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Journal of Interventional Cardiac... Jan 2023Ventricular tachycardia (VT) ablation of mid- or epicardial substrate is difficult and requires a creative approach in patients with a history of coronary bypass that...
BACKGROUND
Ventricular tachycardia (VT) ablation of mid- or epicardial substrate is difficult and requires a creative approach in patients with a history of coronary bypass that precludes percutaneous epicardial catheter manipulation. The coronary venous system (CVS) provides limited access to the epicardial surface of the heart. The objective of this study is to assess the feasibility, safety, and efficacy of epicardial mapping and ablation of VT substrates from the CVS in patients with history of coronary bypass.
METHODS
Patients undergoing VT ablation at our institution were retrospectively reviewed. Those who had basal to mid ventricular substrate based on computed tomography imaging and history of coronary bypass were included. Endocardial and CVS mapping and ablation was performed in standard fashion using 3D electroanatomic mapping. The primary endpoint was defined as VT circuit elimination, termination, non-inducibility, or perturbation of the circuit.
RESULTS
Of 192 consecutive VT ablations from 2017 to 2020, 35 (18%) had a history of coronary bypass and basal to the mid-ventricular substrate by imaging. There were no significant characteristic differences between the endocardial only (n = 19) vs endocardial + CVS (n = 16) groups. In 14 (88%) of patients undergoing CVS mapping, the VT circuit was identified to be within access from the epicardial surface. Ablation was attempted in 8 (57%) of these patients, and the primary endpoint was reached in 88% of those undergoing CVS ablation. There were no complications related to CVS ablation.
CONCLUSION
Mapping and ablation of mid- or epicardial VT circuits from the CVS branches are feasible and safe and may be helpful in the treatment of VT in patients who are otherwise not candidates for percutaneous epicardial ablation.
Topics: Humans; Epicardial Mapping; Retrospective Studies; Tachycardia, Ventricular; Heart Ventricles; Endocardium; Catheter Ablation; Treatment Outcome; Pericardium
PubMed: 35581463
DOI: 10.1007/s10840-022-01250-9 -
Journal of Cardiovascular... Jul 2022In radiofrequency ablation procedures for cardiac arrhythmia, the efficacy of creating repeated lesions at the same location ("insurance lesions") remains poorly...
INTRODUCTION
In radiofrequency ablation procedures for cardiac arrhythmia, the efficacy of creating repeated lesions at the same location ("insurance lesions") remains poorly studied. We assessed the effect of type of tissue, power, and time on the resulting lesion geometry during such multiple ablation procedures.
METHODS
A custom ex vivo ablation model was used to assess lesion formation. An ablation catheter was oriented perpendicular to the tissue and used to create lesions that varied by type of tissue (atrial or ventricular free wall), power (30 or 50 W), and time (30, 40, or 50 s for standard ablations and 5, 10, or 15 s for high-power, short-duration [HPSD] ablations). Lesion dimensions were recorded and then analyzed. Radiofrequency ablations were performed on 57 atrial tissue samples (28 HPSD, 29 standard) and 28 ventricular tissue samples (all standard).
RESULTS
With ablation parameters held constant, performing multiple ablations significantly increased lesion depth in ventricular tissue when ablations were performed at 30 W for 50 s. No other set of ablation parameters was shown to affect the width or depth of the resulting lesions in either tissue type.
CONCLUSION
Multiple ablations created with the same power and time, delivered within 30 s of each other at the same exact location, offer no meaningful benefit in lesion depth or width over single ablations, with the exception of ventricular ablation at 30 W for 50 s. Given the risks associated with excessive ablation, our results suggest that this practice should be re-evaluated by clinical electrophysiologists.
Topics: Catheter Ablation; Heart Atria; Heart Ventricles; Humans; Insurance; Radiofrequency Ablation
PubMed: 35437855
DOI: 10.1111/jce.15497 -
Cells Oct 2021Ischemic heart disease is the most common cause of lethal ventricular arrhythmias and sudden cardiac death (SCD). In patients who are at high risk after myocardial... (Review)
Review
Ischemic heart disease is the most common cause of lethal ventricular arrhythmias and sudden cardiac death (SCD). In patients who are at high risk after myocardial infarction, implantable cardioverter defibrillators are the most effective treatment to reduce incidence of SCD and ablation therapy can be effective for ventricular arrhythmias with identifiable culprit lesions. Yet, these approaches are not always successful and come with a considerable cost, while pharmacological management is often poor and ineffective, and occasionally proarrhythmic. Advances in mechanistic insights of arrhythmias and technological innovation have led to improved interventional approaches that are being evaluated clinically, yet pharmacological advancement has remained behind. We review the mechanistic basis for current management and provide a perspective for gaining new insights that centre on the complex tissue architecture of the arrhythmogenic infarct and border zone with surviving cardiac myocytes as the source of triggers and central players in re-entry circuits. Identification of the arrhythmia critical sites and characterisation of the molecular signature unique to these sites can open avenues for targeted therapy and reduce off-target effects that have hampered systemic pharmacotherapy. Such advances are in line with precision medicine and a patient-tailored therapy.
Topics: Animals; Arrhythmias, Cardiac; Cardiomyopathies; Heart Ventricles; Humans; Myocardial Ischemia; Risk Assessment; Vascular Remodeling
PubMed: 34685609
DOI: 10.3390/cells10102629 -
Journal of Nuclear Cardiology :... Feb 2021
Topics: Arrhythmias, Cardiac; Catheter Ablation; Heart Ventricles; Humans
PubMed: 30719658
DOI: 10.1007/s12350-019-01632-z -
Heart Rhythm Sep 2020Managing arrhythmias from the left ventricular summit and interventricular septum is a major challenge for the clinical electrophysiologist requiring intimate knowledge... (Review)
Review
Managing arrhythmias from the left ventricular summit and interventricular septum is a major challenge for the clinical electrophysiologist requiring intimate knowledge of cardiac anatomy, advanced training and expertise. Novel mapping and ablation strategies are needed to treat arrhythmias originating from these regions given the current suboptimal long-term success rates with standard techniques. Herein, we describe innovative approaches to improve acute and long-term clinical outcomes such as mapping and ablation using the septal coronary venous system and the septal coronary arteries, alcohol ablation, coil embolization, and ablation of all early sites among others.
Topics: Catheter Ablation; Electrophysiologic Techniques, Cardiac; Heart Ventricles; Humans; Tachycardia, Ventricular; Tomography, X-Ray Computed; Ventricular Septum
PubMed: 32333973
DOI: 10.1016/j.hrthm.2020.04.026 -
Cardiac Electrophysiology Clinics Dec 2022Idiopathic ventricular arrhythmias (VAs) most commonly originate from the ventricular outflow tracts. Because the anatomy of this region is complex and some of those VA... (Review)
Review
Idiopathic ventricular arrhythmias (VAs) most commonly originate from the ventricular outflow tracts. Because the anatomy of this region is complex and some of those VA origins are intramural and epicardial, it may sometimes be difficult to locate the site of the VA origin. Meticulous mapping in multiple different locations such as the right and left ventricular outflow tracts, endocardial and epicardial sites, and above and below the aortic and pulmonic valves may be required to achieve successful catheter ablation of those VAs. Special ablation techniques may be considered to improve the outcome of catheter ablation of intramural and epicardial VAs.
Topics: Humans; Catheter Ablation; Heart Ventricles; Arrhythmias, Cardiac; Endocardium; Aorta
PubMed: 36396181
DOI: 10.1016/j.ccep.2022.07.008 -
Expert Review of Medical Devices Feb 2020: Brugada syndrome (BrS) is an inherited disease characterized by an increased risk of sudden cardiac death (SCD). Therapeutic options in symptomatic patients are... (Review)
Review
: Brugada syndrome (BrS) is an inherited disease characterized by an increased risk of sudden cardiac death (SCD). Therapeutic options in symptomatic patients are limited to implantable cardioverter defibrillator (ICD) and quinidine, but catheter ablation of the right ventricular outflow tract (RVOT) offers a potential cure. Different ablation strategies have been used to treat patients with symptomatic Brugada syndrome. Epicardial radiofrequency substrate ablation of the RVOT/right ventricle (RV) has emerged as a promising tool for the management of the disease.: The historical management of BrS, endocardial and epicardial ablation techniques, the use of sodium channel blockers (SCB) and complications are summarized here.: Ventricular fibrillation (VF)-triggering premature ventricular contractions (PVCs) in patients with BrS are unpredictable, spontaneous ones are rarely present to be mapped, making this approach impractical. Furthermore, endocardial mapping for BrS substrates does not seem effective due to the epicardial pathological substrate localization. The size variation of the BrS substrate areas during SCB infusion suggests a dynamic process as arrhythmogenic basis and SCB infusion should guide BrS epicardial ablation of all abnormal potentials areas. If BrS epicardial ablation can truly provide long-term prevention of ventricular arrhythmias it may potentially become an alternative to ICD therapy.
Topics: Ablation Techniques; Brugada Syndrome; Epicardial Mapping; Heart Ventricles; Humans; Pericardium; Thoracoscopy
PubMed: 31986921
DOI: 10.1080/17434440.2020.1719831 -
JACC. Clinical Electrophysiology Jul 2022
Topics: Electrophysiologic Techniques, Cardiac; Heart Ventricles; Humans
PubMed: 35863810
DOI: 10.1016/j.jacep.2022.05.002 -
Journal of Cardiovascular... Mar 2021Ultralow temperature cyroablation (ULTC) is designed to create focal, linear, and circumferential lesions. The aim of this study was to assess the safety, efficacy, and...
BACKGROUND
Ultralow temperature cyroablation (ULTC) is designed to create focal, linear, and circumferential lesions. The aim of this study was to assess the safety, efficacy, and durability of atrial and ventricular ULTC lesions in preclinical large animal models.
METHODS AND RESULTS
The ULTC system uses nitrogen near its liquid-vapor critical point to cool 11-cm ablation catheters. The catheter can be shaped to specific anatomies using pre-shaped stylets. ULTC was used in 11 swine and four sheep to create atrial (pulmonary vein isolation and linear ablation) and ventricular lesions. Acute and 90-day success were evaluated by intracardiac mapping and histologic examination. Cryoadherence was observed during all ULTC applications, ensuring catheter stability at target locations. Local electrograms were completely eliminated immediately after the first single-shot ULTC application in 49 of 53 (92.5%) atrial and in 31 of 32 (96.9%) ventricular applications. Lesion depth as measured on histology preparations was 1.96 ± 0.8 mm in atrial and 5.61 ± 2.2 mm in ventricular lesions. In all animals, voltage maps and histology demonstrated transmural and durable lesions without gaps, surrounded by intact collagen fibers without injury to surrounding tissues. Transient coronary spasm could be provoked with endocardial ULTC in the left ventricle in close proximity to a coronary artery.
CONCLUSIONS
ULTC created effective and efficient atrial and ventricular lesions in vivo without procedural complications in two large animal models. ULTC lesions were transmural, contiguous, and durable over 3 months.
Topics: Animals; Atrial Fibrillation; Catheter Ablation; Cryosurgery; Heart Atria; Heart Ventricles; Pulmonary Veins; Sheep; Swine; Temperature
PubMed: 33476463
DOI: 10.1111/jce.14907 -
JACC. Clinical Electrophysiology Oct 2020This study sought to establish a mapping and ablation strategy to target intramural ventricular arrhythmias (VAs) by identifying the precise arrhythmia site of origin...
OBJECTIVES
This study sought to establish a mapping and ablation strategy to target intramural ventricular arrhythmias (VAs) by identifying the precise arrhythmia site of origin (SOO).
BACKGROUND
Radiofrequency ablation of intramural VAs is challenging because the arrhythmia origin is difficult to localize.
METHODS
In 83 consecutive patients with intramural VAs, a stepwise mapping approach was performed: ablation targeted directly the SOO when possible followed by the closest adjacent anatomical structure when necessary. If the SOO could not be identified, the earliest endocardial breakout sites were ablated. Safety and procedural outcomes between patients in whom the SOO could and could not be identified were compared.
RESULTS
The SOO was identified in 19 of 83 (23%) patients, and radiofrequency ablation was effective in eliminating VAs in all 19 (100%) patients by ablation at the SOO alone (n = 3), at the SOO and an anatomically adjacent area (n = 7), or at an anatomically adjacent area alone (n = 9). Breakout site mapping and ablation in the remaining 64 patients in whom the SOO was not identified was effective in 43 of 64 patients, which was significantly less than in patients in whom the SOO was identified (67% vs. 100%; p < 0.05).
CONCLUSIONS
Identification of the SOO was associated with a successful ablation procedure by either targeting the SOO directly or targeting an adjacent anatomical structure. Ablation at the breakout sites of intramural VAs has a lower efficacy than when the SOO can be directly targeted.
Topics: Arrhythmias, Cardiac; Catheter Ablation; Endocardium; Heart Ventricles; Humans; Tachycardia, Ventricular
PubMed: 33121661
DOI: 10.1016/j.jacep.2020.05.021