Congenitally corrected transposition: the uncorrected misnomer

Management of the Adult Patient With Congenitally Corrected Transposition: Challenges and Uncertainties

Congenitally corrected transposition (ccTGA) is a rare form of congenital heart disease characterized by atrioventricular and ventriculoarterial discordance. Patients with ccTGA usually have associated congenital cardiovascular conditions; less than 1% have no associated lesions. Generally, ccTGA is identified during infancy or childhood with features of heart failure or cyanosis when there are associated lesions such as ventricular septal defect and/or pulmonic stenosis. Presentation later in life generally occurs when there are either mild or no associated lesions. Presentation during adulthood may be prompted by symptoms or signs of cardiovascular disease or due to abnormal findings on cardiac testing. Management of patients with ccTGA depends on presentation, symptoms, and associated defects. In this review, we will focus on the management of adult patients with ccTGA.

Management of labour and delivery in congenitally corrected transposition of great arteries

A descriptive case report of the labour and delivery management of a 28-year-old woman who presented with congenitally corrected transposition of great arteries, dextrocardia, systemic ventricular dysfunction and junctional tachycardia. Patients with congenitally corrected transposition have a thin-walled morphological right ventricle as the systemic circulatory pump. The stress of increased cardiac output can lead to congestive heart failure, systemic atrioventricular valve regurgitation and arrhythmias. We used minimally invasive continuous cardiac output monitoring, fluid balance optimization and good maternal pain control to prevent decompensation and achieve vaginal delivery with a good maternal and neonatal outcome.

Comparison of outcomes in adults with congenitally corrected transposition with situs inversus versus situs solitus

The long-term outcome of patients with congenitally corrected transposition of the great arteries is mainly determined by progressive morphologically tricuspid valve regurgitation, heart block, atrial arrhythmias, and/or systemic ventricular dysfunction. Situs abnormalities have been reported in ≤34% of cases, but whether clinical differences exist between a situs inversus and situs solitus arrangement has not yet been studied. The clinical records of 38 adults with congenitally corrected transposition of the great arteries (mean age 40 ± 15 years) followed for a mean period of 7.4 years were reviewed. Of these 38 patients, 8 presented with situs inversus and 30 with situs solitus. No significant differences were found between the 2 groups in age, gender, ventricular septal defect, pulmonary tract stenosis, previous surgical repair, or duration of follow-up. However, none of the patients with situs inversus presented with an Ebstein-like anomaly of the morphologically tricuspid valve and none developed nonoperative-related complete atrioventricular block compared to 15 (50%; p = 0.013) and 11 (42%; p = 0.032) of the patients with situs solitus, respectively. At follow-up, 2 patients with situs inversus (25%) presented with sustained atrial arrhythmia, severe tricuspid regurgitation, or severe systemic right ventricular systolic dysfunction compared to 22 (73%) of 30 those with situs solitus (p = 0.034). No patient with situs inversus presented with cardiac death or severe heart failure compared to 12 (40%) of 30 with situs solitus (p = 0.038). In conclusion, Ebstein-like anomaly or spontaneous complete atrioventricular block are rare in patients with congenitally corrected transposition of the great arteries with situs inversus, and late complications are uncommon. The long-term outcome of patients with situs inversus was significantly better than that for patients with situs solitus.

Adult congenital heart disease importance of the right ventricle

The right ventricle (RV) is of lesser importance in acquired heart disease, but its role is of increasing importance in congenital heart disease. It may function as a subpulmonary ventricle or as a subaortic (systemic) ventricle in transposition complexes. The RV has a remarkable ability to adapt to pressure and volume load, but its size and function are often overlooked. Patients usually develop symptoms only after RV dysfunction has occurred, and in many diverse clinical scenarios, late referral is common. Advanced RV enlargement and dysfunction are responsible for not only impaired functional capacity but also lethal ventricular arrhythmias and sudden death. Appropriate imaging of the size and function of the RV are important because timely surgery on the pulmonary and tricuspid valves may preserve RV size and function. Adults with congenital heart disease should be followed at centers where there is an understanding of these problems so that valvular surgery can be considered when appropriate.

Transposition of the great arteries

Many patients with ventriculoarterial discordance have survived to adulthood. Those with complete transposition of the great arteries have often had an atrial switch procedure (Mustard or Senning operation) performed, which leaves the morphological right ventricle (RV) supporting the systemic circulation. RV failure and tricuspid regurgitation are common. Some patients may ultimately require cardiac transplantation. Sinus node dysfunction is increasingly common with longer follow-up, and some patients need pacemaker implantation. Atrial arrhythmias are frequent, and atrial flutter may be a marker for sudden death. Patients with an arterial switch procedure are also surviving to adulthood. Long-term problems include coronary stenoses, distortion of the pulmonary arteries, dilatation of the neoaortic root, and aortic regurgitation. Patients with congenitally corrected transposition have both atrioventricular and ventriculoarterial discordance and therefore also have a morphological RV and delicate tricuspid valve in the systemic circulation. Associated defects, such as abnormalities of the tricuspid valve, ventricular septal defect, and pulmonary stenosis, occur in the majority of patients. Heart block occurs with increasing age. Atrial arrhythmias occur frequently, and their occurrence should prompt a search for a hemodynamic problem. Progressive tricuspid regurgitation occurs with age and is associated with deterioration of RV function. Surgical treatment should be considered at the earliest sign of RV dilatation or dysfunction. All patients should be seen periodically in a center where expertise in the clinical evaluation, imaging, and hemodynamic assessment of adult congenital heart disease is available.

[Cerebellum abscess: first demonstration of undiagnosed infective endocarditis in an adult with corrected transposition arteries]

Neurological complications occur in approximately 30% of all patients with infective endocarditis and represent a major factor associated with an increased mortality rate. Third of these complications is represented by cerebral embolism, followed by mycotic aneurysm, meningitis or meningoencephalitis. Brain abscesses are rare; their localization to the cerebellum is exceptional. A case of cerebellum abscess occurring in a 34-year-old patient with non-operated corrected transposition of the great arteries is reported. Occurrence of this abscess was the first demonstration of undiagnosed infective endocarditis.

Outcome of the unoperated adult who presents with congenitally corrected transposition of the great arteries

OBJECTIVES

The goal of this study was to determine the presentation and outcome of the unoperated adult with congenitally corrected transposition of the great arteries.

BACKGROUND

The presentation of this disorder and the outcome in unoperated adults have not been well defined.

METHODS

All unoperated patients > or =18 years old were evaluated for spectrum of disease, hemodynamic severity, timeliness of diagnosis and referral, and outcome.

RESULTS

Forty-four patients aged 20 to 79 years (mean, 44) were followed up to 144 months. In 29 (66%), the correct diagnosis was first made at age > or =18 years; the diagnosis was missed in seven of these patients in a prior cardiology consultation, despite cardiac imaging. Systemic atrioventricular valve (SAVV) regurgitation (grade > or =3/4) was noted in 26 patients (59%). Thirty (68%) had surgical intervention, including SAVV replacement in all, with no early mortality. Preoperatively, this subset had significant dysfunction of the systemic ventricle (SV) (ejection fraction [EF], 40 +/- 10%), and most had advanced symptoms (25 with ability index > or =2/4). In 16 (53%), SAVV regurgitation > or =3/4 and ventricular dysfunction had been documented for >6 months. The mean EF of the SV decreased significantly postoperatively (34 +/- 11%, p = 0.006). Four patients (13%) eventually required cardiac transplantation. Poor preoperative EF of the SV predicted eventual need for transplantation (p = 0.001).

CONCLUSIONS

Patients with unoperated congenitally corrected transposition of the great arteries are often misdiagnosed in adulthood and are referred late despite symptomatic SAVV regurgitation and significant SV dysfunction. Although excellent early surgical results can be achieved, significant residual dysfunction of the SV is common.

Comparable systemic ventricular function in healthy adults and patients with unoperated congenitally corrected transposition using MRI dobutamine stress testing

BACKGROUND

Failure of the systemic right ventricle (RV) often complicates adult survival in unoperated or physiologically repaired congenitally corrected transposition of the great arteries (CCTGA). Healthy controls schematically represent an optimal outcome of anatomic repair, which is increasingly performed to treat CCTGA. Magnetic resonance imaging dobutamine stress testing measures cardiac reserve, and sets to compare the left ventricle of controls with the systemic RV of unoperated and physiologically repaired patients with CCTGA.

METHODS

Baseline and stress magnetic resonance imaging (maximum dobutamine dose, 15 microg/kg/min) assessed systemic RV function in 13 minimally or asymptomatic adult patients with CCTGA (unoperated, n = 7; physiologically repaired, n = 6). The left ventricles of 11 healthy age-matched adults served as controls.

RESULTS

Baseline and stress end-diastolic volumes similar between the systemic RV of unoperated patients and the left ventricle of controls, as well as base end-systolic volumes. Stress ejection fraction was lower in unoperated and physiologically repaired patients (70 +/- 6% and 60 +/- 5%, respectively, vs healthy controls (84 +/- 8%). However, comparable with healthy controls, both subsets of CCTGA patients responded appropriately to dobutamine stress, as illustrated by similar RV stroke volume, heart rate, mean blood pressure, and cardiac index.

CONCLUSIONS

Compared with the left ventricles of healthy controls, both patient groups had larger systemic RV volumes, diminished ejection fraction, but an appropriate response to dobutamine stress. Values of unoperated patients are closer to normal than physiologically repaired patients. Magnetic resonance imaging dobutamine may help to define the subgroups of CCTGA patients with favorable anatomy, whereby asymptomatic adult survival could be anticipated without the need for an operation.

Dobutamine-induced increase of right ventricular contractility without increased stroke volume in adolescent patients with transposition of the great arteries: evaluation with magnetic resonance imaging

OBJECTIVE

Prognosis in patients with surgically corrected (Senning or Mustard) transposition of the great arteries (TGA) depends mainly on right ventricular (RV) function and RV functional reserve. We examined the role of dobutamine stress in the early detection of RV dysfunction in asymptomatic or slightly symptomatic patients with TGA using magnetic resonance imaging (MRI).

DESIGN AND PATIENTS

Twelve asymptomatic or slightly symptomatic patients with chronic RV pressure overload, surgically corrected (Mustard or Senning) TGA (age 22.8 (+/- 3.4) years; New York Heart Association (NYHA) class I/II) and nine age matched healthy volunteers (age 27.3 (+/- 4.4) years) were included. MRI was applied both at baseline and during dobutamine stress (start dose 5 microg/kg/min to maximum dose 15 microg/kg/min) to determine RV and left ventricular (LV) stroke volumes (SV) and ejection fraction (EF).

RESULTS

At baseline only RVEF was significantly higher in controls than in patients (71 (+/- 9) vs. 57 (+/- 10)%, p < 0.001), other RV parameters were not significantly different between the two examined groups: RVSV (86 (+/- 21) vs. 72 (+/- 27) ml, p = ns), RV end-diastolic volume (EDV) (123 (+/- 37) vs. 123 (+/- 33) ml, p = ns), and heart rate (61 (+/- 10) vs. 69 (+/- 14) bpm, p = ns), respectively. During dobutamine stress RVEF increased significantly both in controls and patients (20 (+/- 16) vs. 17 (+/- 18)%, p < 0.01 and p < 0.02 vs. rest, respectively), but stress RVEF was significantly higher in controls than in patients (85 (+/- 3) vs. 66 (+/- 7)%, p < 0.0001). RVSV increased significantly in controls (22 (+/- 19)%, p < 0.02), and there was no significant increase in RVSV in patients (-10 (+/- 28)%, p = ns). The controls showed no change in RVEDV (2 (+/- 17)%, p = ns), but in patients a significant decrease in RVEDV (-24 (+/- 15)%, p < 0.001) was observed. Maximal heart rate was significantly higher in patients than in controls (122 (+/- 20) vs. 101 (+/- 14) bpm, p < 0.02).

CONCLUSION

In asymptomatic or slightly symptomatic patients with surgically corrected TGA dobutamine had a positive inotropic effect on RV, but the increased contractility was not accompanied by an appropriate increase in SV. Our data suggest inadequate RV filling in this category of patients, possibly due to rigid atrial baffles and compromised atrial function or decreased compliance due to RV hypertrophy.

Atrioventricular discordance: results of repair in 127 patients

OBJECTIVE

The conventional management of patients with atrioventricular discordance is directed at associated lesions, taking advantage of physiologic "correction"; however, the morphologic right ventricle and tricuspid valve support the systemic circulation. Questions surrounding survival using this approach led us to analyze our institutional results.

METHODS

All patients with atrioventricular discordance undergoing biventricular repair were analyzed (n = 127, 1959-1997), excluding those with functionally univentricular hearts. The ventriculoarterial connection associated with atrioventricular discordance varied and was most commonly discordant (87%), but occasionally concordant (6%), double-outlet right ventricle (6%), or double-outlet left ventricle (1%). At initial presentation, the most common lesions associated with atrioventricular discordance were ventricular septal defect (86%), pulmonary stenosis (64%), tricuspid regurgitation (28%), and atrioventricular block (12%). Nine patients underwent a double switch procedure to create ventriculoarterial concordance and the remainder were managed conventionally without correcting discordant connections.

RESULTS

Operative mortality was 6% and did not vary by associated lesion. Twenty years after repair, survival was 48%. Within 20 years, 56% of patients required reoperation, usually for atrioventricular valve incompetence (n = 16), pulmonary stenosis (n = 16), or both (n = 3). Pacemakers were required in 50 patients, 4 before repair, 40 within 2 months of repair, and 6 remotely after repair. In early follow-up, the double switch procedure (n = 9) had equivalent mortality and a high pacemaker requirement for atrioventricular block.

CONCLUSIONS

Analysis of conventional management of atrioventricular discordance revealed cumulative increases in mortality, systemic atrioventricular valve (tricuspid) replacement, complete atrioventricular block, and incidence of reoperation. Alternative management should be examined.

Postsurgical course of patients with congenitally corrected transposition of the great arteries

Because congenitally corrected transposition is a rare congenital anomaly, little is known about the prognosis of patients with this syndrome. The present study evaluated the functional status and clinical course of 73 patients (42 male and 31 female) aged 10 days to 73 years. Follow-up was 1 week to 37 years (mean 12.7 years). Particular attention was paid to the systemic right ventricle, considering the current controversies about long-term right ventricular function. Survival of patients with this condition in general was significantly below normal. The total mortality rate was 11% (8 patients) after a mean follow-up of 12.7 years (range 10 days to 37 years). Mean age at death was 18.5 years (range 6 days to 63 years). The mean age of the survivors at latest follow-up was 21.4 years (range 4 months to 73 years). In most patients, right ventricular function deteriorated and tricuspid valve regurgitation increased, which began at a very young age. Patients without associated lesions developed complications at a higher age compared with the total group. Right ventricular and tricuspid valvular function deteriorated more frequently in patients following intracardiac operation (28% and 52%, respectively) compared with patients undergoing palliative intervention (16%) or no surgery at all (28%). We conclude that survival of patients with this condition is substantially reduced compared with the natural history of an age- and gender-matched general population. This could be explained by the associated cardiac defects, but also by the anatomic condition itself.