Exercise-induced bronchoconstriction among Malay schoolchildren.

OBJECTIVE: Exercise-induced bronchoconstriction (EIB) may be demonstrated in 60-70% of asthmatic children in temperate climates. In areas of high humidity it is postulated to be low. The aim of the study was to determine the prevalence of EIB in a population of schoolchildren with wheezing, living in the humid tropical climate of Kuala Lumpur, Malaysia. METHOD: We performed a cross-sectional study using the International Study of Asthma and Allergies in Childhood questionnaire to identify 7-12-year-old Malay children with asthma symptoms from a primary school in central Kuala Lumpur. Sixty-five of 76 children with 'ever wheeze' performed an exercise challenge test successfully in an uncontrolled environment. A random sample of 80 schoolchildren with no history of wheeze were similarly tested as controls. The relative humidity and temperature were recorded. A fall of > 15% was considered as clinically important. RESULTS: The prevalence of EIB in schoolchildren with 'ever wheeze' was 47.7%. The prevalence of EIB in children with 'current wheeze' was 51.6%. The prevalence of EIB in controls was 7.5%. The relative humidity during the study ranged from 41 to 90%. There was no significant relationship between different humidity levels and EIB (P = 0.58, regression analysis). CONCLUSION: This study demonstrates that EIB is present in asthmatic children despite the highly humid tropical environment.

The Amplatzer duct occluder: experience in 209 patients.

OBJECTIVES: The aim of the study was to assess the safety and efficacy of the Amplatzer ductal occluder (ADO) in transcatheter occlusion of patent ductus arteriosus (PDA). BACKGROUND: Transcatheter closure of small to moderate sized PDAs is an established procedure. The ADO is a self-expandable device with a number of salutary features, notably its retrievability, ease of delivery via small 5F to 7F catheters and a range of sizes suitable even for the larger PDAs. METHODS: Between November 1997 and August 1999, the ADO was successfully implanted in 205 of 209 patients with PDA. The inclusion criteria for this device occlusion method were patients with clinical and echocardiographic features of moderate to large PDA, weighing > or =3.5 kg as well as asymptomatic adolescents and adults with PDA measuring > or =5.0 mm on two-dimensional (2D) echocardiogram. Occlusion was achieved via the antegrade venous approach. Follow-up evaluations were performed with 2D echocardiogram, color-flow mapping and Doppler measurement of the descending aorta and left pulmonary artery velocity at 24 h and 1, 3, 6 and 12 months after implantation. RESULTS: Two hundred and five patients had successful PDA occlusion using this device. The patients were between two months and 50 years (median 1.9) and weighed between 3.4 kg and 63.2 (median 8.4). Infants made up 26% of the total patients. The PDA measured from 1.8 to 12.5 mm (mean 4.9) at the narrowest diameter. Forty-four percent of patients achieved immediate complete occlusion. On color Doppler the closure rates at 24 h and 1 month after implant were 66% and 97%, respectively. At 6 and 12 months all except one patient attained complete occlusion. Device embolization occurred in three patients; in two this was spontaneous, and in the other it was due to catheter manipulation during postimplant hemodynamic measurement. Mild aortic narrowing was seen in an infant. CONCLUSIONS: Patent ductus arteriosus occlusion using ADO is safe and efficacious. It is particularly useful in symptomatic infants and small children with relatively large PDA. Embolization can be minimized by selection of appropriate sized devices, and caution should be exercised in infants <5 kg.

Prevalence of childhood asthma and allergy in an inner city Malaysian community: intra-observer reliability of two translated international questionnaires.

OBJECTIVES: (a) To examine the intra-observer reliability of the Malay language versions of two international respiratory questionnaires i.e. the International Study of Asthma and Allergy in Children (ISAAC) and the American Thoracic Society (ATS) questionnaires, and (b) using the more reliable of these questionnaires, to estimate the prevalence of asthma and allergy related symptoms in an ethnically homogenous inner city community in Kuala Lumpur. METHODS: The study was conducted among 7 to 12 year old school children of Malay ethnic origin living in an inner city area of Kuala Lumpur. The sample consisted of 787 children attending the only primary school in the area. The Malay versions of both questionnaires were administered twice, one month apart, and were completed by parents. Agreement between the first and second responses to the same questions were assessed by Cohen's kappa. Kappa values < 0.4 were indicative of poor intra-observer reliability, 0.4-0.59 moderate reliability, 0.6-0.79 good reliability and > 0.79 excellent reliability. RESULTS: 77.9% and 36.3% of parents responded to the first and second administrations of the questionnaires respectively. Kappa values of > 0.4 were obtained in 15/16 (93.8%) and 17/27 (63.0%) questions of the ISAAC and ATS questionnaires respectively. Excellent kappa values were obtained in 4/16 (25%) questions of the ISAAC questionnaire versus only 1/27 (3.7%) questions of the ATS questionnaire. From the ISAAC questionnaire, all questions on wheeze had good reliability while those on asthma had excellent reliability. Questions on allergic symptoms had poor to moderate reliability. In contrast, from the ATS questionnaire, questions on wheeze had moderate reliability while questions on asthma were excellently reliable. Questions on allergic symptoms had moderate to good reliability while those on cough, phlegm and bronchitis had poor reliability. According to the ISAAC questionnaire the prevalence of ever wheeze, wheeze in the last 12 months, ever asthma and wheeze with exercise in the last 12 months was 12.5%, 6.6%, 10.3% and 5.9% respectively. The prevalence of ever sneeze or runny nose, sneeze or runny nose in the last 12 months, watery eyes in the last 12 months and ever eczema was 15.2%, 11.1%, 4.4% and 8.5% respectively. CONCLUSIONS: The translated ISAAC questionnaire was more reliable than the translated ATS questionnaire. Asthma and related symptoms were common among Malay school children in inner city Kuala Lumpur.

Pulmonary atresia with intact ventricular septum percutaneous radiofrequency-assisted valvotomy and balloon dilation versus surgical valvotomy and Blalock Taussig shunt.

OBJECTIVE: We compared the result of radiofrequency (RF)-assisted valvotomy and balloon dilation with closed surgical valvotomy and Blalock Taussig (BT) shunt as primary treatment in selected patients with pulmonary atresia and intact ventricular septum (PA-IVS). BACKGROUND: Patients with PA-IVS who have mild to moderate hypoplasia of the right ventricle (RV) and patent infundibulum have the greatest potential for complete biventricular circulation. The use of RF or laser wires to perforate the atretic valve followed by balloon dilation provides an alternative to surgery. METHODS: Between May 1990 and March 1998, 33 selected patients underwent either percutaneous RF valvotomy and balloon dilation (group 1, n = 21; two crossed over to group 2) or surgical valvotomy with concomitant BT shunt (group 2, n = 14). Second RV decompression by balloon dilation or right ventricular outflow tract (RVOT) reconstruction were performed if necessary. Patients who remained cyanosed were subjected to transcatheter trial closure of the interatrial communication. Partial biventricular repair was offered to those with inadequate growth of the RV. RESULTS: The primary procedure was successful in 19 patients in group 1. There was one in-hospital death and two late deaths. Of the remaining 16 survivors, 12 achieved complete biventricular circulation, 7 of whom required no further interventions. Two patients required repeat balloon dilation, 1 RVOT reconstruction and 2 transcatheter closure of interatrial communication. Two patients underwent partial biventricular repair. In group 2, there were 3 in-hospital deaths after the primary procedure and 1 patient died four months later. All survivors (n = 10) required a second RV decompression, 8 by balloon dilation and 2 by RVOT reconstruction, after which, two patients died. Of the final 8 survivors, 7 achieved complete biventricular circulation, 5 after coil occlusion of the BT shunt and 2 after closure of interatrial communication. CONCLUSIONS: Radiofrequency valvotomy and balloon dilation is more efficacious and safe compared with closed pulmonary valvotomy and BT shunt in selected patients with PA-IVS.