Novel ECG predictor of difficult cases of outflow tract ventricular tachycardia: peak deflection index on an inferior lead.
ABSTRACT An ECG predictor of ablation success has not been determined for difficult cases of outflow tract ventricular tachycardia/ventricular premature contractions (OT-VT/VPC).
ECG analysis and radiofrequency catheter ablation (RFCA) were performed in 70 patients with OT-VT/VPC. The peak deflection index (PDI) was determined in the inferior lead presenting the tallest R wave by dividing the time from QRS onset to peak QRS deflection by total QRS duration. In 10 (14%) of the 70 patients, RFCA performed at a septal or epicardial site was unsuccessful (group 1), but was successful in the remaining 60 patients (group 2). Neither activation time (35+/-15 ms vs 40+/-12 ms, P=0.3) nor QRS duration (141+/-19 ms vs 137+/-19 ms, P=0.6) were significantly different between groups 1 and 2. However, PDI was significantly higher in group 1 than in group 2 (0.62+/-0.06 vs 0.55+/-0.06, P=0.002). A PDI >0.6 identified unsuccessful OT-VT/VPC with 80% sensitivity and 90% specificity, and may indicate that the origin of the OT-VT/VPC is deep within the ventricular septum or at an epicardial site.
A PDI >0.6 is more likely to be associated with a higher rate of RFCA failure.
Article: Ventrikuläre Extrasystolie[Show abstract] [Hide abstract]
ABSTRACT: Ventricular extrasystoles (VES, also known as premature ventricular contraction (PVC) or premature ventricular beat (PVB)) are a common cause for complaints. Normally even frequent VES are not life-threatening if no structural heart disease exists, and treatment is only required for symptomatic reasons. In addition to explaining the harmlessness of the arrhythmia to the patient as well as eliminating possible reversible causes, an attempt of drug treatment ranks first (at first with beta blockers or in individual cases with calcium antagonists of the verapamil type, and if this treatment does not show sufficient impact also with specific membrane stabilising substances). In highly symptomatic patients whose condition cannot be controlled adequately with these measures or in patients with very strong complaints catheter ablation in a centre experienced with this procedure should be considered.In contrast, VES in the presence of heart disease and especially with reduced left ventriclular function are of prognostic importance. In addition to symptomatic treatment it is most important to protect the patient from sudden cardiac death. Treatment of the underlying condition improves the prognosis, and the implantation of a defibrillator also plays an important role.DoctorConsult - The Journal. Wissen fur Klinik und Praxis 08/2011; 2(2). DOI:10.1016/j.dcjwkp.2011.07.009
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ABSTRACT: -Although coronary cusp ventricular arrhythmia (CC-VA) can be treated by catheter ablation, reliable indicators of successful ablation sites have not been fully identified. -This study comprised 392 patients undergoing radiofrequency catheter ablation for outflow tract ventricular arrhythmia (OT-VA) at 3 institutions from January 2007 to August 2012. The successful ablation site was on the left coronary cusp (LCC) or right coronary cusp (RCC) in 35 (8.9%) of the 392 patients. In nine (26%) of these 35 patients, a discrete pre-potential was recognized, 5 of whom had LCC-VAs and 4 of whom had RCC-VAs. Radiofrequency catheter ablation was successful at the site of the pre-potential in all 9 of these patients. The duration of the isoelectric line between the end of the discrete pre-potential and the onset of the ventricular electrogram was 27±13 ms. The time from onset of the discrete pre-potential at the successful ablation site on the CC to the QRS onset (activation time) was 69±20 ms (range 50-98 ms). Pace mapping was graded as excellent at the successful ablation site in one patient only. No discrete pre-potential was recorded in any successful right OT-VA ablation case in this study. -A discrete pre-potential was seen in 9 (26%) of 35 patients with CC-VA. In left and right CC-VA, the site of a discrete pre-potential with ≥ 50 ms activation time may indicate a successful ablation site.Circulation Arrhythmia and Electrophysiology 08/2013; 6(5). DOI:10.1161/CIRCEP.113.000157 · 5.42 Impact Factor
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ABSTRACT: BACKGROUND Although several reports address characteristic 12-lead electrocardiographic findings of outflow tract ventricular arrhythmias (OT-VAs), the accuracy of electrocardiogram-based algorithms to predict the OT-VA origin is sometimes limited. OBJECTIVE This study aimed to develop a magnetocardiography (MCG) based algorithm using a novel adaptive spatial filter to differentiate between VAs originating from the aortic sinus cusp (ASC-VAs) and those originating from the right ventricular outflow tract (RVOT-VAs). METHODS This study comprised 51 patients with an OT-VA as the target of catheter ablation. An algorithm was developed by correlating MCG findings with the successful ablation site. The arrhythmias were classified as RVOT-VAs or ASC-VAs. Three parameters were obtained from 3-dimensional MCG imaging: depth of the origin of the OT-VA in the anteroposterior direction; distance between the earliest atrial activation site, that is, sinus node, and the origin of the OT-VA; and orientation of the arrhythmia propagation at the QRS peak. The distance was indexed to the patient's body surface area (in mm/m(2)). RESULTS Origins of ASC-VAs were significantly deeper (81 +/- 6 mm/m(2) vs 68 +/- 8 mm/m(2); P < .01) and farther from the sinus node (55 +/- 9 mm/m(2) vs 41 9 mm/m(2); P < .01) than those of RVOT-VAs. ASC-VA propagation had a tendency toward rightward axis. Receiver operating characteristic analyses determined that the depth of the origin was the most powerful predictor, with a sensitivity of 90% and a specificity of 73% (area under the curve = 0.90; P < .01). Discriminant analysis combining all 3 parameters revealed the accuracy of the localization to be 94%. CONCLUSION This MCG-based algorithm appeared to precisely discriminate ASC-VAs from RVOT-VAs. Further investigation is required to validate the clinical value of this technique.Heart rhythm: the official journal of the Heart Rhythm Society 05/2014; 11(9). DOI:10.1016/j.hrthm.2014.05.032 · 4.92 Impact Factor