[Persistence of palpitations after successful radiofrequency catheter ablation]. / Palpitações persistentes após ablação por cateter com radiofreqüência.

PURPOSE: The aim of this study was to determine prevalence and the underlying mechanism of persistent palpitations after successful radiofrequency ablation of reentrant nodal tachycardia and atrioventricular tachycardia. METHODS: One hundred twenty consecutive patients (mean age of 36 +/- 16 years) who underwent radiofrequency catheter ablation of atrioventricular or reentrant nodal tachycardia constituted the analyzed group. Prevalence of palpitations was investigated during out-clinic visits and telephone interviews. Patients complaining of palpitations were divided in 2 groups: 1) those in whom palpitations lasted more than 30 seconds, and 2) those in whom the paroxysms lasted < 30 seconds (group II). All patients underwent clinical evaluation, ECG and Holter monitoring. Transesophageal atrial pacing and electrophysiologic stimulation were carried out when judged necessary. RESULTS: During a follow up period of 9 +/- 4 months, 52 patients complained of palpitations. In 31 group I patients, palpitations were related to ventricular and atrial premature beats as shown during Holter monitoring. In group II patients, eight had recurrence, five presented a new arrhythmia not recognized previously to the ablative procedure and two patients had their symptoms related to arrhythmias recognized before ablation but taken as asymptomatic. The mechanism of palpitations was not identified in six patients. CONCLUSION: Palpitations may persist in 43% of patients who undergo radiofrequency ablation to treat reentrant nodal tachycardia and atrioventricular tachycardia. Recurrence and treatment are more likely when palpitations last longer than 30 seconds.

Electrocardiographic identification of mid-septal accessory pathways in close proximity to the atrioventricular conduction system.

In order to identify ECG characteristics of overt mid-septal accessory pathways (APs) predictive of close proximity to the AV conduction system we analyzed data from patients who underwent successful RF catheter ablation of a mid-septal AP. Mean patient age was 31 +/- 16 years, and 13 were male. The 40 degrees right anterior oblique view was used to divide the mid-septal area into 3 zones: 1 (anterior portion); 2 (intermediate); and 3 (posterior portion). The 12-lead ECG was analyzed with regard to delta wave polarity and R/S transition in the precordial leads. The findings from patients ablated at zone 3 were compared to those at zones 1 and 2. All patients had a positive delta wave in the leads I, II, aVL, and negative delta wave in the leads III and aVR. The R/S transition occurred in lead V2 in 80% of patients. The delta wave in lead aVF was the only ECG characteristic that correlated with the AP ablation zone. Six of 8 patients ablated at zone 3 had a negative delta wave in lead aVF while 6 out of 7 patients ablated at zone 1 or 2 had a positive or isoelectric delta wave in lead aVF (P = 0.03). A positive or isoelectric delta wave in lead aVF identifies mid-septal AP in close proximity to the AV conduction system.