Anatomically corrected malposed great arteries misdiagnosed as transposition of great arteries: Diagnosis on fetal echocardiography.

We present a diagnosis of isolated anatomically corrected malposed great arteries on fetal echocardiography at 31 weeks of gestation period. The patient was referred to our institute with a diagnosis of suspected transposition of great arteries.

CASE HISTORY

A 23-year-old primigravida at 31 weeks of gestation period was referred to our institute with a suspected diagnosis of transposition of great arteries on fetal echocardiography.

She was nondiabetic and normotensive. Her previous antenatal scan was normal. Fetal 2D echocardiography at our institute showed situs solitus, levocardia, normal axis of the heart, atrioventricular concordance, and ventriculoarterial concordance. Although the two great vessels were arising from respective ventricles, they ran parallel and side by side to each other. Aorta was to the left of the pulmonary artery [Figures 1–5 and Videos 1 and 2]. There was no subaortic conus. Fetus had no other abnormality on echocardiography. Patient was reassured and advised to report after delivery.

Figure 1

Four-chamber view on 2D and color Doppler showing atrioventricular concordance. Note the descending aorta seen posterior to the left atrium and the flap of foramen ovale opening into the left atrium that is connected to the morphological left ventricle. DA = Descending aorta, LA: Left atrium, LV: left ventricle, RV: right ventricle

Figure 5

RV outlet view. Pulmonary artery is seen arising from RV. RV: Right ventricle

On further anterior sweep from four-chamber view on 2D and color Doppler, aorta is seen arising from the left ventricle and pulmonary artery with branches from the right ventricle. Note that the aorta and pulmonary artery are side by side. AO: Aorta, PA: Pulmonary artery

Short axis view of great vessels is seen. Aorta is on the left and pulmonary artery is on the right side

LV outlet view. Aorta is arising from left-sided morphological LV. LV: Left ventricle

DISCUSSION

Anatomically corrected malposed great arteries is an uncommon and benign entity. It was first described by Theremin in, as early as, 1895; however, the terminology was coined in 1939 by Harris and Faber. Anderson et al.[1] had defined this as any situation in which aorta arises from left ventricle but to the left of the pulmonary artery. Basically, this occurs with ventriculoarterial concordance in which the great vessels arise parallel instead of a twisting fashion. It is an entity that emphasizes on the difference between malposition and transposition of great arteries. It has been classified into four types based on the atrial situs, vent looping, and relationship of great arteries. Van Praagh et al.[2] believe that anatomically corrected malposed great arteries can occur with a subaortic as well as a bilateral conus. The muscular subaortic infundibulum can cause subaortic obstruction. It is also known to have high incidence of anomalous origins of coronary arteries from the right coronary aortic sinus, and hence, counseling is important. Basic tenet of presenting this report was to sensitize regarding its presence and its misdiagnosis as transposition on fetal echocardiography.

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Conflicts of interest

There are no conflicts of interest.