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Heart Rhythm Nov 2023Cardioneuroablation (CNA) is an attractive treatment of vasovagal syncope. Its long-term efficacy and safety remain unknown.
BACKGROUND
Cardioneuroablation (CNA) is an attractive treatment of vasovagal syncope. Its long-term efficacy and safety remain unknown.
OBJECTIVE
The purpose of this study was to develop a chronic porcine model of CNA to examine the susceptibility to ventricular tachyarrhythmia (ventricular tachycardia/ventricular fibrillation [VT/VF]) and cardiac autonomic function after CNA.
METHODS
A percutaneous CNA model was developed by ablation of left- and right-sided ganglionated plexi (n = 5), confirmed by histology. Reproducible bilateral vagal denervation was confirmed after CNA by extracardiac vagal nerve stimulation (VNS) and histology. Chronic studies included 16 pigs randomized to CNA (n = 8) and sham ablation (n = 8, Control). After 6 weeks, animals underwent hemodynamic studies, assessment of cardiac sympathetic and parasympathetic function using sympathetic chain stimulation and direct VNS, respectively, and proarrhythmic potential after left anterior descending (LAD) coronary artery ligation.
RESULTS
After CNA, extracardiac VNS responses remained abolished for 6 weeks despite ganglia remaining in ablated ganglionated plexi. In the CNA group, direct VNS resulted in paradoxical increases in blood pressure, but not in sham-ablated animals (CNA group vs sham group: 8.36% ± 7.0% vs -4.83% ± 8.7%, respectively; P = .009). Left sympathetic chain stimulation (8 Hz) induced significant corrected QT interval prolongation in the CNA group vs the sham group (11.23% ± 4.0% vs 1.49% ± 4.0%, respectively; P < .001). VT/VF after LAD ligation was more prevalent and occurred earlier in the CNA group than in the control group (61.44 ± 73.7 seconds vs 245.11 ± 104.0 seconds, respectively; P = .002).
CONCLUSION
Cardiac vagal denervation is maintained long-term after CNA in a porcine model. However, chronic CNA was associated with cardiovascular dysreflexia, diminished cardioprotective effects of cardiac vagal tone, and increased susceptibility to VT/VF in ischemia. These potential long-term negative effects of CNA suggest the need for rigorous clinical studies on CNA.
Topics: Animals; Autonomic Dysreflexia; Heart; Heart Ventricles; Ischemia; Swine; Tachycardia, Ventricular; Ventricular Fibrillation
PubMed: 37562487
DOI: 10.1016/j.hrthm.2023.08.001 -
JACC. Clinical Electrophysiology Sep 2023Three cases of ventricular tachycardia ablation with pulsed-field ablation technology performed at 2 separate centers are reported, highlighting the advantages and... (Review)
Review
Three cases of ventricular tachycardia ablation with pulsed-field ablation technology performed at 2 separate centers are reported, highlighting the advantages and disadvantages of this tool inside the ventricle: its dependence on proximity rather than contact makes it useful in sites with poor stability, while the speed of application and large scope of action provided by commercially available catheters could help with ablating large diseased areas of endocardium in a fast and hemodynamically well-tolerated fashion. However, lesion depth could be insufficient for guaranteeing efficacy in preventing ventricular tachycardias originating at an epicardial site, even in the right ventricle.
Topics: Humans; Heart Ventricles; Electrocardiography; Tachycardia, Ventricular; Catheter Ablation; Endocardium
PubMed: 37227358
DOI: 10.1016/j.jacep.2023.03.024 -
Cardiac Electrophysiology Clinics Mar 2023Most idiopathic ventricular arrhythmias (VAs) originate from the outflow tract (OT) region and can be targeted with ablation either from the endocardial aspect of the... (Review)
Review
Most idiopathic ventricular arrhythmias (VAs) originate from the outflow tract (OT) region and can be targeted with ablation either from the endocardial aspect of the right and left ventricular outflow tracts or from the aortic sinuses of Valsalva. It is important to exclude scar in patients with OT VAs. In some patients, the site of origin may be intramural. Ablation of intramural OT VAs can be challenging to map and ablate due to deep intramural sites of origin. The coronary venous branches may permit mapping and ablation of intramural OT VAs.
Topics: Humans; Tachycardia, Ventricular; Electrocardiography; Treatment Outcome; Catheter Ablation; Arrhythmias, Cardiac; Heart Ventricles
PubMed: 36774136
DOI: 10.1016/j.ccep.2022.04.006 -
Circulation. Arrhythmia and... Aug 2015
Topics: Bundle of His; Catheter Ablation; Electrocardiography; Heart Atria; Heart Ventricles; Humans; Male; Tachycardia, Ventricular
PubMed: 26286308
DOI: 10.1161/CIRCEP.115.002998 -
Cardiac Electrophysiology Clinics Mar 2023The left ventricular summit (LVS) is the area in the highest portion of the left ventricular epicardium, bounded by the left coronary arteries and the coronary venous... (Review)
Review
The left ventricular summit (LVS) is the area in the highest portion of the left ventricular epicardium, bounded by the left coronary arteries and the coronary venous circulation, and can be surrounded by thick epicardial fat that may preclude epicardial ablation. Ablation of LVS ventricular arrhythmias (VA) can be achieved from adjacent structures with good success rates. The long-term freedom from LVS VA recurrence remains variable. This article reviews the spatial and anatomic relationship of the structures surrounding the LVS, which provide vantage points for ablation, and the acute and long-term outcomes of different ablation approaches in LVS VA ablation.
Topics: Humans; Tachycardia, Ventricular; Treatment Outcome; Heart Ventricles; Arrhythmias, Cardiac; Catheter Ablation; Electrocardiography
PubMed: 36774140
DOI: 10.1016/j.ccep.2022.07.003 -
Cardiac Electrophysiology Clinics Mar 2023The left ventricular summit (LVS) is the highest point of the left ventricular epicardium, and ventricular arrhythmias originating from this area accounts for 10% to 15%... (Review)
Review
The left ventricular summit (LVS) is the highest point of the left ventricular epicardium, and ventricular arrhythmias originating from this area accounts for 10% to 15% of idiopathic outflow tract ventricular arrhythmias. Direct epicardial ablation of outflow tract ventricular arrhythmias arising from the LVS is successful only in a minority of patients because of close proximity to the coronary artery or thick epicardial fat. Therefore, alternative strategies should be prioritized before performing epicardial approach. When performed, electrocardiogram characteristics suggestive of the site of origin to be the accessible area within the LVS needs be evaluated to avoid ineffective epicardial approach.
Topics: Humans; Tachycardia, Ventricular; Electrocardiography; Treatment Outcome; Heart Ventricles; Arrhythmias, Cardiac; Catheter Ablation
PubMed: 36774133
DOI: 10.1016/j.ccep.2022.07.002 -
Herzschrittmachertherapie &... Jun 2022Catheter ablation of ventricular tachycardias (VTs) is one of the most complex tasks in interventional electrophysiology. It is complicated by the fact that VT can recur... (Review)
Review
BACKGROUND
Catheter ablation of ventricular tachycardias (VTs) is one of the most complex tasks in interventional electrophysiology. It is complicated by the fact that VT can recur during treatment which can affect the hemodynamic stability of the patient. In addition, navigation with the ablation or mapping catheter through the valvular apparatus and the trabecularization of the ventricle can be challenging.
MATERIALS AND METHODS
In most cases, a three-dimensional mapping system is used to facilitate orientation and the search for the site where the tachycardia originates. Access to the right ventricle is usually via the tricuspid valve, but in exceptional cases it may also be necessary to use the epicardial venous system. The structures most commonly responsible for an arrhythmia from the right ventricle are the right ventricular outflow tract, the moderator band and the tricuspid valve annulus. The right ventricle is adjacent to vulnerable neighboring structures in many places: In the right ventricular outflow tract, the sinus valsalva, the pulmonary artery and the left ventricular endocardial transition between the aortic and mitral valves must be considered. When ablating along the tricuspid valve annulus, the proximity to the septum and thus to the specific conduction system is particularly important.
CONCLUSION
Knowledge of the surrounding structures helps, on the one hand, to draw the right conclusions about the point of origin in the surface ECG, and, on the other hand, to carry out the ablation successfully and safely.
Topics: Catheter Ablation; Electrocardiography; Heart Ventricles; Humans; Tachycardia, Ventricular; Ventricular Premature Complexes
PubMed: 35552488
DOI: 10.1007/s00399-022-00857-9 -
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 -
Heart, Lung & Circulation Jan 2019Arrhythmogenic cardiomyopathy (ACM) is now commonly used to describe any form of non-hypertrophic, progressive cardiomyopathy characterised by fibrofatty infiltration of... (Review)
Review
Arrhythmogenic cardiomyopathy (ACM) is now commonly used to describe any form of non-hypertrophic, progressive cardiomyopathy characterised by fibrofatty infiltration of the ventricular myocardium. Right ventricular (RV) involvement refers to the classical arrhythmogenic right ventricular cardiomyopathy, but left ventricular, or bi-ventricular involvement are now recognised. ACM is mostly hereditary and associated with mutations in genes encoding proteins of the intercalated disc. ACM classically manifests as ventricular arrhythmias, and sudden death may be the first presentation of the disease. Heart failure is seen with advanced stages of the disease. Diagnosis can be challenging due to variable expressivity and incomplete penetrance, and is guided by established Taskforce criteria that incorporate electrical features (12-lead electrocardiography (ECG), features of ventricular arrhythmias), structural features (on imaging via echo and cardiac magnetic resonance imaging [MRI]), tissue characteristics (via biopsy), and familial/genetic evaluation. Electrical abnormalities may precede structural alterations, which also make diagnosis challenging, especially in differentiating ACM from other conditions such as benign right ventricular arrhythmias, channelopathies such as Brugada, or the Athlete's Heart. Genetic testing is critical in identifying familial mutations and initiating cascade testing, but finds a pathogenic mutation in only ∼50% of patients. Some critical genotype-phenotype correlations do exist and may help guide risk stratification and give clues to disease progression. Therapeutic strategies include restriction from high endurance and competitive sports, ß-blockers, antiarrhythmic drugs, heart failure medications, implantable cardioverter-defibrillators and combined endocardial/epicardial catheter ablation. Ablation has emerged as the treatment of choice for recurrent ventricular arrhythmias in ACM. This state-of-the-art review outlines the pathogenesis, diagnosis and treatment of ACM in the contemporary era.
Topics: Arrhythmogenic Right Ventricular Dysplasia; Diagnosis, Differential; Disease Management; Electrocardiography; Heart Conduction System; Heart Ventricles; Humans; Magnetic Resonance Imaging, Cine; Ventricular Dysfunction, Left
PubMed: 30446243
DOI: 10.1016/j.hlc.2018.10.013 -
Pacing and Clinical Electrophysiology :... Jan 2020Recurrence rates after catheter radiofrequency ablation (RFA) for arrhythmias arising from deep myocardial substrates can exceed 40%. Failure of RFA is in part due to...
BACKGROUND
Recurrence rates after catheter radiofrequency ablation (RFA) for arrhythmias arising from deep myocardial substrates can exceed 40%. Failure of RFA is in part due to the inability of widely used unipolar ablation (UA) to create transmural lesions capable of disrupting the critical components of the arrhythmia circuit. A radiofrequency generator was custom-made to deliver bipolar ablation (BA) to test the hypothesis that BA is more effective compared to UA in achieving transmurality and to determine the optimal configuration for ventricular BA.
METHODS
Sequential UA and BA were created in porcine ventricular septal and free wall preparations using irrigated, contact-force sensing ablation catheters, orientated perpendicularly to the myocardium. Return catheters, durations of ablation, irrigating fluids, and power settings were varied to determine the optimal configuration for BA. Lesion characteristics, transmurality, and occurrence of steam pops were analyzed.
RESULTS
In both ventricular septal and free wall models, BA resulted in significantly more transmural lesions while causing less steam pops (P < .01). BA lesions were deeper, narrower but larger in volume. Use of 8 mm ground catheters in the epicardium resulted in overheating during BA with temperatures exceeding 95°C, limiting power delivery. Increasing duration and powers of BA resulted in progressively larger lesions and increased transmurality (all P < .01), and 0.45% saline as the irrigation did not enhance BA.
CONCLUSION
BA created larger lesions with increased chances of transmurality but at lower risks of steam pops. Use of an irrigated catheter as the return electrode and 30 W of BA delivered over 120 seconds provides the optimal balance between creating deep, transmural lesions and avoiding steam pops.
Topics: Animals; Cardiac Catheters; Catheter Ablation; Electrodes; Equipment Design; Heart Ventricles; In Vitro Techniques; Models, Animal; Swine; Therapeutic Irrigation
PubMed: 31721241
DOI: 10.1111/pace.13844