Srivathsan, Komandoor

ABSTRACT Introduction Atrial fibrillation (AF) is the most common arrhythmia, and atrioventricular (AV) node ablation with pacemaker implantation is a therapeutic option for refractory cases. However, AV node ablation in patients with bioprosthetic tricuspid valves poses technical challenges. Methods An 84‐year‐old male with an EVOQUE transcatheter tricuspid valve replacement underwent AV node ablation (AVNA) under intracardiac echocardiography (ICE) guidance. Results Successful AV block was achieved with precise catheter positioning, improving the patient's symptoms and ventricular rate control. Conclusion This case demonstrates the feasibility of AVNA in patients with tricuspid bioprostheses, demonstrating feasibility with ICE guidance.

Abstract Aims Atrial fibrillation (AF) is the most common cardiac arrhythmia. Although lipoprotein(a) [Lp(a)] is known to be a well-established risk factor for atherosclerotic cardiovascular disease, its role in the development of AF, independent of this association, remains unclear. Methods and results Adult patients from the three Mayo Clinic sites with a baseline Lp(a) and without AF history were included. Patients were categorized into two groups based on their Lp(a) levels: high Lp(a) (≥50 mg/dL) and low Lp(a) (<50 mg/dL). Survival probabilities free from incident AF were compared between Lp(a) groups, during a follow-up period up to 15 years, using the Kaplan–Meier curve and the log-rank test. Multivariable Cox regression analysis was also conducted. A total of 75 376 patients were included (median age: 55 years, 59% males), with a median follow-up duration of 8.8 (inter-quartile range: 3.4, 14.8) years. Incident AF was detected in 5738 (7.6%) patients. Survival probability free from incident AF was significantly lower in patients with elevated Lp(a) (86%) compared with those with low Lp(a) (88%, log-rank P < 0.001). Multivariable analysis adjusted for potential risk factors of AF showed a statistically significant association of elevated Lp(a) with an 11% increase in AF risk (adjusted hazard ratio: 1.11, 95% confidence interval: 1.05–1.18). Conclusion Our study suggests that elevated Lp(a) (≥50 mg/dL) is an independent risk factor for incident AF. Future prospective studies are warranted to validate our results and to test if reducing Lp(a) could mitigate the burden of AF.

This is the first reported case of atrioventricular node ablation (AVNA) in a patient with an EVOQUE transcatheter tricuspid valve, performed for refractory atrial fibrillation with uncontrolled ventricular rates. This case highlights the feasibility and importance of advanced imaging techniques in managing arrhythmias in patients with bioprosthetic valves, offering insights into expanding therapeutic options for complex cardiovascular conditions.

Ebstein’s anomaly (EA) is a rare cyanotic form of congenital heart disease (CHD) characterized by apical displacement of the tricuspid valve, with resultant hemodynamic and electrical manifestations. The severity of symptoms is determined by the degree of apical displacement and deformity and incompetence of the tricuspid valve. As a result, patients with EA can be severely symptomatic during infancy and childhood or can be incidentally discovered in the sixth or seventh decade of life. Hallmarks of Ebstein’s anomaly include progressive cyanosis, right-sided heart failure, and tachyarrhythmias, among which tachyarrhythmias (most commonly atrial, but also ventricular) are the most common presenting symptoms in Ebstein’s anomaly patients during adulthood. This review aims to provide insight into the genetic and electrophysiological (EP) basis underlying the tachyarrhythmias encountered when managing patients with EA.

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.

AbstractIntroductionVentricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years.MethodsWe performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006 to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed.ResultsA total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5–297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545 (IQR 152–1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator (ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES (hazards ratio [HR]: 1.92, 95% CI: 1.39–2.64, p < .001).ConclusionFollowing LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre‐implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Abstract Background Long‐term outcomes of sterile lead management strategies of lead abandonment (LA) or transvenous lead extraction (TLE) remain unclear. Methods We performed a retrospective study of a population residing in southeastern Minnesota with follow‐up at the Mayo Clinic and its health systems. Patients who underwent LA or TLE of sterile leads from January 1, 2000, to January 1, 2011, and had follow‐up for at least 10 years or until their death were included. Results A total of 172 patients were included in the study with 153 patients who underwent LA and 19 who underwent TLE for sterile leads. Indications for subsequent lead extraction arose in 9.1% ( n = 14) of patients with initial LA and 5.3% ( n = 1) in patients with initial TLE, after an average of 7 years. Moreover, 28.6% of patients in the LA cohort who required subsequent extraction did not proceed with the extraction, and among those who proceeded, 60% had clinical success and 40% had a clinical failure. Subsequent device upgrades or revisions were performed in 18.3% of patients in the LA group and 31.6% in the TLE group, with no significant differences in procedural challenges (5.2% vs. 5.3%). There was no difference in 10‐year survival probability among the LA group and the TLE group ( p = .64). Conclusion An initial lead abandonment strategy was associated with more complicated subsequent extraction procedures compared to patients with an initial transvenous lead extraction strategy. However, there was no difference in 10‐year survival probability between both lead management approaches.

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.