| Popis: |
Doppler echocardiography is an excellent tool to study the hemodynamic effects of cardiac drugs. Resting and exercise effects produced by metoprolol and allapinin on Doppler-derived measures of left ventricular (LV) performance were examined in patients with paroxysmal supraventricular tachycardias. Seventeen patients underwent continuous wave Doppler examination from the suprasternal notch at rest and during each stage of a standard exercise protocol. The study was repeated following 3-4 days of treatment with metoprolol given in a daily dose of 200 mg. The hemodynamic effects of allapinin, 100 mg daily, were evaluated in the same manner in 8 patients. With metoprolol, all resting Doppler measurements were altered insignificantly and all Doppler--derived parameters of aortic flow (peak, velocity, mean acceleration, cardiac index and LV ejection force) were much lower at the maximum exercise. Allapinin failed to alter any Doppler measurements of aortic blood flow at rest or during the peak exercise. |
