Antianginal effects of pentaerythritol tetranitrate.

31 patients with confirmed angina pectoris and selected to form an homogenous group entered this double-blind study. Following a period of observation during which the patients were on a placebo and only took nitroglycerin to relieve pain, a randomized treatment of either dipyramidole (DPM) 75 mg or pentaerythritol tetranitrate (PETN) 80 mg 8-hourly was given during 4 weeks. At the end of this period the anti-anginal effects of the drugs were assessed, using the following criteria: incidence of anginal attacks, nitroglycerin consumption, number of attacks per days, changes in exercise capacity and changes in repolarization on ECG. PETN proved distinctly more effective than DPM. The number of attacks per week decreased from 11.5 to 1.5 under PETN and from 12.5 to 9 under DPM. Similarly, nitroglycerin weekly consumption fell from 8 to 1.5 tablets under PETN and from 9 to 7 tablets under DPM.

Determination of ejection fraction by echocardiography in patients treated with P.E.T.N.

The purpose of this single-blind study carried out on 20 patients was to assess the effects of a long-acting nitrate derivative on the stroke index, which reflects left ventricular function. Following a 4 weeks' period of observation without any treatment (except for sublingual nitroglycerin during anginal attacks), an echocardiographic study of the left ventricle was performed. The distance between the endocardium lining the interventricular septum and that lining the posterior wall of the left ventricle was measured at the end of the diastole (R wave of the ECG) and at the end of the systole (shortest measurable distance). The rule of cubes was used to determine the ventricular volume and to calculate the stroke index. The patients then received pentaerythritol tetranitrate in daily doses of 240 mg for 30 consecutive days, after which a new echocardiographic study was done and the stroke index calculated again. The improvement in stroke index was more than three times the standard deviation before treatment in 15 patients (75%) and even six times greater in 8 of these (40%). No improvement was observed in the remaining 5 patients. In the group as a whole the stroke index increased from 0.418 +/- 0.135 to 0.504 +/- 0.115.

[Modifications of the left ventricular function as the result of severe and chronic reduction of the preload]. / Estudio de las modificaciones de la función ventricular izquierda, como resultado de la disminucion crónica y severa de la precarga

In order to evaluate the effect which the cronic, severe, and constant decrease of the preload of the left ventricle has on the contractile function of this chamber, 15 cases, with the strict technical conditions and permitted the planned measurements, were taken from 86 studies of ventricular function in patients with tight mitral stenosis. The following parameters were calculated; the ejection fraction, the maximum DP/dt, the zero point diastolic pressure, the final diastolic pressure, the diastolic AP, the mid-diastolic pressure, the diastolic compliance index, and the passive elastic module of the left ventricle, the pulmonary pressure, the cardiac output, systolic output, and the changes produced by the infusion of Isopropilaminoetanol. It was concluded that the effects of cronic and severe pre-load decrease are: 1. Moderate decrease of the cardiac output with low systolic output and high cardiac frequency. 2. Conserved inotropic reserve. 3. Normal ejection fraction. 4. Normal diastolic tension behavior. 5. Increased compliance and special behavior of the passive elastic module.

[Comparison of the antiangina pectoris action of 2 coronary vasodilators]. / Estudio comparativo de la acción antianginosa de dos vasosdilatadores coronarios

Twenty four patients were studied: 7 males and 17 females, with an average age of 56 plus and minus 6.93 years, with a main diagnosis of ischaemic heart disease and with an average of at least 7 angina attacks per week. The anti-angina effect of 2 drugs, dipridamol and pentaeritritol was compared using the random double blind technique on parallel groups which were comparable. Pentaertritol administered for 4 weeks reduced, with a statistical significance (P 0.01), the average number of angina attacks of the group, as well as with taking nitroglicerine tablets. The number of pain free days was increased from 1.5 per week to 5.5 in 7 days. The effort capacity of the patients increased (P 0.01), and also the degree of elevation of the ST segment during and post effort. The changes obtained in these same areas with dipiridamol had no statistical significance.