Systemic right ventricular function in congenitally corrected transposition depends on septal geometry. Suprasystemic left ventricular systolic pressures and high end-diastolic pressures after Fontan surgery paradoxically preserve right ventricular function.

Congenitally corrected transposition of the great arteries is a rare form of CHD. Situs inversus is a much less common variant of a congenitally corrected transposition of the great arteries. In rare cases, transposition events may be accompanied by various cardiac anomalies. However, situs inversus patients with congenitally corrected transposition, single coronary artery anomaly, and atrioventricular block together have not been reported previously. This combination of abnormalities is presented as a first in the literature.

Patients with congenitally corrected transposition frequently benefit from re-synchronisation therapy or ablation procedures. This is likely to require catheterisation of the coronary sinus. Its anatomy, however, is not always appreciated, despite being well-described. With this caveat in mind, we have evaluated its location and structure in hearts with congenitally corrected transposition in order to reinforce the guidance needed by the cardiac interventionist. We dissected and inspected the coronary sinus, the oblique vein of the left atrium, and the left-sided-circumflex venous channel in eight heart specimens with corrected transposition and eight controls, measuring the orifice and length of the sinus and the atrioventricular valves. In two-thirds of the malformed hearts, the sinus deviated from its anticipated course in the atrioventricular groove, ascending obliquely on the left atrial inferior wall to meet the left oblique vein. The maximal deviation coincided in all hearts with the point where the left oblique vein joined the left-sided-circumflex vein to form the coronary sinus. We describe a circumflex vein, rather than the great cardiac vein, as the latter venous channel is right-sided in the setting of corrected transposition. The length of the sinus correlated positively with the diameter of the tricuspid valve (p=0.02). Compared with controls, the left oblique vein in the malformed hearts joined the circumflex venous channel significantly closer to the mouth of the sinus. The unexpected course of the coronary sinus in corrected transposition and the naming of the cardiac veins have important implications for venous cannulation and interpretation of images.

The aims of this study were to assess the development of heart failure in patients with congenitally corrected transposition of the great arteries in a medium-term follow-up, to identify the impact of tricuspid regurgitation on the development of heart failure, and to determine the most reliable marker for its identification. The prospective 6-year follow-up study included 19 adult patients. All patients were evaluated clinically by the determination of N-terminal pro-hormone brain natriuretic peptide levels, exercise stress testing, echocardiography magnetic resonance, or CT. Among them, two patients died of heart failure. There was a decline in exercise capacity and systolic systemic ventricular function (p=0.011). Systemic ventricular ejection fraction decreased (48.3±13.7 versus 42.7±12.7%, p=0.001). Tissue Doppler imaging showed a decline in peak tricuspid systolic annular velocity (10.3±2.0 versus 8.3±2.5 cm/second, p=0.032) and peak tricuspid early diastolic annular velocity (14.6±4.3 versus 12.0±4.5 cm/second, p=0.048). The tricuspid regurgitation did not increase significantly. N-terminal pro-hormone brain natriuretic peptide levels increased (127.0 ng/L(82.3–305.8) versus 226.0 ng/L(112.5–753.0), p=0.022). Progressive exercise intolerance in congenitally corrected transposition of the great arteries appears to be driven mainly by a progression in systemic right ventricular dysfunction. Tricuspid regurgitation is likely to play a role, especially in patients with structural abnormalities of the tricuspid valve – Ebstein anomaly. The N-terminal pro-hormone brain natriuretic peptide levels and tissue Doppler parameters appear sensitive in detecting changes over time and may guide management.

We report an unusual case with discordant atrioventricular and ventriculoarterial connections. In addition to the commonly associated intracardiac anomalies ofventricular septal defect and subpulmonary tissue tags, a supravalvar ring was present above the left-sided, morphologically tricuspid valve. This case highlights the value of color flow Doppler echocardiography in making the diagnosis, particularly as the supravalvar ring was seen poorly angiographically.

A 29-year-old man, with a diagnosis of congenitally corrected transposition (discordant atrioventricular and ventriculoarterial connections) with associated multiple ventricular septal defects, mild pulmonary valvar stenosis and Ebstein's malformation of a stenotic left-sided morphologically tricuspid valve, died after closure of the ventricular septal defect and insertion of a valved homograft conduit between the morphologically left ventricle and the pulmonary trunk. Death occurred because of failure to appreciate the bizarre and rather stenotic anomaly of the morphologically tricuspid valve, in which the anterosuperior leaflet divided the morphologically right ventricle into an inlet portion and a smaller outlet portion. After closure of the ventricular septal defects, this ventricle could no longer support the systemic circulation. We discuss the natural history and the reasons for the erroneous interpretation of the echocardiographic images of the left-sided tricuspid valve.

We describe a patient with the rare association of the heart in the left chest, congenitally corrected transposition, pulmonary atresia and an intact ventricular septum. There were associated fistulous communications between the morphologically left ventricle and the coronary arteries. Diagnosis was made by echocardiography, and subsequently confirmed by cardiac catheterization.

Obstruction to the left ventricular outflow tract is not uncommon in patients with congenitally corrected transposition. A case of congenitally corrected transposition is described with significant subpulmonary obstruction which was due to a subpulmonary tag. The patient required an aortopulmonary shunt. Her clinical course was subsequently significantly influenced by arrhythmias associated with an accessory pathway. She died suddenly from an arrhythmia. Post-mortem examination confirmed a large subpulmonary tag which originated from both sides of the ventricular septum—a previously unreported finding. Careful evaluation of the nature of left ventricular outflow obstruction is important in this condition as it may alter the surgical management.

A 24-year-old female without previous symptoms or known heart disease consulted a general practitioner with dyspnoea which had slowly worsened over a period of two years. She was treated for asthma, without investigations, until she presented with rapid atrial fibrillation, chest pain and pulmonary oedema necessitating admission to hospital, where she was found to have “mitral” regur-gitation (of the left-sided atrioventricular valve) and congenitally corrected transposition. At operation the grossly regurgitant left-sided morphologically tricuspid valve was replaced by a “top-hat” inverted aortic valve homograft. The procedure resulted in intermittent heart block, needing a pacemaker, and continued myocardial failure which progressed with new right-sided valvar regurgitation. She died a few months later. Post mortem examination confirmed the double discordance, and showed a fistula around the tricuspid valvar prosthesis, left atrial thrombus and changes in the mitral valve. There was also an unsuspected area of old myocardial ischaemia, associated with severe hypoplasia of the circumflex branch of the right-sided coronary artery. This was considered probably to have been of embolic origin.

The classical option for surgical repair in patients with congenitally corrected transposition takes advantage of the physiologic correction provided by nature. At the end of the surgical procedures, however, the morphologically right ventricle remains as the systemic ventricle. Surgical intervention is essentially the correction of associated lesions, including closure of ventricular septal defects, pulmonary valvotomy, placement of a conduit from the morphologically left ventricle to the pulmonary arteries, replacement of the morphologically tricuspid valve, and placement of pacemakers for third degree atrioventricular block. For many years, the classical approach was the “standard” surgical approach.1–4 More recently, newer alternatives have become available, including forms of anatomic repair, the “one-and-a half” ventricular option, and conversion to the Fontan circulation. The goal of anatomic repair is to craft connections such that the morphologically left ventricle becomes the systemic ventricle. Surgical techniques that accomplish this are a Rastelli procedure combined with an atrial baffle,5 and the combination of an arterial switch with an atrial baffle, be it a Mustard or Senning procedure.6

The most appropriate way of describing the congenital cardiac malformations unified because the atrial chambers are joined across the atrioventricular junctions to morphologically inappropriate ventricles has long been contentious. In the past, the lesions have been described in such arcane terms as mixed levocardia,1 while “ventricular inversion” still retains it currency in some circles. As we will show in this review, the abnormal arrangements at the atrioventricular junctions can be found with various patterns, but most frequently the patients also have the arterial trunks arising from morphologically inappropriate ventricles. This combination is best described as congenitally corrected transposition, and will form the focus of our review. It is salutary to note that, when von Rokitansky gave the first description of this combination,2 one of his illustrations was ideally suited to aid the understanding of modern-day echocardiographers (Fig. 1). We hope to emulate von Rokitansky in our own review.

A variety of surgical strategies have been utilized in attempts to accomplish long-term haemodynamic stability in patients with cardiac anomalies characterized by discordant atrioventricular connections, ventricular septal defect, and severe sub-pulmonary obstruction. The majority of these patients have what is commonly referred to as congenitally corrected transposition, together with a ventricular septal defect and pulmonary stenosis or atresia, in the setting of either usual or mirror imaged arrangement of the atrial chambers and the other organs of the body. A smaller sub-group, with discordant atrioventricular connections and double outlet right ventricle, with severe sub-pulmonary obstruction or pulmonary atresia, present similar physiology, and a comparable surgical challenge.

Discordant atrioventricular connections associated with Wolff-Parkinson-White syndrome increase the challenge of radiofrequency ablation. We report the results and techniques of radiofrequency ablation in three patients with discordant atrioventricular connections, including one patient having double outlet right ventricle with atrioventricular reentry tachycardias. There were two males and one female, aged 14 and 22 years old. We found four accessory pathways during our electrophysiological studies, with two of them manifest on the electrocardiogram, corresponding to left paraseptal and right midseptal regions. The electrophysiological study confirmed this localization, and showed two concealed accessory pathways in the right and left paraseptal regions. Radiofrequency ablation was successful in all cases without recurrence at a mean follow-up of 18.6 months. No complications were observed during the procedures. We conclude that radiofrequency ablation is feasible and effective in the ablation of accessory pathways in patients with discordant atrioventricular connections.

We performed a combined Senning and arterial switch operation on a 2-month-old patient with congenitally corrected transposition, Ebstein's malformation producing severe tricuspid regurgitation, ventricular septal defect, pulmonary hypertension, and congestive heart failure. The tricuspid regurgitation was improved. The double switch operation has the advantage of improving the function of the systemic atrioventricular valve, especially in newborns or young infants in whom the outcome of the valvar repair is poor.

Patients with congenitally corrected transposition are at risk of right ventricular dysfunction and failure. With this in mind, we examined 13 patients with congenitally corrected transposition, 7 not having undergone surgery, and 6 after physiological repair, comparing them with 6 healthy subjects matched for age and sex, using cardiac magnetic resonance imaging, at rest and during dobutamine stress, in order to determine regional and global right ventricular response to stress.

At rest, the patients had significantly decreased overall wall motion compared to their healthy peers (7.2 ± 0.5, versus 9.8 ± 0.4 mm). During infusion of dobutamine, overall wall motion increased to 12.8 ± 0.4 mm in the healthy subjects, versus 8.8 ± 1.0 mm in patients. At the regional level, significant differences in mural motion were found between patients and controls in the anterior (9.5 ± 1.1, versus 13.2 ± 0.6 mm), posterior (10.2 ± 1.6, versus 13.2 ± 0.8 mm), and septal segments (5.0 ± 0.8, versus 11.2 ± 0.6 mm).

At rest, overall mural thickening in patients was similar to that of controls, but significantly less in patients during stress. During dobutamine stress, patients showed significantly less regional wall thickening than controls, particularly in the septal (2.7 ± 0.6, versus 6.0 ± 0.4 mm, respectively) and in the anterior segments (4.2 ± 0.6, versus 7.8 ± 0.6 mm, respectively). Right ventricular ejection fraction strongly correlated with mural motion and thickening, both at rest and during stress.

Abnormal regional function in the systemic morphologically right ventricle may occur in patients with congenitally corrected transposition, which strongly correlates with right ventricular ejection fraction. Our findings support the hypothesis that, in patients with congenitally corrected transposition, ischemia of the right ventricular myocardium contributes to the development of right ventricular dysfunction.