Arrhythmic Risk Stratification in Adults with Congenital Heart Disease

Review Article

J Cardiovasc Disord. 2015; 2(2): 1013.

Arrhythmic Risk Stratification in Adults with Congenital Heart Disease

Daliento L*, Mazzotti E, Pomiato E, Spadotto V and Bauce B

Department of Cardiac, University of Padua, Italy

*Corresponding author: Daliento L, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, 2 via Giustiniani, 35100, Padua, Italy

Received: June 23, 2015; Accepted: July 27, 2015; Published: July 29, 2015


As arrhythmias and sudden death may significantly modify natural history of Congenital Heart Disease (CHD), accurate arrhythmic risk stratification is mandatory during clinical follow-up of both native and operated CHD patients, especially in adulthood. This can be obtained using simple and reproducible instruments such as Electrocardiogram (ECG), 24 -hours Holter ECG, signalaveraged ECG and echocardiography. Nonetheless, cardiac magnetic resonance and electrophysiological study with programmed ventricular stimulation and electro-anatomic mapping may help to define a more effective patient management. Correction of residual hemodynamic lesions significantly improves arrhythmia-free survival. Some classes of patients with higher arrhythmic risk have been already identified and, when all residual lesions have been addressed, ICD implantation in primary prevention may represent a valid option. On the other hand, pharmacological therapy of arrhythmias is often non- CHD specific.

Keywords: Congenital heart disease; Grown up heart disease; Arrhythmias; Sudden death


Arrhythmias, together with ventricular dysfunction, are the most important prognostic determinants of natural history of Congenital Heart Disease (CHD), especially in adults after surgical correction, representing the main cause of death and hospitalisation [1,2].

Arrhythmias observed in CHD population

Regarding bradyarrhythmias, perioperative complete Atrioventricular (AV) block is overall rare in the current surgical era, while late complete AV block is observed in patients with history of perioperative transient AV block, with right bundle branch block and left anterior fascicular block, with sick sinus syndrome or with corrected transposition of great arteries (especially when associated with ventricular septal defect) [3]. Sinus node dysfunction can be produced by injury of sinus node or its vessel during cardiopulmonary by-pass (performing cannulation at the junction between the superior vena cava and the roof of the right atrium) or during severe surgical atrial manipulations, such as in Mustard/Senning or atrio-pulmonary operations [4].

On the other hand, hyperkinetic arrhythmias are most commonly observed in both native and surgically corrected CHD, and may result in clinical worsening and sudden death.

In a population-based study Silka et al. [5] reported the postsurgical follow-up of 3589 adult (>19 years old) patients who underwent surgical treatment of common forms of congenital heart disease (atrial septal defects, ventricular septal defects, atrioventricular septal defects, patent ductus arteriosus, pulmonary stenosis, congenital aortic valve stenosis, aortic coarctation, tetralogy of Fallot, complete transposition of the great vessels) in the state of Oregon between 1958 and 1996, retrospectively identifying incidence and causes of late sudden death, with a mean follow-up of 25.3 years (median 25.4, range 1.06 to 35.5). They observed 41 unexpected late sudden deaths during 45,857 patient-years of follow-up (overall event rate 0.9‰ pt/yr, 25–100), 37of which occurred in patients with transposition of great arteries, tetralogy of Fallot, aortic valvular stenosis or aortic recoarctation (event rate 2.2‰ pt/yr), while only 4 were recorded in patients with ventricular septal defect, atrioventricular septal defect or pulmonary stenosis (event rate 0.1‰ pt/yr). Actuarial 10-, 20-, 30- and 36-year survival rates in the 490 patients who survived the first postoperative year were 97%, 94%, 89% and 85%, respectively.

Long term survival after surgical correction of tetralogy of Fallot is about 85% after 35 years of follow-up, but sudden death and ventricular tachycardia occurred with a reported incidence of 1–2% over 5 years for young adults, and an overall prevalence of sudden cardiac death of 3–6% has been reported [6]. In 2000, Gatzoulis et al. [7] analyzed retrospective data from a 10-year period (1985-95) on the occurrence of clinical arrhythmia and sudden death among 793 patients with repaired Tetralogy of Fallot (excluding patients with pulmonary atresia and patients with additional major intra cardiac or extra cardiac abnormalities) who had been referred to six different congenital heart disease centres, allowing for over 7500 patient-years follow-up. Patients mean age was 17.5±10.7 years, mean age at repair was 8,4±6,1 years. Among them, 33 patients developed sustained monomorphic ventricular tachycardia, and 16 died suddenly. The authors reported significantly higher QRS duration and QRS rate of change in 10-years period among the ventricular tachycardia and sudden-death groups, and pulmonary regurgitation as the main underlying hemodynamic lesion within the same group; moreover, they did find an association between older age at repair and risk of sudden death.

Besides the role of life-threatening arrhythmias in causing sudden death, long-standing supraventricular or non-sustained ventricular arrhythmias may cause or be caused by a decrease in ventricular function, thus influencing patient prognosis, such as for Mustard patients, who were reported to have a reduced survival in the presence of both systemic ventricular dysfunction and atrial fibrillation [8].

Supraventricular tachyarrhythmia’s have different clinical and prognostic value, depending on the type of CHD and surgical history. Atrial fibrillation was reported to increase the risk of heart failure in a group of 521 patients > 40 years old with secundum atrial septal defect referred for treatment and who received a median follow-up of 7.3 (range 2-13) years [9]. In Roos-Hesselink et al. work, after 17.5 years (range1.4 to 32 years) of post-surgical follow up of 53 consecutive patients (mean age 26.6 years) with repaired Tetralogy of Fallot (mean age at repair 9.1 years, range, 0.7-55 years), about 20% of patients of suffered from atrial fibrillation, having systemic embolic events in 7% [10]. Atrial flutter in patients who underwent Mustard operation has already been related to sudden death: in a retrospective, multicenter, case-controlled study, 47 patients after Mustard’s or Senning’s operation who experienced a sudden-death event were found to have an history of documented arrhyhtmia, mainly atrial flutter (OR 3.473, CI 95 1.451-8.310) [11]. About 16% of the 145 patients analysed by Kirsh et al. after Mustard/Senning operation, Fontan operation, biventricular repair of complex CHD or other palliative intervention and enrolled after a first atrial cardio version attempt [12] had a recurrence of supraventricular tachyarrhythmia’s (atrial flutter/fibrillation, or intra-atrial arrhythmic re-entry tachycardia — IAART) in a 10-years follow up, with a higher risk of thromboembolism, heart failure and death. One hundred ninetynine patients who underwent the Fontan operation between 1975 and 1993 were followed for more than 10 years in Fujita et al. work [13], and authors reported a probability of freedom from atrial tachycardia of 86% and 62% at 10 and 20 years of follow up. Type of surgery (especially atrio-pulmonary Fontan), duration of postsurgical follow-up and age at operation have been reported to best predict late arrhythmic risk in Fontan populations. In Fishberger et al. [14] group of 334 patients who underwent the Fontan operation between 1973 and 1991, after a mean follow-up of 5.0 ± 3.8 years, late occurrence of arrhythmias was reported to be higher in patients with older age at surgery (12.4 ± 7.6 vs 6.3 ± 5.2 years, p < 0.001) and after a longer follow-up interval (8.7 ± 3.9 vs 4.4 ± 3.4 years; p < 0.001). More recently, a Paediatric Heart Network investigation reported a significant reduction of IAART risk in a contemporary Fontan cohort until 4–6 years of follow up, increasing with patient age [15].

With all this in mind, an accurate identification of CHD patients with high arrhythmic risk is mandatory during long-term follow-up.

This can be obtained using simple and reproducible instruments such as Electrocardiogram (ECG), 24 -hours Holter ECG, signalaveraged ECG and echocardiography. Nonetheless, cardiac magnetic resonance and electrophysiological study with programmed ventricular stimulation and electro-anatomic mapping may help to define a more effective patient management. Medical history collection should include data about native congenital cardiac defect, type of cardiac surgery, age at operation, functional status, and presence of syncope.

Identification of arrhythmic substrates in CHD patients

Arrhythmias in CHD patients may have several causes: anatomical (fibrosis, surgical scar) (Figure 1) [16,17], functional (autonomic nervous system abnormalities) and morpho-functional (such as mechano-electrical interaction).