High-resolution optical mapping of ventricular tachycardia in rats with chronic myocardial infarction.
BACKGROUND
Ventricular tachycardia (VT) is a common cause of mortality in post-myocardial infarction (MI) patients, even in the current era of coronary revascularization treatment. We report a reproducible VT model in rats with chronic MI induced by ischemia-reperfusion and describe its electrophysiological characteristics using high-resolution optical mapping.


METHODS
An MI was generated by left anterior descending coronary ligation (25 minutes) followed by reperfusion in 20 rats. Electrophysiology study and optical mapping were performed 5 weeks later using a Langendorff-perfused preparation and compared to normal rats.


RESULTS
The conduction velocity of the MI border zone was decreased to 53% of the normal areas remote from the infarct (0.37 +/- 0.16 m/sec vs 0.70 +/- 0.09 m/sec, P < 0.0001). The rate of VT inducibility in MI rats was significantly greater than in normal control rats (70% vs 0%, P = 0.00002). VT circuits involving the infarct area were identified with optical mapping in 83% MI rats. In addition, fixed and functional conduction block were observed in the infarct border zone.


CONCLUSIONS
This ischemia-reperfusion MI rat model is a reliable VT model, which simulates clinical revascularization treatment. High-resolution optical mapping in this model is useful to study the mechanism of VT and evaluate the effects of therapies.
Ding
Chunhua
C
Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California 94143, USA.
Gepstein
Lior
L
Nguyen
Duy Thai
DT
Wilson
Emily
E
Hulley
George
G
Beaser
Andrew
A
Lee
Randall J
RJ
Olgin
Jeffrey
J
D000818:Animals; D002908:Chronic Disease; D004195:Disease Models, Animal; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006327:Heart Block / Q000209:etiology / Q000503:physiopathology; D008026:Ligation; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology*; D015428:Myocardial Reperfusion Injury / Q000150:complications; D051381:Rats; D017207:Rats, Sprague-Dawley; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology*; D056969:Voltage-Sensitive Dye Imaging