered in all patients, and mapping of the infero-lateral epicardial wall of the left ventricle was feasible. Fourteen VTs were induced, of which 8 could not be mapped because of poor hemodynamic tolerance. Three of the remaining 6 mappable VTs were eliminated by endocardial ablation, 2 required an epicardial RF pulse to be rendered noninducible, and 1 VT was not eliminated. No intra- or postprocedural complications were noted despite full heparinization. Conclusion: Nonsurgical transthoracic epicardial catheter mapping and ablation of epicardial VT related to the inferolateral left ventricular wall are feasible in patients who have previously undergone open- cardiac surgery.

Unusual complications of percutaneous epicardial access and epicardial mapping and ablation of cardiac arrhythmias.

Background— Percutaneous epicardial access and mapping/ablation of cardiac arrhythmias are being increasingly performed. Although complications such as pericardial effusion are relatively common, other unusual complications may occur due to the complex anatomic architecture of the heart and surrounding tissues. In this report, we report a series of rare and unusual complications related to percutaneous epicardial procedures. Methods and Results— Between 2006 and 2011, 334 patients underwent attempts at percutaneous, subxiphoid access for epicardial mapping/ablation at 5 experienced centers. Seven selected complications are highlighted in this case series. Patient 1 had a 1-cm right ventricular pseudoaneurysm after several unsuccessful attempts at epicardial access. This was successfully managed conservatively. Patient 2 had intra-abdominal bleeding related to puncture of the left lobe of the liver during access that required surgical repair. Patient 3 had a subcapsular hepatic hematoma that was probably related to percutaneous access and was successfully managed conservatively. Patient 4 had severe pericardial bleeding followed by ventricular fibrillation, immediately after obtaining percutaneous epicardial access. A lacerated middle cardiac vein was repaired surgically. However, the patient ultimately died of complications. Patient 5 had a history of cardiothoracic surgery and developed a right ventricle-abdominal fistula after multiple attempts at percutaneous access. This was surgically repaired without major sequelae. Patient 6 had cardiac tamponade caused by a lacerated coronary sinus branch during epicardial catheter ablation and required surgical repair. Patient 7 had severe left coronary vasospasm and ventricular fibrillation during catheter manipulation in the pericardium. This complication was successfully managed with intracoronary nitrates. Conclusions— Though generally safe, percutaneous epicardial access and mapping/ablation can result in uncommon complications. Awareness of these rare complications may facilitate early detection and successful management.

Contemporary real life cardioversion of atrial fibrillation: Results from the multinational RHYTHM-AF study.

AIMS Electrical and pharmacological cardioversion (ECV, PCV) are important treatment options for symptomatic patients with recent onset atrial fibrillation (AF). RHYTHM-AF is an international registry of present-day cardioversion providing information that is not currently available on country differences and acute and long-term arrhythmia outcomes of ECV and PCV. METHODS AND RESULTS 3940 patients were enrolled, of whom 75% underwent CV. All patients were followed for 2 months. There were large variations concerning mode of CV used, ECV being heterogeneous. A choice of PCV drug depended on the clinical patient profile. Sinus rhythm was restored in 89.7% of patients by ECV and in 69.1% after PCV. Among patients not undergoing CV during admission, 34% spontaneously converted to sinus rhythm within 24h. ECV was most successful in patients pretreated with antiarrhythmic drugs (mostly amiodarone). PCV was enhanced by class Ic antiarrhythmic drugs; conversion rate on amiodarone was similar to that seen with rate control drugs. Female patients and those with paroxysmal and first detected AF as well as those without previous ECV responded well to PCV. The median duration of hospital stay was 16.2 and 24.0 h for ECV and PCV patients, respectively. There were very few CV-related complications regardless of mode of CV. Chronic maintenance of sinus rhythm was enhanced in patients on chronic antiarrhythmic drugs, beta-blockers or inhibitors of the renin-angiotensin system. CONCLUSIONS Mode of CV varied significantly, but both PCV and ECV were safe and effective. Class Ic drugs were most effective conversion drugs, but amiodarone is used most frequently despite providing merely rate control rather than shorten time to conversion.

Gastric Hypomotility Following Epicardial Vagal Denervation Ablation to Treat Atrial Fibrillation

We report a case of a 55‐year‐old man with vagal paroxysmal atrial fibrillation (AF) who was submitted to selective epicardial and endocardial atrial vagal denervation with the objective of treating AF. Radiofrequency pulses were applied on epicardial and endocardial surface of the left atrium close to right pulmonary veins (PVs) and also on epicardial surface close to left inferior PV. Following the procedure, patient presented with symptoms of gastroparesis, which was documented on CT scan and gastric emptying scintigraphy. Symptoms were transient and the patient recovered completely.