Performing transcatheter left atrial appendage closure: Techniques and challengesThe left atrial appendage (LAA) has been demonstrated to be the major source of thromboemboli in patients with atrial fibrillation.1 The rationale of LAA closure is based on eliminating LAA continuity with the left atrium (LA), thereby reducing stroke risk. Indeed, left atrial appendage occlusion (LAAO) procedures play an important role in anticoagulation-intolerant patients who are at risk for atrial fibrillation–related stroke. Based on the PROTECT AF (Watchman Left Atrial Appendage System for Embolic PROTECTion in Patients With Atrial Fibrillation)2 and PREVAIL (Prospective Randomized Evaluation of the WATCHMAN LAA Closure Device in Patients With Atrial Fibrillation [AF] Versus Long Term Warfarin Therapy)3 studies, the Food and Drug Administration (FDA) approved use of the Watchman (Boston Scientific, Marlborough, MA) device in 2015, with an updated generation of device subsequently ratified in 2020 following the PINNACLE-FLX (Protection Against Embolism for Nonvalvular AF Patients: Investigational Device Evaluation of the Watchman FLX LAA Closure Technology) study.
How to perform an epicardial ventricular tachycardia ablation: A contemporary and practical approachCatheter ablation is increasingly used for the treatment of cardiac arrhythmias. In the 1990s, in order to treat ventricular arrhythmias resulting from chagasic cardiomyopathy, Sosa et al1 developed a technique to enter the pericardium percutaneously in the absence of a pericardial effusion. Since then, “dry” epicardial access has become a regular part of complex catheter ablation. In this review, we concentrate on the technical aspects of performing epicardial ablation for ventricular tachycardia (VT), including the management of potential complications.
How to perform ethanol ablation of the vein of Marshall for treatment of atrial fibrillationThe arrhythmogenicity of the vein of Marshall (VoM) in atrial fibrillation (AF) has been known for more than 20 years.1 A recent randomized trial showed a reduced odds ratio (0.63; 95% confidence interval 0.41–0.97; P = .04) for the primary outcome of AF or atrial tachycardia (AT) recurrence in patients with persistent AF by adding VoM ethanol infusion (VoM-Et) to the standard ablation approach.2 The VoM is involved in 30% of ATs after AF ablation, and VoM ablation significantly improves the freedom from recurrent arrhythmia.
Left atrial appendage occlusion using intracardiac echocardiographyLeft atrial appendage (LAA) closure (LAAC) has emerged as an alternative prevention strategy for patients with nonvalvular atrial fibrillation and contraindications to long-term anticoagulation.1 In randomized trials studying the Watchman device (Boston Scientific, St. Paul, MN), implantation was performed under transesophageal echocardiography (TEE) guidance.1 The use of TEE often mandates the presence of general anesthesia and an additional cardiologist or anesthesiologist to perform TEE. This uses greater health care resources and adds additional complexity to the procedure.
How to use intracardiac echocardiography to guide catheter ablation of outflow tract ventricular arrhythmiasThe anatomy of the ventricular outflow tracts and semilunar valves as it pertains to catheter ablation of outflow tract ventricular arrhythmias (OTVAs) has been described.1 Assessment of semilunar valve and regional anatomy by fluoroscopy and angiography has limitations. Coronary arteries may be subject to damage from catheter ablation near the semilunar valves due to their proximity to sites of origin of OTVAs. Detailed intracardiac echocardiographic (ICE) views of the semilunar valves may be useful to understand the anatomy, catheter location, and coronary artery proximity and variations.
When bigger is better: Novel use of a 27 F leadless pacemaker delivery sheath for femoral lead extractionsAs the implantation rate of cardiac implantable electronic devices has continued to increase, lead extractions for clinical indications such as infection, lead failure, and lead recall have also increased.1 A femoral approach to transvenous lead extractions is needed when removing previously cut and abandoned leads, leads that disrupt during a superior extraction attempt and in some cases involving central venous obstruction.2
A beginner's guide to permanent left bundle branch pacingStudies have demonstrated the feasibility and clinical benefits of permanent His-bundle pacing (HBP).1 However, concerns regarding higher pacing thresholds, lower R-wave amplitudes, and the potential to develop distal conduction block have limited the clinical application of HBP in certain subgroups.1,2
Mitral isthmus ablation: A hierarchical approach guided by electroanatomic correlationMitral isthmus ablation is an established technique used to treat perimitral atrial flutter. The classic approach involves creating an ablation line connecting the left inferior pulmonary vein (LIPV) to the lateral mitral annulus.1 Its feasibility was first prospectively studied by Jais et al,1 who reported a high rate of bidirectional block. However, subsequent studies by the same group, as well as others, have been less promising.2 This is important because failure to achieve bidirectional block with ablation has been shown to be proarrhythmic.
Retrograde venous ethanol ablation for ventricular tachycardiaRadiofrequency catheter ablation (RFCA) has been considered the first-line therapy for treatment of drug-refractory ventricular arrhythmias (VAs).1 The success of catheter ablation depends on our ability to reach the anatomic location of the ventricular tachycardia (VT) substrate. VTs arising from deep intramural regions2 or in close proximity to coronary vessels3 can have limited RFCA success. Transarterial coronary ethanol ablation has been used as an alternative treatment option and is reasonably successful in treating RFCA-refractory VTs.
Cosmetic aspects of device implantationThe cosmetic aspects of device implantation imply achieving an aesthetically pleasing surgical result. It involves concealing the cardiac implantable electronic device, avoiding unsightly scars, device bulges, and protrusion (Figure 1). Cosmetic device implantation is indicated for the extremely thin patient at risk of erosion and the young patient concerned with body image. These techniques are also important in the pediatric population, patients with burn injury, and patients after mastectomy.
How to perform left atrial appendage electrical isolation using radiofrequency ablationAlthough pulmonary vein (PV) isolation (PVI) has been considered an effective treatment for paroxysmal atrial fibrillation (AF), non-paroxysmal AF is a complex arrhythmia for which no ablation strategy has been demonstrated to be effective and widely accepted. As such, a success rate of ∼55% in these patients with AF (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II [Star AF II trial]) is not acceptable in our opinion and efforts should be made to seek for alternative strategies.
Approach to permanent His bundle pacing in challenging implantsRight ventricular apical pacing has been the cornerstone of bradycardia pacing for decades. It is well established that right ventricular pacing leads to ventricular dyssynchrony, reduced left ventricular function, and heart failure.1,2 Since the initial description of permanent His bundle pacing (HBP) by Deshmukh et al in 2000,3 several investigators have demonstrated the clinical utility of HBP in patients with atrioventricular (AV) nodal block, infranodal AV block, and bundle branch block.4–7 Increasing interest in HBP has been hampered in part by challenges and limitations associated with a limited implantation tool set.
How to map and ablate parahisian ventricular arrhythmiasVentricular tachycardia (VT) and premature ventricular contractions (PVCs) originating in the vicinity of the His-bundle region represent 3%–9% of all idiopathic ventricular arrhythmias (VAs).1,2 In addition, patients with cardiomyopathies and scar-related VT may exhibit septal arrhythmogenic substrate involving the parahisian region.3 Catheter ablation of these arrhythmias poses particular challenges because of the risk of inadvertent atrioventricular (AV) block, and a systematic approach is important to improve outcomes and minimize complications.
Implantation of the subcutaneous implantable cardioverter–defibrillator with truncal plane blocksOperative anesthetic requirements and perioperative discomfort are barriers to wide adoption of the subcutaneous implantable cardioverter–defibrillator (SICD) system. The SICD implant procedure involves incision and dissection in the richly innervated midaxillary line of the chest wall for placement of the pulse generator and tunneling in subcutaneous tissue for implantation of the defibrillator lead.1 Intraoperative local anesthetic wound infiltration is routine and provides moderate analgesia, but the effects are short-lasting, and complete coverage of the affected areas is difficult.
Evaluation of shortness of breath after atrial fibrillation ablation—Is there a stiff left atrium?Ablation has emerged as the most effective therapy for atrial fibrillation (AF), with the primary goal to improve symptoms. However, there is a subset of patients who develop limiting symptoms after successful ablation despite reestablishment of sinus rhythm. There is now recognition of “stiff left atrial (LA) syndrome” related to adverse consequences of ablation itself on LA hemodynamics, as described by Gibson and others.1,2 Although relatively uncommon (1.4% incidence in the Gibson series), this syndrome is important to diagnose, as it can cause severe unexplained dyspnea.
Transcatheter/leadless pacingEntirely self-contained cardiac pacing systems for direct implantation within the heart via deflectable catheter are now available for use in humans. Worldwide, there have been more 7000 implants of the “transcatheter” or “leadless” pacemaker.∗ The concept of these pacing systems is far from new; Spickler et al.1 were able to achieve cardiac pacing in animals using a capsular nuclear-powered system in 1970. However, only recently has technology enabled sufficient miniaturization to make transcatheter pacing feasible.
When and how to target atrial fibrillation sources outside the pulmonary veins: A practical approachPulmonary vein (PV) isolation is an effective procedure in patients with paroxysmal atrial fibrillation (AF). For most patients with persistent AF and a subset of patients with paroxysmal AF, however, PV isolation may not be sufficient. Patients with the persistent form are more often beleaguered with comorbidities, which result in a greater degree of structural alterations that contribute to the maintenance of AF. In addition, the atrial activation rate during AF is higher (as evidenced by a shorter AF cycle length) in patients with persistent AF, consistent with a greater degree of electrical remodeling.