Permanent cardiac pacing in pediatrics: experience in Thailand.

Permanent cardiac pacing in pediatrics is uncommon. There has been limited data in Thailand. A retrospective study of cardiac data and pacing parameters during follow-up periods in patients who underwent permanent pacemaker implantation at the Department of Pediatrics, Siriraj Hospital, from January 1997 to December 2004 was conducted. There were 31 patients in total who have been followed-up for the median period of 34.4 (1.07-91.13) months. All patients had atrio-ventricular block prior to implantation. The etiology were; post cardiac surgery 38.7%, maternal autoimmune diseases 19.4%, post radiofrequency ablation 3.2%, and unknown 38.7%. Twenty three cases (74.2%) were implanted by epicardial approach, and 18 (25.8% were implanted by endocardial approach. Modes of permanent pacemaker were WIR 45.2%, VVI 35.5%, and DDD 19.4%. Age and body sized of the patients using epicardial approach were significantly lower than endocardial approach. Minor complications occurred in 3 cases (9.6%) i.e. 2 with surgical wound infection, 1 with post pericardiotomy syndrome. Minimum energy threshold, sensitivity, and impedance at implantation and during follow up periods were not different statistically. There was significantly less in minimum energy threshold of endocardial lead than epicardial lead. Epicardial lead failure was found in 3 cases (11.5%) at the median time of 8.9 (7.9-62) months post implantation, but was not significant different from endocardial leads. Survival of epicardial leads were 82% at 8 years. Conclusion: Permanent pacemaker implantation in pediatrics was rare (4.4 cases/year). It was feasible in almost all body size and a rather safe procedure. There was no significant change in pacing parameters at the medium-term follow-up period for both epicardial and endocardial leads. Minimum energy threshold of epicardial lead was significantly higher than endocardial lead.

Efficacy of fetal echocardiography and an evaluation of indications.

Fetal echocardiography has been accepted as a prenatal noninvasive diagnostic tool of cardiovascular diseases in fetuses for more than three decades. There are limited data in Thailand. A retrospective study of prenatal, natal and postnatal data of pregnant women who had fetal echocardiography at Siriraj Hospital, Bangkok, Thailand, from January 1999 to July 2005 was conducted. In total, there were 117 pregnant women who had fetal echocardiography under standard indications. Median age of pregnant women was 30.2 (17.3-44.2) years old. Median gestational age at the first fetal echocardiography was 29 (17-40) weeks. Median number of time the women had fetal echocardiography was 1 (1-10). Indications for fetal echocardiography were; obstetricians suspected of fetal cardiovascular diseases, multiple anomalies, family history of congenital heart diseases, chromosome anomalies, hydrops fetalis, and other indications (53.8%, 12%, 11.1%, 8.5%, 8.5% and 6.0% respectively). There were 49 (41.8%) cases who had abnormal cardiovascular problems, i.e., structural heart diseases 26 cases, rhythm disturbance 15 cases, and cardiac masses 8 cases. Upon comparison with postnatal echocardiography and/or autopsy findings, fetal echocardiography had a sensitivity of 96.9%, specificity of 90.6%, and accuracy of 92.8%. There was various degrees of risk to have cardiovascular problems for each of the indication taking fetal echocardiography and postnatal data into consideration. Fetal echocardiography had an impact on the management in 57.3% of cases. Conclusion: Fetal echocardiography is a reliable prenatal diagnostic tool for cardiovascular problems with high accuracy and has an impact on the management at prenatal, natal and postnatal period. Different indications for fetal echocardiography have an effect on the relative risk of fetal cardiovascular diseases.

Prenatal diagnosis of cardiovascular diseases.

Fetal echocardiography is a safe means to obtain reliable anatomical and hemodynamic data of the fetal heart. The procedure is essential for prenatal diagnosis of cardiovascular abnormalities. In addition, fetal echocardiography is useful to follow-up the progression, monitoring during treatment and making a plan of treatment especially in life-threatening cardiac conditions. The objective of this study was to find the distribution of indications for fetal echocardiography, fetal cardiac anomalies detected, outcome of the fetuses and to assess the accuracy of the procedure. A retrospective study was done at Siriraj Hospital, Mahidol University, Bangkok, Thailand. Pregnant women whose fetuses had prenatal echocardiographic data and gave birth from January 1999 to December 2001 were included. The total number of pregnant women was 54 cases. The indications for fetal echocardiography were suspicion of fetal cardiovascular disease by the obstetrician 42.6 per cent, family history of congenital heart diseases 14.8 per cent, multiple organ system anomalies 14.8 per cent, chromosomal anomalies 11.1 per cent, hydrops fetalis 9.3 per cent, maternal systemic diseases 5.6 per cent and previous pregnancy with a dead fetus in utero 1.9 per cent. The gestational age at the time of the first fetal echocardiography ranged from 17 to 39 weeks (median 28 weeks). The number of fetal echocardiography done in each case ranged from 1 to 10 (median 1.4). Prenatal diagnosis of the abnormal cardiovascular system in fetuses was found in 19 cases (35.2%). There were abnormal cardiac anatomies in 42 per cent, cardiac tumors or abnormal masses in 37 per cent and rhythm disturbances in 21 per cent. When compared with postnatal echocardiography and/or autopsy finding, fetal echocardiography had a sensitivity of 100 per cent, specificity of 96.3 per cent and accuracy of 97.8 per cent. Conclusion: Fetal echocardiography has good accuracy in the diagnosis of cardiovascular diseases. Obstetrician's suspicion is important in the prenatal diagnosis of heart disease that would have affected the short and long-term outcome of the fetus.