Human coronavirus-associated myocarditis is known, and a number of coronavirus disease 19 (COVID-19)-related myocarditis cases have been reported. The pathophysiology of COVID-19-related myocarditis ...is thought to be a combination of direct viral injury and cardiac damage due to the host's immune response. COVID-19 myocarditis diagnosis should be guided by insights from previous coronavirus and other myocarditis experience. The clinical findings include changes in electrocardiogram and cardiac biomarkers, and impaired cardiac function. When cardiac magnetic resonance imaging is not feasible, cardiac computed tomographic angiography with delayed myocardial imaging may serve to exclude significant coronary artery disease and identify myocardial inflammatory patterns. Because many COVID-19 patients have cardiovascular comorbidities, myocardial infarction should be considered. If the diagnosis remains uncertain, an endomyocardial biopsy may help identify active cardiac infection through viral genome amplification and possibly refine the treatment risks of systemic immunosuppression. Arrhythmias are not uncommon in COVID-19 patients, but the pathophysiology is still speculative. Nevertheless, clinicians should be vigilant to provide prompt monitoring and treatment. The long-term impact of COVID-19 myocarditis, including the majority of mild cases, remains unknown.
Atrial fibrillation (AF)-the most common arrhythmia-significantly increases the risk of stroke and heart failure. Although catheter ablation can restore normal heart rhythms, patients with persistent ...AF who develop atrial fibrosis often undergo multiple failed ablations, and thus increased procedural risks. Here, we present personalized computational modelling for the reliable predetermination of ablation targets, which are then used to guide the ablation procedure in patients with persistent AF and atrial fibrosis. First, we show that a computational model of the atria of patients identifies fibrotic tissue that, if ablated, will not sustain AF. Then, we report the results of integrating the target ablation sites in a clinical mapping system and testing its feasibility in ten patients with persistent AF. The computational prediction of ablation targets avoids lengthy electrical mapping and could improve the accuracy and efficacy of targeted AF ablation in patients while eliminating the need for repeat procedures.
Left atrial flutter (LAFL) occurs in patients after atrial fibrillation ablation. Identification of optimal ablation targets to terminate LAFL remains challenging.
The purpose of this study was to ...use patient-specific models to simulate LAFL and predict optimal ablation targets using a novel approach based on flow network theory.
Late gadolinium-enhanced cardiac magnetic resonance scans from 10 patients with LAFL were used to construct atrial models incorporating fibrosis by investigators blinded to procedural findings. Rapid pacing was applied in silico to induce LAFL. In each LAFL, we represented reentrant wave propagation as an electric flow network and identified the "minimum cut" (MC), which was the smallest amount of tissue that separated the flow into 2 discontinuous components. In silico ablation was applied at MCs, and targets were compared to those that terminated LAFL during catheter ablation.
Patient-specific atrial models were successfully generated from patient scans. LAFL was induced in 7 of 10 models. Ablation of MCs terminated LAFL in 4 models and produced new, slower LAFL morphologies in the other 3. For the latter cases, flow analysis was repeated to identify MCs of emergent LAFLs. Ablation of these MCs terminated emergent LAFLs. The MC-based ablation lesions in simulations were similar in length and location to ablation targets that terminated LAFL during catheter ablation for these 7 patients.
Personalized atrial simulations can predict ablation targets for LAFL. These simulations provide a powerful tool for planning ablation procedures and may reduce procedural times and complications.
BACKGROUND AND PURPOSE—Emerging data suggest that left atrial disease may cause ischemic stroke in the absence of atrial fibrillation or flutter (AF). If true, this condition may provide a cause for ...many strokes currently classified as cryptogenic.
METHODS—Among 6741 participants in the Multi-Ethnic Study of Atherosclerosis who were free of clinically apparent cerebrovascular or cardiovascular disease (including AF) at baseline, we examined the association between markers of left atrial abnormality on a standard 12-lead ECG—specifically P-wave area, duration, and terminal force in lead V1—and the subsequent risk of ischemic stroke while accounting for incident AF.
RESULTS—During a median follow-up of 8.5 years, 121 participants (1.8%) had a stroke and 541 participants (8.0%) were diagnosed with AF. In Cox proportional hazards models adjusting for potential baseline confounders, P-wave terminal force in lead V1 was more strongly associated with incident stroke (hazard ratio per 1 SD increase, 1.21; 95% confidence interval, 1.02–1.44) than with incident AF (hazard ratio per 1 SD, 1.11; 95% confidence interval, 1.03–1.21). The association between P-wave terminal force in lead V1 and stroke was robust in numerous sensitivity analyses accounting for AF, including analyses that excluded those with any incident AF or modeled any incident AF as having been present from baseline.
CONCLUSIONS—We found an association between baseline P-wave morphology and incident stroke even after accounting for AF. This association may reflect an atrial cardiopathy that leads to stroke in the absence of AF.
Abstract Background Observational studies, including recent large cohort studies that were unavailable for prior meta-analysis, have suggested an association between migraine headache and ischemic ...stroke. We performed an updated meta-analysis to quantitatively summarize the strength of association between migraine and ischemic stroke risk. Methods We systematically searched electronic databases, including MEDLINE and EMBASE, through February 2009 for studies of human subjects in the English language. Study selection using a priori selection criteria, data extraction, and assessment of study quality were conducted independently by reviewer pairs using standardized forms. Results Twenty-one (60%) of 35 studies met the selection criteria, for a total of 622,381 participants (13 case-control, 8 cohort studies) included in the meta-analysis. The pooled adjusted odds ratio of ischemic stroke comparing migraineurs with nonmigraineurs using a random effects model was 2.30 (95% confidence interval CI, 1.91-2.76). The pooled adjusted effect estimates for studies that reported relative risks and hazard ratios, respectively, were 2.41 (95% CI, 1.81-3.20) and 1.52 (95% CI, 0.99-2.35). The overall pooled effect estimate was 2.04 (95% CI, 1.72-2.43). Results were robust to sensitivity analyses excluding lower quality studies. Conclusions Migraine is associated with increased ischemic stroke risk. These findings underscore the importance of identifying high-risk migraineurs with other modifiable stroke risk factors. Future studies of the effect of migraine treatment and modifiable risk factor reduction on stroke risk in migraineurs are warranted.
Variable success rates have been reported after epicardial radiofrequency catheter ablation (RFA) in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). The details of the ...electroanatomic substrate are limited to a few studies, and the characteristics of the recurrent ventricular tachycardia (VT) in ARVD/C remain largely unknown.
The purpose of this study was to report procedural strategy, safety, and efficacy of epicardial RFA at a tertiary single center with a focus on the characteristics of the substrate and recurrent VT.
We included 30 ARVD/C patients (mean age 33.1 ± 11.1 years, 53% male) who underwent endocardial/epicardial mapping and epicardial catheter ablation of VT at the Johns Hopkins Hospital. Implantable cardioverter-defibrillator interrogations were evaluated for VT recurrence.
The majority of critical VT circuits (69%) were on the epicardial surface, mostly in the subtricuspid region. Eight patients (27%) experienced VT recurrence after epicardial RFA, and the VT-free survival was 83%, 76%, and 70% at 6,12, and 24, months respectively. A significant reduction of VT burden was observed (P <.001), even among those with VT recurrence. No complications occurred except for acute pericarditis in 1 patient. The majority of VT recurrences occurred during the first year after RFA, during exercise, had fast cycle lengths, and required implantable cardioverter-defibrillator shock for termination.
The vast majority of critical VT circuits were epicardial, mostly in the subtricuspid region. Epicardial RFA of VT appears to be both safe and effective in achieving arrhythmia control in ARVD/C. The features of the recurrent VT suggest a possible catecholamine-mediated mechanism with an origin in a region not targeted for ablation.
Abstract Objectives The aims of this study were to: 1) use a novel method of late gadolinium enhancement (LGE) quantification that uses normalized intensity measures to confirm the association ...between LGE extent and atrial fibrillation (AF) recurrence following ablation; and 2) examine the presence of interaction and effect modification between LGE and AF persistence. Background Recurrent AF after catheter ablation has been reported to associate with the baseline extent of left atrial LGE on cardiac magnetic resonance. Traditional methods for measurement of intensity lack an objective threshold for quantification and interpatient comparisons of LGE. Methods The cohort included 165 participants (mean age 60.0 ± 10.2 years, 77% men, 57% with persistent AF) who underwent initial AF ablation. The association of baseline LGE extent with AF recurrence was examined using multivariable Cox proportional hazards models. Multiplicative and additive interactions between AF type and LGE extent were examined. Results During 10.2 ± 5.7 months of follow-up, 63 patients (38.2%) experienced AF recurrence. Baseline LGE extent was independently associated with AF recurrence after adjusting for confounders (hazard ratio: 1.5 per 10% increased LGE; p < 0.001). The hazard ratio for AF recurrence progressively increased as a function of LGE. The magnitude of association between LGE >35% and AF recurrence was greater among patients with persistent AF (hazard ratio: 6.5 p = 0.001 vs. 3.6 p = 0.001); however, there was no evidence for statistical interaction. Conclusions Regardless of AF persistence at baseline, participants with LGE ≤35% have favorable outcomes, whereas those with LGE >35% have a higher rate of AF recurrence in the first year after ablation. These findings suggest a role for: 1) patient selection for AF ablation using LGE extent; and 2) substrate modification in addition to pulmonary vein isolation in patients with LGE extent exceeding 35% of left atrial myocardium.
The reported complication rate of catheter ablation of atrial fibrillation (AF) varies.
Our goal was to assess temporal trends and the effect of both institutional and individual operators' ...experience on the incidence of complications.
All patients undergoing AF ablation at Johns Hopkins Hospital between February 2001 and December 2010 were prospectively enrolled in a database. Major complications were defined as those that were life-threatening, resulted in permanent harm, required intervention, or significantly prolonged hospitalization.
Fifty-six major complications occurred in 1190 procedures (4.7%). The majority of complications were vascular (18; 1.5%), followed by pericardial tamponade (13; 1.1%) and cerebrovascular accident (12; 1.1%). No cases of death or atrioesophageal fistula occurred. The overall complication rate decreased from 11.1% in 2002 to 1.6% in 2010 (P <.05). On univariate analysis, demographic and clinical factors associated with the increased risk of complications were CHADS(2) score of ≥2 (hazard ratio HR = 2.5; 95% confidence interval CI = 1.4-4.4; P = .002), female gender (HR = 2.0; 95% CI = 1.2-3.5; P = .014), and age (HR = 1.03; 95% CI = 1.0-1.1; P = .042). Gender and CHADS(2) score of ≥2 remained independent predictors of complication on multivariable analysis.
The complication rate of catheter ablation of AF decreased with increased institutional experience. Female gender and CHADS(2) score of ≥2 are significant independent risk factors for complications and should be considered when referring patients for AF ablation.
Previous studies suggest that magnetic resonance imaging with late gadolinium enhancement (LGE) may identify slowly conducting tissues in scar-related ventricular tachycardia (VT).
To test the ...feasibility of image-based simulation based on LGE to estimate ablation targets in VT.
We conducted a retrospective study in 13 patients who had preablation magnetic resonance imaging for scar-related VT ablation. We used image-based simulation to induce VT and estimate target regions according to the simulated VT circuit. The estimated target regions were coregistered with the LGE scar map and the ablation sites from the electroanatomical map in the standard ablation approach.
In image-based simulation, VT was inducible in 12 (92.3%) patients. All VTs showed macroreentrant propagation patterns, and the narrowest width of estimated target region that an ablation line should span to prevent VT recurrence was 5.0 ± 3.4 mm. Of 11 patients who underwent ablation, the results of image-based simulation and the standard approach were consistent in 9 (82%) patients, where ablation within the estimated target region was associated with acute success (n = 8) and ablation outside the estimated target region was associated with failure (n = 1). In 1 (9%) case, the results of image-based simulation and the standard approach were inconsistent, where ablation outside the estimated target region was associated with acute success.
The image-based simulation can be used to estimate potential ablation targets of scar-related VT. The image-based simulation may be a powerful noninvasive tool for preprocedural planning of ablation procedures to potentially reduce the procedure time and complication rates.
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