Cardiac rhythm and conduction before and after anatomic correction of transposition of the great arteries

To assess pre- and postoperative arrhythmias associated with anatomic correction of transposition of the great arteries, 34 patients had 145 standard electrocardiograms (ECGs) and 24 of these patients had 46 24-hour ECGs from 11 months before to 54 months after anatomic repair. Twenty-two patients underwent balloon atrial septostomy and 7 surgical atrial septectomy before the initial 24-hour ECG. Anatomic correction included repair of a large ventricular septal defect in 16 patients and an aortopulmonary window in 1 patient. The preoperative standard ECG showed sinus rhythm in every patient. Preoperative 24-hour tapes revealed sinus arrhythmias in 2, sinus bradycardia at a rate of less than or equal to 50 beats/min in 1, junctional rhythm in 1 and rare premature ventricular contractions (PVCs) in 1. The postoperative 24-hour ECG showed atrioventricular dissociation in 1 patient, rare premature atrial contractions in 7, rare PVCs in 8 and sinus bradycardia with junctional escape in 1. Eight patients had PVCs on the postoperative ECG that were not noted on preoperative tapes. No patient had prolonged bradycardia (less than or equal to 50 beats/min), life-threatening arrhythmias or sudden death. Except for 1 patient with atrioventricular dissociation believed to be secondary to a preventable cause, 34 patients followed for 890 patient-months after anatomic correction for transposition of the great arteries had no significant arrhythmias.     

Cardiac rhythm and conduction after two-stage anatomic correction of simple transposition of the great arteries

To assess postoperative arrhythmias and AV-conduction defects associated with anatomic correction of simple transposition of the great arteries, 207 standard 12-lead surface and 43 24-hour electrocardiograms of all 17 patients followed after anatomic correction for up to 6.5 years were reviewed. No dysrhythmias or AV-conduction delays definitely attributable to anatomic correction were observed. One patient with a severe complex supraventricular tachyarrhythmia after a Blalock-Hanlon procedure has improved markedly, exhibiting respiratory AV-dissociation and 5 premature atrial complexes/minute 5 years after anatomic correction.     

A quantitative evaluation of aortic regurgitation after anatomic correction of transposition of the great arteries

Twenty patients who had undergone anatomic correction of transposition of the great arteries were assessed by Doppler echocardiography or cardiac catheterization, or both, to identify the presence of aortic regurgitation. The severity of aortic regurgitation was evaluated by radionuclide angiographic measurement of the stroke volume index a mean of 47.1 months postoperatively. The stroke volume index was defined as the ratio of the stroke counts between the left and right ventricles. A value greater than 1.8 was considered to indicate significant left ventricular volume overload. Eight patients (40%) were shown to have various degrees of aortic regurgitation by Doppler echocardiography or cardiac catheterization, or both. The mean (+/- SD) stroke volume index was 1.03 +/- 0.15 in these patients and 1.01 +/- 0.21 in the 12 patients without aortic regurgitation (p = NS). The stroke volume index was not above the normal range in any patient, indicating that the degree of aortic regurgitation present was trivial. This medium-term study indicates that trivial or mild aortic regurgitation is a frequent finding after anatomic correction of transposition of the great arteries. However, it rarely results in an audible cardiac murmur or significant left ventricular volume overload. Long-term evaluation is required to determine its importance.     

Arrhythmias in transposition of the great arteries after the Mustard operation

Disorders of rhythm or conduction in patients with transposition of the great arteries (TGA) after the Mustard operation have been widely reported. This study provides a systematic evaluation of the electrophysiologic function of 87 survivors of the Mustard operation at a single institution. Surface electrocardiograms were reviewed in all 87 patients, Holter monitoring data in 26 patients, exercise electrocardiograms in 21 patients, and invasive electrophysiologic data in 61 patients. Surface electrocardiograms showed normal sinus rhythm in 52%, sinus node dysfunction in 27%, and atrioventricular block in 16%. Holter monitoring was obtained in an unselected subgroup of 26 patients who had a mean age of 12 years and a mean interval from operation of 9 years. Sinus node dysfunction was found in 58%, atrioventricular block in 27% ventricular ectopy in 50%, supraventricular ectopy in 27%, and no abnormalities in only 8%. Intracardiac electrophysiologic evaluation showed a high frequency of abnormal sinus node recovery times and suboptimal response of the atrioventricular-conduction system to rapid atrial pacing. When all modalities used in this study were considered, sinus node dysfunction occurred in 47%, ectopy in 34% and atrioventricular block in 23%. Although only 30% of patients had no evidence of arrhythmia, symptoms of rhythm or conduction disturbances were rare.     

Left ventricular systolic and diastolic function after two-stage anatomic correction of transposition of the great arteries

Anatomic repair of transposition of the great arteries (TGA) has been developed because of concerns about right ventricular function after atrial repair by the Mustard or the Senning technique. This study assessed left ventricular systolic and diastolic function in three patients after two-stage anatomic repair. Two patients had a ventricular septal defect (one with coarctation), and the third patient had right ventricular dysfunction precluding atrial repair. All had pulmonary artery banding. The mean ages at the time of repair and catheterization were 2.75 and 4.9 years, respectively. The control group included 10 patients with insignificant or no cardiac disease. At cardiac catheterization the group with TGA had a higher mean end-diastolic volume index (110.9 +/- 4.74 ml/m2) compared to normal subjects (79.1 +/- 14.55; p less than 0.001), mean end-systolic volume index (37.3 +/- 3.69 vs 22.7 +/- 4.42; p less than 0.001), mass index (101.0 +/- 16.9 vs 68.2 +/- 12.34; p = 0.038), and stroke volume index (73.6 +/- 3.52 vs 56.5 +/- 12.1; p = 0.0027). The ejection fractions, end-diastolic and peak systolic pressures, and stresses were not different. There was no difference in the relationship between the mean rate-corrected velocity of circumferential fiber shortening and end-systolic stress for the group with TGA, but myocardial stiffness was markedly elevated (29.5 +/- 1.84 vs 10.8 +/- 2.20; p less than 0.001). Thus, this study found abnormalities of left ventricular size after two-stage anatomic repair of TGA in this group of patients with TGA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Further experience with the two-stage anatomic correction of simple transposition of the great arteries

Between May 1976 and January 1981 a two-stage anatomic correction was performed in 25 patients with simple transposition of the great arteries, ranging in age from 41/2 to 46 1/2 months (mean 14.8). A first-stage operation, consisting of banding of the pulmonary artery to redevelop the left ventricle, including a Blalock-Taussig-anastomosis in 4 patients was performed prior to anatomic correction. Of 33 patients, who underwent first-stage correction there were 3 early deaths (9%). The interval between the first and second stages was 5 weeks to 9 months (mean 4.3 months). After the first-stage operation, the peak systolic left ventricular pressure rose from 34 +/- 11 mmHg to 80 +/- 16 mmHg with no significant change in enddiastolic pressure. After anatomic correction there were 5 early deaths (20%) of whom 4 were due to left heart failure. There was no correlation between death and the age of the patients at the time of anatomic correction. By our current criteria the ventricles were not adequately prepared for correction in these four patients. The coronary arteries, with different types of origin, could be reimplanted to the posterior vessels without kinking, tension or torsion in all cases. After correction, the ECG and vectorcardiogram rapidly changed toward normal. The arterial oxygen saturation was higher than 95% in all patients. Recatheterization performed in 11 patients, 3 weeks to 27 months after correction, showed normal left ventricular pressure at rest in all children, except in 2 recatheterized early after correction, who had moderately elevated left ventricular enddiastolic pressure. Right ventricular peak systolic pressure decreased to normal limits. The aortic and coronary anastomoses showed normal growth in cineangiography. Although the two-stage corrections of simple TGA may have its own problems, investigation suggests that results are encouraging.     

Fate of pulmonary artery after anatomic correction of simple transposition of great arteries in newborn infants

From April 1984 to April 1987, surgical anatomic correction was performed in 86 newborn infants, 2-23 days old (6.8 +/- 3.6 days, mean +/- SD) with simple transposition of the great arteries. In all patients, the pulmonary artery was reconstructed by end-to-end anastomosis according to the Lecompte maneuver, including eight patients with side-by-side position of the great arteries. Three different approaches were used. In the first 10 patients (group 1, six survivors), two separate patches of preserved tanned pericardium were used to reconstruct the pulmonary artery, whereas in the next 15 patients (group 2, 13 survivors), a single patch of the same material was used, and in the last 61 patients (group 3, 56 survivors), surgery was performed with a single patch of fresh autologous pericardium. Among the 75 survivors, 68 (including six in group 1, 12 in group 2, and 50 in group 3) were followed serially for at least 6 months (6-48 months, 26 +/- 9 months) with sequential noninvasive evaluations. At follow-up, all were asymptomatic with normal growth. Two patients with severe pulmonary artery stenosis (group 1) were successfully reoperated on. Four infants with moderate pulmonary artery stenosis have been followed medically and have had stable right ventricular pressures. The last 62 patients have normal or near-normal right ventricular pressures. The spatial relation of the great arteries did not affect the quality of the results. Group 1 had clearly the worst results.(ABSTRACT TRUNCATED AT 250 WORDS)     

Doppler echocardiography after anatomical correction of transposition of the great arteries

Nineteen patients who had anatomical correction of transposition of the great arteries between the ages of one week and 10 years were investigated by pulsed and continuous wave Doppler echocardiography 1-98 months after operation. Peak blood flow velocities across the atrioventricular valves were significantly higher than normal, but no pathological regurgitation was seen. Systolic aortic velocities were normal in all but one patient, but mild aortic regurgitation was detected in ten. Increased flow velocities either at pulmonary valve level, at the pulmonary artery bifurcation, or in the left pulmonary artery were detected in 14 patients, the maximum calculated pressure drop being 36 mm Hg. Adequate Doppler sampling of the right pulmonary artery was not achieved in any of the cases, and sampling of the left pulmonary artery was possible in only ten. The principal limitation of the Doppler ultrasound method in this study was the inability to obtain flow velocities from the branch pulmonary arteries in most patients. Doppler echocardiography provides valuable information after the arterial switch operation and may reduce the need for repeat cardiac catheterisation.     

Doppler echocardiography after anatomical correction of transposition of the great arteries.

Nineteen patients who had anatomical correction of transposition of the great arteries between the ages of one week and 10 years were investigated by pulsed and continuous wave Doppler echocardiography 1-98 months after operation. Peak blood flow velocities across the atrioventricular valves were significantly higher than normal, but no pathological regurgitation was seen. Systolic aortic velocities were normal in all but one patient, but mild aortic regurgitation was detected in ten. Increased flow velocities either at pulmonary valve level, at the pulmonary artery bifurcation, or in the left pulmonary artery were detected in 14 patients, the maximum calculated pressure drop being 36 mm Hg. Adequate Doppler sampling of the right pulmonary artery was not achieved in any of the cases, and sampling of the left pulmonary artery was possible in only ten. The principal limitation of the Doppler ultrasound method in this study was the inability to obtain flow velocities from the branch pulmonary arteries in most patients. Doppler echocardiography provides valuable information after the arterial switch operation and may reduce the need for repeat cardiac catheterisation.     

Arrhythmias after the Mustard operation for transposition of the great arteries: a long-term study

This study presents follow-up data on 95 patients with transposition of the great arteries who underwent a Mustard intraatrial baffle operation. The patients were followed up serially by means of scalar electrocardiograms and 24 hour Holter monitoring studies. The latter study was effective in documenting abnormal rhythm patterns when the standard electrocardiogram was within normal limits. Twenty percent of the patients had atrial arrhythmias at the time of hospital discharge. new rhythm disturbances were recognized during each year of follow-up; 75% of the patients had atrial rhythm disorders by the sixth year. Slow junctional rhythm was the most common rhythm disturbance found. Complete heart block did not occur. Supraventricular tachycardia occurred within the context of the tachycardia/bradycardia syndrome in 8 of 10 patients, and in all it was documented after hospital discharge. The incidence of sudden death in this series was 3%. Six of the patients have had pacemaker insertions and there have been no deaths among these individuals. It was observed that the slow atrial or junctional rhythms that appeared after intraatrial correction of transposition of the great arteries rarely progressed to life-threatening rhythm disorders in childhood or adolescence, but the prognosis in adult life remains unknown. The three deaths in the series occurred in patients with a history of supraventricular tachyarrhythmias. Elimination of arrhythmias caused by extensive intraatrial surgery is one of the potential advantages of the arterial switch operation for correction of transposition of the great arteries.     

An electrocardiographic midterm follow-up study after anatomic repair of transposition of the great arteries

Prospective studies of rhythm and conduction, before and after 1-stage anatomic repair of simple transposition of the great arteries, were performed on 24 survivors. Pre- and postsurgical serial standard electrocardiograms were obtained on each patient. Fourteen patients underwent perioperative 24-hour electrocardiograms; all had follow-up 24-hour electrocardiograms. Rare atrial or occasional ventricular premature complexes were detected in 3 (11%) patients before operation. After surgery, 1 patient developed right bundle branch block. Two patients developed a left bundle branch block. One patient had a QS pattern in V6, which disappeared on follow-up electrocardiogram. Transient second-degree atrioventricular block was detected in 1 patient. A normal P-R interval and P-wave axis were present in all but 1 patient. Mild sinus bradycardia or rare atrial or ventricular premature complexes were detected in 4 of twenty-nine 24-hour electrocardiograms performed in the first 2 years after surgery. At 3 years after repair, 5 patients had a normal 24-hour electrocardiogram and 1 had low-grade ectopy (rare atrial and ventricular premature complexes). At 4 years, all 4 patients studied had normal 24-hour electrocardiograms. During a mean follow-up of 3 years, we have yet to document any symptomatic arrhythmias.     

Computer assisted echocardiographic assessment of left ventricular function before and after anatomical correction of transposition of the great arteries

Left ventricular function before and after anatomical correction of transposition of the great arteries was assessed by computer assisted analysis of 78 echocardiographs from 27 patients obtained one year before to five years after operation. Sixteen patients had simple transposition, and 11 had complex transposition with additional large ventricular septal defect. Immediately after correction mean shortening fraction fell from 46(9)% to 33(8)%. There was a corresponding drop in normalised peak shortening rate from 5.4(3.7) to 3.3(1.1) s-1 and normal septal motion was usually absent. Systolic shortening fraction increased with time after correction and left ventricular end diastolic diameter increased appropriately for age. The preoperative rate of free wall thickening was significantly higher in simple (5.6(2.8) s-1) and complex transposition (4.5(1.8) s-1) than in controls (2.9(0.8) s-1). After operation these values remained high in both the short and long term. Thus, computer assisted analysis of left ventricular dimensions and their rates of change before and after anatomical correction showed only slight postoperative changes which tended to become normal with time. Septal motion was commonly absent after operation. This was associated with an increase in the rate of posterior wall thickening that suggested normal ventricular function associated with an altered contraction pattern. Computer assisted echocardiographic analysis may be helpful in the long term assessment of ventricular function after operation for various heart abnormalities.     

Catheter evaluation of left ventricular shape and function 1 or more years after anatomic correction of transposition of the great arteries

Twenty-eight children were reinvestigated by cardiac catheterization and angiography > 1 year after anatomic correction of transposition of the great arteries (TGA). Seventeen patients with simple TGA underwent banding of the pulmonary trunk plus or minus systemic to pulmonary artery shunt to prepare the left ventricle for anatomic correction. In addition to TGA, 10 of the remaining 11 patients had a large ventricular septal defect and 1 had an aorticopulmonary window. They required no preparation of the left ventricle. Age at repair ranged from 2 to 120 months (mean 26).Catheterization 12 to 48 months after anatomic repair revealed a left ventricular end-diastolic pressure of 4 to 14 mm Hg (mean 9.5 ± 2.5 [± standard deviation]). Ejection fraction ranged from 52 to 75% (mean 66 ± 8). Frame-by-frame computer-assisted analysis of left ventricular (LV) contraction and relaxation was performed in 14 patients and compared with normal left ventriculograms. Shape index, derived as $\text{4π ×}\text{cavity area}\text{perimeter}{}^2\text{× 100}$, was measured in 24 patients and showed a mean index of 89 ± 3% at end-diastole and 79 ± 8% at end-systole. A control group had a mean diastolic index of 86 ± 6% and mean systolic index of 73 ± 8%.It is concluded that LV shape after anatomic correction tends to be more globular than normal and changes little during systole. LV ejection fraction and end-diastolic pressure are normal.     

Influence of the two-stage anatomic correction of simple transposition of the great arteries on left ventricular function

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great arteries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = 11), and compared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 +/- 10) and between 13 and 47 months (mean 24 +/- 10), respectively. The interval between anatomic correction and the investigation ranged from 10 to 29 months (mean 20 +/- 7). After banding, LV ejection fraction decreased (p less than 0.01) and LV peak systolic pressure (p less than 0.01) as well as LV end-diastolic pressure (p less than 0.05) increased. After anatomic correction, these variables and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 patients after anatomic correction was within control range. The highest values were found in the youngest patients at banding and at anatomic correction. In contrast to measures of global myocardial function, such as LV ejection fraction and LV end-diastolic pressure data, the LV end-systolic stress-ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.     

Functional capacity and rhythm changes after atrial correction of transposition of great arteries

A group of 12 patients, previously submitted to atrial correction of the transposition of the great vessels, were studied through stress test with direct metabolimetry and Holter to assess aerobic functional capacity and its relationship with conduction disturbances. The results were compared with those obtained with a control group of 23 non athletic healthy children. All the patients showed amputation of their heart rates on effort, though this parameter and the oxygen consumption were normal at low work load levels. The VO2 at anaerobic threshold, the maximum VO2, and the maximum work load were also decreased in most of the patients. Holter studies demonstrated sick sinus syndrome in nine of them. Aerobic functional capacity was reduced in most of the patients with atrial correction of the transposition of the great vessels. The amputation of the heart rate on effort is a common finding though its relationship with the decrease of the aerobic functional capacity in these patients is limited. Finally, the stress test is probably more sensible than Holter for the detection of slight degrees of sinus disfunction.     

Left ventricular retraining and anatomic correction in teenage patient with congenitally corrected transposition of the great arteries.

Left ventricular (LV) retraining followed by anatomical repair would be a superior alternative in patients with congenitally corrected transposition (ccTGA) having a deconditioned morphologically left ventricle (MLV); however, LV retraining in older children is a challenging task. A retraining process of the MLV in a teenage patient with ccTGA is reported here. Cardiac catheterization at 7 years of age revealed low pressure of the MLV (33/4 mm Hg) and a LV to right ventricular pressure ratio (LVp/RVp ratio) of 0.32. The first pulmonary artery banding (PAB) was performed at 10 years of age. Although the LVp/RVp ratio reached 0.68, there was no evidence of adequate LV hypertrophy. The second PAB was performed 2 years after the initial PAB, resulting in an increase in the LVp/RVp ratio to 0.93 and an adequate LV hypertrophy. The double switch procedure was successfully performed at 13 years of age. Although the ejection fraction of the MLV mildly decreased, the patient has been doing well during a follow-up period of 4 years. The MLV in the teenage patient with ccTGA was successfully trained using a retraining strategy and has sustained systemic circulation after anatomical repair.     

Computer assisted echocardiographic assessment of left ventricular function before and after anatomical correction of transposition of the great arteries.

Left ventricular function before and after anatomical correction of transposition of the great arteries was assessed by computer assisted analysis of 78 echocardiographs from 27 patients obtained one year before to five years after operation. Sixteen patients had simple transposition, and 11 had complex transposition with additional large ventricular septal defect. Immediately after correction mean shortening fraction fell from 46(9)% to 33(8)%. There was a corresponding drop in normalised peak shortening rate from 5.4(3.7) to 3.3(1.1) s-1 and normal septal motion was usually absent. Systolic shortening fraction increased with time after correction and left ventricular end diastolic diameter increased appropriately for age. The preoperative rate of free wall thickening was significantly higher in simple (5.6(2.8) s-1) and complex transposition (4.5(1.8) s-1) than in controls (2.9(0.8) s-1). After operation these values remained high in both the short and long term. Thus, computer assisted analysis of left ventricular dimensions and their rates of change before and after anatomical correction showed only slight postoperative changes which tended to become normal with time. Septal motion was commonly absent after operation. This was associated with an increase in the rate of posterior wall thickening that suggested normal ventricular function associated with an altered contraction pattern. Computer assisted echocardiographic analysis may be helpful in the long term assessment of ventricular function after operation for various heart abnormalities.     

Long-term growth following neonatal anatomic repair of transposition of the great arteries

Despite generally normal prenatal growth, surviving infants with transposition of the great arteries (TGA) frequently develop severe and progressive growth impairment which is not always fully reversed by elective atrial repair within the first year of life. This study was undertaken to determine the effect of neonatal anatomic repair of TGA on long-term growth. Twenty-three children with uncomplicated TGA were followed for a mean of 60 (12–90) months after anatomic repair at a mean age of 11 (1–40) days. Standardized measurements of weight, height, and head circumference for both patients and normal siblings were expressed as percentiles as well as in Z scores (in standard deviations from the mean for age and sex) based on internationally recognized standards. At latest follow-up, 22 (96%) of the patients were above the 3rd percentile for weight and 21 (91%) for both height and head circumference, with 13 (57%), 11 (48%), and 13 (57%) above the 50th percentile for each respective parameter. The mean Z scores (± SD) for weight, height, and head circumference for the patient group were – 0.1 ± 1.2, – 0.2 ± 1.3, and – 0.1 ± 1.1, respectively, and did not differ significantly from those of the reference population (p > 0.05 for each comparison). Paired comparisons of mean Z scores for each growth parameter with those of 35 normal siblings demonstrated no significant difference for weight or height and a small but significant difference for head circumference. Age at surgical repair (within the first 6 weeks of life), duration of follow-up and the development of moderate supravalvar pulmonary stenosis were not statistically related to long-term growth. These results indicate that in patients without extracardiac abnormalities, neonatal anatomic repair of uncomplicated TGA results in normal long-term growth.     

Surgical implications of early branching of the left coronary artery in anatomic correction of transposition of the great arteries

Early branching of the left coronary artery (LCA) may become an additional operative challenge during coronary transfer in anatomic correction of transposition of the great arteries. An early branch of the LCA running in opposite transfer direction was present in 3 out of 25 patients who underwent anatomic correction. By excising a large cuff of aortic sinus wall around the ostium of the LCA enough length was gained for successful coronary transfer without kinking in 2 patients in whom the first branch was arising at the level of the origin of the circumflex artery. In the third patient with the first branch arising proximal to the origin of the circumflex artery an alternative surgical procedure seemed preferable. In such a coronary anomaly optimal visualization of the coronary branching pattern, possibly including selective coronary angiography, is advisable for better planning of the surgical technique.     

Anatomic correction of simple transposition of the great arteries in 50 neonates

From April 1984 to January 1986, anatomic surgical correction was performed in 50 newborn (2- to 23-day-old, mean 8 +/- 5 [SD]) infants with simple transposition of the great arteries. Before surgery, balloon atrial septostomy was performed in all patients, prostaglandin E1 was infused in 42, and left ventricular shape on a two-dimensional echocardiogram was considered "satisfactory" in 48. Surgery was performed in patients on cardiopulmonary bypass without cardiac arrest; the pulmonary artery was reconstructed by end-to-end anastomosis according to Lecompte's maneuver with a pericardial patch. In all but one patient coronary artery transfer was possible regardless of the distribution of these vessels. There were eight early deaths (16%), but only four (10%) of the last 41 patients treated died. There was one late death (2%) due to a secondary myocardial infarction caused by compression of the left coronary artery. Reoperation was successfully performed in two patients for supravalvar pulmonary artery stenosis. The only late medical complication was a transient episode of myocardial ischemia 6 months after surgery. The 41 late survivors were in excellent condition, were in sinus rhythm, and had a normal left ventricle 1 to 22 months after surgery (mean 7.2 +/- 5.4 [SD]). Aortic growth was normal; pulmonary artery supravalvar stenosis occurred in six patients (mild in four). We conclude that anatomic correction can be applied successfully in the first few days of life in newborns with simple transposition of the great arteries, regardless of coronary distribution.