Discordant atrioventricular with concordant ventriculo-arterial connections is a rare cardiac defect. When isolated, the haemodynamics resemble transposition of the great arteries. In complex heart defects such as heterotaxy, haemodynamics guide the surgical approach.

To report a series of eight patients with discordant atrioventricular and concordant ventriculo-arterial connections focussing on anatomical and diagnostic difficulties, surgical management, and follow-up.

A retrospective review was carried out from 1983 to 2013. Anatomical description was based on segmental analysis. Emphasis was placed on the venoatrial connections.

Segmental arrangement was {I, D, S} in six patients, all with spiralling great vessels. There were two patients with parallel great vessels of whom one had {S, L, D} and the other had {S, L, A} arrangement. Of eight patients, five had heterotaxy syndrome. Median age at repair surgery was 1.4 years (with a range from 1.1 months to 8.1 years). The repair surgery finally performed was the atrial switch procedure in seven out of eight patients. The main post-operative complications were two cases of baffle obstruction and one sick sinus syndrome needing pacemaker implantation. There were two early post-operative deaths and six late survivors. Median follow-up was 4.2 years (with a range from 3.9 to 26.7 years) with good functional status in all survivors.

Diagnosing discordant atrioventricular with concordant ventriculo-arterial connections remains challenging. There are ongoing controversies about the definition of atrial morphology and heterotaxy syndrome animating the anatomic discussion of these complex heart defects. Haemodynamically, the atrial switch procedure is the surgical method of choice with an encouraging long-term follow-up despite rhythm disturbances and baffle obstruction.

Cardiovascular magnetic resonance assessment of adults late after an atrial redirection operation for transposition is demanding and time consuming. We hypothesised that the relatively fast and standardised 3-dimensional time-resolved contrast-enhanced magnetic resonance angiography, or dynamic angiography, would be valuable in the periodic follow-up of these patients.

We investigated prospectively 36 adults with transposition using dynamic angiography, comparing our results against a comprehensive but non-contrast cardiovascular magnetic resonance protocol. We acquired 6 dynamic angiographic datasets after injection of contrast. The primary aim was to detect significant obstruction of the pathways for venous flow.

In 4 patients (11%), we found evidence of moderate-to-severe, and thus clinically important, obstruction of systemic venous channels on standard cardiovascular magnetic resonance. All these patients were correctly identified by dynamic angiography. In 4 additional patients, we found mild and haemodynamically insignificant obstructions in the systemic venous channels. Of the 8 (22%) patients with any obstruction, 6 were detected by angiography. There were no false positives reported, giving sensitivity of 75% and specificity of 100%, a positive predictive value of 100%, and negative predictive value of 93%. In 1 patient, there was a moderate obstruction of the pulmonary venous compartment which was not readily seen by dynamic angiography.

3-dimensional dynamic angiography is a useful method for detecting anatomically moderate-to-severe, but not mild, obstructions in the systemic venous channels following Mustard repair for transposition. This technique can be used as a single imaging method and/or as complimentary to standard two dimensional cardiovascular magnetic resonance techniques for detection of clinically important obstructions in the systemic venous channels.