Iyengar, Shruti Krishna

Background: Cardiac sarcoidosis (CS) is a rare condition marked by conduction disturbances, and ventricular tachycardia (VT) resulting from reentrant pathways. VT ablation is typically considered for patients with refractory VT. This systematic review aims to synthesize reported outcomes and identify potential predictors for the success of VT ablation in CS patients. Methods: A systematic literature review was conducted following the PRISMA guidelines, searching PubMed, Cochrane, Embase, and Scopus databases up to May 2024. A random-effects model was used to evaluate electrophysiologic and procedural variables and compare outcomes to identify potential predictors of success. Results: After excluding duplicates, 473 titles and abstracts were screened. Twenty-five studies were fully reviewed, and 9 studies comprising data from 311 CS patients who underwent VT ablation were included. The mean age of patients was 50.5 years, with 30% being female. Epicardial mapping was performed in 29% (CI 22-36%; 72/251) of cases, and 96% (CI 77-100%; 65/72) of those underwent epicardial ablation. The prevalence of VT storm before the procedure was 28% (CI 16-42%; 89/259), with a suppression success rate of 84% (CI 73-93%; 64/76). The acute complete success rate defined as lack of inducibility was 58% (CI 49-66%; 174/307). During follow-up, which ranged from 19 to 58 months, 34% (CI 21-48%; 113/271) of patients survived free from the composite outcome of death, transplantation, or VT recurrence. Patients with acute success had fewer inducible VTs (MD –1.1; CI: -1.8 to -0.5; p < 0.001). No other variables were significantly associated with acute success. However, patients with acute success tended to be older than those with partial or unsuccessful outcomes (MD 7.5; CI: -0.2 to 15.1; p = 0.055). Conclusion: VT ablation in patients with CS shows acceptable acute success rates. Patients presenting with VT storm have a high rate of arrhythmia acute suppression. A lower number of inducible VTs is associated with higher acute success rates. Despite these results, the prognosis remains poor, with a significant proportion of patients experiencing disease recurrence, death, or requiring heart transplantation.

Introduction: Pulmonary Vein Isolation (PVI) has become the cornerstone during ablation of Atrial Fibrillation. The primary goal of the procedure is to prevent potential arrhythmogenic triggers from accessing the main left atrial substrate. However, incomplete fibrosis leading to PV reconnection has been identified as the primary reason for AF recurrence. It is unclear whether immediate voltage mapping and additional lesions delivered to areas of residual or recovered voltages will improve the outcome. This study evaluates the 1-year success and long-term recurrence-free survival in patients who underwent post-procedure voltage mapping (PPVM) to identify residual Low-Voltage Areas (LVAs) to guide the delivery of additional ablation lesions. Methods: We analyzed 588 patients who underwent PVI from 2015 to 2023. Of these, 243 had PPVM done to determine LVAs and guide additional ablation lesions. The control arm comprised 345 patients who underwent PVI by the same operators without PPVM. The primary endpoints were 1-year success and longer-term recurrence-free survival. Secondary endpoints were the incidence of complications and the prevalence of LVAs in patients who underwent PPVM. Results: Patients who underwent remapping were older than the control arm (68.3 vs 65.6 years, p = 0.005). There were no other significant differences in baseline characteristics between the two groups. At 1-year follow-up, the success rates were 79% in the treatment arm compared to 72% in the control arm (p = 0.038). Patients in the intervention arm had a recurrence-free survival rate of 65% and 54% at 2 and 4 years, respectively, compared to 62% and 43% in the control arm (p = 0.044). The prevalence of LVAs in the treatment arm was 56.8%. Additionally, complication rates were not increased in the remapping arm (3% vs 8%, p = 0.012). Conclusion: PPVM-guided incremental ablation lesions improve the 1-year success rate and recurrence-free survival at 2 and 4 years compared to traditional PVI without increasing complications due to additional lesion delivery.

The landscape of cardiac pacemaker technology has undergone significant evolution over the last two decades, transitioning from simple single-chamber devices to sophisticated multi-chamber rate-responsive systems and cardioverter defibrillators. This progression has introduced a complex array of complications inherent to device implantation and operation, encompassing both mechanical and clinical challenges. These complications notably include lead dislodgment, device migration, venous thrombosis, and hemothorax, which not only affect patient outcomes but also impose substantial economic burdens. This review meticulously analyzes these complications, elucidating their mechanisms, clinical implications, and the economic consequences associated with their management. It also outlines current and emerging strategies aimed at mitigating these complications, emphasizing the need for continual updates in clinical practices and protocols. Through this discourse, the review seeks to equip clinicians with a comprehensive understanding of these complications, thereby enhancing the safety and efficacy of cardiac pacing interventions.

Despite advances in ablative therapies, outcomes remain less favorable for persistent atrial fibrillation often due to presence of non-pulmonary vein triggers and abnormal atrial substrates. This review highlights advances in ablation technologies and notable scientific literature on clinical outcomes associated with pursuing adjunctive ablation targets and substrate modification during persistent atrial fibrillation ablation, while also highlighting notable future directions.

Background: Fasciculoventricular pathway (FVP) is a rare form of preexcitation without known clinical tachycardia. As it is connected to the His bundle, they conduct whenever it is engaged. Conduction through the His Bundle but block at FVP has not been reported. Case presentation: We present a case of a 42-year-old male with a history of Wolff-Parkinson-White syndrome (WPWS), supraventricular tachycardia (SVT), syncope, embolic stroke, paroxysmal atrial fibrillation, hypertension, hypothyroidism, Sjogren's syndrome and prior unsuccessful attempts at elimination of the preexcitation. He underwent electrophysiology (EP) study for presumed SVT ablation. The EP study identified an FVP as the cause of preexcitation, and the planned accessory pathway ablation was deemed unnecessary. Atrial tachycardia originating from the right superior pulmonary vein (PV) was induced, eventually degenerating into atrial fibrillation, and the patient successfully underwent pulmonary vein isolation with the resolution of symptoms. Discussion: FVP is usually an incidental finding when patients with symptomatic preexcitation are studied. If tachycardia is induced, it is unrelated to the preexcitation. The FVP is connected to the His bundle and invariably conducts if the impulse engages the His Bundle. We are unaware of a case when the His bundle conducts, but the impulse loses preexcitation due to a block in the FVP. This unusual finding was noted in our case. To further confirm the location of the accessory pathway, IV adenosine was given with a complete heart block suggesting the preexcitation is beyond the level of the AV node and within the conduction system. It is not at the annulus with independent atrial and ventricular insertion, typical of an accessory pathway. Conclusions: This case demonstrates an FV pathway's unusual conduction block and physiological characteristics.