ABSTRACT

Background The ventricular tachycardia (VT) substrate map is influenced by the rhythm during mapping. This study aimed to elucidate the effects of different pacing sites on substrate mapping using decrement-evoked potential (DEEP) mapping in patients with scar-related VT.

Methods Patients with ischemic cardiomyopathy (ICM) or nonischemic cardiomyopathy (NICM) who underwent substrate mapping and ablation for scar-related VT were included. DEEP mapping was performed during right ventricular apex (RVA) and left ventricular outflow tract (LVOT) pacing. We analyzed the number, location, shape, and timing of lines of conduction block (LOB) using substrate maps obtained during RVA and LVOT pacing.

Results A total of 19 patients (mean age, 62.7 ± 16.6 years; 17 males; 10 with ICM and 9 with NICM) were studied. DEEP mapping during RVA and LVOT pacing was performed in 16 patients. The number of pacemap-matching LOBs identified from the RVA S1, RVA S2, LVOT S1, and LVOT S2 maps were 0.61 ± 0.70, 1.24 ± 1.09, 1.00 ± 0.85, and 1.50 ± 1.17, respectively. The number of final pacemap-matching LOBs was 1.58 ± 1.07. Two LOBs were visible only during RVA pacing because they were parallel to the conduction direction. Six LOBs were visible only during LVOT pacing—five LOBs were parallel to the conduction direction, and one LOB was located at the wavefront collision area. During a mean follow-up of 7.6 ± 3.9, VT recurred in 26.3% of patients.

Conclusion A high number of LOBs on critical substrates can be identified using two-site pacing DEEP mapping.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

no

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethnics committee/IRB of Severance Hospital gave ethical approval for this work.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Data Availability

The data are available in response to the appropriate requirement.

Non-standard Abbreviations and AcronymsCIEDcardiac implantable electronic deviceCRT-Dcardiac resynchronization therapy-defibrillatorDEEPdecrement-evoked potentialHFheart failureICMischemic cardiomyopathyLOBline of conduction blockLVOTleft ventricular outflow tractLVEFleft ventricular ejection fractionNICMnonischemic cardiomyopathyRVAright ventricular apexRVOTright ventricular outflow tractVTventricular tachycardia