-
The New England Journal of Medicine Dec 2017Recent advances have enabled noninvasive mapping of cardiac arrhythmias with electrocardiographic imaging and noninvasive delivery of precise ablative radiation with...
BACKGROUND
Recent advances have enabled noninvasive mapping of cardiac arrhythmias with electrocardiographic imaging and noninvasive delivery of precise ablative radiation with stereotactic body radiation therapy (SBRT). We combined these techniques to perform catheter-free, electrophysiology-guided, noninvasive cardiac radioablation for ventricular tachycardia.
METHODS
We targeted arrhythmogenic scar regions by combining anatomical imaging with noninvasive electrocardiographic imaging during ventricular tachycardia that was induced by means of an implantable cardioverter-defibrillator (ICD). SBRT simulation, planning, and treatments were performed with the use of standard techniques. Patients were treated with a single fraction of 25 Gy while awake. Efficacy was assessed by counting episodes of ventricular tachycardia, as recorded by ICDs. Safety was assessed by means of serial cardiac and thoracic imaging.
RESULTS
From April through November 2015, five patients with high-risk, refractory ventricular tachycardia underwent treatment. The mean noninvasive ablation time was 14 minutes (range, 11 to 18). During the 3 months before treatment, the patients had a combined history of 6577 episodes of ventricular tachycardia. During a 6-week postablation "blanking period" (when arrhythmias may occur owing to postablation inflammation), there were 680 episodes of ventricular tachycardia. After the 6-week blanking period, there were 4 episodes of ventricular tachycardia over the next 46 patient-months, for a reduction from baseline of 99.9%. A reduction in episodes of ventricular tachycardia occurred in all five patients. The mean left ventricular ejection fraction did not decrease with treatment. At 3 months, adjacent lung showed opacities consistent with mild inflammatory changes, which had resolved by 1 year.
CONCLUSIONS
In five patients with refractory ventricular tachycardia, noninvasive treatment with electrophysiology-guided cardiac radioablation markedly reduced the burden of ventricular tachycardia. (Funded by Barnes-Jewish Hospital Foundation and others.).
Topics: Aged; Aged, 80 and over; Catheter Ablation; Cicatrix; Defibrillators, Implantable; Electrocardiography; Electrophysiologic Techniques, Cardiac; Fatal Outcome; Female; Heart Ventricles; Humans; Male; Middle Aged; Myocardium; Radiosurgery; Stroke; Stroke Volume; Tachycardia, Ventricular; Tomography, X-Ray Computed
PubMed: 29236642
DOI: 10.1056/NEJMoa1613773 -
Progress in Biophysics and Molecular... Jan 2016Many cardiac electrophysiological abnormalities are accompanied by autonomic nervous system dysfunction. Here, we review mechanisms by which the cardiac nervous system... (Review)
Review
Many cardiac electrophysiological abnormalities are accompanied by autonomic nervous system dysfunction. Here, we review mechanisms by which the cardiac nervous system controls normal and abnormal excitability and may contribute to atrial and ventricular tachyarrhythmias. Moreover, we explore the potential antiarrhythmic and/or arrhythmogenic effects of modulating the autonomic nervous system by several strategies, including ganglionated plexi ablation, vagal and spinal cord stimulations, and renal sympathetic denervation as therapies for atrial and ventricular arrhythmias.
Topics: Animals; Heart Atria; Heart Diseases; Heart Ventricles; Humans; Nervous System Physiological Phenomena
PubMed: 26780507
DOI: 10.1016/j.pbiomolbio.2015.12.015 -
Cardiac Electrophysiology Clinics Dec 2019Mapping and ablation of ventricular arrhythmias in patients with nonischemic cardiomyopathies remain a major challenge. The electroanatomic abnormalities are frequently... (Review)
Review
Mapping and ablation of ventricular arrhythmias in patients with nonischemic cardiomyopathies remain a major challenge. The electroanatomic abnormalities are frequently inaccessible to conventional endocardial ablations. Diagnostic diligence with a thorough understanding of the potential mechanisms/substrate, coupled with detailed electroanatomic mapping, is essential. Careful procedural planning, advanced imaging, and unipolar recordings help to formulate ablation strategy, facilitate work flow, and improve outcomes. Inaccessibility of arrhythmogenic substrate and disease progression are important causes of ablation failure. Early intervention may help to improve outcome and minimize complications. Several novel adjunctive ablation techniques are capable of serving as alternative options in refractory cases.
Topics: Adult; Aged; Arrhythmias, Cardiac; Cardiomyopathies; Catheter Ablation; Electrocardiography; Electrophysiologic Techniques, Cardiac; Female; Heart Ventricles; Humans; Male; Middle Aged
PubMed: 31706471
DOI: 10.1016/j.ccep.2019.08.005 -
Journal of the American Society of... Jun 2024Hypertrophic cardiomyopathy (HCM), the most common inherited cardiomyopathy, exhibits left ventricular hypertrophy not secondary to other causes, with varied phenotypic... (Review)
Review
Hypertrophic cardiomyopathy (HCM), the most common inherited cardiomyopathy, exhibits left ventricular hypertrophy not secondary to other causes, with varied phenotypic expression. Enhanced actin-myosin interaction underlies excessive myocardial contraction, frequently resulting in dynamic obstruction within the left ventricle. Left ventricular outflow tract obstruction, occurring at rest or with provocation in 75% of HCM patients, portends adverse prognosis, contributes to symptoms, and is frequently a therapeutic target. Transthoracic echocardiography plays a crucial role in the screening, initial diagnosis, management, and risk stratification of HCM. Herein, we explore echocardiographic evaluation of HCM, emphasizing Doppler assessment for obstruction. Echocardiography informs management strategies through noninvasive hemodynamic assessment, which is frequently obtained with various provocative maneuvers. Recognition of obstructive HCM phenotypes and associated anatomical abnormalities guides therapeutic decision-making. Doppler echocardiography allows monitoring of therapeutic responses, whether it be medical therapies (including cardiac myosin inhibitor therapy) or septal reduction therapies, including surgical myectomy and alcohol septal ablation. This article discusses the hemodynamics of obstruction and practical application of Doppler assessment in HCM. In addition, it provides a visual atlas of obstruction in HCM, including high-quality figures and complementary videos that illustrate the many facets of dynamic obstruction.
Topics: Humans; Cardiomyopathy, Hypertrophic; Ventricular Outflow Obstruction; Echocardiography, Doppler; Echocardiography; Heart Ventricles
PubMed: 38428652
DOI: 10.1016/j.echo.2024.02.010 -
Cardiac Electrophysiology Clinics Jun 2015Left ventricular noncompaction (LVNC) is a newly recognized form of cardiomyopathy that has been associated with heart failure, arrhythmias, thromboembolic events, and... (Review)
Review
Left ventricular noncompaction (LVNC) is a newly recognized form of cardiomyopathy that has been associated with heart failure, arrhythmias, thromboembolic events, and sudden death. Both ventricular and supraventricular arrhythmias are now well described as prominent clinical components of LVNC. Throughout the spectrum of age, these arrhythmias have been associated with prognosis and outcome, and their clinical management is therefore an important aspect of patient care. The risk of sudden death seems to be associated with ventricular dilation, systolic dysfunction, and the presence of arrhythmias. Proposed management strategies shown to have efficacy include antiarrhythmic therapy, ablation techniques, and implantable cardioverter-defibrillator implantation.
Topics: Arrhythmias, Cardiac; Cardiomyopathies; Death, Sudden, Cardiac; Heart Defects, Congenital; Heart Failure; Heart Ventricles; Humans
PubMed: 26002396
DOI: 10.1016/j.ccep.2015.03.007 -
Heart, Lung & Circulation Jan 2019Frequent ventricular ectopy is a common clinical presentation in patients suffering idiopathic ventricular outflow tract arrhythmias. These are focal arrhythmias that... (Review)
Review
Frequent ventricular ectopy is a common clinical presentation in patients suffering idiopathic ventricular outflow tract arrhythmias. These are focal arrhythmias that generally occur in patients without structural heart disease and share a predilection for characteristic anatomic sites of origin. Mechanistically, they are generally due to cyclic adenosine monophosphate (cAMP)-mediated triggered activity. As a result, there is typically an exercise or catecholamine related mode of induction and often a sensitivity to suppression with adenosine. Treatment options include clinical surveillance, medical therapy with anti-arrhythmic agents or catheter ablation. Medical therapy may offer symptomatic benefit but may have side-effects and usually results in burden reduction rather than eradication of ectopy. Catheter ablation using contemporary mapping techniques, whilst associated with some inherent procedural risk, is a potentially curative and safe option in most patients. Although usually associated with a good prognosis, some patients may develop an ectopy-mediated cardiomyopathy or, rarely, ectopy-induced polymorphic ventricular arrhythmias; catheter ablation is the treatment of choice in those patients.
Topics: Catheter Ablation; Electrocardiography; Global Health; Heart Ventricles; Humans; Incidence; Ventricular Premature Complexes
PubMed: 30322758
DOI: 10.1016/j.hlc.2018.09.009 -
Cardiac Electrophysiology Clinics Mar 2023The left ventricular summit is a site of origin for idiopathic ventricular arrhythmias. With advancements in mapping and ablation techniques, sites previously considered... (Review)
Review
The left ventricular summit is a site of origin for idiopathic ventricular arrhythmias. With advancements in mapping and ablation techniques, sites previously considered inaccessible can now be approached. Anatomical knowledge of the 3-dimensional landmarks of this space is important, as critical structures reside within its boundaries and are potentially liable to collateral injury during ablation. This article reviews reported complications from ablation of ventricular arrhythmias arising from the left ventricular summit and its vicinity and discusses the pros and cons of different ablation technique and the role of an individualized anatomical approach to reduce procedural related complications and improve outcomes.
Topics: Humans; Electrocardiography; Treatment Outcome; Catheter Ablation; Heart Ventricles; Arrhythmias, Cardiac; Tachycardia, Ventricular
PubMed: 36774142
DOI: 10.1016/j.ccep.2022.07.004 -
Heart Rhythm Nov 2020Multiple decades of work have recognized complexities of substrates responsible for ventricular tachycardia (VT). There is sufficient evidence that 3 critical components... (Review)
Review
Multiple decades of work have recognized complexities of substrates responsible for ventricular tachycardia (VT). There is sufficient evidence that 3 critical components of a re-entrant VT circuit, namely, region of slow conduction, zone of unidirectional block, and exit site, are located in spatial vicinity to each other in the ventricular scar. Each of these components expresses characteristic electrograms in sinus rhythm, at initiation of VT, and during VT, respectively. Despite this, abnormal electrograms are widely targeted without appreciation of these signature electrograms during contemporary VT ablation. Our aim is to stimulate physiology-based VT mapping and a targeted ablation of VT. In this article, we focus on these 3 underappreciated aspects of the physiology of ischemic scar-related VT circuits that have practical applications during a VT ablation procedure. We explore the anatomic and functional elements underlying these distinctive bipolar electrograms, specifically the contribution of tissue branching, conduction restitution, and wave curvature to the substrate, as they pertain to initiation and maintenance of VT. We propose a VT ablation approach based on these 3 electrogram features that can be a potential practical means to recognize critical elements of a VT circuit and target ablation.
Topics: Body Surface Potential Mapping; Heart Conduction System; Heart Rate; Heart Ventricles; Humans; Tachycardia, Ventricular
PubMed: 32590152
DOI: 10.1016/j.hrthm.2020.06.022 -
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