Radiofrequency catheter ablation in pediatrics: experience at Siriraj Hospital.

UNLABELLED: Tachyarrhythmia is one of the life threatening cardiac electrophysiology problems in children. It also affects quality of life of the patients. Radiofrequency catheter ablation (RFCA) has made a significant impact in the treatment of tachyarrhythmia since 1989. The present report is the first and largest report in Thai children. There have been 24 RFCA procedures in 21 children since it was initially performed at Siriraj Hospital from January 1996 to December 1999. The electrophysiology studies and medical records were analyzed retrospectively. Median age and weight at the time of the procedure were 11 (1.1-13) years old and 38.8 (6.8-78.2) kg respectively. The presenting symptoms were palpitation 66.7 per cent, presyncope 16.7 per cent, congestive heart failure and cardiogenic shock 8.3 per cent, syncope 4.2 per cent, and chest pain 4.2 per cent. Median duration of symptom was 3.5 (0.1-8.0) years. The underlying cardiac arrhythmias were Wolff Parkinson White (WPW) syndrome 50 per cent, concealed accessory pathway 16.7 per cent, atrioventricular node re-entry tachycardia (AVNRT) 16.7 per cent, atrial ectopic tachycardia (AET) 12.5 per cent, and WPW with AVNRT 4.2 per cent. The median fluoroscopy time and procedure time were 25 (4-145) minutes and 125 (60-320) minutes respectively. The median tachycardia cycle length was 332.5 (220-460) seconds. The immediate success rate was 21/24 (87.5%) procedures. The procedural complication was 1/24 (4.2%). Two patients (8.3%) had recurrences of tachycardia and were successfully controlled with antiarrhythmic drugs. CONCLUSION: RFCA is a safe, effective, and curative procedure with high success rate for pediatric tachyarrhythmias.

Radiofrequency catheter ablation in symptomatic ventricular arrhythmia.

BACKGROUND: Radiofrequency catheter ablation (RFCA) is an effective method to cure both supraventricular and ventricular arrhythmia (VA) in certain centres. AIM: To assess the results of RFCA in VA at Siriraj Hospital. METHOD: Electrophysiologic study, mapping, using both earliest endocardial activation and pace mapping, and ablation were performed. RESULTS: Thirty patients with symptomatic VA underwent RFCA. The mean age was 44 years. Eight patients had underlying heart disease (two prolapsed mitral valve, three myocarditis, two dilated cardiomyopathy and one mitral stenosis). Thirty-six morphologies of VA were detected from the study. Thirty-three morphologic tachycardias attempted were successfully ablated; 17, 10 and six were right VT, left VT and premature ventricular contraction (PVC), respectively. Failure of ablation occurred in one patient with left VT. Only minor complications occurred in this study. There was no difference in cycle length and endocardial activation time between right and left VT. 12/12 identical pace mapping was more easily performed in right VT than in left VT. The fluoroscopic and procedure times in left VT were significantly longer than in right VT. Relapse occurred in six patients. Re-ablation was successfully performed in four patients, giving a final success rate of 93%. CONCLUSION: RFCA is an effective treatment and should be considered as an alternative method to cure VT and refractory PVC.

Successful implantation of transvenous automatic implantable cardioverter defibrillator (AICD): the first case report in Thailand.

We successfully implanted transvenously the AICD in a case of sudden cardiac arrest survivor. Though the device is very expensive, it is useful in some selected cases. With its diagnostic capabilities, the device may be useful in elucidating the underlying mechanism of Lai Tai.

Radiofrequency ablation of cardiac arrhythmia: the first fifty cases experience in Siriraj Hospital.

In our series of 50 consecutive patients with a wide variety of cardiac arrhythmia, a combined approach to electrophysiological diagnosis and definitive treatment with catheter ablation was associated with a high degree of efficacy, low procedural complication and low rate of arrhythmia recurrence. The radiofrequency catheter ablation should be considered as the acceptable or preferable first line treatment in patients with supraventricular tachycardia and idiopathic ventricular tachycardia.

Radiofrequency catheter ablation in monomorphic ventricular tachycardia.

Twenty patients with symptomatic monomorphic ventricular tachycardia (VT) underwent radiofrequency (RF) energy catheter ablation. Four patients (20%) had underlying heart disease (1 prolapse mitral valve, 1 dilated cardiomyopathy and 2 myocarditis). Five patients (25%) had left sided VT and right sided VT in the remainder (75%). Radiofrequency catheter ablation was initially successful in all patients without major complication. Recurrence occurred in three patients (15%). In conclusion, RF ablation is an effective treatment for symptomatic monomorphic right and left sided VT especially in patients who do not want long term antiarrhythmic agents.

Resolution of dilated cardiomyopathy after radio-frequency catheter ablation of atrial tachycardia.

The dilated cardiomyopathies are characterized by an increase in left ventricular internal dimensions without an appropriate increase in ventricular wall thickness. Sustained tachyarrhythmia, either supraventricular or ventricular, may be associated with this condition and may improve after termination of the tachycardia. We report a case of secondary dilated cardiomyopathy caused by incessant atrial tachycardia who underwent successful radiofrequency catheter ablation and left ventricle returned to normal size and function in six months post ablation.

Radiofrequency catheter ablation in idiopathic ventricular tachycardia with structurally normal heart.

In conclusion, we reported two cases of idiopathic right and left VT who presented with syncope and palpitation. The surface QRS during VT and electrophysiologic studies showed the site of origin at RVOT in the first case and inferoapical area of left ventricle in the other. RF ablation was an effective treatment in both patients without any serious complication. Both of them are free of symptoms without any medication.