Relationships between verapamil plasma concentrations and its antihypertensive action

Twenty-seven hypertensive outpatients were studied to evaluate the efficacy of verapamil after a single oral dose as well as following a short-term treatment and also in combination with oxprenolol. Blood pressure was significantly reduced (p 0.01) after verapamil monotherapy and the combined treatment. PR interval was lengthened from 30 min to 4 h during acute testing, and also after short-term treatment. QT was only prolonged after the verapamil monotherapy. Systolic time intervals (STIs) were not modified, except left ventricular ejection time (LVETc). Direct correlations were found among verapamil plasma concentrations and changes provoked on blood pressure and PR interval. The mean side effects found were disturbance of atrioventricular conduction in two patients without ulterior complications. The results suggest that verapamil monotherapy or in combination with oxprenolol could be useful in the treatment of essential hypertension.

Measurement of right and left ventricular ejection fractions by gated equilibrium scintigraphy using Fourier functional images

Left and right ventricular ejection fractions (LVEF and RVEF) were calculated by gated equilibrium scintigraphy in 28 normal controls and in 21 patients with heart disease. Regions of interest (ROIs) for the ventricles were assigned on the amplitude and phase Fourier images. Two methods of preprocessing of data were compared. In Method 1 the resolution was improved and the statistical noise was reduced, while in Method 2 only the statistical noise was reduced. There were no differences between the results of the two methods for the left ventricle. The mean LVEF for normal subjects was 0.63 +/- 0.06. For the right ventricle, Method 1 showed higher sensitivity in detecting reduced RVEF in pathological situations. The mean RVEF by Method 1 for normal controls was 0.56 +/- 0.07, which is significantly different (p less than 0.001) than that found by Method 2 (0.36 +/- 0.05), and similar to those reported by others employing the firstpass method. The results show the usefulness of the phase Fourier image and the importance of a suitable preprocessing of data for determining RVEF by gated equilibrium scintigraphy.

Measurement of Right and Left Ventricular Ejection Fractions by Gated Equilibrium Scintigraphy Using Fourier Functional Images

Left and right ventricular ejection fractions (LVEF and RVEF) were calculated by gated equilibrium scintigraphy in 28 normal controls and in 21 patients with heart disease. Regions of interest (ROIs) for the ventricles were assigned on the amplitude and phase Fourier images. Two methods of preprocessing of data were compared. In Method 1 the resolution was improved and the statistical noise was reduced, while in Method 2 only the statistical noise was reduced. There were no differences between the results of the two methods for the left ventricle. The mean LVEF for normal subjects was 0.63 ± 0.06. For the right ventricle, Method 1 showed higher sensitivity in detecting reduced RVEF in pathological situations. The mean RVEF by Method 1 for normal controls was 0.56 ± 0.07, which is significantly different (p < 0.001) than that found by Method 2 (0.36 ± 0.05), and similar to those reported by others employing the firstpass method. The results show the usefulness of the phase Fourier image and the importance of a suitable preprocessing of data for determining RVEF by gated equilibrium scintigraphy.

Quantitative comparison of the anticholinergic and antiarrhytmic actions of disopyramide and quinidine

With the purpose of estimating quantitative differences between disopyramide and quinidine two experimental series were designed. In order to establish the atropinic potency of both drugs, pA2 values were determined in rabbits right atria, using acetylcholine as agonist. The capacity to prevent ventricular fibrillation in albino mice subjected to chloroform apnea was also tested using various doses of the drugs. An effective median dose (ED50) to each of the drugs was calculated and the relative antiarrhythmic potency was compared. Disopyramide showed in both experimental series to be a more potent agent than quinidine.