Ritodrine Hydrochloride Induced Cardiopulmonary and Placental Hemodynamic Changes in Normal and Hypertensive Late Pregnancy

Abstract

Cardiopulmonary parameters (minute volume, heart rate, stroke volume, right heart, pulmonary and left heart blood volumes), blood pressure and placental blood flow were evaluated in 20 normal patients, nine patients with preeclamptic disease and 12 with essential hypertension in late pregnancy before and 60 minutes after a single i.m. dose of 10 mg of ritodrine hydrochloride. The drug caused a statistically significant increase in heart rate in all the patient groups, while the systolic and diastolic blood pressures were only slightly affected. Minute volume was unchanged in the group of normal patients, but in both hypertensive groups there was a significant increase. The placental perfusion index was statistically nearly significantly decreased in the group of uncomplicated pregnancies, statistically significantly increased in preeclamptic patients, and not affected in the group with essential hypertension. Ritodrine hydrochloride medication can be expected to have a positive effect on placental blood flow only in preeclamptic disease, and then probably in the milder forms of the disease.

Assessment of Cardiac Blood Pools in Radiocardiography by Various Indicator Dilution Models

“…This confirms the reliability and small deviation of the calculated parameters, which are in a simple algebraic form (23). The gamma variate model proved its clinical usefulness during the study of the effect of a beta-sympathomimetic drug on pregnant patients (21). Our study suggests that indicator dispersion is an essential physiological flow parameter which must be considered in central circulatory model analyses.…”

Determination of Placental Blood Flow by External Monitoring of 113mIn

“…This assumption was made during the study of the changes in the placental blood flow provoked by the alterations in maternal posture (16). The present method confirmed its clinical usefulness during a study of ritodrine hydrochloride induced cardiopulmonary and placental hemodynamic changes in normal and hypertensive pregnancy (17).…”

“…Owing to this and its short half-life, H3 m ln introduces a considerably lower radiation dose to the fetus than 99m Tc. In addition, us^In has an established use in evaluation of the cardiac output (7) and the cardiopulmonary volumes in radiocardiography (11,17). The present work introduces the use of isotope nsmln in the assessment of placental blood flow.…”

Effect of Intravenous Infusion of Betasympathomimetic Agents on Plasma Renin Activity During Pregnancy

“…Beta-adrenergic drugs are used to inhibit uterine contractions and to improve uteroplacental blood flow (Brettes et al, 1976;Suonio et al, 1976). Haemodynamic studies of various beta-adrenergic agents in animals have, however, given contradictory results, and there are no reports on the reaction of renin-angiotensin system to these drugs .…”