Cardiac Arrhythmias in Adults with Congenital Heart Disease: Pacemakers, Implantable Cardiac Defibrillators, and Cardiac Resynchronization Therapy Devices

Single-Chamber and Dual-Chamber Pacemaker Devices in Adults with Moderate and Complex Congenital Heart Disease: A Single Tertiary Referral Center Experience

The number of device implantation procedures has increased in adult patients with congenital heart disease (ACHD). Despite significant improvements in materials and implantation techniques, these patients are exposed to higher risk of device related complications than general population. Herein, we describe our single tertiary referral center experience on transvenous pacemaker (PM) implantation and follow-up in adult patients with moderate and complex congenital heart disease (CHD) as limited data are available on long-term outcome. We considered all adults with moderate and complex CHD aged more than 16 years who underwent transvenous single-chamber and dual-chamber PM implant for sinus node dysfunction or atrioventricular block between January 2013 to December 2022 at our Unit. Seventy-one ACHD patients were included in the study (mean age 38.6 ± 15.2 years, 64% with moderate CHD, 36% with complex CHD). Among 32 patients implanted with a dual chamber PM (DDD PM), 4 devices were reprogrammed in VDD mode, 3 in VVI and 2 in AAI mode during follow-up because of lead dysfunction or permanent atrial arrhythmia. In addition, 26 patients had a single chamber PM (AAI or VVI PM) and 13 patients had single-lead pacing system with a free-floating atrial electrode pair (VDD PM). Just one of 13 single-lead VDD PM was reprogrammed in VVI mode due to a low atrial sensing. In DDD PM group, 10 re-interventions were needed due to lead dysfunction (8 cases) and lead-related infective endocarditis (2 cases). Only 3 patients in the single-lead PM group developed lead dysfunction with 2 re-interventions needed, but no infective endocarditis was reported. The rate of long-term complications is high in moderate and complex ACHD with transvenous PM devices, and it is mainly lead-related. In our experience, the less leads implanted, the less complications will occur. Considering the heterogeneity of the ACHD population, transvenous single-chamber or dual-chamber PM device implantation should always be tailored on the single patient, balancing risks and benefits in this complex population.

Cardiac implantable device outcomes and lead survival in adult congenital heart disease

BACKGROUND

Long-term outcomes of cardiac implantable electronic devices (CIEDs) are ill-defined in adult congenital heart disease (ACHD).

OBJECTIVE

To assess outcomes of transvenous (TV) and epicardial (EPI) CIEDs in ACHD.

METHODS

A retrospective review of CIEDs implanted in patients >18 yrs. followed at the Ahmanson/UCLA ACHD Center was performed. Patients were grouped by implant approach. Primary outcomes included time to CIED dysfunction, lead dysfunction and unplanned CIED reintervention.

RESULTS

Over a 27-year period, 283 CIEDs (208 TV, 75 EPI) were implanted in 260 ACHD patients. Dysfunction developed in 77 CIEDs (50 TV, 27 EPI) for which 62 underwent unplanned reintervention (47 TV, 15 EPI). Time to CIED dysfunction and unplanned reintervention did not differ by implant approach; however lead dysfunction was greater for EPI vs TV (HR 2.0, 95% CI 1.2-3.2, p = 0.01). Independent predictors of lead failure included cyanosis (HR 2.6, 95% CI 1.1-6.3; p = 0.03), implant indication other than bradycardia (HR 3.3, 95% CI 1.6-6.5; p < 0.01), right-sided Maze operation (HR 2.5, 95% CI 1.3-5.0; p = 0.01), and unipolar lead design (HR 4.5, 95% CI 1.8-11.5; p < 0.01). Importantly, EPI vs TV approach was not associated with lead dysfunction after adjusting for baseline covariates (HR 0.6, 95% CI 0.6-4.3; p = 0.3).

CONCLUSION

Overall CIED system dysfunction and reinterventions are similar, whereas lead dysfunction is greater among EPI than TV devices. Patient and procedural differences, rather than EPI vs TV implant approach alone, appear to drive CIED lead outcomes in the ACHD population.

Strategies for directing cells into building functional hearts and parts

The increasing population of patients with heart disease and the limited availability of organs for transplantation have encouraged multiple strategies to fabricate healthy implantable cardiac tissues. One of the main challenges in cardiac tissue engineering is to direct cell behaviors to form functional three-dimensional (3D) biomimetic constructs. This article provides a brief review on various cell sources used in cardiac tissue engineering and highlights the effect of scaffold-based signals such as topographical and biochemical cues and stiffness. Then, conventional and novel micro-engineered bioreactors for the development of functional cardiac tissues will be explained. Bioreactor-based signals including mechanical and electrical cues to control cardiac cell behavior will also be elaborated in detail. Finally, the application of computational fluid dynamics to design suitable bioreactors will be discussed. This review presents the current state-of-the-art, emerging directions and future trends that critically appraise the concepts involved in various approaches to direct cells for building functional hearts and heart parts.

Adult Congenital Heart Disease in a Nationwide Population 2000-2014: Epidemiological Trends, Arrhythmia, and Standardized Mortality Ratio

BACKGROUND

The adult congenital heart disease (ACHD) population will grow with medical advances, but data are limited. We investigated the epidemiological profile of ACHD in Taiwan, a country with a congenital heart disease program since 1955, population of 23 million, and easily accessible high-standard medical care.

METHODS AND RESULTS

ACHD patients, born after 1954, were identified from the nationwide database 2000-2014. The ACHD prevalence in the population aged 18 to 59 was 140.53, 157.08, 182.45, and 217.00 per 100 000 in 2000, 2005, 2010, and 2014, respectively (increasing time trend, P<0.0001). Percentage of severe ACHD also increased over time (P<0.0001) and was 11.70% in 2014. The 5 leading ACHD diagnoses were ventricular septal defect, secundum atrial septal defect, patent ductus arteriosus, pulmonary stenosis, and tetralogy of Fallot. Freedom from tachyarrhythmia at age 50 years was 0.574 and 0.710 for severe and simple ACHD, respectively. Cardiac causes accounted for the majority of deaths, followed by malignancy in simple ACHD and external causes/sudden death/out-of-hospital death in severe ACHD patients. The proportion of unexpected death was 10%. Compared with the general population, the standardized mortality ratio was higher not only in severe ACHD (3.164; 95% confidence interval, 2.664-3.664), but also in women with simple ACHD (1.704; 95% confidence interval, 1.499-1.909), with a higher proportion of cardiac, labor, and sudden death as causes of death.

CONCLUSIONS

We demonstrated an increasing trend in ACHD prevalence and medical complexity. They are at risk of tachyarrhythmia, higher mortality, and unexpected deaths, suggesting a gap in their medical care.

Noteworthy Literature published in 2017 for Congenital Cardiac Anesthesiologists

This review focuses on the literature published during the 13 months from December 2016 to December 2017 that is of interest to anesthesiologists taking care of children and adults with congenital heart disease. Five themes are addressed during this time period and 100 peer-reviewed articles are discussed.