The Postnatal Risk, Resuscitation Success Rate and Outcomes of Pediatric Sudden Death in Taiwan.

BACKGROUND: The epidemiology of pediatric potentially sudden death (SD) events and the rescue rate remain unclear. METHODS: We established a birth cohort (2000-2014) from a national database 2000-2015. RESULTS: Of 3,097,277 live births, we identified 3126 children (56.1% male) with potentially SD events, including 887 who were rescued. The cumulative risk of potentially SD events for each neonate was 0.30, 0.62, 0.91, 1.05, and 1.13 per 1000 by 2 months, 0, 5, 11 and 14 years of age, respectively. Overall, 28.3% of the children were rescued from SD events, with a higher rate in neonates (69.6%) but lower rate in postneonatal infants. A cardiac diagnosis was noted in 596 (19.1%) patients, including congenital heart disease (CHD) (388), cardiac arrest (151), cardiomyopathy (23), myocarditis (12), Kawasaki disease (7) and arrhythmia (36). Coexisting severe CHD and events in postneonatal infancy were associated with a lower chance of resuscitation, whereas events within 1 week of age had a higher chance of resuscitation. Anoxic brain damage was noted in 174 (19.7%) patients and late death occurred in 348 (39.3%) patients after being rescued from SD. Late death was more common in males, those with anoxic brain damage, those with coexisting severe CHD, and postneonatal infants. CONCLUSIONS: In this birth cohort study, the postnatal cumulative risk of potentially SD events was 1 in 885 newborns by 14 years of age. Postneonatal infants and those with coexisting severe CHD had the highest risk and worst outcomes.

Cumulative postnatal risk of pediatric sudden death and all-cause mortality in nationwide birth cohorts of Taiwan and the United States.

BACKGROUND: To investigate the cumulative postnatal risk of pediatric sudden death (SD) for each neonate and the temporal/regional differences which are still unclear. METHODS: We established a birth cohort (2000-2014) from our national database and obtained reference data about the United States (US) from the national website. RESULTS: Among 3,097,277 live births, we identified 1661 children with SD (56.8% male). The postnatal cumulative risk of SD was 0.35, 0.49, 0.56 and 0.59/1000 by age 0, 5, 11 and 14 years. Coexisting cardiac diagnosis was noted in 347 (20.9%) and non-cardiac diagnosis in 300 (18.1%) patients. Cumulative all-cause mortality was 5.3, 6.78, 7.63 and 8.06/1000 by age 0, 5, 11 and 14 years. Risks of SD and all-cause death decreased over birthyear. SD risk decreased particularly after the 2008 birthyear. Risks of SD and all-cause death were the highest in Eastern Taiwan, but SD/all-cause death ratio was high in Taipei metropolitan and Northern Taiwan. Cumulative risk of SD (0.54/1000 by age 14) and all-cause mortality (9.06/1000 by age 14) in the US decreased over time. African-Americans were at the highest risks of SD and all-cause mortality. However, American-Indians/Alaska-natives exhibited the highest SD/all-cause death ratio. CONCLUSION: This study provides the cumulative risk of SD (1 in 1694 newborns) by age 14 years. The time trend underlines the effect of medical advance and education on SD prevention. Distinct regional/ethnic differences in risks of SD and all-cause death in Taiwan and the US indicate the necessity of different strategies to diminish the disparity.

Atrial fibrillation in adult congenital heart disease and the general population.

BACKGROUND: Atrial fibrillation (AF) in adult patients with congenital heart disease (ACHD) may appear early, depending on individual characteristics. OBJECTIVES: The goals of this study were to investigate the epidemiological spectrum of AF in the entire cohort of ACHD and compare it with that in the general population. METHODS: A retrospective study was performed in the nationwide cohort 2000-2014 with AF onset during 2003-2014. RESULTS: In the cohort of ACHD, 2350 patients had AF; the incidence increased with age, plateauing around age 70. In patients aged 25-29, 45-49, 65-69, 75-79, and ≥80 years, the annual incidence was 1.3, 7.9, 20.6, 23.7, and 21.4/1000 per year, respectively. In the general population without CHD, 347,979 patients had AF; the annual incidence was <1/1000 per year in those aged <55 years but increased steadily with age (3.6, 8.6, and 14.2/1000 per year in aged 65-69, 75-79, and ≥80 years, respectively). Compared with individuals without ACHD, ACHD patients aged <50 years and those aged both 50-54 and 55-59 years exhibited a 20-fold and 10-fold higher incidence of AF, respectively. Patients with complex congenital heart disease and Ebstein's anomaly had the highest risk of AF (cumulative risk >10% by age 50 and >20% by age 60), followed by those with tetralogy of Fallot, tricuspid atresia, endocardial cushion defect, and secundum atrial septal defect (cumulative risk >5% by age 50 and >10% by age 60). CONCLUSION: Compared with individuals without ACHD, AF in patients with ACHD likely appeared 30 years earlier, with a 10- to 20-fold higher incidence plateauing around age 70. Yet, incidence in individuals without ACHD continued to increase. AF burden in patients with ACHD is not expected to increase in a never-ending way.

Long-term outcome of repaired tetralogy of Fallot: Survival, tachyarrhythmia, and impact of pulmonary valve replacement.

BACKGROUND: Pulmonary valve replacement (PVR) is recommended for severe pulmonary regurgitation in repaired tetralogy of Fallot (rTOF). OBJECTIVE: The purpose of this study was to investigate the event rate and effectiveness of PVR. METHODS: A retrospective study of tetralogy of Fallot patients who survived total repair from 1970 to 2020 was conducted. RESULTS: We identified 1744 rTOF patients; 86.6% with classic rTOF, 11.5% with pulmonary atresia, 0.8% with endocardial cushion defect, and 1.1% with absent pulmonary valve. Annual risks of tachyarrhythmia/sudden cardiac arrest (SCA) increased to 0.295% and 1.338% in patients aged 10-30 and 30-60 years, respectively, without sex predominance. PVR (223 surgical and 39 percutaneous) event rate was 34.7% ± 2.1% by 30 years after repair (annual risk: 1.57% between 10 and 30 years after repair). The second PVR rate was 9.9% ± 4.1% by 20 years after the first PVR. Tachyarrhythmia/SCA risk was higher in PVR patients than in No PVR patients and was reduced in PVR patients without tachyarrhythmia/SCA before PVR. However, survival in patients with ventricular tachyarrhythmia/SCA still was better after PVR. At PVR, 13% of patients had tachyarrhythmia/SCA, which was the major predictor of events after PVR. Before PVR, although the ventricular tachyarrhythmia/SCA risks included QRS duration >160 ms and New York Heart Association functional class III or IV, supraventricular tachyarrhythmia was associated with PVR age ≥28 years and N-terminal pro-brain natriuretic peptide >450 pg/mL. CONCLUSION: Tachyarrhythmia/SCA occurrence and the need for PVR increased with age during young adulthood. PVR reduced subsequent arrhythmias only in those patients without arrhythmias before PVR.

Twin atrioventricular nodes, arrhythmias, and survival in pediatric and adult patients with heterotaxy syndrome.

BACKGROUND: Heterotaxy syndrome is likely to involve arrhythmias from associated conduction system abnormalities, which are distinct in different subtypes of isomerism and may change further after interventions and remodeling. OBJECTIVE: The purpose of this study was to understand the risk of arrhythmias and its relation to isomerism subtypes. METHODS: Patients diagnosed between 1980 and 2019 as having heterotaxy syndrome were enrolled and grouped as right atrial isomerism (RAI), left atrial isomerism (LAI), or indeterminate isomerism. RESULTS: Of the 366 patients enrolled, 326 (89.1%) had RAI, 35 (9.6%) LAI, and 5 (1.4%) indeterminate isomerism; 71 (19.4%) patients were adults. Arrhythmias occurred in 37.2% of patients (109 supraventricular tachycardia [SVT], 8 atrial fibrillation/flutter, 12 ventricular tachycardia, and 14 paced bradycardia). Freedom from arrhythmias by the age of 1, 5, 10, 20, and 40 years was 0.849, 0.680, 0.550, 0.413, and 0.053, respectively. Twin atrioventricular nodes were identified in 51.5% of patients with RAI, 8.7% of patients with LAI, and 40.0% of patients with indeterminate isomerism and were the key predictors of SVT. Indeterminate isomerism was also a risk factor for SVT. Other forms of tachycardia appeared relatively late. Sinus bradycardia with junctional rhythm was common in LAI (48.7%) and less in indeterminate isomerism (20.0%), with none occurring in RAI. Only in patients with RAI who showed the poorest survival, ventricular tachycardia worsened the long-term survival. CONCLUSION: RAI was the predominant subtype of heterotaxy in this cohort. Collectively, the median RAI/LAI ratio was 0.731 and 5.450 in Western and East Asian studies, respectively. Arrhythmias, tachycardia, or paced bradycardia were common, but the spectrum was distinct among subtypes.

Left ventricular outflow tract obstruction in complete transposition of the great arteries--echocardiography criteria for surgical strategies.

BACKGROUND: The arterial switch operation (ASO) may be infeasible in patients with transposition of the great arteries (TGA) and left ventricular outflow tract obstruction (LVOTO). METHODS AND RESULTS: Patients with LVOTO were identified among the 229 patients with TGA repaired between 1991 and 2006. Dynamic LVOTO was defined as LVOTO without LVOT abnormalities requiring resection (group I, receiving ASO). Fixed LVOTO was defined as LVOTO with LVOT abnormalities that could (group IIa, receiving ASO) or could not be resected (group IIb, receiving operations other than ASO). Preoperative echocardiography parameters were compared to identify criteria predicting the surgical findings of LVOTO. LVOTO was found in 63 patients (27.5%): 39 with dynamic and 24 with fixed (14 group IIa and 10 IIb) LVOTO. Late, severe neo-aortic regurgitation occurred more frequently in group IIa patients. Echocardiography evidence of isolated subvalvular stenosis, pulmonary to aortic valvular annulus ratio >0.98 or LVOT pressure gradient <22 mmHg predicted dynamic LVOTO (sensitivity 86.3%, specificity 94.7%), whereas that of an annulus ratio <0.85 and a pressure gradient >35 mmHg predicted fixed and non-resectable LVOTO (sensitivity 100%, specificity 100%). CONCLUSIONS: Approximately one-fourth of TGA patients had LVOTO. Echocardiography criteria identified those with dynamic or fixed but resectable (ASO) LVOTO with satisfactory sensitivity and specificity.

Clinical spectrum and long-term outcome of Ebstein's anomaly based on a 26-year experience in an Asian cohort.

Ebstein's anomaly is a rare, congenital cardiac anomaly that may result in cyanosis, right heart failure, and tachyarrhythmia during the newborn stage or after adolescence. This study investigated the data of 77 patients diagnosed between 1980 and 2006 at a tertiary care center in Taiwan. Patients were grouped into either an early group or a late group. Survival declined rapidly within the newborn stage in the early group, but declined only during the third decade in the late group. Surgical results were poor (20% success rate) for neonatal systemic-to-pulmonary shunts in those cases with associated pulmonary atresia, but were satisfactory for other surgical modes. Supraventricular tachyarrhythmia occurred in 31 (41%) patients at a median age of 10 years and could be eliminated by radiofrequency ablation (81% success rate), though the recurrence rate was high (41%). In conclusion, other than those cases requiring shunts at the newborn stage, the long-term outcome was favorable.

Resolution of pathologic Q wave, left ventricular dysfunction and mitral regurgitation after dual coronary repair of the anomalous origin of the left coronary artery from the pulmonary artery.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital cardiac defect that usually presents as dilated cardiomyopathy in infancy. From 1984 to 2005, 13 (five males and eight females, 0.13%) out of 9,950 patients with congenital heart disease were identified as ALCAPA at our institute. Corrective surgery was performed at a median age of 9 months (range: 2 months to 5 years). Eleven patients underwent direct reimplantation of the left coronary artery (LCA) to the aorta, while two received extrapulmonary baffling. The overall survival rate was 92%. Only one patient died 5 months after reimplantation of the LCA due to acute myocardial ischaemia. Left ventricular ejection fraction (LVEF) was significantly lower in the eight (62%) patients operated during infancy than in those operated beyond 5 months (median: 35% vs. 75%). Left ventricle function was normalised in 11 patients (85%). Among the eight patients without concomitant mitral annuloplasty, mitral regurgitation (MR) improved to a mild or trivial degree in six patients and remained at the pre-operative level in two patients. Pathologic Q wave was noted in 11 patients, which eventually regressed in all except two cases. The median interval of recovery was 16 days, 6 months and 24 months for MR, LVEF and electrocardiogram (ECG) changes, respectively. In conclusion, ALCAPA is also a rare disease in Asian countries, such as Taiwan. The subsequent recovery of MR, left ventricular (LV) function and even pathologic Q wave can be expected after dual coronary repair, regardless of the age at repair.

Arrhythmic burdens in patients with tetralogy of Fallot: a national database study.

BACKGROUND: Tetralogy of Fallot (TOF) is a common cyanotic congenital heart disease with increasingly recognized late morbidity. OBJECTIVE: The purpose of this study was to explore the long-term outcome by using a national database of Taiwan, a country with national health insurance and easily accessible medical care. METHODS: Data on TOF patients were retrieved from database records from 2000 to 2010. Complications and therapies were identified by their respective codes. RESULTS: We identified 4781 TOF patients (prevalence 0.63/1000 in pediatric patients and 0.06/1000 in adult patients). Arrhythmias were identified in 219 patients (8.3% for adult patients and 2.8% for pediatric patients): 160 tachycardia and 59 bradycardia (4 with tachy-bradycardia syndrome). The occurrence of arrhythmias was associated with higher mortality (excluding cardiac surgical death, 15.6% vs 8.6%, P = .001). Patients with atrial fibrillation were the oldest (median age 44.3 years), followed by those with tachy-bradycardia syndromes (32.4 years) and atrial flutter (31.5 years). The incidence of nonperioperative tachycardia increased with age (1.4%, 1.7%, 3.3%, 5.2%, 10.2%, and 16.9% in age group 0-9, 10-19, 20-29, 30-39, 40-49, and ≥50 years, respectively). Tachycardia therapy (ablation and implantable cardioverter-defibrillator) was administered in 20.4% (annually 2.4%) of patients with nonperioperative tachycardia. In the subgroup born 2000-2010 with complete postnatal data, mortality was 15.1% (296/1960), and 1-, 5-, and 10-year survival was 0.911, 0.826, and 0.788, respectively. Risk of atrioventricular block requiring a pacemaker was 0.6%. CONCLUSION: Arrhythmias are common in TOF patients and increase mortality risk. Medical needs because of tachycardia often appear late in adulthood.

Ventricular septal defect with secondary left ventricular-to-right atrial shunt is associated with a higher risk for infective endocarditis and a lower late chance of closure.

OBJECTIVE: Although ventricular septal aneurysm may diminish or even close the shunt through the ventricular septal defect (VSD), developing a left ventricular-to-right atrial (LV-RA) shunt may be unfavorable. This study sought to clarify this issue on the basis of an extended observation of such patients. METHODS: Sixty-eight patients (1201 patient-years) who had small perimembranous VSD and LV-RA shunt and were not operated on before 6 years of age were studied. RESULTS: The onset age of LV-RA shunt was 5.8 +/- 3.3 years, with clinical improvement later observed in 23 (34%). The murmur disappeared and showed spontaneous closure in 5 (7%). Seven episodes of infective endocarditis occurred in 6 (8.7%, or 58 per 10000 patient-years), with 2 receiving surgery. Another 4 received surgery during follow-up. With echocardiography, aneurysmal transformation involving the anterior and septal leaflets of tricuspid valve (double sac) was found in 56 (85%), whereas only the septal leaflet (single sac) was involved in 10. Patients with double sac were less likely to show improvement, whereas patients who had superior QRS axis and were female showed clinical improvement more frequently. CONCLUSIONS: VSD with secondary LV-RA shunt is associated with a higher risk for infective endocarditis but still has a low chance for late improvement and even closure.

Clinical implications of major aortopulmonary collateral arteries in patients with right isomerism.

BACKGROUND: The presence of major aortopulmonary collateral arteries (MAPCA) in patients with right isomerism may alter the prognosis, which is still unclear. METHODS: From 1994 to 2003, 138 out of 155 patients (89%) with right isomerism had pulmonary stenosis or pulmonary atresia and constituted the study population. RESULTS: Two groups of patients were identified, one with MAPCA and the other without. The MAPCA originating from descending thoracic aorta or aortic arch was noted in 9 patients (6.5%), with a median number of MAPCA being 3 (range, 2 to 4). Patients with MAPCA commonly had congestive heart failure (8/9, 89%) and frequent lower airway infection (6/9, 67%). In comparison with patients with MAPCA and without, the intrapericardial pulmonary artery was more frequently absent (2 of 9 vs 1 of 129, p < 0.001), and the pulmonary arterial size was smaller (McGoon ratio <1.5, 8 of 9 vs 57 of 129, p = 0.009) in the MAPCA group. The mean pulmonary arterial pressure measured was often higher than the suggested limit for Fontan circulation. Major aortopulmonary collateral arteries were addressed at a median of 6 months old (2 to 19 months old) in 5 patients. Although surgical mortality was not different for first-stage palliation and Glenn shunt in both groups, total cavopulmonary connection could only be performed in one patient with MAPCA with poor results. However, the 5-year survival of patients with and without MAPCA was not statistically different (74.1% vs 55.2%, p = 0.19). CONCLUSIONS: The presence of MAPCA was uncommon but still noted in patients with right isomerism. It may cause heart failure and a less favorable pulmonary vasculature for a complete Fontan-type operation.