Pacing-associated cardiomyopathy in adult congenital heart disease

Long Term Efficacy and Safety of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease Patients: A Single Center Cohort Study

Heart failure constitutes a major cause for morbidity amongst patients with adult congenital heart disease (ACHD). Cardiac resynchronization therapy (CRT) is a recommended therapeutic measure for patients with heart failure. Data on the efficacy and safety of CRT amongst patients with ACHD is limited. This study analyzed data from a retrospective cohort of patients with ACHD and implantation of CRT between 2015 and 2022. The primary outcome was echocardiographic response to CRT, defined as either: (1) an increase in systemic ventricular ejection fraction (EF) of ≥ 5% in patients with baseline EF <50% (therapeutic efficacy) or (2) maintenance of EF in patients with EF ≥ 50% (preventative efficacy). The outcomes were assessed by subgroups of systemic left or right ventricle ventricle. In a cohort of 45 patients, mean age was 54 ± 14 years, 26 patients had a systemic left ventricle (57.8%) and 19 patients had a systemic right ventricle (42.2%). The average follow-up was 5.2 ± 0.5 years. Primary outcome amongst patients with reduced EF at baseline was achieved in 69.0%; and in 92.3% amongst patients with preserved EF at baseline. There was no significant difference in the response to CRT as per systemic left or right ventricle (p = 0.15) or per baseline EF (p = 0.10). Complications occurred in 28.9% of patients. In conclusion, CRT appears to be effective in patients with ACHD in reducing rates of heart failure, regardless of baseline EF or systemic ventricle morphology. The percentage of patients with a safety outcome was relatively high and highlights the need for careful patient selection.

Cardiovascular imaging in children with cardiac implantable electronic devices

The number of children with cardiac implantable electronic devices (CIEDs) is increasing at a time of rapid growth in cardiac magnetic resonance (MR) and cardiac computed tomography (CT) utilization. The presence of CIEDs poses challenges with respect to imaging safety and quality. A thoughtful approach to cardiovascular imaging in patients with CIEDs begins with an awareness of the clinical indications to determine the most appropriate imaging modality. Understanding device characteristics allows one to ensure that the proper safety measures are taken before and during cardiac MR and cardiac CT examinations. Despite the propensity of CIEDs to cause image artifact, several techniques are available to counteract these artifacts and preserve imaging quality.

Interventional Cardiac Electrophysiology for the Management of Adults With Congenital Heart Disease

Congenital heart disease (CHD) is the most common congenital anomaly in newborns. Advances in catheter and surgical techniques led to the majority of these patients surviving into adulthood, leading to evolving challenges due to the emergence of long-term complications such as arrhythmias. Interventional electrophysiology (EP) has had remarkable advances over the last few decades, and various techniques and devices have been explored to treat adult patients with CHD. This comprehensive review aims to summarize findings from recent studies exploring advances in the use of interventional electrophysiology to manage adult patients with CHD. While pacemaker therapy has some indications in adults with CHD, various long-term consequences include pacing-induced cardiomyopathy and complications requiring reintervention. Cardiac resynchronization therapy has shown promising results in some studies to treat CHD patients with heart failure, although further research to clarify guidelines is encouraged. Implantable cardiac defibrillators have demonstrated clear benefits in CHD patients and are indicated for primary prevention of sudden cardiac death, although selection criteria for secondary prevention of sudden cardiac death are uncertain. Catheter ablation has also been used for various atrial and ventricular arrhythmias in patients with CHD with high success rates, although the likelihood of success depends on patient characteristics and the type of arrhythmia, and multidisciplinary assessment is encouraged to improve the chance of successful therapy.

Conduction System Pacing in Children and Congenital Heart Disease

Permanent cardiac pacing in children with congenital complete atrioventricular block (CCAVB) and/or congenital heart disease (CHD) is challenging. Conduction system pacing (CSP) represents a novel pacing strategy aiming to preserve physiological ventricular activation. Patients with CCAVB or CHD are at high risk of developing pacing-induced cardiomyopathy with chronic conventional right ventricular myocardial pacing. CSP may be a valuable pacing modality in this particular setting because it can preserve ventricular synchrony. In this review, we summarise implantation techniques, the available clinical evidence and future directions related to CSP in CCAVB and CHD.

Updates in Arrhythmia Management in Adult Congenital Heart Disease

Arrhythmias are highly prevalent in adults with congenital heart disease. For the clinician caring for this population, an understanding of pathophysiology, diagnosis, and management of arrhythmia is essential. Herein we review the latest updates in diagnostics and treatment of tachyarrhythmias and bradyarrhythmias, all in the context of congenital anatomy, hemodynamics, and standard invasive palliations for congenital heart disease.

Medical Therapy for Heart Failure in Adult Congenital Heart Disease Patients

There is an increasing recognition of heart failure among adults with congenital heart disease as a result of the advancements in medical, interventional, and surgical care. The long-term consequences of palliative therapy in infancy, childhood, and adulthood are incompletely understood. Medical therapy, including pharmacologic and device therapies, have been used for the treatment of heart failure. This review summarizes care strategies that have been applied within the spectrum of adults with congenital heart disease, including failing systemic ventricles, single ventricles, and Eisenmenger physiology.

Arrhythmias in Adult Congenital Heart Disease Heart Failure

Heart failure and arrhythmias represent 2 major causes of mortality and morbidity in adults with congenital heart disease. Arrhythmias and heart failure are interdependent, and one may exacerbate the other. Treatment of one also has a positive impact on the other. Management approaches need to be multifaceted, including pharmacotherapy, optimization of hemodynamic status with catheter-based or surgical interventions, and specific management of arrhythmia with device or catheter ablation therapy.

Heart failure in systemic right ventricle: Mechanisms and therapeutic options

d-loop transposition of the great arteries (d-TGA) and congenitally corrected transposition of the great arteries (cc-TGA) feature a right ventricle attempting to sustain the systemic circulation. A systemic right ventricle (sRV) cannot support cardiac output in the long run, eventually decompensating and causing heart failure. The burden of d-TGA patients with previous atrial switch repair and cc-TGA patients with heart failure will only increase in the coming years due to the aging adult congenital heart disease population and improvements in the management of advanced heart failure. Clinical data still lags behind in developing evidence-based guidelines for risk stratification and management of sRV patients, and clinical trials for heart failure in these patients are underrepresented. Recent studies have provided foundational data for the commencement of robust clinical trials in d-TGA and cc-TGA patients. Further insights into the multifactorial nature of sRV failure can only be provided by the results of such studies. This review discusses the mechanisms of heart failure in sRV patients with biventricular circulation and how these mediators may be targeted clinically to alleviate sRV failure.

Left Bundle Area Pacing for Tachycardia-Bradycardia Syndrome in a Patient With Dextrocardia

We present the case of an 81-year-old woman with a background of situs inversus with dextrocardia who was successfully treated for tachycardia-bradycardia syndrome with left bundle area pacing. This report describes how this approach can circumvent the limitations of other pacing approaches to optimize patient outcomes. (Level of Difficulty: Intermediate.)

Impact and Modifiers of Ventricular Pacing in Patients With Single Ventricle Circulation

BACKGROUND

Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPM_v) may be associated with additional adverse long-term outcomes.

OBJECTIVES

The goal of this study was to quantify the attributable risk of PPM_v in patients with SV, and to identify modifiable risk factors.

METHODS

This international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPM_v. Enrollment was at implantation. Controls were matched 1:1 to PPM_v subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death.

RESULTS

In total, 236 PPM_v subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPM_v cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPM_v was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPM_v population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation.

CONCLUSIONS

PPM_v in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPM_v cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors.

Atrioventricular Block Necessitating Chronic Ventricular Pacing After Tricuspid Valve Surgery in Patients With a Systemic Right Ventricle: Long-Term Follow-Up

Background

Patients with transposition of the great arteries (TGA) after an atrial switch or congenitally corrected TGA (ccTGA) are prone to systemic right ventricular (sRV) failure. Tricuspid valve (TV) regurgitation aggravates sRV dysfunction. Timely TV surgery stabilizes sRV function, yet the development of atrioventricular (AV)-conduction disturbances in the course of sRV failure can contribute to sRV dysfunction through pacing-induced dyssynchrony. This study aims to explore the incidence, timing, and functional consequences of AV-block requiring ventricular pacing after TV surgery in patients with sRV.

Methods

Consecutive adolescent and adult patients with an sRV who underwent TV surgery between 1989 and 2020 and followed-up at our center were included in this observational cohort study.

Results

The data of 28 patients (53% female, 57% ccTGA, and a mean age at surgery 38 ± 13 years) were analyzed. The mean follow-up was 9.7 ± 6.8 years. Of the remaining 22 patients at the risk of developing high degree AV-block after TV surgery, 9 (41%) developed an indication for chronic ventricular pacing during follow-up, of which 5 (56%) within 24 months postoperatively (3 prior to hospital discharge). The QRS duration, a surrogate marker for dyssynchrony, was significantly higher in patients with chronic left ventricular pacing than in patients with native AV-conduction (217 ± 24 vs. 116 ± 23 ms, p = 0.000), as was the heart failure biomarker NT-pro-BNP [2,746 (1,242-6,879) vs. 495 (355-690) ng/L, p = 0.004] and the percentage of patients with ≥1 echocardiographic class of deterioration of systolic sRV function (27 vs. 83%, p = 0.001). Of the patients receiving chronic subpulmonary ventricular pacing (n = 12), 9 (75%) reached the composite endpoint of progressive heart failure [death, ventricular assist device implantation, or upgrade to cardiac resynchronization therapy (CRT)]. Only 4 (31%) patients with native AV-conduction (n = 13) reached this composite endpoint (p = 0.027).

Conclusion

Patients with a failing sRV who undergo TV surgery are prone to develop AV-conduction abnormalities, with 41% developing an indication for chronic ventricular pacing during 10 years of follow-up. Patients with chronic subpulmonary ventricular pacing have a significantly longer QRS complex duration, have higher levels of the heart failure biomarker NT-pro-BNP, and are at a higher risk of deterioration of systolic sRV function and progressive heart failure.