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Updated: Jun 29, 2026
Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction
Published on: October 14, 2016
Endothelin-1 is not predictive of ventricular ectopy or ventricular fibrillation during acute myocardial ischemia
Atman P Shah1, James T Niemann, Scott Youngquist
1Department of Medicine, Harbor-UCLA Medical Center, Torrance, California 90502, USA. ashah@labiomed.org
Insights
Endothelin-1 (ET-1) levels rise during acute myocardial ischemia, but this increase does not predict ventricular fibrillation (VF) in swine. Other endothelin (ET) types did not change significantly.
Area of Science:
- Cardiovascular Physiology
- Molecular Cardiology
- Ischemic Heart Disease
Background:
- Endothelin-1 (ET-1) elevation post-myocardial infarction may impact cardiac function.
- ET-1's effect on action potential (AP) suggests potential arrhythmogenic properties, predisposing to ventricular fibrillation (VF).
- The roles of ET-2 and ET-3 in this context remain unclear.
Purpose of the Study:
- To investigate if endothelin (ET) levels increase during acute myocardial ischemia.
- To determine if plasma ET levels predict ischemically induced VF.
- To assess the changes in ET-1, ET-2, and ET-3 concentrations during acute ischemia.
Main Methods:
- Thirty-four swine underwent proximal LAD coronary artery occlusion.
- Venous blood samples were collected from the right atrium for 30 minutes or until VF induction.
- Plasma concentrations of ET-1, ET-2, and ET-3 were quantified using ELISA.
Main Results:
- Successful LAD occlusion was confirmed angiographically in all animals.
- ET-1 levels significantly increased by 20 minutes and remained elevated throughout 30 minutes of occlusion.
- No significant changes in ET-2 or ET-3 levels were observed; peak ET-1 values did not differ between VF and non-VF groups.
Conclusions:
- Acute myocardial ischemia triggers a significant increase in ET-1 within 20 minutes.
- Despite known effects on AP, the observed rise in ET-1 did not correlate with the occurrence of VF.
- Plasma ET levels, particularly ET-1, were not found to be predictive of ischemically induced VF in this swine model.
Abstract:
Endothelin(ET)-1 (ET-1) increases after myocardial infarction and may have effects on myocardial function. ET-1 has also been shown to affect the action potential (AP) which may be arrhythmogenic and predispose to ventricular fibrillation (VF). The effects of ET-2 and ET-3 are uncertain. We hypothesized that the ETs increase during acute ischemia and that plasma levels are predictive of ischemically induced VF. Thirty-four domestic swine underwent balloon occlusion of the proximal LAD coronary artery. Occlusion was confirmed angiographically. Venous samples were collected from the right atrium at baseline and at 5 min intervals for 30 min or until VF induction. ET-1, ET-2, and ET-3 were measured using ELISA. Changes in plasma concentrations were assessed using repeated measures ANOVA with Dunnett's. A p < 0.05 was considered statistically significant. All animals had angiographic evidence of successful proximal LAD occlusion. ET-1 levels were significantly increased from a baseline at 20 min and remained elevated during 30 min of occlusion. ET-2 and ET-3 levels did not change from baseline values (figure, mean +/- SE). VF occurred in 60% of animals. Peak ET-1 values were not significantly different between VF and non-VF animals (6.2 +/- 2.2 vs. 4.8 +/- 2.3 pg/mL). No single ET-1 value had a VF predictive value >50%. There is a significant increase in ET-1 level within 20 min of acute myocardial ischemia. Despite known effects of ET-1 on the AP, this increase did not correlate with the occurrence of VF.
