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Effects of tiapamil on myocardial performance in coronary artery disease
Abstract:
Tiapamil has been extensively investigated for treatment of cardiac arrhythmias. Concern persists, however, that, as a calcium antagonist, it may seriously depress myocardial function. To investigate this possibility, 20 patients were given tiapamil intravenously and studied by radionuclide ventriculography. Tiapamil markedly lowered arterial pressure. Left ventricular ejection fraction increased from 54 +/- 3.3 to 57 +/- 3.3%. No significant change in heart rate was noted. Tiapamil did not increase the extent of left ventricular asynergy. The potent vasodilator properties of tiapamil compensate for any intrinsic decrease in left ventricular contractibility, and therefore overall cardiac function is not worsened by the drug in patients with normal or moderately reduced resting ventricular ejection fractions.
Insights
Tiapamil, a calcium antagonist, was studied in cardiac arrhythmia patients. Despite concerns, it did not worsen cardiac function, with vasodilation compensating for potential myocardial depression.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Tiapamil is investigated for cardiac arrhythmias.
- Concerns exist regarding its potential to depress myocardial function as a calcium antagonist.
Purpose of the Study:
- To investigate the effects of tiapamil on myocardial function in patients with cardiac arrhythmias.
Main Methods:
- Intravenous administration of tiapamil to 20 patients.
- Assessment of cardiac function using radionuclide ventriculography.
Main Results:
- Tiapamil caused a marked decrease in arterial pressure.
- Left ventricular ejection fraction showed a slight, non-significant increase.
- No significant changes in heart rate or left ventricular asynergy were observed.
Conclusions:
- Tiapamil's potent vasodilator effects offset potential negative inotropic effects.
- Overall cardiac function is not impaired in patients with normal or moderately reduced ejection fractions.