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Acute haemodynamic effects of cromakalim in patients with angina pectoris
P Thomas1, M S Dixon, S J Winterton
1Department of Cardiology, St Mary's Hospital Medical School, London.
Insights
Cromakalim, a potassium channel activator, improved cardiac output and reduced vascular resistance in patients with ischemic heart disease. This vasodilator demonstrates potential therapeutic benefits for heart conditions.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Ischemic heart disease (IHD) poses significant challenges in cardiovascular medicine.
- Vasodilators that activate smooth muscle potassium channels are a potential therapeutic avenue.
Purpose of the Study:
- To investigate the acute hemodynamic effects of cromakalim in patients with IHD.
- To assess cromakalim's impact on cardiac output, blood pressure, and vascular resistance.
Main Methods:
- A randomized, placebo-controlled study involving 11 patients with IHD receiving cromakalim and 6 receiving placebo.
- Acute hemodynamic parameters were measured during cardiac catheterization following intravenous administration.
Main Results:
- Cromakalim significantly increased cardiac output by 30% (P < 0.05) and decreased systolic arterial pressure by 8% (P < 0.05).
- Systemic vascular resistance decreased by 29% (P < 0.01) and pulmonary vascular resistance by 24% (P < 0.01).
- No significant changes were observed in diastolic arterial pressure, left ventricular dP/dt, or stroke volume.
Conclusions:
- Cromakalim acts as an effective arteriolar vasodilator, enhancing cardiac performance.
- Cromakalim shows promise as a treatment for patients suffering from ischemic heart disease.
Abstract:
1. We studied the acute haemodynamic effects of cromakalim, a vasodilator which activates smooth muscle potassium channels, in 11 patients with ischaemic heart disease undergoing routine cardiac catheterisation. A similar group of six patients given placebo were studied under identical conditions. 2. There were no significant differences in baseline haemodynamic parameters between the two groups. 3. Following intravenous cromakalim (15 micrograms kg-1) cardiac output increased by 30% (P less than 0.05 vs placebo) while systolic arterial pressure decreased by 8% (P less than 0.05), systemic vascular resistance decreased by 29% (P less than 0.01) and pulmonary vascular resistance decreased by 24% (P less than 0.01) at plasma concentrations of the (+)- and (-)-enantiomers of cromakalim of 6.2 +/- 0.5 ng ml-1 and 10.0 +/- 1.0 ng ml-1 respectively. 4. There were no significant differences in diastolic arterial pressure, left ventricular dP/dt and stroke volume between the two groups. Heart rate increased by 11% following cromakalim but this did not achieve significance. 5. These findings confirm that cromakalim acts primarily as an arteriolar vasodilator producing an improvement in cardiac performance. Cromakalim may be of benefit in the treatment of patients with ischaemic heart disease.