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Europace : European Pacing,... May 2023Ablation of outflow tract ventricular arrhythmias may be limited by a deep intramural location of the arrhythmogenic source. This study evaluates the acute and long-term...
AIMS
Ablation of outflow tract ventricular arrhythmias may be limited by a deep intramural location of the arrhythmogenic source. This study evaluates the acute and long-term outcomes of patients undergoing ablation of intramural outflow tract premature ventricular complexes (PVCs).
METHODS AND RESULTS
This multicenter series included patients with structurally normal heart or nonischemic cardiomyopathy and intramural outflow tract PVCs defined by: (a) ≥ 2 of the following criteria: (1) earliest endocardial or epicardial activation < 20ms pre-QRS; (2) Similar activation in different chambers; (3) no/transient PVC suppression with ablation at earliest endocardial/epicardial site; or (b) earliest ventricular activation recorded in a septal coronary vein. Ninety-two patients were included, with a mean PVC burden of 21.5±10.9%. Twenty-six patients had had previous ablations. All PVCs had inferior axis, with LBBB pattern in 68%. In 29 patients (32%) direct mapping of the intramural septum was performed using an insulated wire or multielectrode catheter, and in 13 of these cases the earliest activation was recorded within a septal vein. Most patients required special ablation techniques (one or more), including sequential unipolar ablation in 73%, low-ionic irrigation in 26%, bipolar ablation in 15% and ethanol ablation in 1%. Acute PVC suppression was achieved in 75% of patients. Following the procedure, the PVC burden was reduced to 5.8±8.4%. The mean follow-up was 15±14 months and 16 patients underwent a repeat ablation.
CONCLUSION
Ablation of intramural PVCs is challenging; acute arrhythmia elimination is achieved in 3/4 patients, and non-conventional approaches are often necessary for success.
Topics: Humans; Tachycardia, Ventricular; Ventricular Premature Complexes; Heart Ventricles; Catheter Ablation; Endocardium; Treatment Outcome
PubMed: 37096979
DOI: 10.1093/europace/euad100 -
Cardiac Electrophysiology Clinics Mar 2023The left ventricular summit is a source of idiopathic ventricular arrhythmias and presents distinct challenges for mapping and ablation. These arrhythmias are typically... (Review)
Review
The left ventricular summit is a source of idiopathic ventricular arrhythmias and presents distinct challenges for mapping and ablation. These arrhythmias are typically targeted from the distal coronary venous system or most often from endocardial vantage points such as the left coronary cusp, basal left ventricle or septal right ventricular outflow tract. In this article, we review the electrocardiographic patterns that suggest a possible origin from the left ventricular summit and the features that may help to predict the most likely site of successful ablation.
Topics: Humans; Heart Ventricles; Catheter Ablation; Arrhythmias, Cardiac; Electrocardiography; Tachycardia, Ventricular
PubMed: 36774141
DOI: 10.1016/j.ccep.2022.04.004 -
JACC. Clinical Electrophysiology Sep 2023
Topics: Humans; Tachycardia, Ventricular; Heart Conduction System; Heart Ventricles; Catheter Ablation
PubMed: 37498240
DOI: 10.1016/j.jacep.2023.05.021 -
Cardiac Electrophysiology Clinics Mar 2023Idiopathic ventricular arrhythmias (VA), particularly left ventricular outflow tract (LVOT) VA accounts for up to 10% of all VAs referred for ablative therapy. In... (Review)
Review
Idiopathic ventricular arrhythmias (VA), particularly left ventricular outflow tract (LVOT) VA accounts for up to 10% of all VAs referred for ablative therapy. In addition to being infrequent, its intricate anatomy and its pathophysiology make catheter ablation (CA) of these arrhythmias a challenge even for experts. In this scenario, detailed right ventricular outflow tract as well as LVOT electroanatomic mapping including epicardial mapping are essential. In this article, we will emphasize our approach toward the CA technique used for LVOT VA, particularly IVS and/or LVS VA originating from intramural foci, along with its acute and long-term efficacy and safety.
Topics: Humans; Tachycardia, Ventricular; Heart Ventricles; Arrhythmias, Cardiac; Epicardial Mapping; Catheter Ablation; Electrocardiography; Treatment Outcome
PubMed: 36774134
DOI: 10.1016/j.ccep.2022.10.001 -
JACC. Clinical Electrophysiology Aug 2023Ablation index (AI) is used for guiding therapy during pulmonary vein isolation. However, its potential utility in ventricular myocardium is unknown.
BACKGROUND
Ablation index (AI) is used for guiding therapy during pulmonary vein isolation. However, its potential utility in ventricular myocardium is unknown.
OBJECTIVES
This study sought to examine the correlation between AI and lesion dimensions in healthy and infarcted ventricles.
METHODS
In ex vivo experiments using healthy swine ventricles, the correlation between AI (400-1,200) and lesion dimensions was examined at fixed power (30 W) and contact force (CF) (15 g). To examine the accuracy of AI in predicting lesion dimensions created by different combinations of ablation parameters, applications with a similar prespecified AI value created using different power (30 vs 40 W), CF (15 vs 25 g) or impedance (130-170 Ω) were created. In in vivo experiments, the correlation between AI and lesion dimensions was examined in healthy and infarcted myocardium.
RESULTS
Ex vivo experiments (247 lesions, 36 hearts) showed good correlation between AI and lesion depth (R = 0.93; P < 0.001). However, in vivo experiments (9 healthy swine and 10 infarcted swine) showed moderate correlation in healthy myocardium (R = 0.64; P < 0.01) and poor correlation in infarcted myocardium (R = 0.23; P = 0.61). AI values achieved using different combinations of power, CF, and baseline impedance resulted in different lesion depths: Ablation at 30 W produced deeper lesions compared with 40 W, ablation with CF of 15 g produced deeper lesions compared with CF of 25 g, and ablation at lower impedance produced larger lesions at similar prespecified AI values (P < 0.01 for all).
CONCLUSIONS
AI has limited value for guiding ablation in ventricular myocardium, particularly scar. This may be related to small proportional significance of application duration and complex tissue architecture.
Topics: Swine; Animals; Catheter Ablation; Myocardium; Heart Ventricles; Heart; Electric Impedance
PubMed: 37354172
DOI: 10.1016/j.jacep.2023.03.020 -
Cardiac Electrophysiology Clinics Sep 2019Knowledge of relevant cardiac anatomy is crucial in understanding the pathophysiology and treatment of arrhythmias, and helps avoid potential complications in mapping... (Review)
Review
Knowledge of relevant cardiac anatomy is crucial in understanding the pathophysiology and treatment of arrhythmias, and helps avoid potential complications in mapping and ablation. This article explores the anatomy, relevant to electrophysiologists, relating to atrial flutter and atrial fibrillation, ventricular tachycardia relating to the outflow tracts as well as endocardial structure, and also epicardial considerations for mapping and ablation.
Topics: Arrhythmias, Cardiac; Heart Atria; Heart Ventricles; Humans
PubMed: 31400867
DOI: 10.1016/j.ccep.2019.04.003 -
Heart Rhythm May 2023
Topics: Humans; Ventricular Premature Complexes; Papillary Muscles; Heart Ventricles; Catheter Ablation
PubMed: 36717009
DOI: 10.1016/j.hrthm.2023.01.027 -
Cardiac Electrophysiology Clinics Mar 2023Endocardial catheter ablation of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) at remote structures adjacent to the LVS may be an... (Review)
Review
Endocardial catheter ablation of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) at remote structures adjacent to the LVS may be an alternative (anatomic approach) but may not be so successful. This type of catheter ablation is successful most commonly in the left ventricular outflow tract followed by the aortic cusps and rarely in the right ventricular outflow tract. A right bundle branch block QRS morphology and anatomic distance between the earliest ventricular activation site in the coronary venous system and endocardial ablation site (<13 mm) could be predictors of a successful endocardial catheter ablation of LVS VAs.
Topics: Humans; Treatment Outcome; Electrocardiography; Heart Ventricles; Arrhythmias, Cardiac; Bundle-Branch Block; Catheter Ablation; Tachycardia, Ventricular
PubMed: 36774132
DOI: 10.1016/j.ccep.2022.04.005 -
Cardiac Electrophysiology Clinics Sep 2020Important physiologic and anatomic differences exist between the epicardium and endocardium, particularly of the ventricles, and these differences affect ablation... (Review)
Review
Important physiologic and anatomic differences exist between the epicardium and endocardium, particularly of the ventricles, and these differences affect ablation biophysics. Absence of passive convective effects conferred by circulating blood as well as the presence of epicardial fat and vessels and absence of intracavitary ridges and structures affect ablation lesion size when performing epicardial catheter-based ablation, whether using radiofrequency or cryothermal energy. Understanding differential effects in each environment is important in informing strategies to increase ablation lesion depth. When using actively cooled radiofrequency ablation, local impedance can be altered to selectively augment energy delivery.
Topics: Biophysical Phenomena; Catheter Ablation; Endocardium; Epicardial Mapping; Heart Ventricles; Humans; Patient Safety; Pericardium; Tachycardia, Ventricular
PubMed: 32771193
DOI: 10.1016/j.ccep.2020.05.006 -
Cardiac Electrophysiology Clinics Sep 2020Catheter ablation can effectively reduce the frequency of ventricular tachycardia in ischemic cardiomyopathy by ablating sites of reentry within complex regions of... (Review)
Review
Catheter ablation can effectively reduce the frequency of ventricular tachycardia in ischemic cardiomyopathy by ablating sites of reentry within complex regions of myocardial scar. In cases of near transmural infarction, this arrhythmia substrate may be nearer the epicardium than the endocardium, and epicardial ablation may be necessary. An epicardial substrate location can potentially be predicted by imaging that suggests transmural infarction. Percutaneous epicardial ablation improves outcomes in selected patients, but is higher risk and avoided in patients with prior coronary artery bypass grafting.
Topics: Cardiac Imaging Techniques; Cardiomyopathies; Catheter Ablation; Epicardial Mapping; Humans; Myocardial Ischemia; Pericardium; Tachycardia, Ventricular
PubMed: 32771185
DOI: 10.1016/j.ccep.2020.05.003