Endothelin-1 (ET-1) is a potent vasoconstrictor peptide, which may also elicit severe ventricular arrhythmias. The aims of our study were apply infrared imaging to compare the effects of total left anterior descending coronary artery (LAD) occlusion to intracoronary (ic.) ET- 1 administration and to investigate the pathomechanism of ET-1 induced arrhythmias in 3 groups of anesthetized, open-thoracic mongrel dogs. In group A (n= 10) a total LAD occlusion was carried out for 30 min, followed by a 60 min reperfusion period. In groups B and C ET-1 was administered into LAD for 30 min at a rate of 30 pmol/min (n=6) and 60 pmol/min (n=8). Infrared imaging was applied to follow the epimyocardial heat emission changes. Significant epimyocardial temperature decrease indicating ischemia was observed only in group A (ΔT30MIN:-1.44±0.21°C, p<0.01). At the end of the ET-1 infusion period coronary blood flow (CBF) was reduced significantly in groups B and C (ΔCBF30MiNB: 21±2%, p<0.05; C: 35±2%,p<0.05), paralleled by a significant epimyocardial temperature decrease in group C (ΔT30MIN: -O.65±0.29°C, p<0.05). Two dogs died of ventricular fibrillation (VF) in the reperfusion period in group A. Ventricular premature contractions and ventricular tachycardic episodes appeared in group B, where six dogs died of VF in group C. In conclusion, although ET-I reduced CBF significantly in groups B and C, cardiothermography did not indicate ischemic changes. ET-I induced major ventricular arrhythmias appeared before signs of myocardial ischemia developed, though reduced coronary blood flow presumably contributed to sustaining the arrhythmias.
|Number of pages||9|
|Publication status||Published - Jan 1 2002|
- Infrared imaging
ASJC Scopus subject areas
- Complementary and alternative medicine