Cheema, Kamal Preet P

Background: We aimed to evaluate the outcomes of patients with confirmed and possible cardiac sarcoidosis who had an ICD implant and identify predictors of ventricular arrhythmias and mortality in this patient population. Methods: We performed a retrospective study patients with a diagnosis of cardiac sarcoidosis (CS) at Mayo Clinic and had an ICD implanted for primary or secondary prevention indication. Adult patients (≥18 years) with a diagnosis of possible or confirmed (biopsy-proven) CS with an ICD implanted between 1993 and 2022 were included. Primary outcomes included sustained ventricular arrhythmia (VT) resulting in a documented appropriate ICD shock and death from any cause. Secondary outcomes included ICD-related complications. Results: We identified 148 patients, in which 23 patients (15.5%) experienced VT events with a total of 160 treated episodes. 4 patients (2.7%) experienced inappropriate ICD shocks (11 episodes). During a median follow up of 3.1 years, 26 patients deceased, and the overall survival was 98% and 77% at 1 and 5 year. Older age, CAD, CKD, paced rhythm and QRS duration were associated with worse survival (Figure 1 – 4) . Device related complications were rare, except for the higher percentage of CHF in patients with VT after implant, however this was not statistically significant. Patients with ICD therapies were younger (53 vs 58 years, p=0.029), had higher LGE burden (26.9 vs 16.3%, p=0.01), and higher percentage of LV mass (26.9 vs 16.3, p=0.011). Multivariate logistic regression model which showed that patients with biopsy proven sarcoidosis had significantly higher odds of VT events (OR: 3.04, 95% CI: 1.02 to 9.08, p = 0.046). In patients with increased LV mass (every 10 g increase), the odds of developing VT increased by 1.49 (95% CI: 1.02 to 2.19, p = 0.041). LV mass and LGE percentage showed fair ability of predicting the outcome by ROC analysis. Youden’s index showed 26 for LV mass and 16% for LGE percent as the optimal cut-off points for predicting VT outcomes (Figure 5) . The sensitivity, specificity, positive predictive value, negative predictive value were 81.8%, 74.1%, 37.5%, 95.6% and 75.4% respectively for an LV mass of 26 grams and 81.8%, 63.8%, 30.0%, 94.9% and 66.7% respectively for an LGE percentage of 16%. Conclusion: LGE burden continues to be a major predictor for VT events in patients with CS. Myocardial tissue burden and electrical abnormalities from CS predict mortality than myocardial function loss.

Introduction: Atrial arrhythmias are common in patients with D-TGA and atrial switch. We sought to analyze the arrhythmia substrate and catheter ablation approaches and outcomes. Methods: We performed a retrospective review of all clinical and procedural data in patients with D-TGA followed at a large tertiary care center. Results: In a cohort of 152 patients (mean age 30±11 years), atrial tachycardia was present in 69(45%) patients. Ablations were performed in 39(26%) patients: macro-reentrant atrial flutter (N=37), atrial fibrillation (N=4), and focal automatic atrial tachycardia (N=3). Detailed electrophysiology study data was available for 34 patients. At first ablation (N=28), cavo-tricuspid isthmus dependent flutter (CTI, 23(82%)) was most common, followed by right atriotomy-related flutter (IART, 16(57%)) and focal atrial tachycardia (FAT, 1(3.5%)). Bidirectional CTI block often required ablation on both sides of the baffle to complete the isthmus line. Access to the pulmonary venous atrium was obtained in 82% of first-time ablations (via retrograde aortic access, 74%, baffle puncture, 6%, or baffle fenestration, 12%) and in 100% of redo procedures. The first ablation was acutely successful in 25 (89%) patients; the other 3 patients had either partial procedural success (1), failed ablation (1), or underwent an empirical ablation (1). Long-term arrhythmia recurrence occurred in 13(46%) after the first ablation and class III antiarrhythmic medications were utilized in 12 patients. At least one long-term recurrence occurred in 11(44%) patients. Importantly, clinical arrhythmia burden was significantly reduced post-ablation, with rare and short-limited episodes amenable to antiarrhythmic drugs or cardioversion. Repeat ablation was required in 3 cases. Long-term arrhythmia recurrence after a previously completed CTI line involved different arrhythmia mechanisms: scar-related reentry (80%) and automatic atrial tachycardia (40%). Conclusions: Atrial arrhythmia in patients with D-TGA often involves the CTI and atriotomy scars. Ablation of the CTI typically requires access to the pulmonary venous atrium to achieve bidirectional block. Despite late recurrence, the clinical arrhythmic burden is substantially improved.

Introduction: Patients with D-TGA palliated with atrial switch operations have the morphologic right ventricle in the systemic position. There is increased risk of atrial arrhythmias and systemic right ventricle (SRV) failure. We sought to analyze the long term outcomes of these patients. Methods: All patients with D-TGA and SRV followed in the Adult Congenital Heart Disease Clinic of a large tertiary care institution were reviewed. A comprehensive retrospective analysis of the medical record was performed, including consult notes, ECGs, echocardiograms and electrophysiology reports. Results: A total of 154 patients (63% male) aged 29±11 years were followed for a mean of 10±9 years (range 0-51). During follow-up, 3 patients underwent cardiac transplantation and 15 died; 5 had sudden death, 2 had cardiogenic shock, 5 had non-cardiac death (i.e., infective endocarditis, sepsis) and 3 had unknown causes of death. Heart failure symptoms were present in 53(34%) patients. Severe SRV systolic dysfunction occurred in 37(24%) patients, with a mean EF of 23±5.5%; moderate SRV dysfunction occurred in 67(44%) patients, mean EF 35±4%. Sinus node dysfunction was present in 75(49%) patients, complete AV block in 9(5%) patients, and a pacemaker placed in 60(39%) patients, with cardiac resynchronization therapy in 5. Atrial arrhythmias occurred in 94(61%) patients and ablations were performed in 47(31%) patients. An ICD was implanted in 37 patients; 5 patients had appropriate shocks, but 7 had inappropriate shocks due to atrial arrhythmias. Age (HR 1.07, p=001), heart failure symptoms (HR 4.9, p= 0.007), severe SRV enlargement (HR 3.7, p=0.03), severe systolic dysfunction (HR 5.4, p=0.003), severe systemic AV valve regurgitation (HR 5.2, p=0.002) and a QRS duration> 122ms (HR 3.7, p=0.02) were significant predictors of mortality. The 15 year probability of sudden death was 3.2%(95% CI 0-6.9%). Conclusions: Atrial arrhythmias are common after atrial switch operations secondary to atriotomy scars. Further studies will need to determine whether restoration of sinus rhythm or cardiac synchrony may prevent further deterioration of the systemic right ventricle. Severe SRV dysfunction and prolonged QRS duration >122ms were significantly correlated with mortality.