Adults with Congenital Heart Disease and Arrhythmia Management

Arrhythmia Burden Among Adult Patients With Congenital Heart Disease: A Population-Based Study

BACKGROUND

A significant percentage of patients with congenital heart disease surviving into adulthood will develop arrhythmias. These arrhythmias are associated with an increased risk of adverse events and death. We aimed to assess arrhythmia prevalence, risk factors, and associated health care usage in a large national cohort of patients with adult congenital heart disease.

METHODS AND RESULTS

Adults with a documented diagnosis of congenital heart disease, insured by Clalit and Maccabi health services between January 2007 and December 2011, were included. We assessed the associations between arrhythmia and subsequent hospitalization rates and death with mixed negative binomial and Cox proportional hazard models, respectively. Among 11 653 patients with adult congenital heart disease (median age, 47 years [interquartile range, 31-62]), 8.7% had a tachyarrhythmia at baseline, 1.5% had a conduction disturbance, and 0.5% had both. Among those without a baseline arrhythmia, 9.2% developed tachyarrhythmias, 0.9% developed a conduction disturbance, and 0.3% developed both during the study period. Compared with no arrhythmia (reference group), arrhythmia in the previous 6 months was associated with a higher multivariable adjusted hospitalization rate, 1.33-fold higher than the rate of the reference group (95% CI, 1.00-1.76) for ventricular arrhythmia, 1.27-fold higher (95% CI, 1.17-1.38) for atrial arrhythmias, and 1.33-fold higher (95% CI, 1.04-1.71) for atrioventricular block. Atrial tachyarrhythmias were associated with an adjusted mortality hazard ratio (HR) of 1.65 (95% CI, 1.44-2.94), and ventricular tachyarrhythmias with a >2-fold increase in mortality risk (HR, 2.06 [95% CI, 1.44-2.94]).

CONCLUSIONS

Arrhythmias are significant comorbidities in the adult congenital heart disease population and have a significant impact on health care usage and survival.

Subcutaneous cardioverter-defibrillator implantation in an adult with congenital heart disease and left infra-mammary pacemaker

The approach/type of an implantable cardioverter defibrillator (ICD) is determined by the underlying cardiac anatomy, venous access, and pre-existing cardiac implantable electronic devices. We describe a case of subcutaneous ICD implantation in an adult with congenital heart disease (CHD) with a pre-existing inframammary transvenous pacemaker. This was preferred over adding a defibrillator coil to existing pacing leads, extraction/replacement of pacing system, or a sternotomy/epicardial ICD placement. The procedure was accomplished uneventfully with successful defibrillation threshold testing. Innovative approaches are required to manage arrhythmias in adults with CHD, with shared decision making playing a critical role.

Arrhythmias in Patients with Congenital Heart Disease: An Ongoing Morbidity

With the aging of congenital heart disease (CHD) patients, the burden of arrhythmias is expanding. Atrial arrhythmias, especially intra-atrial reentrant tachycardia and atrial fibrillation, are the most prevalent forms of arrhythmia. Managing comorbidities, such as obesity, using pharmacotherapy, including antiarrhythmics and anticoagulants, and ablation therapy has become the cornerstone of arrhythmia management. Ventricular tachycardias are also not rare; however, except for tetralogy of Fallot patients, recommendations for the use of implantable cardioverter defibrillators for primary prevention in other CHD patients are still not well established. Patients with CHD might also present with atrioventricular blockages because of their anatomy or following a surgical procedure. The scope of this article is to review the current knowledge and discuss the future directions regarding arrhythmia management in CHD patients.

Special Considerations in Critical Care of the Congenital Heart Disease Patient

Outcomes of congenital heart disease have improved markedly over the past 20 years, with survival to adulthood now close to 90%. The mean age of admission to an intensive care unit (ICU) is 40 years. The incidence of hospital and critical care admissions have increased significantly as a consequence of this improved survival. Intensivists are now confronted with the management not only of complex adult congenital heart disease (ACHD) lesions from a cardiac perspective, but also of extracardiac organ consequences of years of abnormal circulation after surgical or palliative correction. Kidney and liver dysfunction and respiratory and hematologic abnormalities are very common in this population. ACHD patients can present to the ICU for a vast number of reasons, classified in this review as medical noncardiac, medical cardiac, and surgical. Community/hospital-acquired infections, cerebrovascular accidents, and respiratory failure, alongside arrhythmias and heart failure, are responsible for medical admissions. Surgical admissions include postoperative management after correction or palliation, but also medical optimisation and work-up for advanced therapies. ICU management of this large heterogeneous group requires a thorough understanding of the pathophysiology in order to apply conventional adult critical care modalities; left ventricular or right ventricular dysfunction, pulmonary hypertension, intracardiac, extracardiac, and palliative surgical shunts can be present and require additional consideration. This review focuses on the pathophysiology, long-term sequelae, and different treatment modalities to supply a framework for the ICU physician caring for these patients. Successful outcome, especially in complex lesions, depends on early involvement of specialised ACHD centres.

Arrhythmias in adults with congenital heart disease and heart failure

Arrhythmias and heart failure are among the most common complications encountered by adults with congenital heart disease (CHD). In this contemporary review, we explore the interactions between arrhythmias and heart failure and discuss management strategies. Major knowledge gaps are highlighted throughout. Interactions between arrhythmias and heart failure are complex and bidirectional, with one begetting the other. Arrhythmias can provoke heart failure through various mechanisms: conduction disturbances may contribute to inefficient ventricular filling and contraction patterns; bradyarrhythmias and tachyarrhythmias can result in a reduction in cardiac output; hypoxemia may be exacerbated by right-to-left shunting; and tachycardia-induced cardiomyopathy has potentially devastating consequences if the diagnosis is delayed. In turn, heart failure promotes arrhythmogenesis through various structural (eg, fibrosis, chamber dilation, hypertrophy) and electrical remodeling effects that include changes to ion currents and channels and connexin expression, along with shortening of atrial and ventricular refractory periods with increased heterogeneity. Several shared comorbidities can contribute to, and modulate the impact of, arrhythmias and heart failure. Preemptive arrhythmia management can potentially mitigate effects on heart failure exacerbations. Similarly, optimal heart failure control could curtail its impact on arrhythmogenesis. Treatment strategies to prevent or treat heart failure in adults with CHD encompass pharmacological agents, catheter ablation, and device therapies including defibrillators, cardiac resynchronization therapy, and His bundle pacing. High-priority research avenues with major knowledge gaps include tachycardia-induced cardiomyopathy, catheter ablation of atrial fibrillation, defibrillator indications in high-risk subsets, and the role of cardiac resynchronization therapy and His bundle pacing in diverse forms of CHD.

Sudden Death in Congenital Heart Disease: The Role of the Autopsy in Determining the Actual Cause

Congenital heart defects (CHDs) have undergone a large change in epidemiology due to prenatal screening and improved outcomes with surgery and percutaneous procedures. In patients with complex CHD there is an increased risk of sudden cardiac death (SCD) and up to 11% of all SCDs in the young occur in people with CHD. It is essential for clinicians to be aware of the risk factors, and for all patients to be followed up in specialised centres. When an SCD occurs, it is important that an autopsy is done and for the pathologist to have an in-depth knowledge of the particular defect and the corrective surgical techniques employed, as well as any complications due to these procedures. Both pathologist and cardiologist should work closely together to explain the cause of death to the family. A terminal cardiac arrhythmia explains many of the SCD cases, often with underlying cardiac fibrosis due to previous procedures. SCD may also be the first presentation of CHD, so great care is required when examining such cases and referral for a detailed expert opinion is recommended in all CHD-SCD cases.