Clinical Use of Electrocardiography in Adults With Congenital Heart Disease

The population of adults with congenital heart disease (ACHD) has increased dramatically over the past few decades, with many people who are now middle-aged and some in the geriatric age range. This improved longevity is leading to increased use of the medical system for both routine and episodic care, and caregivers need to be prepared to diagnose, follow up, and treat the older adult with congenital heart disease (CHD). The predictable natural progression of CHD entities and sequelae of previous interventions must now be treated in the setting of late complications, acquired cardiac disease, multiorgan effects of lifelong processes, and the unrelenting process of aging. Despite the advances in this field, death rates in the population from 20 to >70 years of age may be twice to 7 times higher for the ACHD population than for their peers.1 This American Heart Association (AHA) scientific statement will focus on the older adult (>40 years old) with CHD. It is meant to be complementary to the 2008 American College of Cardiology (ACC)/AHA guidelines for ACHD and orient the reader to the natural history, ramifications of childhood repair, and late initial diagnosis of CHD in the older adult. This population with CHD is unique and distinct from both the pediatric and young adult populations with CHD. Much of the information we provide is from scientific research combined with clinical experience from longitudinal care. We emphasize that this is the beginning of a discussion regarding this rapidly growing population, and continued research aimed at the progression of disease and complications reviewed here is necessary to advance the field of ACHD with the scientific rigor it deserves. ACHD encompass a broad range of presentations. There are people who are diagnosed for the first time in adulthood, as well as those with prior palliative repair …

Surgical Management of Three Dogs with an Interatrial Communication and Atrioventricular Valve Abnormalities

Left bundle pacing in a patient with atrioventricular canal defect presenting with atrial standstill and junctional bradycardia

Atrioventricular nodal reentrant tachycardia in patients with complex congenital heart disease and twin atrioventricular nodes

Correction of Complete Atrioventricular Canal

Unrepaired Transitional Atrioventricular Septal Defect in a 52-Year-Old Patient

By the time patients with congenital heart disease (CHD) reach adolescence and early adulthood, rhythm status has often become an active issue, if not the central issue, in their cardiac management. For some, arrhythmias are intrinsic to the structural malformation itself, as is the case with Wolff-Parkinson-White syndrome in the setting of Ebstein’s anomaly, or atrioventricular (AV) block in the setting of “congenitally corrected” transposition of the great arteries (L-TGA). For most other CHD patients, arrhythmias represent an acquired condition related to the unique myocardial substrate created by surgical scars in conjunction with cyanosis and abnormal pressure/volume loads of long duration. This review will attempt to address the major rhythm difficulties faced by adults with CHD, concentrating on electrophysiological features that distinguish CHD from more conventional forms of adult heart disease. A listing of specific arrhythmias and commonly associated congenital defects is provided in Table 1 to serve as an outline for the discussion. View this table: TABLE 1. Specific Arrhythmias and Associated Defects in Adults With Congenital Heart Disease As of 2001, there were estimated to be 800 000 adults with CHD living in the United States,1 a number that has grown steadily as more survivors of childhood surgery reach maturity. Of these, roughly 45% are considered to have mild forms of CHD (eg, atrial septal defect, valvar pulmonary stenosis), 40% are classified as having moderate disease (eg, tetralogy of Fallot, Ebstein’s anomaly), and 15% are considered to have complex disease (eg, single ventricle, transposition of the great arteries). Although arrhythmias can develop within any of the 3 subgroups, the incidence is highest for patients in the moderate and severe categories. Tetralogy of Fallot is an instructive example of moderate CHD with a large arrhythmia burden. As many as one third of patients with repaired tetralogy develop symptomatic atrial tachycardias by …

Presentation of Congenital Heart Disease in the Neonate and Young Infant

Selective cardioneuroablation of the posteromedial left ganglionated plexus for drug-resistant swallow syncope with functional atrioventricular block

The treatment of congenital heart disease is unsatisfactory.As a rule, nothing can be done to improve patients symptomatically; in some instances digitalis may be of help."

Approach to pacing in patients with various septal defects

The human heart beats 2.5 billion times during a normal lifespan, a feat accomplished by cells of the cardiac conduction system (CCS). The functional components of the CCS can be broadly divided into the impulse-generating nodes and the impulse-propagating His-Purkinje system. Human diseases of the conduction system have been identified that alter impulse generation, impulse propagation, or both. CCS dysfunction is primarily due to acquired conditions such as myocardial ischemia/infarct, age-related degeneration, procedural complications, and drug toxicity. Inherited forms of CCS disease are rare, but each new mutation provides invaluable insight into the molecular mechanisms governing CCS development and function. Applying a multidisciplinary approach, which includes human genetic screening, biophysical analysis, and transgenic mouse technology, has yielded a broad array of gene families involved in maintaining normal CCS physiology (Figure 1). In this review, we discuss gene families that have been implicated in human CCS diseases of rhythm, conduction block, accessory conduction, and development (Table). We also investigate evolving therapeutic strategies that may serve as adjuvant or replacement therapy to current implantable pacemakers. Figure 1. Cardiac conduction system cell. Genes identified in human cardiac conduction system disease are highlighted. View this table: Table. Genetic Basis of Conduction System Disease The human sinoatrial node (SAN) is a crescent-shaped, intramural structure with its head located subepicardially at the junction of the right atrium and the superior vena cava and its tail extending 10 to 20 mm along the crista terminalis.26 The SAN has complex 3-dimensional tissue architecture with central and peripheral components made up of distinct ion channel and gap junction expression profiles.27 Central and peripheral cells have different action potential characteristics and conduction properties (Figure 2).27 Experimental and computational models have demonstrated that SAN heterogeneity is necessary to maintain normal automaticity and impulse conduction.28,–,30 Figure 2. Electrophysiological heterogeneity of the …

Ventricular septal defects (VSD) represent the most common congenital heart defect in newborns. We assessed the electrocardiographic characteristics of newborns with VSDs in a general population sample. The Copenhagen Baby Heart Study is a prospective population–based cohort study offering cardiac evaluation of newborns. Echocardiograms and electrocardiograms were obtained within 30 days after birth and systematically analysed. A VSD was identified in 530 newborns (mean age 11 ± 7 days, 42% boys). Newborns with VSDs had a more left-shifted QRS axis (116 ± 34 vs. 120 ± 3°, p = 0.02), and a higher S-wave amplitude in V1 (721 ± 584 vs. 636 ± 549 µV, p = 0.001) than controls. The largest differences were found in newborns with large or perimembraneous VSDs with a higher frequency of left axis deviation, higher S-wave amplitudes in V1, and higher R- and S-wave amplitudes in V6 compared with controls. R-waves in V1 and V6 were significantly associated to left ventricular mass, whereas S-waves in V1 and V6 were dependent on left ventricular end-diastolic diameter on echocardiography. Conclusion: Newborns with VSDs showed significant differences in QRS axis, and R- and S-wave precordial amplitudes compared to matched controls. Perimembranous and large VSDs had the greatest effect on the neonatal ECG.What is Known:• Ventricular septal defects in newborns are prevalent and may affect cardiac function and structure.What is New:• The Copenhagen Baby Heart Study is the largest study including a cohort of unselected newborns undergoing postnatal cardiac examination.• We found that newborns with VSD showed significant electrocardiographic differences depending on size and type of VSD compared with healthy newborns.

Evidence from animal experiments indicates that the autonomic nervous system may influence the sinus (SA) and atrioventricular (AV) nodes differently. We investigated, therefore, whether there are spontaneous functional differences in the innervation of the SA and AV nodes in man. This study was performed in 10 healthy males (ages 21 to 26 years) during strict bed rest from 10 pm to 6 am. Three ECG leads were digitized on-line. PR and PP intervals were determined on a beat-to-beat basis off-line using a correlation algorithm with an accuracy of +/- 2 msec and were verified visually. During major body movements, there were sudden decreases in PP intervals of 36 to 827 msec (mean 335) for periods of 6 to 265 seconds (mean 24). During these phases of heart rate (HR) acceleration, PR intervals showed either concomitant shortening (9 to 30 msec), no change, or lengthening (6 to 25 msec). Furthermore, tonic changes in the PR interval occurred over 15-minute periods during which the range of PP intervals was constant. Additionally, recovery-adjusted PR interval (PR-b2/RP) and cycle length were negatively correlated for some periods, which confirmed independent autonomic effects on SA node and AV node. Beat-to-beat measurement of PR intervals allows for evaluation of autonomic effects on the human AV node. The different patterns in PR intervals during sudden spontaneous increases in HR and the tonic changes in PR interval indicate that the autonomic inputs to the SA and AV nodes are, in principle, independent of each other.

Advantages and pitfalls of selective cardioneuroablation targeting the atrioventricular node