An efficient algorithm based on electrograms characteristics to identify ventricular tachycardia isthmus entrance in post-infarct patients

Abstract

Aims Our study assesses the value of electrograms (EGMs) characteristics to identify a ventricular tachycardia (VT) isthmus entrance in patients with post-infarct VT. Post-infarct VTs are mostly due to a re-entrant circuit. A pacemapping (PM) approach is able to localize the VT isthmus during sinus rhythm. Limited data are available about the role of local EGMs in defining VT isthmus location. Methods and results Twenty consecutive patients (70% male) referred for post-infarct VT catheter ablation were included in the present study. The VT isthmus was defined according to the PM method. At each recording site, 10 characteristics of the local EGM were assessed to predict the location of the VT isthmus entrance. In total, 924 EGMs were acquired, of which 127 were located in the VT isthmus entrance. Logistic regression analysis showed that bipolar voltage, number of EGM positive peaks, and sQRS interval were independently associated with VT isthmus entrance location. The ROC curve best fitted the model at the cut-off 0.1641 (sensitivity 72%, specificity 75.2%, positive predictive value 31.3%, negative predictive value 94.4%, area under the curve 0.78, P < 0.001). Based upon these results, we developed an algorithm implemented in an automatic calculator to determine the likelihood that an EGM is located at a VT isthmus entrance. Conclusion Our study suggests that three EGM characteristics: bipolar voltage, number of positive peaks, and sQRS interval can successfully identify a VT isthmus entrance in post-infarct patients.

How to use pace mapping for ventricular tachycardia ablation in postinfarct patients

“…Moreover, PM is used to identify the exit of the VT in reentrant VTs, as found in ischemic cardiomyopathies 5,6 . Critical sites of the reentry circuit and regions of slow conduction can be identified based on PM and electrogram characteristics 7,8 …”

“…5,6 Critical sites of the reentry circuit and regions of slow conduction can be identified based on PM and electrogram characteristics. 7,8 2 | TECHNICAL ASPECTS OF PM…”

Twenty-five years of research in cardiac imaging in electrophysiology procedures for atrial and ventricular arrhythmias

“…Because many VTs are poorly tolerated, which impedes VT mapping, 84 substrate-based VT ablation that circumvents this issue, by targeting LAVAs, has early become very popular. 75 LAVAs related to VT circuits 85 can be directly 86 or indirectly 87 identified during 3D-EAM. Areas harbouring slow conduction can also be unveiled by pace-mapping 88 or by pacing with double ventricular extrastimuli.…”

A Paced-ECG Detector and Delineator for Automatic Multi-Parametric Catheter Mapping of Ventricular Tachycardia

“…Correlation gradient values were considered to be defined only when the site-to-site distance was less than 20 mm. The rationale for computing these three maps is that sQRS maps are expected to highlight VT circuit entrance sites [13] and correlation gradient maps are expected to highlight VT circuit core zones [12]. Finally, voltage maps are expected to help identify the exit of the VT circuit, which should be at the border between scar and healthy tissue.…”

“…It uses correlation gradient maps, indicating zones of abrupt changes on the surface ECG as the catheter is moved to neighboring ventricular sites. Additionally, the entrance of the circuit has been shown to be associated with long (or longer) intervals between pacing and the resulting QRS complex (sQRS intervals) [13]. A combined analysis of these multi-parametric pace-mapping data may therefore help better identify all likely VT circuits for one patient and determine the minimal surface where tissue destruction needs to be applied.…”