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Hemodynamic response to digitalization in patients with hypertensive cardiovascular disease
Insights
Digitalis did not consistently improve cardiac function in patients with hypertensive cardiovascular disease and myocardial dysfunction. Patients without coronary artery disease showed improved hemodynamics after digitalis, unlike those with prior heart attacks.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Hypertensive cardiovascular disease (HCD) can lead to myocardial dysfunction.
- Digitalis glycosides are used to treat heart failure, but their efficacy in HCD with incipient dysfunction is debated.
Purpose of the Study:
- To evaluate the hemodynamic effects of intravenous beta-methyl-digoxin in patients with HCD and myocardial dysfunction.
- To determine if the presence of coronary artery disease (CAD) influences the response to digitalis.
Main Methods:
- Twenty-eight HCD patients underwent right heart catheterization at rest and during exercise.
- Hemodynamic parameters, including pulmonary artery wedge pressure (PAWP) and cardiac output (CO), were measured before and after intravenous beta-methyl-digoxin administration.
- Patients were divided into two groups: Group I (with prior myocardial infarction or CAD) and Group II (without CAD).
Main Results:
- Overall, digitalis did not consistently improve cardiac performance in all HCD patients.
- Group I patients showed minimal changes in PAWP and CO, with no significant improvement.
- Group II patients exhibited a significant decrease in PAWP during exercise after digitalis administration, indicating improved cardiac performance.
Conclusions:
- The hemodynamic response to digitalis in HCD patients with incipient myocardial dysfunction is variable.
- Patients without coronary artery disease (CAD) are more likely to benefit from digitalis, showing improved pulmonary artery wedge pressure during exercise.
- The presence of CAD may predict a non-response to digitalis in this patient population.
Abstract:
Twenty-eight patients with hypertensive cardiovascular disease (HCD) and incipient myocardial dysfunction underwent hemodynamic studies at rest and during exercise before and 30 minutes after administration of 0.6 mg beta-methyl-digoxin intravenously. Measurements were made during right heart catheterization with a balloon-tipped catheter. The hemodynamic changes after administration of digitalis did not demonstrate a consistent and uniform improvement of cardiac performance in all patients with HCD and myocardial dysfunction. When separating 11 patients with pervious myocardial infarctions or documented coronary artery disease (CAD) (= Group I) from the remaining 17 subjects without clinical and/or angiographic signs of CAD (= Group II), there were significant differences in the hemodynamic response to digitalis: In Group I, pulmonary artery wedge pressure (PAWP) after digitalis decreased only slightly and insignificantly from 8.7 to 7.4 mm Hg at rest and from 27.6 to 26.4 mm Hg during steady state exercise. Cardiac output (CO) remained essentially unchanged with a tendency to decrease after digitalis: 5.9 vs. 5.8 L/min at rest and 11.5 vs 11.1 L/min during exercise. At rest, even patients of Group II showed only minor decrease of PAWP from 8.8 to 7.2 mm Hg; during exercise these patients demonstrated marked improvement of cardiac performance with a significant decrease of PAWP after digitalis from 27.8 to 22.3 mm Hg (p less than 0.01). With one exception, there was a more or less pronounced reduction of PAWP after the drug was given. No significant change of CO after digitalis was measured in this group: 6.2 vs. 5.9 L/min at rest and 13.4 vs. 13.5 L/min during exercise. The different hemodynamic patterns of responders and non-responders to the glycoside will be discussed.