Diagnosis of ventriculo-arterial discordance (transposition of the great ...

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From Department of Cardiology, NewcastleGeneral Hospital, Newcastle upon Tyne. The constant anatomical relation of the aortic arch and the pulmonary artery ...
British Heart Journal, 1977, 39, 844-846

Diagnosis of ventriculo-arterial discordance (transposition of the great arteries) by contrast echocardiography CARLOS MORTERA, STEWART HUNTER, AND MICHAEL TYNAN From Department of Cardiology, Newcastle General Hospital, Newcastle upon Tyne

The constant anatomical relation of the aortic arch and the pulmonary artery bifurcation permits echocardiographic differentiation of the two great arteries when viewedfrom the suprasternal notch. When this technique was employed with contrast echocardiography in 12 infants, 6 of whom had ventriculo-arterial discordance (transposition of the great arteries), it was possible to establish with certainty in all but 1 case which great artery was most directly connected to the systemic venous return. With a standard single probe echocardiogram, the suprasternal notch (Goldberg, 1970) the aorta is morphology of the various cardiac structures is in- always closer to the transducer than is the pulferred mainly from their anteroposterior relation, monary artery. If an ultrasonic indicator (for inthough some additional subjective evidence can be stance 5 per cent dextrose), introduced into the obtained from their lateral relation. This approach peripheral systemic veins, can be detected when it is reliable only when the position of the heart in the reaches the great arteries (Valdes-Cruz et al., 1976) chest is normal and when the connections of the then this should allow us to identify whether the various chambers and vessels are also normal. The pulmonary artery or the aorta is most directly scarcity of echocardiographic features which un- connected to the systemic venous ventricle. equivocally differentiate intracardiac structures is a serious limitation of the technique in the diagnosis Technique of complex congenital cardiac malformations. In this report we describe a method for deter- An intravenous catheter (Longwell 20) is placed in a mining which great artery receives most of the vein on the dorsum of the hand. The electrocardiosystemic venous return, thus improving the accuracy graphic electrodes are applied and the baby is with which we can detect abnormal cardiac connec- allowed to settle with a rolled up napkin beneath its tions such as ventriculo-arterial discordance (trans- shoulders to extend the neck. When the infant is position of the great arteries). The method we quiet, an echocardiogram is recorded with the describe is valid only when two great arteries and transducer placed in the suprasternal notch. The their semilunar valves have been unequivocally beam is directed posteriorly and somewhat caudally identified using standard parasternal echocardio- until the echo-free spaces corresponding to the aorta, pulmonary artery, and left atrium are located. graphy. To be certain that the beam cuts the arch of the aorta and the bifurcation of the pulmonary artery, Anatomical considerations no portion of either semilunar valve should be seen. In complex congenital heart disease the relation A 1 ml bolus of 5 per cent dextrose is injected of the great arteries at their origin from the heart is rapidly through the cannula during continuous extremely variable and this relation is frequently recording of the echocardiogram. We used this independent of their ultimate venous connections. technique retrospectively in 6 infants known to have In contrast, the anteroposterior relation of the arch normal ventriculoarterial connections and no signiof the aorta to the bifurcation of the pulmonary ficant shunts, and in 6 infants with discordant venartery is always constant (Gray's Anatomy, 1969). triculoarterial connections (transposition of the This means that when the great arteries are both great arteries). In the group with normal ventriculovisualised with the echocardiographic probe in the arterial connections only the pulmonary artery opacified (Fig. a). In the group with discordant Received for publication 23 February 1977 844

Diagnosis of ventriculoarterial discordance by contrast echocardiography

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