Purkinje involvement in arrhythmias after coronary artery reperfusion

2002 ◽  
Vol 282 (4) ◽  
pp. H1189-H1196 ◽  
Author(s):  
David O. Arnar ◽  
James B. Martins
Keyword(s):  
Ventricular Tachycardia ◽  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Cycle Length ◽  
Ischemic Myocardium ◽  
Risk Zone ◽  
Purkinje System ◽  
Mean Cycle

Previous studies have indicated that the endocardium may be responsible for a large portion of ventricular tachycardia (VT) seen with reperfusion of ischemic myocardium. To evaluate the role of the Purkinje system in nonreentrant VT arising from the endocardium after reperfusion, the anterior descending coronary artery was occluded for 20 min and then reperfused in 23 dogs after instrumentation of the risk zone with 21 multipolar plunge needles. VT with focal Purkinje origin was defined as a focal endocardial VT with Purkinje potentials recorded before the earliest endocardial myopotential. A total of 19 VTs (mean cycle length 214 ± 2 ms) were observed with 11 (58%) having focal Purkinje origin. Fifty-eight percent of the VTs degenerated to ventricular fibrillation, with occurrences of two or more independent foci per complex (seen in 7 of 11 compared with 1 of 8 nonsustained VTs). In conclusion, these data show that Purkinje tissue may be important in the genesis of reperfusion VT.

Effect of coronary occlusion on arrhythmias and conduction in the ovine heart

1983 ◽  
Vol 245 (1) ◽  
pp. H82-H89 ◽  
Author(s):  
D. E. Euler ◽  
J. F. Spear ◽  
E. N. Moore
Keyword(s):  
Ventricular Tachycardia ◽  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Electrical Activity ◽  
Coronary Occlusion ◽  
Circumflex Coronary Artery ◽  
Pentobarbital Sodium ◽  
Normal Zone ◽  
Ventricular Tachycardia And Fibrillation ◽  
Observation Period

The proximal left circumflex coronary artery was occluded for 1 h in 16 open-chest sheep anesthetized with pentobarbital sodium. Epicardial conduction was monitored at three or four sites within the ischemic zone and one site in the normal zone. Eight of the sheep developed ventricular fibrillation within the first 15 min of occlusion; the remaining sheep survived the 1-h observation period. In the sheep that developed spontaneous ventricular fibrillation, the circumflex perfused a significantly greater amount of the left ventricle (44 +/- 3 vs. 39 +/- 3%; P = 0.008). The occurrence of spontaneous ventricular fibrillation was invariably preceded by a period of sustained (0.5-4 min) ventricular tachycardia. Six of the surviving sheep developed episodes of sustained (2-10 min) tachycardia that were self-terminating. The ischemic zone electrograms showed continuous fractionated electrical activity during both self-terminating tachycardias and tachycardias ending in fibrillation. The continuous epicardial electrical activity did not appear to cause the tachycardias but rather occurred as a result of the tachycardias. The genesis of ventricular tachycardia and fibrillation in this model may involve mechanisms different from ischemia-induced ventricular tachycardia and fibrillation in canine and porcine hearts.

Discordant S-T alternans contributes to formation of reentry: a possible mechanism of reperfusion arrhythmia

1998 ◽  
Vol 275 (1) ◽  
pp. H116-H121 ◽  
Author(s):  
Hidetada Tachibana ◽  
Isao Kubota ◽  
Michiyasu Yamaki ◽  
Tetsu Watanabe ◽  
Hitonobu Tomoike
Keyword(s):  
Coronary Artery ◽  
Ventricular Fibrillation ◽  
Conduction Block ◽  
Activation Time ◽  
Reperfusion Arrhythmia ◽  
Open Chest ◽  
Life Threatening ◽  
Control State ◽  
Reentrant Circuit

Although a relationship between S-T alternans and life-threatening arrhythmia has been recognized, the mechanism is poorly understood. We examine the role of S-T alternans in the occurrence of ventricular fibrillation (VF) after reperfusion. The left anterior descending coronary artery was occluded for 20 min and then abruptly reperfused in 12 intravenously anesthetized open-chest dogs. Sixty unipolar epicardial electrograms were recorded during the control state, at the end of occlusion, and after reperfusion. The largest magnitude of S-T alternans among 60 leads was defined as the maximum S-T alternans. Isochronal maps of activation time in paced beat and spontaneous ventricular premature contractions (VPC) were analyzed. After reperfusion, VF ensued in six dogs. The maximum S-T alternans augmented progressively with time after reperfusion until VF occurred. In three dogs with VF, when activation of VPC resulted in conduction block and formed reentry, VF ensued. The conduction block was located between sites of discordant S-T alternans (S-T alternans at adjacent leads was out of phase). These data indicate that discordant S-T alternans relates to VF by facilitating the formation of a reentrant circuit.

Sign in / Sign up

Export Citation Format

Share Document