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Clinical Medicine (London, England) Sep 2023Ventricular tachycardia (VT) describes rapid heart rhythms originating from the ventricles. Accurate diagnosis of VT is important to allow prompt referral to specialist... (Review)
Review
Ventricular tachycardia (VT) describes rapid heart rhythms originating from the ventricles. Accurate diagnosis of VT is important to allow prompt referral to specialist services for ongoing management. The diagnosis of VT is usually made based on electrocardiographic data, most commonly 12-lead echocardiography (ECG), as well as supportive cardiac telemetric monitoring. Distinguishing between VT and supraventricular arrhythmias on ECG can be difficult. However, the VT diagnosis frequently needs to be made rapidly in the acute setting. In this review, we discuss the definition of VT, review features of wide-complex tachycardia (WCT) on ECG that might be helpful in diagnosing VT, discuss the different substrates in which VT can occur and offer brief comments on management considerations for patients found to have VT.
Topics: Humans; Tachycardia, Supraventricular; Diagnosis, Differential; Tachycardia, Ventricular; Heart Ventricles; Electrocardiography
PubMed: 37775174
DOI: 10.7861/clinmed.2023-23.5.Cardio3 -
Circulation Feb 2022Left ventricular noncompaction cardiomyopathy (LVNC) was discovered half a century ago as a cardiomyopathy with excessive trabeculation and a thin ventricular wall. In...
BACKGROUND
Left ventricular noncompaction cardiomyopathy (LVNC) was discovered half a century ago as a cardiomyopathy with excessive trabeculation and a thin ventricular wall. In the decades since, numerous studies have demonstrated that LVNC primarily has an effect on left ventricles (LVs) and is often associated with LV dilation and dysfunction. However, in part because of the lack of suitable mouse models that faithfully mirror the selective LV vulnerability in patients, mechanisms underlying the susceptibility of LVs to dilation and dysfunction in LVNC remain unknown. Genetic studies have revealed that deletions and mutations in (PR domain-containing 16) cause LVNC, but previous conditional knockout mouse models do not mirror the LVNC phenotype in patients, and the underlying molecular mechanisms by which PRDM16 deficiency causes LVNC are still unclear.
METHODS
cardiomyocyte-specific knockout () mice were generated and analyzed for cardiac phenotypes. RNA sequencing and chromatin immunoprecipitation deep sequencing were performed to identify direct transcriptional targets of PRDM16 in cardiomyocytes. Single-cell RNA sequencing in combination with spatial transcriptomics was used to determine cardiomyocyte identity at the single-cell level.
RESULTS
Cardiomyocyte-specific ablation of in mice caused LV-specific dilation and dysfunction, as well as biventricular noncompaction, which fully recapitulated LVNC in patients. PRDM16 functioned mechanistically as a compact myocardium-enriched transcription factor that activated compact myocardial genes while repressing trabecular myocardial genes in LV compact myocardium. Consequently, LV compact myocardial cardiomyocytes shifted from their normal transcriptomic identity to a transcriptional signature resembling trabecular myocardial cardiomyocytes or neurons. Chamber-specific transcriptional regulation by PRDM16 was attributable in part to its cooperation with LV-enriched transcription factors Tbx5 and Hand1.
CONCLUSIONS
These results demonstrate that disruption of proper specification of compact cardiomyocytes may play a key role in the pathogenesis of LVNC. They also shed light on underlying mechanisms of the LV-restricted transcriptional program governing LV chamber growth and maturation, providing a tangible explanation for the susceptibility of LV in a subset of LVNC cardiomyopathies.
Topics: Animals; DNA-Binding Proteins; Heart Ventricles; Mice; Mice, Knockout; Myocardium; Myocytes, Cardiac; Transcription Factors
PubMed: 34915728
DOI: 10.1161/CIRCULATIONAHA.121.056666 -
Journal of Arrhythmia Jun 2021Coronary injury presenting as ST segment elevation (STE) during ablation procedures for different arrhythmias is a rare and most feared complication. There have been... (Review)
Review
Coronary injury presenting as ST segment elevation (STE) during ablation procedures for different arrhythmias is a rare and most feared complication. There have been multiple reports on STE during various ablation procedures in the recent past. Herein, we review various mechanisms, presentations, and management of STE observed during various ablations, including atrial fibrillation ablation cavotricuspid isthmus and ablation, supraventricular tachycardia ablations, coronary sinus ablation, and ventricular arrhythmia ablations.
PubMed: 34141005
DOI: 10.1002/joa3.12526 -
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 -
Reviews in Cardiovascular Medicine Mar 2022Outflow tract (OT) premature ventricular complexes (PVCs) are being recognized as a common and often troubling, clinical electrocardiographic finding. The OT areas... (Review)
Review
Outflow tract (OT) premature ventricular complexes (PVCs) are being recognized as a common and often troubling, clinical electrocardiographic finding. The OT areas consist of the Right Ventricular Outflow Tract (RVOT), the Left Ventricular Outflow Tract (LVOT), the Aortomitral Continuity (AMC), the aortic cusps and the Left Ventricular (LV) summit. By definition, all OT PVCs will exhibit an inferior QRS axis, defined as positive net forces in leads II, III and aVF. Activation mapping using the contemporary 3D mapping systems followed by pace mapping is the cornerstone strategy of every ablation procedure in these patients. In this mini review we discuss in brief all the modern mapping and ablation modalities for successful elimination of OT PVCs, along with the potential advantages and disadvantages of each ablation technique.
Topics: Catheter Ablation; Electrocardiography; Heart Ventricles; Humans; Tachycardia, Ventricular; Ventricular Premature Complexes
PubMed: 35345270
DOI: 10.31083/j.rcm2303103 -
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 -
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 -
JACC. Clinical Electrophysiology Feb 2023Frequent premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy that usually affects the left ventricle (LV).
BACKGROUND
Frequent premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy that usually affects the left ventricle (LV).
OBJECTIVES
The objective of this study was to assess whether frequent PVCs have an impact on right ventricular (RV) function.
METHODS
Serial cardiac magnetic resonance (CMR) studies were performed in a series of 47 patients before and after ablation of frequent PVCs.
RESULTS
Patients with RV cardiomyopathy (ejection fraction [EF] <0.45) had more frequent PVCs than did patients without decreased RV function (23% ± 11% vs 15% ± 11%, P = 0.03). Likewise, patients with LV cardiomyopathy (EF <0.50) had more frequent PVCs than did patients without decreased LV function (23% ± 10% vs 14% ± 12%, P = 0.003). LV dysfunction was present in 21 patients (45%). In patients with LV dysfunction, 15 patients (32%) had biventricular dysfunction, and 6 patients (13%) had isolated LV dysfunction. A total of 19 patients (40%) had RV dysfunction, and 4 of the patients with RV dysfunction (9%) had isolated RV dysfunction. Cardiac magnetic resonance was repeated 1.9 ± 1.3 years after ablation. In patients with successful ablation, RV function improved, and in patients without successful ablation, RV function did not significantly change (before and after ablation RVEF 0.45 ± 0.09 and 0.52 ± 0.09; P < 0.001 vs. 0.46 ± 0.07 and 0.48 ± 0.04; P = 0.14, respectively).
CONCLUSIONS
Frequent PVCs can cause RV cardiomyopathy that parallels LV cardiomyopathy and is reversible with successful ablation.
Topics: Humans; Heart; Heart Ventricles; Ventricular Premature Complexes; Ventricular Dysfunction, Right; Ventricular Dysfunction, Left
PubMed: 36858685
DOI: 10.1016/j.jacep.2022.09.016 -
Journal of Cardiovascular... Mar 2022Ethanol ablation (EA) is an alternative option for subjects with ventricular arrhythmias (VAs) refractory to conventional medical and ablative treatment. However, data... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Ethanol ablation (EA) is an alternative option for subjects with ventricular arrhythmias (VAs) refractory to conventional medical and ablative treatment. However, data on the efficacy and safety of EA remain sparse.
METHODS
A systematic literature search was conducted. The primary outcomes were 1) freedom from the targeted VA and 2) freedom from any VAs post-EA. Additional safety outcomes were also analyzed.
RESULTS
Ten studies were selected accounting for a population of 174 patients (62.3 ± 12.5 years, 94% male) undergoing 185 procedures. The overall acute success rate of EA was 72.4% (confidence interval [CI ]: 65.6-78.4). After a mean follow-up of 11.3 ± 5.5 months, the incidence of relapse of the targeted VA was 24.4% (CI : 17.1-32.8), while any VAs post-EA occurred in 41.3% (CI : 33.7-49.1). The overall incidence of procedural complications was 14.1% (CI : 9.8-19.8), with pericardial complications and complete atrioventricular block being the most frequent. An anterograde transarterial approach was associated with a higher rate of VA recurrences and complications compared to a retrograde transvenous route; however, differences in the baseline population characteristics and in the targeted ventricular areas should be accounted.
CONCLUSION
EA is a valuable therapeutic option for VAs refractory to conventional treatment and can result in 1-year freedom from VA recurrence in 60%-75% of the patients. However, anatomical or technical challenges preclude acute success in almost 30% of the candidates and the rate of complication is not insignificant, highlighting the importance of well-informed patient selection. The certainty of the evidence is low, and further research is necessary.
Topics: Arrhythmias, Cardiac; Catheter Ablation; Ethanol; Female; Heart Ventricles; Humans; Male; Retrospective Studies; Tachycardia, Ventricular; Treatment Outcome
PubMed: 34921464
DOI: 10.1111/jce.15336 -
Pacing and Clinical Electrophysiology :... Feb 2024The left ventricular summit (LVS) refers to the highest portion of the left ventricular outflow tract (LVOT). It is an epicardially delimited triangular area by the left... (Review)
Review
The left ventricular summit (LVS) refers to the highest portion of the left ventricular outflow tract (LVOT). It is an epicardially delimited triangular area by the left coronary arteries and the coronary venous circulation. Its deep myocardium correlates closely with the left coronary cusp, aortic-mitral continuity, and right ventricular outflow tract (RVOT), complicating the anatomical relationship. Ventricular arrhythmias (VAs) originating from this area are common, accounting for 14.5% of all VAs origin from left ventricle. Specific electrocardiogram (ECG) characteristics may assist in locating LVS-VAs pre-procedure and facilitate procedure planning. However, catheter ablation of LVS-VAs remains challenging because of anatomical constraints. This paper reviews the recent understanding of LVS anatomy, concludes ECG characteristics, and summarizes current mapping and ablation methods for LVS-VAs.
Topics: Humans; Heart Ventricles; Tachycardia, Ventricular; Arrhythmias, Cardiac; Aorta; Myocardium; Catheter Ablation; Electrocardiography; Treatment Outcome
PubMed: 38291856
DOI: 10.1111/pace.14932