592 Induction of atrial fibrillation during ventricular Defibrillation Threshold Testing shock on t vs. direct current

2005 Europace  
Purpose: Previous studies analyzing the diagnostic value of the 12-lead ECG criteria differentiating atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) due to concealed accessory pathway (AP) have shown inconsistent resuks. ST depression has been reported as a reliable diagnostic tool in pediatric patients. The present study was done to assess the value of different ECG criteria as well as to search for other possible discrimination criteria
more » ... adult patients. Methods: In 97 patients (age _> 15 year), 50 with typical AVNRT and 47 with AVRT via a concealed AP, the 12qead ECG of sinus rhythm and tachycardia (QRS duration < 120 ms) were recorded. ECGs were analyzed by two electrophysiologist independently for the heart rate during tachycardia, QRS oscillation, cycle length oscillation, presence of retrograde P wave, RP interval (in case of visible P wave), Pseudo r/S, ST depression > 2ram and the number and the location of the leads with ST depression. Results: The proposed algorithm by Jaeggi et al. accurately classified the SVT in 81.4% of cases (76% for AVNRT vs. 88% for AVRT). ST depression in our patients was not as useful as previously described (sensitivity = 43%, specificity = 68% and positive predictive value=56%) and it accounted for 6 of 12 (50%) cases of misdiagnosed AVNRT. However, ST depression > 2ram among patients with no visible P wave or RP interval < lOOms, had sensitivity, specificity, positive and negative predictive value of 88%, 75%, 54% and 95%, respectively for the diagnosis of AVRT. Location of leads with ST depression > 2ram was not different among AVRT and AVNRT patients. QRS oscillation in univariate analysis was useful especially in cases without concomitant ST depression >2ram, but adding QRS oscillation to other parameters (Pseudo r/S, retrograde P wave, RP duration and ST depression > 2mm) did not increase the overall diagnostic accuracy. Conclusions: While ST depression _> 2 mm was not as useful as proposed in paediatric cases, the total accuracy of the algorithm was acceptable (81.4%). However, with a NPV of 95% and a PPV of 54% among patients with no visible P wave or RP < lOOms, lack of ST depression is much more useful predicting AVNRT, than the presence of ST depression predicting AVRT.
doi:10.1016/eupace/7.supplement_1.132-b fatcat:g7xifiyxnbe4tiiqjfzf3pqhri