Submitral aneurysm: An antenatal diagnosis
A 26-year-old primigravida with gestation of 26 weeks presented for fetal echocardiography with fetal tachycardia on antenatal ultrasound. Fetal echocardiography showed large aneurysm arising from the submitral region, protruding predominantly into the right atrium (8 × 7 mm) and partly into the left atrium [Figure and , ]. The aneurysm expanded with ventricular systole and decompressed with ventricular diastole. Considering this characteristic feature, the possibility of a submitral aneurysm was considered. The differential diagnosis of atrial septal aneurysm was considered, but as the aneurysm projected predominantly into the right atrium and expanded in systole, this diagnosis was excluded. There was no inflow obstruction with normal tricuspid and mitral valve inflow velocities. There was no mitral regurgitation. There was no other intracardiac abnormality []. The characteristic movement of the aneurysm, i.e., the expansion with ventricular systole and its collapse with ventricular diastole was seen. There was transient fetal tachycardia (heart rate of 210/min) with PR interval of 70 m sec and 1:1 atrioventricular (AV) conduction. During the rest of the study, the heart rates varied from 140 to 160/min with 1:1 AV conduction. Ventricular contractility was normal and there was no pericardial effusion. The baby was delivered at term through normal vaginal delivery. The birth weight was 3 kg. Postnatal evaluation confirmed the diagnosis of submitral aneurysm [Figures and , , ]. The child is asymptomatic after birth with sinus rhythm and is under close follow-up for the size of the aneurysm and any other hemodynamic compromise. The child is planned for an elective surgery.