Myocardial perfusion scanning in patients considered for late arterial switch

BACKGROUND: Our aims were to evaluate left ventricular uptake of radionuclide in patients with Mustard's or Senning's procedure, comparing them with patients who had undergone banding of the pulmonary trunk and conversion to the arterial switch. METHODS: Technetium perfusion scans were performed on 27 patients (25 male), aged from 10 to 28 years with a mean of 17.8 years and a standard deviation of 5.8 years, who had undergone Mustard's or Senning's procedure for correction of complete transposition. Of the 27 patients, six had been accepted for staged conversion to an arterial switch. At the time of the study, two of the six patients had undergone completion to the switch and four had undergone banding of the pulmonary trunk with two then proceeding to the arterial switch. Cardiac catheterisation to measure left ventricular pressure was performed in all six patients and scores for left ventricular uptake of isotope were compared with echocardiographic index of the thickness of the left ventricular posterior wall and measurements of left ventricular pressure. RESULTS: Uptake of isotope by the left ventricle was generally poor, but was higher in patients following banding and conversion to the arterial switch, as well as in two patients with native obstruction of the left ventricular outflow tract, and one other who subsequently was found to have pulmonary venous obstruction. There was a positive correlation between the thickness of the left posterior wall in diastole and left ventricular uptake of isotope (r = 0.74, p < 0.05). There also a positive correlation between left ventricular pressure and uptake of the isotope (r = 0.68, p < 0.05). CONCLUSIONS: Uptake of radionuclide by the left ventricle after Mustard's or Senning's procedure for complete transposition appears to reflect ventricular pressure and myocardial mass. A prospective study would be required to determine the predictive ability of such scans regarding the ultimate outcome of conversion to arterial switch, but our initial findings suggest that the technique provides an additional non-invasive method of monitoring left ventricular response to pulmonary arterial banding.     

Transposition of the great arteries. Successful Senning's operation in 35 consecutive patients.

Mustard's operation for TGA (transposition of the great arteries) has been obstructive complications. In order to try to avoid these complications, we used Senning's operation for TGA. Our experience in 35 consecutive cases is reported. There were no operative or late deaths. Four patients had a PDA; three had a significant VSD with subpulmonary stenosis in two. Previous atrial septectomy and persistent LSVC did not represent contraindications to this procedure. The postoperative course has been smooth and uneventful in all patients. Follow-up periods of one to twenty months demonstrated sinus rhythm in all patients and there were no significant gradients between the venae cavae and the new systemic atrium in 12 reinvestigated patients. On the basis of these results, Senning's operation is recommended as a valid alternative to Mustard's operation.     

Abnormalities of right ventricular function following Mustard's operation for transposition of the great arteries.

Postoperative data were obtained at cardiac catheterization in twelve patients studied 6-29 months following Mustard's operation for transposition of the great arteries (TGA) to assess the incidence and severity of abnormalities of right ventricular (RV) function. Age at operation was 5-13 months in seven patients (infant group) and 19-25 months in the remaining five patients. RV end-diastolic volume (EDV) decreased in all patients following surgery and averaged 123% of normal in the postoperative group (NS). RV ejection fraction (EF) was depressed postoperatively averaging 0.45 (69% of normal (P less than 0.001) as was RV systolic output (78% of normal, P less than 0.01). LVEDV averaged 65% of normal (P less than 0.001), LVEF 0.67 (103% of normal, NS), and LV systolic output 67% of normal (P less than 0.001) following operation. Left atrial (systemic venous) volume was decreased in all postoperative patients averaging only 39% of normal (P less than 0.001). A high incidence (greater than 50%) of partial baffle obstruction was found and LV systolic output showed a significant negative correlation with baffle gradients. The low output postoperatively may be related to decreased LV filling pressure, a small LV reservoir, and thus a small atrial "booster pump." Pressure-velocity indices of RV contractile function in four patients showed a poor correlation with pump function. Long-term follow-up will be required to determine the clinical significance of the abnormalities of venous return and ventricular function.     

Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: detection by combined two-dimensional and Doppler echocardiography

Obstruction to pulmonary venous return may be associated with a number of congenital cardiovascular abnormalities occurring both before and after surgery. Hemodynamic assessment by cardiac catheterization is often difficult. A noninvasive method for detection and quantitation of obstruction to systemic ventricular inflow would be clinically useful. Two-dimensionally directed pulsed and continuous wave Doppler echocardiography was performed before cardiac catheterization in 31 patients thought clinically to have possible obstruction to left ventricular inflow or pulmonary venous return. Primary diagnoses included transposition of the great arteries after the Mustard or Senning procedure in nine patients, total anomalous pulmonary venous connection in nine (in two after surgical repair), cor triatriatum in eight (in four after surgical repair), congenital mitral stenosis in four (in one after surgical repair) and mitral atresia in one. Severe obstruction was defined as a mean pressure gradient at catheterization of greater than or equal to 16 mm Hg at any level of the pulmonary venous return or of the systemic ventricular inflow. Severe obstruction was predicted if Doppler examination measured a flow velocity of greater than or equal to 2 m/s across any area of inflow obstruction. At catheterization, 12 patients (39%) had severe obstruction to left ventricular inflow or pulmonary venous return and all obstructions were correctly detected by Doppler echocardiography. The site of pulmonary venous obstruction was localized by two-dimensionally directed pulsed Doppler study. Patients with a lesser degree of obstruction had a lower Doppler velocity, but none had a maximal Doppler velocity of greater than or equal to 2 ms/s.(ABSTRACT TRUNCATED AT 250 WORDS)     

Late development of pulmonary venous obstruction following Mustard's operation using a dacron baffle.

Three patients developed late pulmonary vein obstruction (PVO) following Mustard's operation for transposition of the great arteries. In all three the absence of PVO had been documented by an earlier postoperative cardiac catheterization. At reoperation shrinkage and kinking of the dacron baffle was evident. After Mustard's operation, patients should be observed closely for symptoms and signs of PVO since it can occur insidiously despite previously proven absence of this complication.     

Predictors of sudden cardiac death after Mustard or Senning repair for transposition of the great arteries.

OBJECTIVES: The goal of this research was to identify predictors for sudden death (SD) in patients with transposition of the great arteries (TGA) who have undergone atrial inflow repair. BACKGROUND: Sudden death is the most common cause of late death after atrial inflow repair of TGA. Little is known about the predictors of SD. METHODS: This was a retrospective, multicenter, case-controlled study. We identified 47 patients after Mustard's or Senning's operation who experienced an SD event (34 SD, 13 near-miss SD). Each patient was matched with two controls with the same operation, but without an SD event. Information on numerous variables before the event was obtained and compared with controls at the same time frame. RESULTS: Presence of symptoms of arrhythmia or heart failure at most recent follow-up and history of documented arrhythmia (atrial flutter [AFL]/atrial fibrillation [AF]) were found to increase the risk of SD. Electrocardiogram (ECG), chest X-ray, and Holter ECG findings were not predictive of SD. Neither medication nor pacing was found to be protective. Most SD events (81%) occurred during exercise. Ventricular tachycardia/ventricular fibrillation were the recorded rhythm during SD in 21 of 47 patients. CONCLUSIONS: Presence of symptoms and documented AFL/AF are the best predictors of SD in TGA patients. Patients with these findings should be further evaluated for risk of SD.     

Two dimensional and Doppler echocardiographic evaluation of double chambered right ventricle.

Two-dimensional and Doppler echocardiographic findings in 20 patients with double chambered right ventricle are described. All patients had the diagnosis established by cardiac catheterisation and confirmed at operation. Echocardiographic evaluation was done prior to surgical correction. Anomalous muscle bands in right ventricular cavity were detected in 16 patients. Doppler flow velocities in the right ventricular cavity suggested infundibular obstruction to blood flow at a low level in all 17 patients studied by Doppler echocardiography. Ventricular septal defects (11 patients), pulmonary stenosis (3 patients), and aortic regurgitation (3 patients) were detected accurately before operation by echocardiographic examination. Failure to detect the anomalous muscles in right ventricular cavity may occur in adult patients with poor anterior resolution and in those with severe right ventricular outflow obstruction and myocardial hypertrophy. Two dimensional echocardiography with Doppler flow analysis is useful in the evaluation and differential diagnosis of right ventricular outflow obstructions prior to invasive studies and surgical intervention.     

Medium-term clinical results after the Senning procedure with haemodynamic and angiographic evaluation of the venous pathways.

OBJECTIVE--To assess the clinical condition of patients and the adequacy of their newly constructed venous pathways after the Senning operation for simple transposition of the great arteries. PATIENTS AND DESIGN--All 34 patients who had the Senning operation between March 1983 and December 1986 were reviewed. Survivors had detailed cardiac catheterisation studies one to two years later and clinical evaluation two to six years after surgery. RESULTS--There were two operative deaths (6%), one sudden late death (after two years), and 31 survivors (91%). No clinical evidence of obstructed venous pathways was found and there was no need for reoperation for any reason. The average mean (SD) pressure gradient at the junction of the superior vena cava and systemic venous atrium was 2.0 (1.7) mm Hg, although two patients had gradients of 7 mm Hg. The average gradient was 0.7 (1) mm Hg in the inferior vena caval pathway, and 1.4 (1.1) mm Hg between the mean pulmonary arterial wedge and pulmonary venous atrial pressures. Only the two patients with gradients of 7 mm Hg at the junction of the superior vena cava and the systemic venous atrium had considerable narrowing of the pathway and retrograde flow in the azygos vein to below the diaphragm. CONCLUSION--A small series of patients were comprehensively studied after the Senning operation for simple transposition of the great arteries. Scrupulous technique in the construction of the venous pathways has had excellent results with no need for reoperation for obstruction in either the systemic or pulmonary pathways. Clinical observation alone may fail to identify patients with venous pathway obstruction, therefore careful assessment is required, even in patients who are physically normal.     

Functional assessment of the Fontan operation: combined M-mode, two-dimensional and Doppler echocardiographic studies

Combined M-mode, two-dimensional and Doppler echocardiographic studies were used to assess the postoperative status of 33 patients who had undergone the modified Fontan procedure. Twenty-four patients had surgical repair with use of a simple direct right atrium to pulmonary artery anastomosis. The remaining patients had repair with use of a prosthesis or associated Glenn shunt. Twenty-seven patients were studied early in the postoperative period (2 months or less) and the remaining patients were studied up to 6 years postoperatively. A total of 36 examinations were performed. Of the 33 patients, 13 had tricuspid atresia, 12 had double inlet left ventricle with hypoplastic right ventricular outlet chamber and 8 had complex lesions with atrioventricular canal, double outlet right ventricle or a hypoplastic ventricle. Postoperative assessment by M-mode and two-dimensional echocardiography demonstrated normal or mildly reduced ventricular function (ejection fraction greater than 40%) in 22 patients. In 24 patients, a "normal" flow pattern was observed in the pulmonary artery by pulsed Doppler echocardiography, with predominant diastolic flow and accentuation by atrial systole somewhat similar to the venous flow pattern observed in the superior vena cava. "Abnormal" flow patterns (disorganized systolic flow, absence of atrial waves and little or no increase with inspiration) were observed in nine patients with reduced ventricular function or residual shunt. Continuous wave Doppler study also demonstrated mild dynamic subaortic obstruction in two patients. Combined pulsed and continuous wave studies showed atrioventricular valve insufficiency in 10 patients. Follow-up studies revealed a satisfactory clinical course in most patients. Three patients died approximately 4 to 8 months after their Fontan operation.     

Pulmonary venous flow pattern--its relationship to cardiac dynamics. A pulsed Doppler echocardiographic study

We studied the physiology of pulmonary venous flow in 13 normal subjects and five patients with atrial rhythm disorders and atrioventricular conduction disturbances with pulsed Doppler and two-dimensional echocardiography. The left atrium, mitral valve, and pulmonary venous ostia were visualized through the apical four-chamber view. Mitral and pulmonary venous flows were obtained by placing the Doppler sample volume at the appropriate orifice. Pulmonary venous flow was biphasic: a rapid filling wave was observed during systole when the mitral valve was closed; a second wave was observed in diastole during the rapid ventricular filling phase of mitral flow, but was significantly delayed. In patients without atrial contraction (atrial fibrillation and sinoatrial standstill), the initial rapid filling was greatly diminished and only the second diastolic wave appeared to contribute to left atrial filling. In patients with high-grade atrioventricular block, each atrial contraction was followed by a surge in flow from the pulmonary veins. These results are consistent with data obtained from invasive measurements in both dogs and man, and confirm the validity of the use of pulsed Doppler echocardiography in the study of pulmonary venous flow. We suggest that pulmonary venous flow is influenced by dynamic changes in left atrial pressure created by contraction and relaxation of the atrium and ventricle. The initial peak in pulmonary venous flow occurs with atrial relaxation simultaneously with the reduction of left atrial pressure, and the second peak occurs with left ventricular relaxation and rapid transmitral filling of the ventricle.     

Hemodynamic function after the mustard operation for transposition of the great arteries

Pre- and postoperative cardiac catheterization data and cinenangiocardiograms of 82 patients who survived the Mustard operation for transposition of the great arteries (TGA) were reviewed. The postoperative catheterizations were performed 20 days to 10 years after operation (mean 2.5 years). Forty-six patients (56%) had no or insignificant associated cardiac lesions, whereas 36 (44%) had ventricular septal defect, pulmonary stenosis, or both, and required surgical intervention at the time of the Mustard operation. Postoperatively, 11 patients (13%) had significant systemic venous obstruction. Of the 11 patients, 6 required reoperation, and 2 patients had evidence of restenosis or complete obstruction in the superior vena cava after reoperation. In most patients, superior vena caval obstruction was well tolerated even in the presence of high pressure in the superior vena cava. Pulmonary venous obstruction occurred in 5 patients (6 % ), 3 of whom had no clinical symptoms despite severe pulmonary venous obstruction, although all had radiographic evidence of pulmonary venous congestion. The incidence of obstruction was drastically reduced after the Mustard operation was modified to include routine enlargement of the pulmonary venous atrium. Tricuspid regurgitation was uncommon (10%), but did occur in patients who had transatrial closure of a ventricular septal defect. Preoperatively, left ventricular outflow obstruction occurred in 38%. In 12 patients an attempt was made to relieve the obstruction at surgery. The 6 patients who had localized obstruction had a good result, but patients with more diffuse narrowing of left ventricular outflow had little or no relief of obstruction. Mild to moderate left ventricular outflow gradients regressed spontaneously in most patients after the Mustard operation.     

The value of 2-D Doppler echocardiography in the evaluation of asymptomatic patients with Mustard operation for transposition of the great arteries.

2-D Doppler echocardiography was used to assess the occurrence of haemodynamic abnormalities in 45 asymptomatic patients, aged 4 to 16 years (median 7.4) after a Mustard operation for transposition of the great arteries. The findings were compared with those derived from cardiac catheterization. Thirty-five cardiac lesions were correctly diagnosed by 2-D Doppler echocardiography in 23 patients, but on six occasions, minor abnormalities were missed. 2-D Doppler echocardiography demonstrated systemic venous pathway obstruction of more than 3 mmHg at cardiac catheterization in nine patients, and in five of the six patients with pulmonary venous channel obstruction. A left ventricular outflow tract obstruction (pressure difference greater than 15 mmHg) was diagnosed correctly by Doppler echocardiography in seven patients. Baffle leakage was found in two patients with a left to right shunt of 25% or more of pulmonary blood flow, but was missed in five out of nine patients with small shunts. Tricuspid regurgitation was well defined in eight patients. The absence of symptoms and a routine examination after a Mustard operation do not rule out haemodynamic abnormalities. However, these, with the possible exception of minor baffle leakage, can be detected by 2-D Doppler echocardiography.     

Does Doppler analysis of hepatic venous flow predict increased right atrial pressure and right ventricular dysfunction?

The aim of this study was to test the hypothesis that Doppler study of hepatic venous flow, reflecting right atrial pressures and right ventricular dysfunction, allows prediction of increased right atrial pressure and right ventricular dysfunction in patients with right ventricular infarction. The authors studied 30 patients (27 men, mean age 54 +/- 12 years) in sinus rhythm with acute inferior myocardial infarction who underwent right heart catheterisation and Doppler echocardiography including recording of regurgitant and hepatic vein flow within 48 hours of hospital admission. Hepatic venous flow was used to measure peak velocity and velocity time integrals (VTI) of the systolic (S), diastolic (D) and atrial (a) contraction waves. The fraction of systolic filling was calculated: VTI S/VTI S + VTI D. The pressure half-time of pulmonary regurgitant flow (PHT IP) was also measured. Using haemodynamic criteria (non-compliant right atrial pressure wave form or right ventricular end diastolic pressure/pulmonary capillary pressure > or = 0.8), patients were divided into two groups: Group 1: right ventricular infarction (VD+, N = 22). Group 2: no right ventricular infarction (VD-, N = 8). No correlation was observed between Doppler parameters of hepatic venous flow and haemodynamic data, in particular right atrial pressure and pressure wave form. Moreover, no statistically significant difference was observed between the two groups with respect to the Doppler parameters derived from hepatic venous flow. On the other hand, the results confirmed good diagnostic performance of Doppler analysis of pulmonary regurgitant flow: sensitivity 80%, specificity 83%, positive predictive value 94%, negative predictive value 55%. The authors conclude that, in patients with acute inferior wall infarction, Doppler analysis of hepatic venous flow does not allow assessment of right atrial pressure or of ischaemic right ventricular dysfunction.     

Abnormal right heart filling after cardiac surgery: time course and mechanisms.

OBJECTIVE--To study the time course and underlying mechanisms of right heart filling after cardiac surgery. DESIGN--A prospective observational study of adult patients undergoing cardiac surgery. SETTING--Echocardiography laboratory of the Stanford University Medical Center. PATIENTS--Twenty six patients (mean age 54.9) undergoing cardiac surgery were studied before and two days, one week, six weeks, and six months after cardiac surgery. MAIN OUTCOME MEASURES--Flow in the hepatic veins and superior vena cava, tricuspid and mitral annulus motion, signs of tricuspid regurgitation, and right ventricular size were assessed by echocardiography. RESULTS--Right heart filling, expressed as the ratio of systolic to diastolic forward flow Doppler velocity integrals in the superior vena cava and by tricuspid annulus motion, decreased in parallel from before surgery baseline values of 3.5 (SD 3.1) and 21.9 (3.4) mm, respectively to 0.2 (0.1) and 8.1 (2.3) mm two days after operation. A gradual increase towards baseline values was noted after six months, to 1.4 (1.3) and 15.1 (2.3) mm respectively; however, these values were still significantly less than those before operation. Similar changes were seen in the hepatic venous flow pattern. The decrease in total tricuspid annulus motion was most pronounced in its lateral segment and the atrial component of the tricuspid annulus motion showed similar changes. CONCLUSIONS--The pronounced decrease in tricuspid annulus motion during the early postoperative period suggests right atrial and right ventricular dysfunction as mechanisms responsible for the early changes seen. The progressive return to a normal venous filling pattern and the partial recovery of annular motion six months after operation further support the influence of the above mechanisms, as well as their resolution with time. The persistent flow abnormalities and compromised motion of the free aspects of the tricuspid annulus, however, suggest long term tethering of the right heart wall.     

Abnormal right heart filling after cardiac surgery: time course and mechanisms.

OBJECTIVE--To study the time course and underlying mechanisms of right heart filling after cardiac surgery. DESIGN--A prospective observational study of adult patients undergoing cardiac surgery. SETTING--Echocardiography laboratory of the Stanford University Medical Center. PATIENTS--Twenty six patients (mean age 54.9) undergoing cardiac surgery were studied before and two days, one week, six weeks, and six months after cardiac surgery. MAIN OUTCOME MEASURES--Flow in the hepatic veins and superior vena cava, tricuspid and mitral annulus motion, signs of tricuspid regurgitation, and right ventricular size were assessed by echocardiography. RESULTS--Right heart filling, expressed as the ratio of systolic to diastolic forward flow Doppler velocity integrals in the superior vena cava and by tricuspid annulus motion, decreased in parallel from before surgery baseline values of 3.5 (SD 3.1) and 21.9 (3.4) mm, respectively to 0.2 (0.1) and 8.1 (2.3) mm two days after operation. A gradual increase towards baseline values was noted after six months, to 1.4 (1.3) and 15.1 (2.3) mm respectively; however, these values were still significantly less than those before operation. Similar changes were seen in the hepatic venous flow pattern. The decrease in total tricuspid annulus motion was most pronounced in its lateral segment and the atrial component of the tricuspid annulus motion showed similar changes. CONCLUSIONS--The pronounced decrease in tricuspid annulus motion during the early postoperative period suggests right atrial and right ventricular dysfunction as mechanisms responsible for the early changes seen. The progressive return to a normal venous filling pattern and the partial recovery of annular motion six months after operation further support the influence of the above mechanisms, as well as their resolution with time. The persistent flow abnormalities and compromised motion of the free aspects of the tricuspid annulus, however, suggest long term tethering of the right heart wall.     

Left ventricle to pulmonary artery conduit in treatment of transposition of great arteries, restrictive ventricular septal defect, and acquired pulmonary atresia.

Progressive cyanosis after banding of the pulmonary artery in infancy occurred in a child with transposition of the great arteries and a ventricular septal defect, and a Blalock-Taussig shunt operation had to be performed. At the time of correction a segment of pulmonary artery between the left ventricle and the band was found to be completely occluded so that continuity between the left ventricle and the pulmonary artery could not be restored. A Rastelli type of operation was not feasible as the ventricular septal defect was sited low in the muscular septum. Therefore, in addition to Mustard's operation, a Dacron conduit was inserted from the left ventricle to the main pulmonary artery to relieve the obstruction. Postoperative cardiac catheterization with angiocardiography indicated a satisfactory haemodynamic result. The patient remains well 11 months after the operation. This operation, a left ventricle to pulmonary artery conduit, may be used as an alternative procedure in patients with transposition of the great arteries, intact interventricular septum, and obstruction to the left ventricular outflow, if the obstruction cannot be adequately relieved.     

Discrete subaortic stenosis.

Data concerning 17 consecutive patients with discrete subaortic stenosis are recorded. Twelve patients underwent operative resection of the obstructing lesion. Of these all except one were symptomatic and all had electrocardiographic evidence of left ventricular hypertrophy or left ventricular hypertrophy with strain. They had a peak resting systolic left ventricular outflow tract gradient of greater than 50 mmHg as predicted from the combined cuff measurement of systolic blood pressure and the echocardiographically estimated left ventricular systolic pressure and/or as determined by cardiac catheterisation. The outflow tract gradient as predicted from M-mode echocardiography and peak systolic pressure showed close correlation with that measured at cardiac catheterisation or operation. During the postoperative follow-up from one month to 11 years, of 11 patients, one patient required a further operation for recurrence of the obstruction four years after the initial operation. All patients are now asymptomatic. Five patients have not had an operation. The left ventricular outflow tract gradient as assessed at the time of cardiac catheterisation was greater than 50 mmHg. One patient has been lost to follow-up. The remaining four have been followed from four to eight years and have remained asymptomatic and the electrocardiograms have remained unchanged. Careful follow-up of all patients is essential with continuing clinical assessment, electrocardiograms, M-mode and two-dimensional echocardiograms, and if necessary cardiac catheterisation. Prophylaxis against bacterial endocarditis is also essential.     

Accuracy of prospective two-dimensional/Doppler echocardiography in the assessment of reparative surgery

Between January 1987 and January 1989, all 129 patients (aged 11 days to 25 years, median 39 months) undergoing both an echocardiographic examination and cardiac catheterization after reparative surgery were prospectively included in a study to assess the accuracy of combined two-dimensional and Doppler color flow imaging. The patient diagnoses were transposition of the great arteries (n = 20), tetralogy of Fallot (n = 38), coarctation of the aorta (n = 24), complete atrioventricular (AV) canal (n = 15), atrial septal defect (n = 8), ventricular septal defects (n = 3), pulmonary stenosis (n = 4), aortic stenosis (n = 8) and subaortic stenosis (n = 9). In arterial tract stenosis, there was high correlation between Doppler estimates and catheterization-derived measurements of residual right ventricular outflow tract obstruction in patients after the arterial switch operation for transposition of the great arteries (r = 0.95) as well as in patients after corrective repair of tetralogy of Fallot (r = 0.84). In semilunar/AV valve regurgitation, graded as none, mild, moderate or severe, echocardiographic estimates correlated exactly with angiographic grading in 84% and differed by one angiographic grade in the other 16%. In residual left to right shunting, no hemodynamically significant shunt was missed by echocardiography. For residual shunts at the ventricular level (n = 32), addition of Doppler color flow imaging improved the sensitivity (from 63% to 94%) and the negative predictive value (from 88% to 98%). In elevated right ventricular pressure, Doppler-derived right ventricular-right atrial pressure estimates in 24 patients correlated well with catheterization measurements (r = 0.93). Combined two-dimensional and Doppler color flow echocardiography was highly accurate in the prospective evaluation of these four types of postoperative residual.     

Technical advances in the Senning operation

Since March 1978, 59 patients with transposition of the great arteries (TGA) ranging in age from 2 months to 6 years have undergone the Senning operation. Forty-six patients (77.9%) had transposition with intact ventricular septum, 8 of them with patent ductus arteriosus; 8 patients (13.5%) had TGA with ventricular septal defect (VSD), 3 of them with previously performed banding; 4 patients (6.7%) had TGA with VSD and pulmonary stenosis (PS), and one (1.6%) had TGA with PS. Prior to correction, 38 cases had undergone a Rashkind septotomy and 15 had had a previous Blalock-Hanlon septectomy. During this time we have introduced some technical modifications of the original Senning operation: (A) right atrial incision, (B) large left atrial wall window, (C) infrasinal suture of the left atrial flap, (D) avoidance of damage to the hypothetical anterior atrioventricular conduction bundle, and recently, in 12 patients, we have used (E) an inverted left atrial appendage as an interatrial flap. There were 9 hospital deaths (15.2%) caused by low cardiac output (4 cases), severe hypoxemia and low cardiac output (4 cases) and one patient with pulmonary venous drainage obstruction died following reoperation. Two patients developed neurological complications that disappeared without sequela. Another complication was a right chylothorax (4 patients), which improved without the necessity of surgical repair. Eighteen patients developed a junctional rhythm for a period over 24 hours. We think that the technical modifications which we present here, partially contribute to improving the Senning operation.     

Echocardiographic visualisation of the interatrial baffle after Mustard's operation.

Thirty children aged from 7 weeks to 14 years were examined by echocardiography after Mustard's operation for transposition of the great arteries. Discrete and persitent echoes were noted within the original left atrial cavity and contrast echocardiography was used to establish that these originated from the interatrial baffle. In the presence of caval channel obstruction, caused by malposition or shrinkage of the baffle, significant differences were seen in the echocardiographic appearances of the baffle, namely limitation of baffle motion, thickening, and multiplicity of the baffle echoes. These findings suggest that the technique may be of value in the postoperative assessment of patients with transposition of the great arteries.