Cellular Basis for Trigger and Maintenance of Ventricular Fibrillation in the Brugada Syndrome Model
High-Resolution Optical Mapping Study
Takeshi Aiba, MD, PhD*,
Wataru Shimizu, MD, PhD ,*,
Ichiro Hidaka, MS*,
Kazunori Uemura, MD*,
Takashi Noda, MD, PhD*,
Can Zheng, PhD*,
Atsunori Kamiya, MD*,
Masashi Inagaki, MD*,
Masaru Sugimachi, MD, PhD* and
Kenji Sunagawa, MD, PhD*
* Department of Cardiovascular Dynamics, Research Institute, National Cardiovascular Center, Suita, Japan
Division of Cardiology, Department of Internal Medicine, National Cardiovascular Center, Suita, Japan.
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Figure 1 Schematic diagram showing the major components of high-resolution optical mapping of the epicardial (Epi) or endocardial (Endo) surface in an arterially perfused canine right ventricular (RV) wedge preparation. CMOS = complementary metal oxide semiconductor.
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Figure 2 Representative episodes of polymorphic ventricular tachycardia or ventricular fibrillation (VF) in a canine wedge model of the Brugada syndrome. All arrhythmias were spontaneously developed after the electrocardiogram with coved-type ST-segment elevation. Many of the arrhythmias (numbers 1 to 6) terminated within a few seconds, but the others (numbers 7 to 9) with a shorter cycle length (CL) degenerated into VF, which continued more than 5 s.
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Figure 3 Representative action potential duration measured at 50% repolarization (APD50) contour map on the right ventricular epicardium (Epi) and endocardium (Endo) in control condition (A and D, respectively), in the ST-segment elevation (Brugada-ECG) without phase 2 re-entrant (P2R) extrasystoles (B and E, respectively), and in the Brugada-ECG just before P2R extrasystoles (C and F, respectively) and representative optical action potentials at each site (a to c). White arrow = initial site of P2R. DR = dispersion of repolarization; GRmax = maximum gradient of repolarization.
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Figure 4 Scatter plots of the maximum gradient of repolarization (GRmax) in the epicardial (Epi) and endocardial (Endo) surfaces (A) and transmural dispersion of repolarization (DR) (B) in control and the ST-segment elevation (Brugada-ECG) condition with (closed circles) or without (open circles) phase 2 re-entrant (P2R) extrasystoles. Values are mean ± SD. *p < 0.05 versus control condition; p < 0.05 versus Brugada-ECG condition without P2R-extrasystole by analysis of variance with Scheffe’s test.
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Figure 5 Snapshots of a color optical isopotential movie on the epicardial surface for the continuous two beats with (Beat 2) and without (Beat 1) a phase 2 re-entrant extrasystole (P2R-extrasystole) in the Brugada-ECG condition (A). Depolarization map of a P2R-extrasystole (B) and optical action potentials at each site (a to f) and transmural electrocardiogram (ECG) (C). Please see the for accompanying video.
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Figure 6 Representative repolarization and depolarization maps on the epicardial surface in the ST-segment elevation (Brugada-ECG) condition just before non-sustained polymorphic ventricular tachycardia (VT) (A, B), snapshots of phase movie during polymorphic VT originated from the epicardial phase 2 re-entry (C), and optical action potentials at each site (a to f) together with a transmural electrocardiogram (ECG) (D). Open circles = singularity points. APD50 = action potential duration at 50% repolarization. Please see the for accompanying video.
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Figure 7 Representative repolarization and depolarization maps on the epicardial surface in the ST-segment elevation (Brugada-ECG) condition just before ventricular fibrillation (VF) (A, B), snapshots of phase movie during VF originated from the epicardial phase 2 re-entry (C), and optical action potentials at each site (a to f) together with a transmural electrocardiogram (ECG) (D). Open circles = singularity points. APD50 = action potential duration at 50% repolarization. Please see the for accompanying videos.
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Figure 8 Representative epicardial depolarization maps paced from the epicardium by S1-S2 method in the control and ST-segment elevation (Brugada-ECG) condition with polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF) (A), and longitudinal (L) and transverse (T) conduction velocity ( ) restitution curves in each condition (B). Values are mean ± SEM.
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Figure 9 Representative epicardial repolarization maps paced from the epicardium by S1-S2 method and plot of the restitution of action potential duration at each site (a to e) and superimposed optical action potentials at site b in control condition (A), and the Brugada-ECG condition with polymorphic ventricular tachycardia (PVT) (B) or ventricular fibrillation (VF) (C). APD50 = action potential duration at 50% repolarization; DI = diastolic interval.
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