Type I second-degree AV block (Mobitz type I, Wenckebach AV block) during ritodrine therapy for preterm labor.

A patient, while on intravenous ritodrine therapy for preterm labor, experienced an episode of acute chest pain. The electrocardiogram (ECG), which was read as normal prior to ritodrine infusion, demonstrated a type I second-degree AV block which disappeared upon discontinuation of ritodrine therapy. This case illustrates the need for close ECG monitoring during ritodrine treatment when clinical symptoms arise.