Publications by authors named "Calkins H"

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease characterized by fibrofatty replacement of the ventricular myocardium, a high risk of ventricular arrhythmias, and progressive ventricular dysfunction. The clinical course is highly variable, and optimal approaches to management remain undefined. ARVC is associated with pathogenic variants in genes encoding the cardiac desmosome.

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Background: Arrhythmogenic right ventricular cardiomyopathy is an inherited cardiomyopathy characterized by fibrofatty replacement of right ventricular myocardium resulting in reentrant ventricular tachycardia (VT). Cardiac magnetic resonance imaging (CMR) can noninvasively measure regional abnormalities using tissue-tracking strain as well as late gadolinium enhancement (LGE). In this study, we examine arrhythmogenic substrate using regional CMR strain, LGE, and electroanatomic mapping (EAM) in arrhythmogenic right ventricular cardiomyopathy patients presenting for VT ablation.

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Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy that is predominantly known to affect the ventricles. Evidence for atrial involvement remains limited. Therefore, we aimed to characterize atrial involvement in ARVC using functional cardiac magnetic resonance, define the extent of atrial size and function variation attributable to ventricular variables, and identify cardiac magnetic resonance-based predictors of atrial arrhythmias (AA) in ARVC.

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The diagnosis of cardiac sarcoidosis (CS), especially in cases where there is limited or no extracardiac involvement, is challenging. Patients with CS are at increased risk of ventricular arrhythmias and sudden cardiac death. Several techniques for risk stratification for sudden cardiac death have been proposed in this population, including advanced cardiac imaging and electrophysiology study.

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Objectives: This study examined the trend in growth of catheter ablation for ventricular tachycardia (VT) performed in the United States with analysis of rates and predictors of major adverse events.

Background: Sustained VT is a significant cause of sudden death, heart failure (HF), and recurrent shocks in implantable cardioverter-defibrillator (ICD) recipients. Catheter ablation for VT reduces arrhythmia recurrence.

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Focal impulse and rotor mapping (FIRM) involves intracardiac detection and catheter ablation of re-entrant drivers (RDs), some of which may contribute to arrhythmia perpetuation in persistent atrial fibrillation (PsAF). Patient-specific computational models derived from late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) has the potential to non-invasively identify all areas of the fibrotic substrate where RDs could potentially be sustained, including locations where RDs may not manifest during mapped AF episodes. The objective of this study was to carry out multi-modal assessment of the arrhythmogenic propensity of the fibrotic substrate in PsAF patients by comparing locations of RD-harboring regions found in simulations and detected by FIRM (RD and RD) and analyze implications for ablation strategies predicated on targeting RDs.

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Background: Patients go without pacemaker, defibrillator, and cardiac resynchronization therapies (devices) each year due to the prohibitive costs of devices.

Objective: We sought to examine data available from studies regarding contemporary risks of reused devices in comparison with new devices.

Methods: We searched online indexing sites to identify recent studies.

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Aims: Likely pathogenic/pathogenic variants in genes encoding desmosomal proteins play an important role in the pathophysiology of arrhythmogenic right ventricular cardiomyopathy (ARVC). However, for a substantial proportion of ARVC patients, the genetic substrate remains unknown. We hypothesized that plectin, a cytolinker protein encoded by the PLEC gene, could play a role in ARVC because it has been proposed to link the desmosomal protein desmoplakin to the cytoskeleton and therefore has a potential function in the desmosomal structure.

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Purpose To compare epicardial fat in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with that in healthy subjects. Materials and Methods In this retrospective study, cardiac CT scans in 44 patients with ARVD/C (mean age, 39 years ± 12; 23 men) were compared with those in 45 control group participants between January 2008 and July 2015. Volumes of intrathoracic adipose tissue, mediastinal adipose tissue (MAT), and total epicardial adipose tissue (EAT) were quantified.

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Background: Reliable identification of atrial fibrillation (AF) patients more likely to be AF-free long-term post-single catheter ablation (CA) would facilitate appropriate risk communication to patients. We validated the recently proposed MB-LATER score for prediction of late recurrences of AF (LRAF) post-CA.

Methods: Patients who underwent CA for symptomatic AF refractory to ≥1 antiarrhythmic drugs at the Johns Hopkins Hospital, Baltimore, between March 2003 and December 2015, for whom ≥1-year post-CA follow-up data were available, were enrolled.

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Article Synopsis
  • Deliberate practice (DP) is a teaching method aimed at mastering skills, crucial for competency-based healthcare education, and this pilot project tested a simulation-based approach to enhance mastery learning.
  • A simulation module was developed focused on supraventricular tachycardia (SVT) management, incorporating American Heart Association guidelines, and was tested by ten emergency medicine interns.
  • Results showed improved performance with increased attempts leading to quicker cardioversion times and enhanced resident confidence in SVT management, indicating the effectiveness of simulation-based DP methods in training.
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The mechanism of atrial fibrillation (AF) maintenance in humans is yet to be determined. It remains controversial whether cardiac fibrillatory dynamics are the result of a deterministic or a stochastic process. Traditional methods to differentiate deterministic from stochastic processes have several limitations and are not reliably applied to short and noisy data obtained during clinical studies.

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Conducted Electrical Weapons (CEWs) are being used as the preferred non-lethal force option for police and special forces worldwide. This new technology challenges an exposed opponent similarly to the way they would be challenged by physical exercise combined with emotional stress. While adrenergic and metabolic effects have been meta-analyzed and reviewed, there has been no systematic review of the effects of CEWs on skeletal and cardiac muscle.

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The P-wave terminal force in lead V (PTFV) on the 12-lead electrocardiogram (ECG) quantifies left atrial (LA) structural and electrophysiologic abnormalities. We aimed to evaluate the association between PTFV and cerebrovascular accident (CVA) as well as LA structure and function in patients with atrial fibrillation (AF). We conducted a cross-sectional study of 229 patients with AF (60 ± 10years, 72% men) with (n = 21) and without (n = 208) a history of CVA, who underwent preablation ECG and cardiac magnetic resonance in sinus rhythm.

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Background: Prior studies have shown a close link between exercise and development of arrhythmogenic right ventricular cardiomyopathy. How much exercise restriction reduces ventricular arrhythmia (VA), how genotype modifies its benefit, and whether it reduces risk sufficiently to defer implantable cardioverter-defibrillator (ICD) placement in arrhythmogenic right ventricular cardiomyopathy are unknown.

Methods And Results: We interviewed 129 arrhythmogenic right ventricular cardiomyopathy patients (age: 34.

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Background: Implantable defibrillators (ICD) are an important therapy for arrhythmogenic right ventricular cardiomyopathy (ARVC) patients at high risk of sudden death. Given the high appropriate ICD therapy rate, some have argued that the mere act of implanting an ICD inflates the malignant arrhythmia rate in ARVC.

Objective: To report the arrhythmic course of ARVC patients without ICDs at the fulfillment of the 2010 Task Force Criteria and explore predictors of malignant ventricular arrhythmias.

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Atrial fibrillation (AF) affects more than 33 million individuals worldwide and has a complex heritability. We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis.

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Background: Contrast-enhanced cardiac computed tomography (CE-CT) provides useful substrate characterization in patients with ventricular tachycardia (VT).

Objective: The purpose of this study was to describe the association between endocardial electrogram measurements and myocardial characteristics on CE-CT, in particular the field of view of electrogram features.

Methods: Fifteen patients with postinfarct VT who underwent catheter ablation with preprocedural CE-CT were included.

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Objectives: This study sought to evaluate the spatial relationships of focal electrical sources (FSs) to complex fractionated atrial electrograms (CFAE) and continuous electrical activity (CEA).

Background: Fractionated atrial electrograms have been associated with atrial fibrillation (AF) drivers in computational studies and represent ablation targets in the management of persistent AF.

Methods: We included a subset of 66 patients (age: 63 [56, 67] years, 69% persistent AF) with electroanatomic data from the SELECT AF (Selective complex fractionated atrial electrograms targeting for atrial fibrillation) randomized control trial that compared the efficacy of CFAE with CEA ablation in AF patients undergoing pulmonary vein antral ablation.

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