RESUMO
OBJECTIVES: To delineate the long-term outcomes and mechanisms of pediatric sinus bradycardia. STUDY DESIGN: Participants with sinus bradycardia who were identified from a survey of 432,166 elementary and high school students, were enrolled 10 years after the survey. The clinical course, heart rate variability, and hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) gene were assessed. RESULTS: A total of 104 (male:female was 60:44; prevalence, 0.025%) participants were observed to have sinus bradycardia at age 15.5 ± 0.2 years with a mean heart rate of 48.4 ± 0.4 beats per minute; 86 study participants (83%) responded to clinical assessment and 37 (36%) underwent laboratory assessment. Athletes composed 37.8% of the study participants. During the extended 10-year follow-up, 15 (17%) of the participants had self-limited syncopal episodes, but none had experienced life-threatening events. According to Holter recordings, none of the participants had heart rate <30 beats per minute or a pause longer than 3 seconds. Compared with 67 age- and sex-matched controls, the variables of heart rate based on the spectral and time domain analysis of the participants with sinus bradycardia were all significantly higher, indicating higher parasympathetic activity. The results of mutation analysis were negative in the HCN4 gene in all of our participants. CONCLUSIONS: The long-term outcomes of the children and adolescents with sinus bradycardia identified using school electrocardiographic survey are favorable. Parasympathetic hyperactivity, instead of HCN4 gene mutation, is responsible for the occurrence of sinus bradycardia.
Assuntos
Bradicardia/diagnóstico , Adolescente , Adulto , Bradicardia/genética , Bradicardia/fisiopatologia , Estudos de Casos e Controles , Criança , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Eletrocardiografia , Feminino , Seguimentos , Marcadores Genéticos , Inquéritos Epidemiológicos , Frequência Cardíaca/fisiologia , Humanos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Masculino , Proteínas Musculares/genética , Mutação , Canais de Potássio , Prognóstico , Estudos Retrospectivos , Taiwan , Adulto JovemRESUMO
OBJECTIVE: To delineate the prevalence and clinical implications of cardiac conduction disturbance (CCD) in school-age children. STUDY DESIGN: Between 1999 and 2001, a citywide survey of 432,166 elementary and high school students had been performed in Taipei by questionnaire, electrocardiography, phonocardiography, and physical examination. Patients with any abnormalities on this survey were referred for final diagnosis. RESULTS: After excluding those with congenital heart disease (CHD), the prevalence of CCD was 0.75%, higher in males than in females (0.78% vs 0.71%). Incomplete right bundle branch block (IRBBB; 0.32%), complete right bundle branch block (CRBBB; 0.11%), ventricular premature contraction (0.11%), and Wolff-Parkinson-White syndrome (0.067 %) were the most common diagnoses. Second-degree atrioventricular block, IRBBB, CRBBB, and intraventricular conduction delay were more common in males; and atrial premature contraction was more common in females. The prevalence of CCD increased with age, from 0.48% in elementary school students to 0.97% in high school students. After detection of CCD, 39 patients with previously undiagnosed atrial septal defect (ASD) and 15 high-risk patients were found. The sensitivity of IRBBB in screening for ASD was 34.67%. CONCLUSIONS: The prevalence of CCD in children without CHD was 0.75%. Detection of CCD helped identify patients with unrecognized ASD and high-risk cardiac patients.
Assuntos
Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiologia , Sistema de Condução Cardíaco/fisiopatologia , Comunicação Interatrial/diagnóstico , Adolescente , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/epidemiologia , Criança , Eletrocardiografia , Feminino , Comunicação Interatrial/complicações , Comunicação Interatrial/epidemiologia , Comunicação Interatrial/fisiopatologia , Humanos , Masculino , Fonocardiografia , Prevalência , Sensibilidade e Especificidade , Fatores Sexuais , Inquéritos e Questionários , Taiwan/epidemiologia , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/epidemiologia , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/epidemiologiaRESUMO
OBJECTIVES: To find a noninvasive method to detect coarctation of the aorta (CoA) in the presence of a patent ductus arteriosus (PDA) in neonates. STUDY DESIGN: From 1994 to 1998, 36 neonates with CoA and PDA confirmed by surgery or cardiac catheterization were studied; another 19 neonates with isolated PDA served as control patients. The prospective study was conducted from 2001 to 2002 on 162 neonates. RESULTS: Among the 36 neonates in the CoA group, 14 patients (39%) had blood pressure discrepancy, 26 patients (72%) had a visualized posterior shelf by echocardiogram, and the ratio of isthmus/descending aorta diameters (I/D ratio) was below 0.64 in 32 patients (89%). None of the control patients had these features. A diagnostic approach was subsequently proposed, according to which a neonate with PDA who fulfilled any of the above features was diagnosed as CoA plus PDA. In the prospective study, the sensitivity and positive predictive values of this method were both 91.7%, whereas the specificity and negative predictive values were both 99.3%. CONCLUSIONS: Echocardiographic measurements of I/D ratio along with the delineation of posterior shelf and a BP discrepancy can satisfactorily identify CoA in the presence of PDA in neonates.
Assuntos
Coartação Aórtica/diagnóstico , Permeabilidade do Canal Arterial/diagnóstico , Ecocardiografia Doppler de Pulso , Aorta/anormalidades , Aorta/diagnóstico por imagem , Coartação Aórtica/complicações , Coartação Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Estudos de Casos e Controles , Permeabilidade do Canal Arterial/complicações , Permeabilidade do Canal Arterial/fisiopatologia , Feminino , Humanos , Recém-Nascido , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To define the risk of sudden death in patients with right isomerism (asplenia) after palliation. STUDY DESIGN: A total of 154 patients with right isomerism was identified from 1980 to 1999. Sudden death was defined as acute cardiovascular collapse from which death occurred within 24 hours. RESULTS: A total of 620 patient-years were evaluated. The 1-year and 5-year survival was 72% and 50%, respectively. There were 22 sudden unexpected deaths (14%, 35 events/1000 patient-years). Sudden death tended to occur in infancy or early childhood (12 +/- 9 months; median, 9 months). The mechanisms were classified as sudden tachyarrhythmic in 2 (9%), sudden cardiac but nontachyarrrhythmic (sudden onset severe cyanosis) in 15 (68%), and sudden noncardiac in 5 (23%)(fulminant sepsis with positive blood culture: streptococcus pneumonia (3), Escherichia coli (1), and yeast-like organism (1)). The incidence of sudden death steadily decreased with age until the age of 3 years. CONCLUSION: The incidence of sudden death in patients with right isomerism after initial palliation remained high. Sudden death was related to complex cardiac anomalies, a susceptibility to fulminant infection, and arrhythmia.
Assuntos
Morte Súbita/epidemiologia , Cardiopatias Congênitas/complicações , Adolescente , Adulto , Criança , Pré-Escolar , Morte Súbita/etiologia , Seguimentos , Humanos , Incidência , Lactente , Recém-Nascido , Cuidados Paliativos , Fatores de Risco , Fatores de TempoRESUMO
OBJECTIVE: To study the epidemiology of leprosy in children in Taiwan. SETTING: Taiwan, with a population increase from 3.3 to 21.7 million, several tides of immigration and national leprosy control programs, from 1910 to 1997. DESIGN: To collect and analyze the documents of Taiwan leprosy surveys and charts of the National Leprosy Control Center. PATIENTS AND MEASUREMENTS: Cumulative and new number of all-age and pediatric-age patients, prevalence rates, new case detection rates, and results of skin bacterial smears. RESULTS AND CONCLUSIONS: The prevalence rates of all-age leprosy ranged between 1.54 and 3.22 per 10,000 population. The proportion of children among all-age patients reached the highest of 4.93% in 1966, dropping to 0% in 1984 and thereafter, until 1988 and 1991 when two and one pediatric-age patients appeared, respectively, following the influx of immigrants from leprosy-endemic countries. The rise and fall of new patients younger than 15 years and 15 years or older were slightly correlated (r = 0.935, p < 0.001). Detection and confirmation of leprosy in children are usually belated. Physicians should still be acquainted with the clinical diagnosis of leprosy since sporadic cases of leprosy can reappear, particularly among children coming from endemic countries.