Natural aortic valve complications of ventricular septal defect: a prospective cohort study.

OBJECTIVE: To study the incidence and onset of aortic valve prolapse (AVP) and aortic regurgitation (AR) in the ventricular septal defect (VSD). STUDY DESIGN: A prospective cohort study POPULATION: The less than one-year-old children with diagnosis of isolated VSD were studied from October 2000 to September 2006 at Queen Sirikit National Institute of Child Health. Clinical follow-up and echocardiographic studies were scheduled every 2-3 months in the first year of age and then every 6 months to evaluate the size, location, flow across VSD, aortic valve morphology and aortic regurgitation. RESULTS: Three hundred and twenty-one cases of VSD were followed up. One was excluded due to associated hypoplastic RV An overall of 2,644 echocardiograms were performed. The percentage of perimembranous, subpulmonic, muscular inlet and multiple types were 70.3%, 19.4%, 5.6%, 3.1% and 1.6%, respectively. Size of the VSD was diagnosed to be small, moderate, and large VSD in 62.5%, 15.9% and 21.6% respectively. At the end of the study, the incidence of AVP in subpulmonic VSD was 87.1% compared to 16.4% in perimembranous VSD, with a relative risk of 5.30 and the incidence of AR in subpulmonic VSD was 37.1% compared to 5.3% in perimembranous VSD, with a relative risk of 6.95. From the survival analysis, the patient with subpulmonic VSD developed AVP at 46%, 77%, 90% and 94% compare to 8%, 13%, 20% and 23% of perimembranous VSD at 12, 24, 36 and 48 months of age respectively (p < 0.001). The patient with subpulmonic VSD developed AR at 8%, 17%, 35% and 38% compare to 2%, 4%, 5% and 7% of perimembranous VSD at 12, 24, 36 and 48 months of age respectively (p < 0.001). At the end of the study, ninety-six cases (30%) underwent cardiac operation with the indication of heart failure or the occurrence of AR. Sixty one cases (19.1%), including two cases of subpulmonic type had spontaneous closure of VSD. Seven cases (2.2%) had lost to follow up and five cases (1.6%) died during the follow up period. CONCLUSION: The incidence of AVP and AR are high in subpulmonic VSD being much higher than perimembranous VSD with a relative risk of 5.30 and 6.95 respectively. These complications are significantly from infancy period and are an indication for early cardiac surgery.

A comparison of oral chloral hydrate and sublingual midazolam sedation for echocardiogram in children.

OBJECTIVE: To compare the efficacy and safety of oral chloral hydrate and sublingual midazolam to sedate the children undergoing echocardiography. MATERIAL AND METHOD: A double-blind, randomized trial study in the children judged to require sedation prior echocardiogram were performed. Two hundred sixty-four patients between 6 months and 5 years of age were randomized to chloral hydrate or midazolam groups. Either 50 mg/kg of chloral hydrate orally or 0.3 mg/kg of midazolam sublingually was given in each groups. If the child was not responded within 30 minutes after the first dose, another half dose of each drug for the second dose will be required. The action duration time, sedation score level and the ability to complete echocardiogram were collected. RESULTS: Both groups were comparable with respect to age, sex, body weight, underlying heart disease, baseline O2 saturation and functional heart classification. The children in chloral hydrate group needed the second dose for sedation more than midazolam group (10.6%, 5.3% p = 0.111). The onset, action duration and total study time were significantly shorter in midazolam than in chloral hydrate group (p < 0.001). The number of the patients who had the action duration within the optimal time (< 45 min) were significantly more cases in midazolam than in chloral hydrate group (93.1%, 43.5% p < 0.001). Success rate of echocardiogram was 99.2% in each group. There was no difference in echocardiographic time performed in both groups. The children in chloral hydrate group had deeper in level of sedation (p < 0.001). Both groups showed no significant difference in term of the ability to complete echocardiographic examination. The reaction of the children to take the medication and the number of the patients who had systemic O2 saturation change more than 5%from the baseline were higher in chloral hydrate group significantly (14.4%, 4.5% p = 0.006 and 9.9%, 3.1% p = 0.025). CONCLUSION: Sublingual midazolam at the dose of 0.3 mg/kg can be used to sedate the children at age group between 6 months to 5 years who undergoing echocardiogram with comparable rate of success and safety as 50 mg/kg of chloral hydrate orally. The less depth in the level of consciousness after sedation with midazolam compare to chloral hydrate may be advantage in a high risk patient to avoid deep sedation but may be disadvantage in case who need more comprehensive echocardiographic evaluation.

Pediatric heart surgery waiting time in Thailand and its effect on mortality: A cooperative study from Chulalongkorn, Children and Chiang Mai University hospitals.

BACKGROUND: Thai children who need cardiac surgery are often put on a waiting list. The waiting time and mortality during waiting have not been previously systematically studied. MATERIAL AND METHOD: A cooperative study was conducted at King Chulalongkorn Memorial hospital (Chula), Children hospital (CH), and Chiang Mai University hospital (CMU). The status of children who were referred for cardiac surgery at these hospitals in the year 1999-2000 (Chula and CMU) and the year 2000 (CH) were analyzed by Kaplan-Meier survival curve. The patients who lost to follow up and could not be contacted were censored at the time of last clinic visit. Log-Rank test was used to compare the survival curve and waiting time between three hospitals. RESULTS: The averaged annual referrals for cardiac surgery at the three hospitals were 846 cases (205 for Chula, 462 for CH and 179 for CMU). Mean age was 4.3 +/- 4.2 years and 51% were male. Follow up data were complete in 96.3%. Surgical procedures were correction of simple shunt lesions (ASD, VSD, AV canal) in 33.9%, close heart surgery (PDA ligation, coarctation repair, BT shunt) in 29.9%, total repair TOF in 19.6%, complex surgery in neonate and infants (arterial switch, TAPVR repair, Norwood procedure, truncus and interrupted aortic arch repair) in 4.2% and others in 12.3%. Median waiting time was 195 days and was significantly different between the three hospitals (p < 0.01). Mortality while waiting were approximately 5% at 2 years at Chula and CH, which was significantly higher than CMU (0%, p = 0.02). Further analysis revealed difference in age (lower Chula than CH than CMU) and types of surgery (more complex at Chula and CH) which may be the causes for difference in the mortality observed. CONCLUSION: Waiting time for cardiac surgery for children in Thailand is long and should be viewed as a problem in public health policy. Optimal waiting time at each hospital may not have to be the same, depending on the type and severity of the disease seen at each particular center Attempt should be made to solve this problem at the national level.

Aortic valve prolapse in subpulmonic ventricular septal defect.

BACKGROUND: Ventricular septal defect (VSD) is the most common congenital heart disease worldwide. Subpulmonic type VSD is an interesting subtype due to the aortic valve complications rate, which can change the prognosis of the VSD. Higher prevalence rates have been reported with this subtype in Eastern countries but there has been no report from Thailand so far. OBJECTIVE: 1. To determine the prevalence of subpulmonic VSD. 2. To determine the prevalence and demographic data of aortic valve prolapse (AVP) and aortic regurgitation (AR) in subpulmonic VSD. METHOD: A retrospective study of 1,977 patients with isolated VSD, diagnosed from January 1995 to June 2002 at the Cardiology Unit, Queen Sirikit National Institute of Child Health was reviewed to differentiate types of VSD. Color flow doppler echocardiogram was performed in all cases to confirm the diagnosis and differentiate the types of VSD. Patients with subpulmonic VSD were studied to find out the presence of the aortic valve prolapse and aortic regurgitation. Those who had subpulmonic VSD were called for reevaluation of aortic valve complications, from January 2000 to June 2002. MAIN OUTCOME MEASURE: Subpulmonic VSD, aortic valve prolapse (AVP) and aortic regurgitation (AR). RESULTS: Subpulmonic VSD was diagnosed in 312 cases (17.5%). At the mean age of 3.47 yr, AVP was found in 101 cases (32.4%) and AR was found in 54 cases (17.3%) at the first echocardiogram. Subsequent echocardiography follow-up showed that the overall number of AVP cases was 153 (49%) and AR was 84 (26.9%) at the mean age of 5.5 and 6.3 year respectively. CONCLUSION: The prevalence of subpulmonic VSD was high among Thai children. Aortic valve complication is common in this group and can occur from early infancy. The present findings support the progressive increase in this complication with age.