Rates of pulmonary vein reconnection at repeat ablation for recurrent atrial fibrillation and its impact on outcomes among females and males.

BACKGROUND: Several studies have demonstrated that females have a higher risk of arrhythmia recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF). There are limited data on sex-based differences in PV reconnection rates at repeat ablation. We aimed to investigate sex-based differences in electrophysiological findings and atrial arrhythmia recurrence after repeat AF ablation METHODS: We conducted a retrospective study of 161 consecutive patients (32% female, age 65 ± 10 years) who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Demographics, procedural characteristics and follow-up data were collected. Recurrent atrial tachycardia (AT)/AF was defined as any atrial arrhythmia ≥30 s in duration. RESULTS: Compared to males, females tended to be older and had a significantly higher prevalence of prior valve surgery (10 vs. 2%; P = .03). At repeat ablation, PV reconnection was found in 119 (74%) patients. Males were more likely to have PV reconnection at repeat ablation compared to females (81 vs. 59%; P = .004). Excluding repeat PV isolation, there were no significant differences in adjunctive ablation strategies performed at repeat ablation between females and males. During follow-up, there were no significant differences in freedom from AT/AF recurrence between females and males after repeat ablation (63 vs. 59% at 2 years, respectively; P = .48). CONCLUSIONS: After initial PV isolation, significantly fewer females have evidence of PV reconnection at the time of repeat ablation for recurrent AF. Despite this difference, long-term freedom from AT/AF was similar between females and males after repeat ablation.

Localized Re-Entry Is a Frequent Mechanism of De Novo Atypical Flutter.

BACKGROUND: Limited data exist about the origins and mechanisms of atypical atrial flutter that occurs in the absence of prior ablation or surgery. OBJECTIVES: The aims of this study were to report a large cohort of patients who presented for catheter ablation of de novo atypical flutters, to identify the most common locations and mechanisms of arrhythmia, and to describe outcomes after ablation. METHODS: Demographic, electrophysiological, and outcome data were collected for patients who underwent ablation of de novo atypical flutter. RESULTS: The mechanisms of 85 atypical flutters were identified in 62 patients and localized to the left atrium (LA) in 58 and right atrium (RA) in 27. In the LA, mechanisms were classified as macro-re-entry in 29 (50%) and localized re-entry in 29 (50%), whereas in the RA, mechanisms were macro-re-entry in 8 (30%) and localized re-entry in 19 (70%) (proportion of localized re-entry in the LA vs. RA, P = 0.08). Nine patients had both localized and macro-re-entrant atypical flutters. In the LA, localized re-entry was commonly found in the anterior LA, followed by the pulmonary veins and septum. In the RA, localized re-entry was found at various sites, including the lateral or posterior RA, septum, and coronary sinus ostium. During 39.4 months (Q1-Q3: 18.2-65.8 months) of follow-up, atrial arrhythmias occurred in 66% of patients after a single ablation and in 50% after >1 ablation. Among patients who underwent repeat ablation, compared with the index arrhythmia, different tachycardia circuits or arrhythmias were documented in 13 of 18 cases (72%). CONCLUSIONS: Atypical atrial flutters in patients without prior surgery or complex ablation are often due to localized re-entry (approximately 50% in the LA and a higher frequency in the RA). Other atrial tachycardias commonly occur during long-term follow-up following ablation, suggesting progressive atrial myopathy in these patients.

Ventricular Tachycardia Due to Triggered Activity: Role of Early and Delayed Afterdepolarizations.

Most forms of sustained ventricular tachycardia (VT) are caused by re-entry, resulting from altered myocardial conduction and refractoriness secondary to underlying structural heart disease. In contrast, VT caused by triggered activity (TA) is unrelated to an abnormal structural substrate and is often caused by molecular defects affecting ion channel function or regulation of intracellular calcium cycling. This review summarizes the cellular and molecular bases underlying TA and exemplifies their clinical relevance with selective representative scenarios. The underlying basis of TA caused by delayed afterdepolarizations is related to sarcoplasmic reticulum calcium overload, calcium waves, and diastolic sarcoplasmic reticulum calcium leak. Clinical examples of TA caused by delayed afterdepolarizations include sustained right and left ventricular outflow tract tachycardia and catecholaminergic polymorphic VT. The other form of afterpotentials, early afterdepolarizations, are systolic events and inscribe early afterdepolarizations during phase 2 or phase 3 of the action potential. The fundamental defect is a decrease in repolarization reserve with associated increases in late plateau inward currents. Malignant ventricular arrhythmias in the long QT syndromes are initiated by early afterdepolarization-mediated TA. An understanding of the molecular and cellular bases of these arrhythmias has resulted in generally effective pharmacologic-based therapies, but these are nonspecific agents that have off-target effects. Therapeutic efficacy may need to be augmented with an implantable defibrillator. Next-generation therapies will include novel agents that rescue arrhythmogenic abnormalities in cellular signaling pathways and gene therapy approaches that transfer or edit pathogenic gene variants or silence mutant messenger ribonucleic acid.

Trends in the Incidence of Cardiogenic Shock, and Utilization of Mechanical Circulatory Support in Myocarditis: Insights from the National Inpatient Sample 2016 to 2019.

A subset of patients with myocarditis present with cardiogenic shock. There is a lack of contemporary data assessing the use of mechanical circulatory support (MCS) in these patients. Myocarditis hospitalizations were analyzed using the National Inpatient Sample between 2016 and 2019. Characteristics of patients with and without cardiogenic shock were assessed. Trends in mortality, MCS, right-sided cardiac catheterization (RHC) and endomyocardial biopsy were evaluated. The impact of RHC on consequent MCS and mortality was studied. A total of 38,300 hospitalizations for myocarditis were included in the study, of which 3,490 hospitalizations (9.1%) had cardiogenic shock. Patients with cardiogenic shock were older (p <0.001) and had more chronic kidney disease and atrial fibrillation. Between 2016 and 2019, there was an increase in myocarditis admissions but no difference in rates of cardiogenic shock and mortality and the use of extracorporeal membrane oxygenation, percutaneous ventricular assist devices, intra-aortic balloon pumps, left ventricular assist devices, and cardiac transplant. The most common form of MCS used in myocarditis was extracorporeal membrane oxygenation. The rates of RHC (p = 0.02) and endomyocardial biopsy (p = 0.03) increased over time. Patients who underwent RHC were more likely to receive mechanical support, and in patients with shock, RHC was associated with lower mortality (adjusted odds ratio 0.34, p <0.01). Myocarditis admissions increased over time but with no increase in the rates of cardiogenic shock and MCS. In patients with cardiogenic shock, RHC resulted in lower mortality.

A mimicker of constriction: a case report of a rare case of cardiac angiosarcoma.

Background: Cardiac angiosarcoma is an exceptionally rare primary malignant tumour with an aggressive course and typically poor prognosis. Diagnosis is difficult, and patients often present with metastatic disease. We report the rare case of a patient with cardiac angiosarcoma who presents with constrictive physiology due to tumour encasement. Case summary: A 65-year-old female with a past medical history of Hodgkin's lymphoma and limited scleroderma presented with progressive dyspnoea on exertion. Multimodality imaging and haemodynamics with echocardiography, cardiac magnetic resonance imaging (MRI), and cardiac catheterization showed findings of constrictive physiology. Cardiac MRI showed areas of pericardial enhancement, so she was initially started on colchicine, prednisone, and mycophenolate mofetil to treat pericardial inflammation. However, her symptoms progressed, and she underwent pericardiectomy with cardiac surgery. Pericardium was noted to be thickened and a mass-like substance was densely adherent and potentially invading the heart itself and could not be dissected free. Surgical pathology showed features consistent with epithelioid angiosarcoma. Patient had rapid progression of her disease and was started on chemotherapy. Her course, however, was complicated by acute gastrointestinal bleeding, atrial fibrillation with rapid rates, and persistent volume overload. She elected for comfort measures and passed away shortly after her diagnosis. Discussion: Our case shows an extremely rare diagnosis, cardiac angiosarcoma, presenting with typical findings of constrictive physiology. The case shows the typical features of constrictive physiology using multimodality imaging and haemodynamics and emphasizes the need to always think broadly in creating a differential diagnosis for constriction to ensure that rare diseases are considered.

Mortality of patients with ST-segment-elevation myocardial infarction without standard modifiable risk factors among patients without known coronary artery disease: Age-stratified and sex-related analysis from nationwide readmissions database 2010-2014.

Objective: The proportion of ST-segment elevation myocardial infarction (STEMI) patients without standard modifiable risk factors (SMuRFs: hypertension, diabetes, hypercholesterolemia and smoking) has increased over time. The absence of SMuRFs is known to be associated with worse outcomes, but its association with age and sex is uncertain. We sought to evaluate the association between age and sex with the outcomes of post-STEMI patients without SMuRFs among patients without preexisting coronary artery disease. Methods: Patients who underwent primary PCI for STEMI were identified from the Nationwide Readmission Database of the United States. Clinical characteristics, in-hospital, and 30-day outcomes in patients with or without SMuRFs were compared in men versus women and stratified into five age groups. Results: Between January 2010 and November 2014, of 474,234 patients who underwent primary PCI for STEMI, 52,242 (11.0%) patients did not have SMuRFs. Patients without SMuRFs had higher in-hospital mortality rates than those with SMuRFs. Among those without SMuRFs, the in-hospital mortality rate was significantly higher in women than men (10.6% vs 7.3%, p<0.001), particularly in older age groups. The absence of SMuRFs was associated with higher 30-day readmission-related mortality rates (0.5% vs 0.3% with SMuRFs, p<0.001). Among patients without SMuRFs, women had a higher 30-day readmission-related mortality rates than men (0.6% vs 0.4%, p<0.001). After multivariable adjustment, the increased rates of in-hospital (odds ratio 1.89 (95% CI 1.72 to 2.07) and 30-day readmission-related mortality (hazard ratio 1.30 (95% CI 1.01 to 1.67)) in patients without SMuRFs remained significant. Conclusions: STEMI patients without SMuRFs have a significantly higher risk of in-hospital and 30-day mortality than those with SMuRFs. Women and older patients without SMuRFs experienced significantly higher in-hospital and 30-day readmission-related mortality.

Update on cardiac sarcoidosis.

Cardiac sarcoidosis is an inflammatory myocardial disease of unknown etiology. It is characterized by the deposition of non-caseating granulomas that may involve any part of the heart. Cardiac sarcoidosis is often under-diagnosed or recognized partly due to the heterogeneous clinical presentation of the disease. The three most frequent clinical manifestations of cardiac sarcoidosis are atrioventricular block, ventricular arrhythmias, and heart failure. A definitive diagnosis of cardiac sarcoidosis can be made with histology findings from an endomyocardial biopsy. However, the diagnosis in the majority of cases is based on findings from the clinical presentation and advanced imaging due to the low sensitivity of endomyocardial biopsy. The Heart Rhythm Society (HRS) 2014 expert consensus statement and the Japanese Ministry of Health and Welfare criteria are the two most commonly used diagnostic criteria sets. This review article summarizes the available evidence on cardiac sarcoidosis, focusing on the diagnostic criteria and stepwise approach to its management.

Post-operative atrial fibrillation and risk of heart failure hospitalization.

AIMS: Post-operative atrial fibrillation (POAF) is associated with stroke and mortality. It is unknown if POAF is associated with subsequent heart failure (HF) hospitalization. This study aims to examine the association between POAF and incident HF hospitalization among patients undergoing cardiac and non-cardiac surgeries. METHODS AND RESULTS: A retrospective cohort study was conducted using all-payer administrative claims data that included all non-federal emergency department visits and acute care hospitalizations across 11 states in the USA. The study population included adults aged at least 18 years hospitalized for surgery without a prior diagnosis of HF. Cox proportional hazards regression models were used to examine the association between POAF and incident HF hospitalization after making adjustment for socio-demographics and comorbid conditions. Among 76 536 patients who underwent cardiac surgery, 14 365 (18.8%) developed incident POAF. In an adjusted Cox model, POAF was associated with incident HF hospitalization [hazard ratio (HR) 1.33; 95% confidence interval (CI) 1.25-1.41]. In a sensitivity analysis excluding HF within 1 year of surgery, POAF remained associated with incident HF hospitalization (HR 1.15; 95% CI 1.01-1.31). Among 2 929 854 patients who underwent non-cardiac surgery, 23 763 (0.8%) developed incident POAF. In an adjusted Cox model, POAF was again associated with incident HF hospitalization (HR 2.02; 95% CI 1.94-2.10), including in a sensitivity analysis excluding HF within 1 year of surgery (HR 1.49; 95% CI 1.38-1.61). CONCLUSIONS: Post-operative atrial fibrillation is associated with incident HF hospitalization among patients without prior history of HF undergoing both cardiac and non-cardiac surgeries. These findings reinforce the adverse prognostic impact of POAF and suggest that POAF may be a marker for identifying patients with subclinical HF and those at elevated risk for HF.

Constitutively Activating GNAS Somatic Mutation in Right Ventricular Outflow Tract Tachycardia.

[Figure: see text].

Characteristics and Outcomes of Patients Admitted With Type 2 Myocardial Infarction.

Type 2 myocardial infarction (Type 2 MI) is a common problem and carries a high diagnostic uncertainty. Large studies exploring outcomes in type 2 MI are lacking. Nationwide Readmission Database (2017) was queried using the International Classification of Diseases codes (ICD-10-CM) to identify type 2 MI patients. Characteristics, in-hospital outcomes, 30-day readmissions, and predictors of in-hospital mortality as well as 30-day readmissions were explored. We identified 21,738 patients with a diagnosis of type 2 MI. Most common primary diagnosis at presentation included infection/sepsis (27.5%), hypertensive heart disease (15.3%) and pulmonary diseases (8.5%). Overall, in-hospital mortality and 30-day readmission for patients with type 2 MI were 9.0% and 19.1% respectively. On multivariable analysis, significant predictors of increased in-hospital mortality included male gender, coexisting atrial fibrillation/flutter, peripheral vascular disease, coagulopathy, malignancy, and fluid/electrolyte abnormalities. Significant predictors of 30-day readmission were coexisting diabetes mellitus, atrial fibrillation/ flutter, carotid artery stenosis, anemia, COPD, CKD and prior history of myocardial infarction, A primary diagnosis of sepsis, pulmonary issues including respiratory failure, neurological conditions including stroke carried highest risk of mortality however readmission risk was not influenced by primary diagnosis at presentation. In conclusion, approximately 1 in 10 patients admitted for type 2 MI died during admission, and nearly 1 in 5 patients were readmitted at 30 days after discharge. In-hospital mortality varied based on associated primary diagnosis at presentation. Proposed predictive model for mortality and 30-day readmission in our study can help to target high risk patients for post-Type 2 MI care.

Thirty-Day Readmission Rates after Takotsubo Syndrome with or without Malignancy: A Nationwide Readmissions Database Analysis.

The association between malignancy and readmission after Takotsubo syndrome (TTS) hospitalization has not been fully described. We sought to examine the rates, cause, and cost of 30-day readmissions of TTS, with or without malignancy, by utilizing Nationwide Readmissions Databases from 2010 to 2014. We identified 61,588 index hospitalizations for TTS. TTS patients with malignancy tended to be older (70.6 ± 0.2 vs. 66.1 ± 0.1, p < 0.001), and the overall burden of comorbidities was higher than in those without malignancy. TTS patients with malignancy had significantly higher 30-day readmission rates than those without malignancy (15.9% vs. 11.0%; odds ratio (OR), 1.35; 95% confidence interval (CI), 1.18-1.56). Non-cardiac causes were the most common causes of readmission for TTS patients with malignancy versus without malignancy (75.5% vs. 68.1%, p < 0.001). The 30-day readmission rate due to recurrent TTS was very low in both groups (0.4% and 0.5%; p = 0.47). The total costs were higher by 25% (p < 0.001) in TTS patients with vs. without malignancy. In summary, among patients hospitalized with TTS, the presence of malignancy was associated with increased risk of 30-day readmission and increased costs. These findings highlight the importance of optimized management for TTS patients with malignancy.

Sex-Based Differences in Revascularization and 30-Day Readmission After ST-Segment-Elevation Myocardial Infarction in the United States.

BACKGROUND: Cardiovascular disease is the leading cause of death for women in the United States. Revascularization is considered the standard of care for treatment of ST-segment elevation myocardial infarction (STEMI) and is known to reduce readmission. However there is a paucity of data that examines the sex-dependent impact of revascularization on readmission. We aimed to investigate sex differences in revascularization rates, 30-day readmission rates, and primary cause of readmissions following STEMIs. METHODS: STEMI hospitalizations were selected in the Nationwide Readmissions Database from 2010 to 2014. Revascularization rates, 30-day readmission rates, and primary cause of readmission were examined. Interaction between sex and revascularization was assessed. Multivariable regression analysis was performed to identify predictors of 30-day readmission and revascularization for both sexes. RESULTS: 219,944 women and 489,605 men were admitted with STEMIs. Women were more likely to be older, and have more comorbidities. Women were less likely to undergo revascularization by percutaneous coronary intervention (adjusted odds ratio [OR]: 0.68; 95% confidence interval [CI]: 0.66-0.70) or coronary artery bypass graft surgery (adjusted OR 0.40; CI 0.39-0.44). Women had higher 30-day readmission rates (15.7% vs. 10.8%, p < 0.001; OR 1.20, CI 1.17-1.23), and revascularization in women was not associated with a decreased likelihood of 30-day readmission. The primary cardiac cause of readmission in women was heart failure. CONCLUSION: Compared to men, women with STEMIs had lower rates of revascularization and higher rates of 30-day readmission. When revascularized, women were still more likely to be readmitted as compared to non-revascularized women.

Modeling polymorphic ventricular tachycardia at rest using patient-specific induced pluripotent stem cell-derived cardiomyocytes.

BACKGROUND: While mutations in the cardiac type 2 ryanodine receptor (RyR2) have been linked to exercise-induced or catecholaminergic polymorphic ventricular tachycardia (CPVT), its association with polymorphic ventricular tachycardia (PMVT) occurring at rest is unclear. We aimed at constructing a patient-specific human-induced pluripotent stem cell (hiPSC) model of PMVT occurring at rest linked to a single point mutation in RyR2. METHODS: Blood samples were obtained from a patient with PMVT at rest due to a heterozygous RyR2-H29D mutation. Patient-specific hiPSCs were generated from the blood samples, and the hiPSC-derived cardiomyocytes (CMs) were generated via directed differentiation. Using CRIPSR/Cas9 technology, isogenic controls were generated by correcting the RyR2-H29D mutation. Using patch-clamp, fluorescent confocal microscopy and video-image-based analysis, the molecular and functional properties of RyR2-H29D hiPSCCMs and control hiPSCCMs were compared. FINDINGS: RyR2-H29D hiPSCCMs exhibit intracellular sarcoplasmic reticulum (SR) Ca2+ leak through RyR2 under physiological pacing. RyR2-H29D enhances the contribution of inositol 1,4,5-trisphosphate receptors to excitation-contraction coupling (ECC) that exacerbates abnormal Ca2+ release in RyR2-H29D hiPSCCMs. RyR2-H29D hiPSCCMs exhibit shorter action potentials, delayed afterdepolarizations, arrhythmias and aberrant contractile properties compared to isogenic controls. The RyR2-H29D mutation causes post-translational remodeling that is fully reversed with isogenic controls. INTERPRETATION: To conclude, in a model based on a RyR2 point mutation that is associated with short-coupled PMVT at rest, RyR2-H29D hiPSCCMs exhibited aberrant intracellular Ca2+ homeostasis, shortened action potentials, arrhythmias and abnormal contractile properties. FUNDING: French Muscular Dystrophy Association (AFM; project 16,073, MNM2 2012 and 20,225), "Fondation de la Recherche Médicale" (FRM; SPF20130526710), "Institut National pour la Santé et la Recherche Médicale" (INSERM), National Institutes of Health (ARM; R01 HL145473) and New York State Department of Health (NYSTEM C029156).

Robotics for catheter ablation of cardiac arrhythmias: Current technologies and practical approaches.

Robotic technology has emerged as an important tool to facilitate catheter ablation of arrhythmias. Robotic cardiac electrophysiology technology includes remote magnetic navigation and manual robotic navigation. Robotics can confer advantages with respect to ease of catheter manipulation in anatomically challenging spaces, minimization of fluoroscopic exposure to both patients and operators, and reduction in operator fatigue. This review provides a comprehensive summary of robotic electrophysiology technology, its practical applications and its safety and efficacy for targeting cardiac arrhythmias.

Regional isolation in the right atrium with disruption of intra-atrial conduction after catheter ablation of atrial tachycardia.

BACKGROUND: Ablation of atrial tachycardia (AT) that occurs after cardiac surgery or prior ablation often requires complex lesion sets. In combination with the pre-existing atrial scar, these lesion sets may result in inadvertent intra-atrial conduction block. This study reports the phenomenon of incidental isolation of right atrial (RA) regions that occurs secondary to AT ablation, which in some cases results in profound bradycardia due to sinus exit block. METHODS AND RESULTS: Intracardiac electrograms were examined in consecutive patients who underwent AT ablation in the RA. Cases of localized isolation of the RA were defined as areas that developed electrical dissociation during ablation. Of 132 patients having ablation in both the RA free wall and the cavotricuspid isthmus (CTI), 10 (7.6%) developed unintentional isolation of the lateral RA. Five of these patients had prior mitral valve surgery, comprising 12.2% of all 41 patients with mitral surgery who underwent ablation in the CTI and the RA free wall. All patients with regional isolation had a pre-existing scar in the lateral wall of the RA. In six patients, isolation of the lateral RA resulted in profound bradycardia due to exit block from the peri-sinus node myocardium. CONCLUSIONS: Complex ablation lesions in patients with prior valve surgery, prior ablation, or atrial myopathy may result in unintended localized conduction block in the RA. In some cases, isolation of the lateral RA can result in complete sinus exit block with profound bradycardia requiring pacemaker implantation.

Outcomes, Costs, and 30-Day Readmissions After Catheter Ablation of Myocardial Infarct-Associated Ventricular Tachycardia in the Real World: Nationwide Readmissions Database 2010 to 2015.

BACKGROUND: Patients undergoing catheter ablation of myocardial infarction-associated ventricular tachycardia (VT) have significant comorbidities that can increase the risks of adverse outcomes. The rates of readmissions after VT ablation are unknown. We sought to examine in-hospital outcomes, costs, and 30-day readmissions after catheter ablation of myocardial infarction-associated VT. METHODS: Using the Nationwide Readmissions Database, we evaluated 4109 admissions for catheter ablation of myocardial infarction-associated VT occurring between 2010 and 2015. On the basis of International Classification of Diseases, Ninth Revision, Clinical Modification and Clinical Classification Software codes, we identified comorbidities, procedural complications, 30-day readmissions, and costs associated with VT ablation. RESULTS: The index admission in-hospital mortality rate and procedural complication rate after VT ablation were 2.7% and 11.5%, respectively. Independent predictors of mortality included pulmonary hypertension, lung disease, obesity, and coagulopathy. Following discharge after VT ablation, the 30-day readmission rate was 19.2% with a median time to readmission of 10.0 days (IQR, 3.8-17.6 days) and an in-hospital mortality rate of 2.9%. Cardiac causes accounted for 74% of readmissions, with VT and congestive heart failure constituting 41% and 14% of all readmissions, respectively. Pulmonary hypertension, congestive heart failure, smoking, chronic pulmonary disease, and prolonged index hospitalization were significant independent predictors of 30-day readmission. After adjustment, 30-day readmissions were associated with a 38.9% increase in cumulative hospitalization costs. CONCLUSIONS: Thirty-day readmissions after catheter ablation of VT occur in nearly 1 out of 5 cases, with the majority of readmissions being caused by recurrent VT or congestive heart failure. Baseline comorbidities are significant predictors of procedural mortality, complications, and readmissions. Strategies to reduce recurrent VT postablation by improving procedural success, optimizing postablation heart failure treatment, and ensuring close postdischarge follow-up may help reduce readmissions and healthcare costs.