A case of isolated atrioventricular discordance.

Abstract

SUMMARY A case of isolated atrioventricular discordance in situs solitus is described.The importance of a well defined situs and of the presence of both ventricles in making this diagnosis is underlined and previous published reports reviewed.It is suggested that the haemodynamic concept of isolated atrioventricular discordance cannot be described only by the spatial relation between the ventricles (isolated ventricular inversion), but it should be indicted by the pattern of the connection between various flows, as shown by hearts with a normal relation between the ventricles and crossed atrioventricular connection.We consider that "A-V discordance with ventriculoarterial concordance and normally related great arteries"' is the best way to describe the anatomical and the haemodynamic pattern in so called isolated ventricular inversion.In this paper we report a new example of this rare anomaly which we call "isolated atrioventricular discordance". To our knowledge, this is the first reported case in which a straddling left atrioventricular valve was present. Case reportA 2-month-old female infant (birthweight 2-5 kg) was admitted with dyspnoea and cyanosis which had been present from birth.A xiphoid impulse was present and a grade 3/6 harsh early and mid-systolic murmur was heard at the left lower sternum; the second heart sound was normal. The peripheral pulses were diminished and the liver was much enlarged. Chest x-ray film showed a left cardiac apex, cardiomegaly, and increased pulmonary flow. The electrocardiogram showed normal sinus rhythm, left atrial enlargement, and a QRS axis at + 1400 in the frontal plane. An Laevocardia and solitus visceroatrial situs were present, with normal atrial morphology and the normal relation between the atrial chambers. Systemic and pulmonary connections were normal. The atrioventricular connection was discordant with two separated atrioventricular valves, the left of which was straddling. The right atrium was connected to a right sided and morphologically left ventricle through a bicuspid valve (Fig. IA). The subvalvular apparatus was normal. A normal-sized ventricle was connected to a right sided and posterior aorta (Fig. 1B). Fibrous continuity between the anteromedial leaflet of the right atrioventricular valve and the aortic cusps was documented. A fibromuscular membrane obstructing the aortic outflow tract was present (Fig. IB). The ventricular septum was abnormally orientated, so that its posterior aspect was to the left of its anterior aspect; a perimembranous ventricular septal defect was present (Fig. IB). Some chordae from the left atrioventricular valve had their insertion on the base of the septal defect on its right side. The left atrium was connected to a left sided, morphologically right ventricle through a tricuspid valve (Fig. 2A). The normal sized atrioventricular valve annulus was shifted medially and to the right but did not override the ventricular septum. The anterior leaflet of the left tricuspid atrioventricular valve had its insertion on the anter...

What is anatomically corrected malposition?

“…It remains a fact, nonetheless, that many paediatric cardiologists and surgeons remain unaware of the significance of the malformation, or else are unsure of its make-up, in particular its distinction from other malformations which are currently described using arcane terms such as "isolated ventricular inversion", [23][24][25][26][27][28][29][30] or "isolated ventricular discordance". 31,32 These terms are not immediately meaningful, and it could be argued that the term "anatomically corrected malposition" would better be applied to the normal heart, in which any malpositions are certainly anatomically corrected. Irrespective of such niceties, the unifying feature of all these unusual entities is that the arterial trunks, whilst arising from their morphologically appropriate ventricles, exit from the ventricular mass in parallel rather than spiral fashion.…”

“…In almost threefifths of cases (58%), the aortic valve is posterior and right-sided, with a subpulmonary infundibulum lifting the pulmonary trunk away from the ventricular base. 3,[23][24]27,[31][32][33]39 Rarely, the aorta was described as being anterior and right-sided, with either bilateral or subaortic infundibulums. 22,31 Usual atrial arrangement with univentricular atrioventricular connection (Table 3) Overall, just over one-fifth (22%) of reported cases exhibited univentricular atrioventricular connections.…”

“…3,[23][24]27,[31][32][33]39 Rarely, the aorta was described as being anterior and right-sided, with either bilateral or subaortic infundibulums. 22,31 Usual atrial arrangement with univentricular atrioventricular connection (Table 3) Overall, just over one-fifth (22%) of reported cases exhibited univentricular atrioventricular connections. Of these, greater than four-fifths (81%) had absence of the right atrioventricular connection, with the left atrium communicating with a dominant left ventricle, the incomplete right ventricle being in right-sided and anterior position, in other words the typical findings of tricuspid atresia.…”

Staged Surgical Management of Anatomically Corrected Malposition of Great Arteries

“…1 In contrast to isolated ventricular inversion (IVI), ACM is characterized by ventriculo-arterial (VA) concordance but with abnormal connection of the aorta to the left ventricle via a conus that can become obstructed as in our case. The group of atrio-ventricular (AV) discordance with VA concordance are a set of rare congenital lesions, [2][3][4][5][6] with sporadic case reports published on surgical management. The first report on the pathology diagnosed during life was published by van Praagh et al 7 in 1966 and another two cases in 1975 by Quero-Jiménez.…”

“…2 Less than 30 IVI cases have been reported since the first report in 1966. [1][2][3][4][5][6][7] Careful examination of cardiac morphology including complete and thorough sequential analysis is crucial for correct diagnosis. Due to transposition physiology, clinical features those of hypoxemia, pulmonary overcirculation, and congestive heart failure can also be present.…”