Related Experiment Videos
[The hypertensive heart. VI. Ventricular function and coronary artery haemodynamics as influnced by digitalis
Insights
Intravenous digoxin increased left ventricular inotropism in patients with essential hypertension but did not improve pumping function. The drug also induced coronary vasoconstriction and potential ischemia.
Area of Science:
- Cardiovascular Physiology
- Clinical Pharmacology
Context:
- Essential hypertension affects ventricular function and coronary hemodynamics.
- Digoxin is used to treat heart failure, but its effects in hypertensive patients without heart failure are less understood.
Purpose:
- To investigate the impact of intravenous digoxin on left ventricular function, coronary hemodynamics, and myocardial oxygen uptake in patients with essential hypertension.
- To assess the therapeutic utility and potential adverse effects of digoxin in this specific patient population.
Summary:
- In 12 hypertensive patients without heart failure, digoxin (0.01 mg/kg IV) increased left ventricular inotropic function by 19.4% but decreased pumping function by 6.5-11.2%.
- Coronary blood flow decreased by 8.8%, while coronary vascular resistance and arteriovenous oxygen difference increased. Myocardial oxygen uptake remained unchanged.
Impact:
- Intravenous digoxin does not offer therapeutically useful improvement in left ventricular pumping function in essential hypertension.
- Digoxin exhibits coronary constrictor and ischemia-inducing effects on the coronary arterial system in this patient group.
Abstract:
The effect of intravenous digoxin (0.01 mg/kg) on ventricular function, coronary arterial haemodynamics and myocardial oxygen uptake was studied in 12 patients with essential hypertension but no heart failure, significant left ventricular hypertrophy and normal coronary arteriogram. There was a definite, velocity-related increase in the inotropic function of the left ventricle, by 19.4%, 50 min after digoxin injection, while ventricular pumping function decreased by between 6.5 and 11.2%. Coronary blood flow through the left ventricle decreased by 8.8%. On the other hand, coronary vascular resistance and coronary arteriovenous oxygen difference increased by 11 and 5.9%, respectively. Oxygen uptake remained essentially unchanged (-2.1%). These results indicate that the increase in inotropism caused by intravenous digoxin in essential hypertension without heart failure produces not only no therapeutically useful improvement in left ventricular pumping function: there is also a coronary constrictor and ischaemia-inducing effect on the coronary arterial system.