Catheter ablation of atrial fibrillation in patients with and without hypertrophic cardiomyopathy: systematic review and meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). There is limited data regarding the outcomes of AF catheter ablation in HCM patients. In this study, we aimed to synthesize all available evidence on the effectiveness of ablation of AF in patients with HCM compared to those without HCM. METHODS AND RESULTS: We systematically reviewed bibliographic databases to identify studies published through February 2023. We included cohort studies with available quantitative information on rates of recurrent atrial arrhythmias, anti-arrhythmic drug (AAD) therapy, and repeat ablation procedures after initial AF ablation in patients with vs without HCM. Estimates were combined using random-effects meta-analysis models and reported as risk ratios (RR) and 95% confidence intervals (CI). Eight studies were included in quantitative synthesis (262 HCM and 642 non-HCM patients). During median follow-up 13-54 months across studies, AF recurrence rates ranged from 13.3% to 92.9% in HCM and 7.6% to 58.8% in non-HCM patients. The pooled RR for recurrent atrial arrhythmia after the first AF ablation in HCM patients compared to non-HCM controls was 1.498 (95% CI = 1.305-1.720; P < 0.001). During follow-up, HCM patients more often required AAD therapy (RR = 2.844; 95% CI = 1.713-4.856; P < 0.001) and repeat AF ablation (RR = 1.544; 95% CI = 1.070-2.228; P = 0.02). The pooled RR for recurrent atrial arrhythmias after the last AF ablation was higher in patients with HCM than those without HCM (RR = 1.607; 95% CI = 1.235-2.090; P < 0.001). CONCLUSIONS: Compared to non-HCM patients, those with HCM had higher rates of recurrent atrial arrhythmias, AAD use, and need for repeat AF ablation after initial ablation of AF.

Catheter ablation versus medical therapy for atrial fibrillation: Penny-wise Pound-foolish.

Catheter ablation for atrial fibrillation has emerged as a mainstay for the management of atrial fibrillation. It has been shown to be clinically effective and cost-effective in multiple trials.

A real-world experience of atrioventricular synchronous pacing with leadless ventricular pacemakers.

AIMS: The MicraTM transcatheter pacing system (TPS) (Medtronic) is the only leadless pacemaker that promotes atrioventricular (AV) synchrony via accelerometer-based atrial sensing. Data regarding the real-world experience with this novel system are scarce. We sought to characterize patients undergoing MicraTM -AV implants, describe percentage AV synchrony achieved, and analyze the causes for suboptimal AV synchrony. METHODS: In this retrospective cohort study, electronic medical records from 56 consecutive patients undergoing MicraTM -AV implants at the Mayo Clinic sites in Minnesota, Florida, and Arizona with a minimum follow-up of 3 months were reviewed. Demographic data, comorbidities, echocardiographic data, and clinical outcomes were compared among patients with and without atrial synchronous ventricular pacing (AsVP) ≥ 70%. RESULTS: Sixty-five percent of patients achieved AsVP ≥ 70%. Patients with adequate AsVP had smaller body mass indices, a lower proportion of congestive heart failure, and prior cardiac surgery. Echocardiographic parameters and procedural characteristics were similar across the two groups. Active device troubleshooting was associated with higher AsVP. The likely reasons for low AsVP were small A4-wave amplitude, high ventricular pacing burden, and inadequate device reprogramming. Importantly, in patients with low AsVP, subjective clinical worsening was not noted during follow-up. CONCLUSION: With the increasing popularity of leadless pacemakers, it is paramount for device implanting teams to be familiar with common predictors of AV synchrony and troubleshooting with MicraTM -AV devices.

Efficacy of ICD/CRT-D Remote Monitoring in Patients With HFrEF: a Bayesian Meta-analysis of Randomized Controlled Trials.

PURPOSE OF REVIEW: To evaluate remote monitoring using implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) devices as an adjunctive tool to the traditional care of patients with heart failure (HF). RECENT FINDINGS: We included 11 trials encompassing 5965 patients. Absolute risk difference (ARD) with 95% credible interval (CrI) was estimated. Pooled (posterior) risk difference was computed using Bayesian hierarchical methods. The ARD for mortality was centered at - 0.01 (95% CrI: - 0.03; 0.01, Tau: 0.02), with an 82% probability of ARD of ICD/CRT-D remote monitoring with respect to control being less than 0. The ARD for cardiovascular mortality was centered at - 0.03 (95% CrI: - 0.11; 0.05, Tau: 0.10), with an 84% probability of ARD of ICD/CRT-D remote monitoring with respect to control being less than 0. ICD/CRT-D remote monitoring in patients with HF is associated with a higher probability of reduced all-cause and cardiovascular mortality compared with standard care alone.

Efficacy of intentional permanent atrial pacing in the long-term management of congenital long QT syndrome.

BACKGROUND: Unfortunately, some patients with long QT syndrome (LQTS) experience breakthrough cardiac events (BCEs) despite maximal therapy. Small studies have shown that refractory LQTS cases may benefit from intentional permanent atrial pacing (IPAP). As such, we sought to determine the genotype-specific utilization and efficacy of IPAP in a single-center LQTS registry. METHODS AND RESULTS: In this retrospective study, electronic medical records from 1065 patients diagnosed with LQTS were used to identify individuals that received IPAP. Pre- and post-IPAP heart rate, heart rate-corrected QT (QTc) values, annual BCE rate, and IPAP-related complications were compared between genotypes. BCEs were defined as LQTS-associated syncope/seizures, sustained ventricular arrhythmia (VA)-terminating ICD therapies, and sudden cardiac arrest/death. Overall, 52 out of 1065 LQTS patients received adjunctive IPAP therapy (77% female; median age 18.5 [interquartile range, 1-35.5] years; 73% with prior VA). Over an average IPAP follow-up of 121 ± 82 months, the average heart rate increased from 65.8 ± 20.4 bpm to 78.9 ± 17.1 bpm; (p < .01) and the average QTc decreased from 533.4 ± 66.6 to 488.3 ± 52.4 ms; (p < .01). The mean BCE rate dropped from 0.88 to 0.19 per patient-year (p = .01), driven by a marked decrease in the LQT2 cohort (1.01 BCE/year to 0.02 BCE/year; p = .003). No serious IPAP-related complications were observed. CONCLUSION: In high-risk LQTS patients, namely those with recalcitrant LQT2, IPAP appears to be a safe and efficacious adjunct therapy. The beneficial effects of IPAP may stem from attenuating the QTc and circumventing a pause-dependent trigger. Whether IPAP might obviate the need for an ICD in some instances warrants further study.

Atrial fibrillation in the athlete: Case report and a contemporary appraisal.

INTRODUCTION: Atrial fibrillation (AF) is the most prevalent sustained arrhythmia affecting up to 1% of the world's population. The overwhelming majority of patients with AF have concomitant structural heart disease and comorbidities, including hypertension and diabetes mellitus. One out of ten AF patients has no substantial comorbidities and has been traditionally termed "lone AF". Paradoxically, there exists an association of highintensity endurance exercises and AF. CASE: 43-year-old competitive cyclist and cross-country skier with no known cardiac comorbidities who presented with multiple episodes of dyspnea and palpitations. He was found to have exercise-induced AF without structural heart abnormalities. DISCUSSION: This case highlights the clinical diversity of AF in athletes. In this review, we delve into the specifics of the pathophysiology and clinical features of AF in athletes. We then review the key points in managing AF in athletes, including medical therapy and catheter ablation. CONCLUSION: AF in the athletes is incompletely understood due to a lack of prospective study volume. There exist some crucial pathophysiological differences between AF in athletes and AF in older patients with structural heart disease. Treating physicians must be aware of the nuances of management of AF in athletes, including the concepts of detraining, medical therapy options, and ablation.

Management of ventricular electrical storm: a contemporary appraisal.

Ventricular electrical storm (VES) is a clinical scenario characterized by the clustering of multiple episodes of sustained ventricular arrhythmias (VA) over a short duration. Patients with VES are prone to psychological disorders, heart failure decompensation, and increased mortality. Studies have shown that 10-28% of the patients with secondary prevention ICDs can sustain VES. The triad of a susceptible electrophysiologic substrate, triggers, and autonomic dysregulation govern the pathogenesis of VES. The rate of VA, underlying ventricular function, and the presence of implantable cardioverter-defibrillator (ICD) determine the clinical presentation. A multi-faceted approach is often required for management consisting of acute hemodynamic stabilization, ICD reprogramming when appropriate, antiarrhythmic drug therapy, and sedation. Some patients may be eligible for catheter ablation, and autonomic modulation with thoracic epidural anesthesia, stellate ganglion block, or cardiac sympathetic denervation. Hemodynamically unstable patients may benefit from the use of left ventricular assist devices, and extracorporeal membrane oxygenation. Special scenarios such as idiopathic ventricular fibrillation, Brugada syndrome, Long and short QT syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy, and cardiac sarcoidosis have been described as well. VES is a cardiac emergency that requires swift intervention. It is associated with poor short and long-term outcomes. A structured team-based management approach is paramount for the safe and effective treatment of this sick cohort.

Post-extrasystolic potentiation as a predictor of premature ventricular contraction-cardiomyopathy in an animal model.

AIMS: High premature ventricular contractions (PVCs) burden does not always predict the development of PVC-cardiomyopathy (CM). We sought to evaluate post-extrasystolic potentiation (PESP) of left ventricular ejection fraction (LVEF) to predict the severity of PVC-CM in an animal model. METHODS AND RESULTS: Right ventricular apical bigeminal PVCs were introduced for 12 weeks in 11 canines to induce PVC-CM. Echocardiograms were performed to obtain LVEF without ectopy (Echo-1) and during PVCs (200 and 350 ms coupling intervals, Echo-2, and Echo-3, respectively), and premature atrial contractions (PACs) (Echo-4) at baseline and after 12 weeks of bigeminal PVCs. PESP was calculated as delta-LVEF between the sinus beat post-ectopy LVEF (Echo-2, -3, and -4, respectively) and LVEF without PVC (Echo-1) at baseline and 12 weeks of high PVC burden. A hyperdynamic LV function (LVEF > 70%) was noted in all animals only with early-coupled PVCs (LVEF at 200 ms: 74.4 ± 6%) at baseline. While PVC PESP at 200 ms had a strong significant correlation with the final 12-week LVEF (R = 0.8, P = 0.003), PVC PESP at 350 ms and PAC PESP had a positive but non-significant correlation (R = 0.53, P = 0.09, and R = 0.29, P = 0.34, respectively). Premature ventricular contraction PESP at 350 ms was significantly higher after PVC-CM had developed (delta-LVEF baseline 2.7 ± 2.9% vs. 12 weeks 18.6 ± 12.3% P < 0.001). CONCLUSION: Bigeminal early-coupled PVCs cause hyperdynamic left ventricular function in the structurally normal canine heart due to PESP. The degree of PESP at baseline is inversely proportional to the PVC-CM severity at 12 weeks and maybe a predictor of PVC-CM as it may assess the myocardial adaptation reserve to PVCs.

The Impact of Coronary Artery Disease and Statins on Survival After Liver Transplantation.

Cardiovascular disease (CVD) is a major contributor to longterm mortality after liver transplantation (LT) necessitating aggressive modification of CVD risk. However, it is unclear how coronary artery disease (CAD) and the development of dyslipidemia following LT impacts clinical outcomes and how management of these factors may impact survival. Patients undergoing LT at Virginia Commonwealth University from January 2007 to January 2017 were included (n = 495). CAD and risk factors in all potential liver transplantation recipients (LTRs) over the age of 50 years were evaluated via coronary angiography. The impact of pre-LT CAD after transplantation was evaluated via a survival analysis. Additionally, factors associated with new-onset dyslipidemia, statin use, and mortality were assessed using multiple logistic regression or Cox proportional hazards models. The mean age of the cohort was 55.3 ± 9.3 years at the time of LT, and median follow-up was 4.5 years. CAD was noted in 129 (26.1%) patients during the pre-LT evaluation. The presence or severity of pre-LT CAD did not impact post-LT survival. Dyslipidemia was present in 96 patients at LT, and 157 patients developed new-onset dyslipidemia after LT. Statins were underused as only 45.7% of patients with known CAD were on therapy. In patients with new-onset dyslipidemia, statin therapy was initiated in 111 (71.1%), and median time to initiation of statin therapy was 2.5 years. Statin use conferred survival benefit (hazard ratio, 0.25; 95% confidence interval, 0.12-0.49) and was well tolerated with only 12% of patients developing an adverse event requiring the cessation of therapy. In conclusion, pre-LT CAD did not impact survival after LT, potentially suggesting a role of accelerated atherosclerosis that may not be captured on pre-LT testing. Although statin therapy confers survival benefit, it is underused in LTRs.

Atypical presentation of fever as hypersensitivity reaction to oxaliplatin.

Oxaliplatin, a third-generation, platinum-based agent is widely used, most commonly in the FOLFOX (5-fluorouracil, leucovorin and oxaliplatin) regimen, which is the first-line therapy in metastatic colorectal adenocarcinoma and adjuvant chemotherapy in stage III colorectal cancer. Platinum-based products are well known for causing hypersensitivity reactions. Fever associated with oxaliplatin-hypersensitivity reactions typically follows a specific pattern. It usually starts during the oxaliplatin infusion or immediately after (within hours instead of days) and happens after several administrations (mean 2-25) with unpredictable clinical presentations. We report a case of oxaliplatin-induced hypersensitivity reaction manifesting as fever but with unusual presentation than the aforementioned features.

Retinal Detachment and Symptomatic Hypercalcemia in a Patient with Sarcoidosis: Unusual Presentation of a Granulomatous Disease.

Sarcoidosisis amultisystemic granulomatous disease, potentially affecting any organ system of the body. Calcium metabolism disturbances occur in up to 20% of patients, of which hypercalciuria and asymptomatic hypercalcemia are most common. Ocular sarcoid typically presents with anterior chamber manifestations such as uveitis, iritis, and iridocyclitis, but can involve posterior chamber as well. We describe herein a unique presentation of sarcoidosis with retinal detachment and symptomatic hypercalcemia as its first manifestation. Prompt therapy with steroids is indicated in these cases, and an immediate ophthalmology referral cannot be overemphasized.

Mantle Cell Lymphoma With Cardiac Involvement Presenting as Complete Heart Block.

A 50-year-old woman presented with complete heart block on electrocardiogram. Echocardiogram revealed an intracardiac mass with extensive cardiac involvement. The patient was diagnosed with mantle cell lymphoma, confirmed via lymph node biopsy. Pacemaker implantation and chemotherapy were initiated, with subsequent improvement noted. This showcases an unusual manifestation of intracardiac metastasis with conduction system infiltration.

Trends in the 30-year span of noninfectious cardiovascular implantable electronic device complications in Olmsted County.

Background: Cardiac implantable electronic devices (CIEDs), such as permanent pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy devices, alleviate morbidity and mortality in various diseases. There is a paucity of real-world data on CIED complications and trends. Objectives: We sought to describe trends in noninfectious CIED complications over the past 3 decades in Olmsted County. Methods: The Rochester Epidemiology Project is a medical records linkage system comprising records of over 500,000 residents of Olmsted County from 1966 to present. CIED implantations between 1988 and 2018 were determined. Trends in noninfectious complications within 30 days of implantation were analyzed. Results: A total of 157 (6.2%) of 2536 patients who received CIED experienced device complications. A total of 2.7% of the implants had major complications requiring intervention. Lead dislodgement was the most common (2.8%), followed by hematoma (1.7%). Complications went up from 1988 to 2005, and then showed a downtrend until 2018, driven by a decline in hematomas in the last decade (P < .01). Those with complications were more likely to have prosthetic valves. Obesity appeared to have a protective effect in a multivariate regression model. The mean Charlson comorbidity index has trended up over the 30 years. Conclusion: Our study describes a real-world trend of CIED complications over 3 decades. Lead dislodgements and hematomas were the most common complications. Complications have declined over the last decade due to safer practices and a better understanding of anticoagulant management.

Management of Premature Ventricular Complexes in the Outpatient Setting.

With an aging population and an explosion in ambulatory electrocardiographic monitoring, primary care clinicians will undoubtedly see an increase in patients presenting with premature ventricular complexes (PVCs), especially given how common they are in the general population. A sizable number of patients with PVCs are asymptomatic, and these PVCs have no significant clinical implications. In contrast, PVCs can predispose patients to or are a clinical marker of an underlying cardiomyopathy, heart failure, or sudden cardiac death. Such a dichotomy can create fear in dealing with PVCs in the outpatient setting, both in immediate situations and for surveillance and follow-up. In this review, we provide a comprehensive overview of the pathophysiologic basis of PVCs, appropriate diagnostic testing, management, and prognostic considerations necessary when faced with PVCs in the outpatient clinic. We also provide a simplistic approach to help guide the initial work-up of PVCs, basic treatment strategies, and indications of when to refer for cardiovascular specialty consultation to improve physician comfort and to enhance patient care.

Antiarrhythmic drugs for atrial fibrillation in the outpatient setting.

With burgeoning evidence for early rhythm control in patients with atrial fibrillation (AF), the management of AF in the outpatient setting has become more challenging. The primary care clinician often serves as the frontline in the pharmacologic management of AF. Because of drug interactions and the risk of proarrhythmia, many clinicians remain hesitant about the initiation and chronic management of antiarrhythmic drug prescriptions. However, with the likely increased use of antiarrhythmics for early rhythm control, understanding and familiarity with these medications have likewise become more important, especially since patients with AF probably have other non-cardiac medical conditions that can impact their antiarrhythmic therapy. In this comprehensive review, we provide informative, high-yield cases and edifying references that will help primary care providers become comfortable handling various clinical scenarios.

Failure of Intrinsic Antitachycardia Pacing to Terminate Ventricular Tachycardia and Potential Proarrhythmic Effects.

Intrinsic antitachycardia pacing (iATP) is a novel, automated antitachycardia pacing (ATP) algorithm that provides individualized therapy to terminate ventricular tachycardia (VT). If the first ATP attempt is unsuccessful, the algorithm analyzes the tachycardia cycle length and the postpacing interval and adjusts the subsequent sequence to successfully terminate VT. This algorithm was effective in a single clinical study without a comparator arm. However, iATP failure has not been well-documented in the literature. This publication represents the first case series with episode analysis of iATP failure, including a demonstration of its proarrhythmic effect.