Samuel C. Siu

Mode of death in adults with congenital heart disease

An increasing number of patients with congenital heart disease (CHD) are entering adulthood. Although prior studies have focused on the causes of death in the pediatric population, the modes of death for adults with CHD have not been well defined. In a cross-sectional study performed on a population of 2,609 consecutive adults assessed at a CHD specialty clinic, there were adequate information available in 197 of 199 deceased patients. Mean age at death was 37 +/- 15 years. Mortality was highest in patients with congenitally corrected transposition of the great arteries (26%), tricuspid atresia (25%), and univentricular connection (23%). Youngest mean age at death was observed in patients with tricuspid atresia (27 +/- 5 years), complete transposition of the great arteries (27 +/- 7 years), pulmonary atresia (27 +/- 6 years), and aortic coarctation (29 +/- 6 years). Sudden death (26%) was the most common cause of death followed by progressive heart failure (21%) and perioperative death (18%). Postmortem examinations were performed in 77 of 197 deceased patients (39%) and provided incremental data on the mechanism of death in 22% of autopsies. Thus, the 3 major causes of death in the growing population of adults with CHD are sudden, perioperative, and progressive heart failure.

Left ventricular dysfunction is a risk factor for sudden cardiac death in adults late after repair of tetralogy of fallot

OBJECTIVESnThe purpose of this study was to determine if left ventricular (LV) systolic dysfunction was also a predictor of sudden cardiac death (SCD) in adults late after repair of tetralogy of Fallot (TOF).nnnBACKGROUNDnPrevious studies looking at risk factors for SCD in adults with repair of TOF have focused on the right ventricle (RV).nnnMETHODSnA retrospective chart review of patients assessed at the Toronto Congenital Cardiac Centre for Adults was performed. Twelve adult patients with repaired TOF and SCD were identified (SCD group). A total of 125 living adult patients with repaired TOF were randomly selected for comparison (control group).nnnRESULTSnPatients with SCD were more likely to exhibit moderate or severe pulmonary regurgitation (92% vs. 51%, p = 0.02), have a history of sustained ventricular tachycardia (42% vs. 6%, p < 0.01), and have a QRS > or =180 ms (56% vs. 13%, p = 0.02). Moderate or severe LV systolic dysfunction was also significantly more common in patients with SCD than in the control group (42% vs. 9%, p < 0.01) with a positive predictive value of 29%. The combination of moderate or severe LV systolic dysfunction and QRS > or =180 ms had a positive and negative predictive value for SCD of 66% and 93%, respectively.nnnCONCLUSIONSnModerate or severe LV systolic dysfunction is significantly more common in adult patients with repaired TOF and SCD. The combination of QRS > or =180 ms and significant LV systolic dysfunction has high positive and negative predictive value for SCD. The implication of the role of prophylactic antiarrhythmic implantable cardiac defibrillator insertion in these patients needs further elucidating.

Outcomes of late atrial tachyarrhythmias in adults after the Fontan operation

OBJECTIVESnThe purpose of this study was to compare the clinical and echocardiographic features of adults who developed atrial tachyarrhythmias (ATs) late after a Fontan procedure with those who have remained free of arrhythmias.nnnBACKGROUNDnAtrial tachyarrhythmias are a frequent complication of the Fontan operation. However, the outcomes in adult patients with AT who have had the Fontan operation have not been well defined.nnnMETHODSnWe reviewed the outcomes of 94 consecutive patients who underwent the Fontan operation between 1977 and 1994 and were followed as adults at the University of Toronto Congenital Cardiac Centre for Adults. Sixty patients had an atriopulmonary connection, 21 patients had an atrioventricular connection, and 13 patients received a lateral tunnel connection.nnnRESULTSnThirty-nine patients (41%) had sustained AT (atrial fibrillation, atrial flutter or supraventricular tachycardia) after their Fontan procedure. Compared with patients who did not develop AT, those who did were more likely to develop heart failure (46% vs. 13%, p = 0.003) and right atrial thrombus (31% vs. 4%, p = 0.006), exhibit left atrial enlargement (mean [+/-SD] diameter: 44 +/- 10 vs. 37 +/- 9 mm, p = 0.002), exhibit right atrial enlargement (mean [+/-SD] volume: 139 +/- 149 vs. 76 +/- 54 ml, p = 0.040) and have moderate-to-severe systemic valve regurgitation (31% vs. 7%, p = 0.010). The mean survival time was not significantly different between the arrhythmia group and the arrhythmia-free group (21.2 +/- 1.3 and 18.0 +/- 0.7 years, respectively; p = 0.900).nnnCONCLUSIONSnSystemic atrioventricular valvular regurgitation and biatrial enlargement are commonly observed in patients who develop AT after the Fontan procedure. These patients are more likely to develop right atrial thrombus and heart failure.

Sustained atrial arrhythmias in adults late after repair of tetralogy of fallot

We determined the prevalence of sustained atrial tachyarrhythmia (AT) in adults late after repair of tetralogy of Fallot (ToF) and examined its impact on subsequent heart failure, reoperation, and mortality. Ventricular arrhythmias are associated with increased morbidity and mortality in patients with repair of ToF. The clinical impact of AT in this population has not been established. A retrospective cohort study of 242 patients with repaired ToF identified 29 patients (prevalence of 12%) with sustained episodes of AT. Patients with repaired ToF but without sustained arrhythmia (n = 213) constituted a comparison group. Baseline characteristics and clinical outcomes in the 2 groups were compared. An echocardiographic analysis compared 15 patients with AT and 15 matched for age at operation and timing of echocardiography. The development of AT was associated with substantial morbidity including congestive heart failure, reoperation, subsequent ventricular tachycardia, stroke, and death (combined events, 20 of 29 patients [69%]). The rate of combined events (congestive heart failure, stroke, and deaths) in the 213 arrhythmia-free patients was 30% (64 of 213 patients). Event-free survival after repair was 18 +/- 2 years for the AT group and 28 +/- 1 years for the arrhythmia-free group (p < 0.001). Patients with AT were older at surgical repair (25 +/- 16 vs 10 +/- 9 years, p = 0.001), and at most recent assessment were aged 48 +/- 12 vs 32 +/- 10 years (p = 0.001). The AT group had a higher mean right atrial volume and proportion of significant pulmonary regurgitation than matched controls. The development of AT in the adult late after ToF repair identifies patients at risk and is associated with older age at repair, a higher frequency of hemodynamic abnormalities, and increased morbidity.

Intracardiac echocardiography guided device closure of atrial septal defects

OBJECTIVESnThis study was designed to determine the feasibility and accuracy of intracardiac echocardiography (ICE) in guiding percutaneous closure of atrial septal defects (ASD).nnnBACKGROUNDnIntracardiac echocardiography is a novel imaging technique that might be used to guide interventional procedures. The sensitivity and specificity of ICE, compared to standard imaging techniques, in detecting potentially adverse procedural events and guiding remedial action will be an important consideration in its use.nnnMETHODSnIn a prospective study, 24 patients underwent device closure of ASD using ICE as the primary echocardiographic imaging modality. Feasibility was expressed as proportion of cases in which complete diagnostic ICE imaging was achieved. Accuracy was expressed as the percent agreement between ICE and simultaneously performed transesophageal echocardiography (TEE).nnnRESULTSnHigh-quality ICE images were acquired in all patients, though images were limited in two patients with aneurysmal septa. Intracardiac echocardiography successfully guided closure of 24 out of 25 ASDs (96%) in 23 patients. There was close agreement between ICE and TEE in their assessment of device position and the adequacy of septal capture before device release (98%) and in identifying the presence of significant residual shunts. Intracardiac echocardiography detected all potentially adverse events, including four malpositions, and guided appropriate remedial action.nnnCONCLUSIONSnIntracardiac echocardiography guided device closure of secundum ASDs is feasible in the majority of patients and provides diagnostic data comparable to TEE. These data indicate that ICE may be used to guide routine closure of ASDs in adults without the need for TEE and general anesthesia.

Outcomes and alternative techniques for device closure of the large secundum atrial septal defect

Outcomes of device closure of large and small secundum atrial septal defects (ASDs) as related to rim anatomy with the Amplatzer atrial septal occluder were compared. Rim adequacy (≥ 5mm) of the anterior, inferior, posterior, and superior rims was determined using transesophageal echocardiography. Balloon‐stretched defect size defined patients into two groups: group 1, ≤ 25 mm (n = 138); group 2, > 25 mm (n = 34). Rim deficiency (n = 62) was more frequent in group 2 compared to group 1 (50% vs. 33%; P = 0.07), especially inferior rim deficiency (35% vs. 2%; P = 0.005). Device deployment was successful in group 1 and group 2 (100% vs. 91%; P = 0.007). Unsuccessful deployment was associated with an ASD of > 25 mm (P = 0.007) and inferior rim deficiency (P = 0.001). At first follow‐up (54 ± 16 days), right ventricular systolic pressure had improved in both groups (P < 0.001). Closure of a large ASD associated with a lack of support in the inferior rim may warrant alternative strategies to position the device successfully. Catheter Cardiovasc Interv 2004;61:131–139.

Images in cardiovascular medicine. Anomalous origin of the left coronary artery from the main pulmonary artery in adults: coronary collateralization at its best.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA, or Bland-White-Garland syndrome) occurs once per 300 000 live births, usually as an isolated cardiac lesion. In fetal life, this anomaly is well tolerated because pulmonary pressure equals systemic pressure and oxygen content is identical in the main pulmonary artery (PA) and aorta. Therefore, coronary collateral growth is not especially promoted before birth. After birth, as soon as pulmonary pressure and saturation fall, left ventricular (LV) oxygen demands no longer can be accommodated by the left coronary artery (LCA), and ALCAPA leads to myocardial ischemia. Subendocardial ischemia can occur even in the presence of well-established coronary collateral vessels because of preferential coronary blood flow into the low-pressure pulmonary circulation instead of high-resistance …Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA, or Bland-White-Garland syndrome) occurs once per 300 000 live births, usually as an isolated cardiac lesion. In fetal life, this anomaly is well tolerated because pulmonary pressure equals systemic pressure and oxygen content is identical in the main pulmonary artery (PA) and aorta. Therefore, coronary collateral growth is not especially promoted before birth. After birth, as soon as pulmonary pressure and saturation fall, left ventricular (LV) oxygen demands no longer can be accommodated by the left coronary artery (LCA), and ALCAPA leads to myocardial ischemia. Subendocardial ischemia can occur even in the presence of well-established coronary collateral vessels because of preferential coronary blood flow into the low-pressure pulmonary circulation instead of high-resistance …

Determinants of health-related quality of life in adults with congenital heart disease.

OBJECTIVEnTo examine health-related quality of life (HR-QoL) of adults with congenital heart disease (CHD).nnnDESIGNnThe HR-QoL of a large consecutive series of adults with CHD was prospectively studied using the Medical Outcome Study-Short Form 36.nnnRESULTSnExcept for very young men who report normal health, young adults describe poor health and exercise limitations relative to their peers in the community. In addition, middle-aged men report fatigue, psychological distress, impaired social functioning, and disability because of emotional difficulties. Among structurally defined subgroups, palliated and repaired cyanotic groups describe poor health. Patients with unoperated and palliated cyanotic lesions and men with repaired cyanotic defects or unoperated shunts also report exercise intolerance. Current cyanosis emerged as an important influence on HR-QoL. Patients with acquired cyanosis report poor health, exercise intolerance, fatigue, psychological difficulties, and social impairment. Chronic cyanosis was associated with only patient reports of poor health, exercise limitations, exercise-related disability, and social difficulties. Although adults with repaired cyanotic defects report poor health, no other HR-QoL deficits were reported by acyanotic patient groups. Pulmonary hypertension and rhythm disorders also influenced specific HR-QoL domains. Although gross structural and pathophysiologic factors influenced perceived health and exercise ratings, these variables were relatively poor predictors of self-reported health status and exercise capacity.nnnCONCLUSIONSnMany adults with CHD do not meet normative expectations for perceived health status and exercise tolerance. The principal determinants of self-reported health status and perceived exercise tolerance in adults with CHD are not known. Gender differences in outcome require further investigation.

Anomalous Origin of the Left Coronary Artery From the Main Pulmonary Artery in Adults: Coronary Collateralization at Its Best

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA, or Bland-White-Garland syndrome) occurs once per 300 000 live births, usually as an isolated cardiac lesion. In fetal life, this anomaly is well tolerated because pulmonary pressure equals systemic pressure and oxygen content is identical in the main pulmonary artery (PA) and aorta. Therefore, coronary collateral growth is not especially promoted before birth. After birth, as soon as pulmonary pressure and saturation fall, left ventricular (LV) oxygen demands no longer can be accommodated by the left coronary artery (LCA), and ALCAPA leads to myocardial ischemia. Subendocardial ischemia can occur even in the presence of well-established coronary collateral vessels because of preferential coronary blood flow into the low-pressure pulmonary circulation instead of high-resistance …Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA, or Bland-White-Garland syndrome) occurs once per 300 000 live births, usually as an isolated cardiac lesion. In fetal life, this anomaly is well tolerated because pulmonary pressure equals systemic pressure and oxygen content is identical in the main pulmonary artery (PA) and aorta. Therefore, coronary collateral growth is not especially promoted before birth. After birth, as soon as pulmonary pressure and saturation fall, left ventricular (LV) oxygen demands no longer can be accommodated by the left coronary artery (LCA), and ALCAPA leads to myocardial ischemia. Subendocardial ischemia can occur even in the presence of well-established coronary collateral vessels because of preferential coronary blood flow into the low-pressure pulmonary circulation instead of high-resistance …

Outcome of previous tricuspid valve operation and arrhythmias in adult patients with congenital heart disease

BACKGROUNDnTricuspid valve operation or replacement has been associated with high perioperative mortality and poor long-term results. The prevalence of atrial arrhythmias before and after operation in these patients is undefined.nnnMETHODSnWe retrospectively examined the outcome and frequency of atrial arrhythmias in 85 adult patients (46% men) with congenital heart defects who underwent tricuspid valve operation between 1961 and 1995.nnnRESULTSnThe majority had either Ebsteins anomaly (22%), congenitally corrected transposition (19%), tetralogy of Fallot (15%), atrial (13%), or ventricular (11%) septal defects. Forty-two (49%) patients had sustained arrhythmias within 1 year before operation. After tricuspid valve operation, 21 patients (50%) had recurrence of atrial arrhythmias, and 7 in preoperative sinus rhythm developed late rhythm disturbances. Multivariate analysis identified age at operation and preoperative arrhythmias as independent predictors of late arrhythmias. Perioperative mortality was 5%, and there were seven late deaths. Survival was 91% at 5 years, and 83% at 10 years.nnnCONCLUSIONSnSurgical intervention does not prevent recurrence of atrial arrhythmias. Tricuspid valve operation in patients with congenital heart disease can be performed with a low risk of perioperative mortality and good long-term outcome.