Effects of ritodrine hydrochloride tocolysis on echocardiographic parameters

Abstract

Objective. Preterm delivery is a leading cause of perinatal mortality and morbidity. The aim of this study was to determine the effect of ritodrine hydrochloride, used for tocolysis and having serious cardiovascular side effects, on echocardiographic parameters.

Methods. Sixty-two pregnant women were included in our study. The study and control groups were composed of patients with preterm labor (group A, N = 30) and patients with uneventful pregnancies (group B, N = 32), respectively. While the patients in group A were evaluated before and during treatment, those in group B were evaluated only once for ejection fraction and fractional shortening of the left side of the heart with echocardiography and for the regional systolic and diastolic functions with the tissue Doppler technique. One-way ANOVA and a t-test (paired comparison) were used for statistical purposes.

Results. For the left side of the heart, it was shown that while fractional shortening increased with tocolysis (p < 0.05), neither the ejection fraction nor E/A ratio, showing diastolic function, changed significantly (p < 0.01). While systolic function parameters (S_asep and S_alat) increased due to the inotropic and chronotropic actions of the beta-mimetic agents (p < 0.05), regional diastolic function parameters (E_asep/A_asep and E_alat/A_alat) did not change (p > 0.05).

Conclusions. Due to its potent inotropic and chronotropic effects, ritodrine hydrochloride increases myocardial oxygen demand significantly. Therefore, it should be used sparingly or avoided altogether in patients with ischemic or structural heart disease.

Keywords:

• Ritodrine hydrochloride
• tocolysis
• preterm labor
• echocardiography
• tissue Doppler echocardiography