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Effects of nifedipine on hemodynamics and cardiac function in patients with normal left ventricular ejection fraction
Insights
Nifedipine administration in patients pre-treated with propranolol led to decreased blood pressure and increased cardiac output. This study explored the combined effects of these cardiovascular drugs.
Area of Science:
- Cardiology
- Pharmacology
Background:
- The combined use of nifedipine and propranolol is common in cardiovascular therapy.
- Understanding their interaction on cardiac function is crucial for patient management.
Purpose of the Study:
- To investigate the combined effects of nifedipine and propranolol on cardiac hemodynamics and function.
- To assess the impact of nifedipine administration in patients already on propranolol therapy.
Main Methods:
- Cardiac catheterization was performed on 9 patients with normal left ventricular function.
- Patients were pre-treated with propranolol, and nifedipine was administered subsequently.
- Hemodynamic parameters including blood pressure, heart rate, and cardiac output were monitored.
Main Results:
- Nifedipine caused a significant decrease in blood pressure and an increase in heart rate.
- Cardiac index and stroke volume index increased, indicating enhanced cardiac output.
- Systemic vascular resistance decreased, while pulmonary vascular resistance remained unchanged.
Conclusions:
- Nifedipine, when added to propranolol, results in vasodilation and increased cardiac performance in patients with normal left ventricular function.
- The combination may favorably alter hemodynamics, but careful monitoring is advised.
Abstract:
The interaction between nifedipine and propranolol on cardiac hemodynamics and function was investigated in 9 patients with normal left ventricular (LV) function who were undergoing cardiac catheterization for complaints of chest pain. Only 2 patients had angiographic evidence of significant coronary artery disease but no patient had clinical evidence of ischemia during the study. All patients were pre-treated with propranolol, 30 to 320 mg/day (mean +/- standard deviation 210 +/- 122); the propranolol serum level ranged from 43 to 246 ng/ml (mean 203 +/- 62). The administration of nifedipine resulted in a decrease in blood pressure (from 94 +/- 11 to 85 +/- 13 mm Hg, p less than 0.05), increase in heart rate (from 59 +/- 6 to 65 +/- 7 beats/min, p less than 0.05), and an increase in both mean right atrial and mean pulmonary artery wedge pressures (from 8 +/- 3 to 9 +/- 3 mm Hg and from 13 +/- 3 to 14 +/- 4 mm Hg, respectively, both p less than 0.05). Cardiac index increased (from 2.3 +/- 0.3 to 2.7 +/- 0.2 liters/min/m2, p less than 0.01). Stroke volume index also increased significantly (from 39 +/- 5 to 43 +/- 6 ml/m2) and systemic vascular resistance decreased (from 1,715 +/- 369 to 1,255 +/- 271 dynes s cm-5, p less than 0.01). No significant change was noted in pulmonary vascular resistance (148 +/- 94 vs 140 +/- 62 dynes s cm-5), LV stroke work index (44 +/- 9 vs 42 +/- 10 g-m/m2), LV end-diastolic pressure (15 +/- 2 vs 16 +/- 2 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)