Electrophysiologic features of protected channels in late postinfarction patients with and without spontaneous ventricular tachycardia

TY - JOUR

T1 - Electrophysiologic features of protected channels in late postinfarction patients with and without spontaneous ventricular tachycardia

AU - Nayyar, Sachin

AU - Wilson, Lauren

AU - Ganesan, Anand

AU - Sullivan, Thomas

AU - Kuklik, Pawel

AU - Young, Glenn

AU - Sanders, Prashanthan

AU - Roberts-Thomson, Kurt C

PY - 2018/1

Y1 - 2018/1

N2 - PURPOSE: Protected channels of surviving myocytes in late postinfarction ventricular scar predispose to ventricular tachycardia (VT). However, only a few patients develop VT spontaneously. We studied differences in electric remodeling and protected channels in late postinfarction patients with and without spontaneous VT.METHODS: Patients with ischemic cardiomyopathy (ICM) with recurrent sustained monomorphic VT (n = 22) were compared with stable ICM patients without spontaneous VT (control group; n = 5). Left ventricular mapping was performed with a 20-pole catheter. Detailed pace mapping was used to identify channels of protected conduction, and confirmed, when feasible, by entrainment. Anatomical and electrophysiological properties of VT channels and non-VT channels in VT patients and channels in controls were evaluated.RESULTS: Seventy-three (median 3) VTs were inducible in VT patients compared to two (median 0) in controls. The VT channels in VT patients (n = 57, 3 ± 1 per patient) were lengthier (mean ± SEM 53 ± 5 vs. 33 ± 4 vs. 24 ± 8 mm), had longer S-QRS (73 ± 4 vs. 63 ± 3 vs. 44 ± 8 ms), longer conduction time (103 ± 13 vs. 33 ± 4 vs. 24 ± 8 ms), and slower conduction velocity (CV) (0.85 ± 0.21 vs. 1.39 ± 0.20 vs. 1.31 ± 0.41 m/s) than non-VT channels in VT patients (n = 183, 8 ± 6 per patient) (p ≤ 0.01) and channels in controls (n = 46, 9 ± 8 per patient) (p ≤ 0.01). Additionally, non-VT channels in VT patients had longer S-QRS (p = 0.02); however, they were similar in length, conduction time, and CV compared to channels in controls.CONCLUSIONS: Channels supporting VT are lengthier, with longer conduction times and slower CV compared to channels in patients without spontaneous VT. These observations may explain why some ICM patients have spontaneous VT and others do not.

AB - PURPOSE: Protected channels of surviving myocytes in late postinfarction ventricular scar predispose to ventricular tachycardia (VT). However, only a few patients develop VT spontaneously. We studied differences in electric remodeling and protected channels in late postinfarction patients with and without spontaneous VT.METHODS: Patients with ischemic cardiomyopathy (ICM) with recurrent sustained monomorphic VT (n = 22) were compared with stable ICM patients without spontaneous VT (control group; n = 5). Left ventricular mapping was performed with a 20-pole catheter. Detailed pace mapping was used to identify channels of protected conduction, and confirmed, when feasible, by entrainment. Anatomical and electrophysiological properties of VT channels and non-VT channels in VT patients and channels in controls were evaluated.RESULTS: Seventy-three (median 3) VTs were inducible in VT patients compared to two (median 0) in controls. The VT channels in VT patients (n = 57, 3 ± 1 per patient) were lengthier (mean ± SEM 53 ± 5 vs. 33 ± 4 vs. 24 ± 8 mm), had longer S-QRS (73 ± 4 vs. 63 ± 3 vs. 44 ± 8 ms), longer conduction time (103 ± 13 vs. 33 ± 4 vs. 24 ± 8 ms), and slower conduction velocity (CV) (0.85 ± 0.21 vs. 1.39 ± 0.20 vs. 1.31 ± 0.41 m/s) than non-VT channels in VT patients (n = 183, 8 ± 6 per patient) (p ≤ 0.01) and channels in controls (n = 46, 9 ± 8 per patient) (p ≤ 0.01). Additionally, non-VT channels in VT patients had longer S-QRS (p = 0.02); however, they were similar in length, conduction time, and CV compared to channels in controls.CONCLUSIONS: Channels supporting VT are lengthier, with longer conduction times and slower CV compared to channels in patients without spontaneous VT. These observations may explain why some ICM patients have spontaneous VT and others do not.

KW - Body Surface Potential Mapping/methods

KW - Cardiac Catheterization/methods

KW - Catheter Ablation/methods

KW - Cicatrix/diagnostic imaging

KW - Electrophysiologic Techniques, Cardiac

KW - Female

KW - Follow-Up Studies

KW - Humans

KW - Imaging, Three-Dimensional

KW - Male

KW - Myocardial Infarction/diagnostic imaging

KW - Myocardial Ischemia/complications

KW - Reference Values

KW - Risk Assessment

KW - Severity of Illness Index

KW - Survival Rate

KW - Time Factors

KW - Treatment Outcome

U2 - 10.1007/s10840-017-0299-6

DO - 10.1007/s10840-017-0299-6

M3 - SCORING: Journal article

C2 - 29236200

VL - 51

SP - 13

EP - 24

JO - J INTERV CARD ELECTR

JF - J INTERV CARD ELECTR

SN - 1383-875X

IS - 1

ER -