Fetal Right Ventricular Diverticulum Detected by Prenatal Ultrasound Screening

Prenatal ultrasound screening has allowed for the detection of in utero cardiac abnormalities. Specifically, distinction is possible between ventricular diverticula and aneurysms, which is important because each condition has a different clinical outcome. We report the case of a 35-year-old, gravida 1, para 1 woman, with no significant past medical history, who underwent routine prenatal ultrasound screening at 32 weeks' gestation. A four-chamber ultrasound of the fetal heart combined with M-mode echocardiography showed abnormal dilatation of the right ventricular chamber measuring 2.2 cm × 1.0 cm but with normal contractility. Delivery was performed at full term by cesarean section, and a right ventricular diverticulum was confirmed by postnatal cardiac computed tomography. The baby developed normally with no cardiac sequelae during followup. This case demonstrates the importance of making a correct diagnosis of ventricular diverticula by prenatal ultrasound when abnormal dilatation of the fetal ventricle is identified during routine screening. Because evaluating the wall contractility by M-mode ultrasound leads to evaluating whether it has the myocardium, we conclude that M-mode echocardiography is effective for the purpose of prenatal cardiac diagnosis and can distinguish between ventricular aneurysms and functioning ventricular diverticula.