[Arterial switch operation: late results and a future perspective].

Intermediate results of the arterial switch operation for variety of cardiac anomaly with the transposed great arteries were studied to elucidate late results and problems. Seventy-five survivors of the arterial switch operation at our institute between 1991 and January 2007 were studied retrospectively. Mean follow-up time was 7.5 years. There were 2 late deaths, 3 reoperations, and 9 cases of catheter intervention, resulting in actuarial survival of 97%, and event-free rate of 83% at 16 years. Seventy patients (93%) were medication free and had no restriction on physical activities. Moderate pulmonary stenosis in 2 patients and mild pulmonary stenosis in 14 were observed. Moderate aortic regurgitation in 2 and mild aortic regurgitation in 20 were observed. Risk factors for right ventricular outflow obstruction were a diagnosis of double outlet right ventricle (DORV), association with aortic arch obstruction, and prior pulmonary artery banding (PAB). Risk factors for branch pulmonary artery stenosis (PS) were not clear; however, scar formation with use of xenograft patch and in-fold formation by redundant autologous pericardial patch for closure of the defects in the old aortic root seemed to be related with the stenosis. Risk factors for aortic regurgitation were age at operation and prior PAB. Early primary arterial switch operation may resolve these problems.

Portosystemic shunt with polysplenia and hypoplastic left heart syndrome.

We report a unique case of portosystemic shunt with polysplenia and hypoplastic left heart syndrome. The abnormal vessel connected the right renal vein and the splenic vein. The shunt flow was from the systemic vein to the portal vein before the Fontan-type operation, but it reversed and ran from portal vein to systemic vein after the Fontan-type operation.

[A surgical case of supravalvular aortic stenosis with severe hypoplastic ascending aorta (diffuse type) in Williams-Beuren syndrome].

We report a six-year-old boy who underwent ascending aortic reconstruction for supravalvular aortic stenosis of diffuse type associated with Williams-Beuren syndrome. The diagnosis was first made at the age of six months. Because of progressive left ventricular hypertrophy, cardiac catheterization was performed at the age of five years and showed left ventricular pressure of 200 mmHg, the ascending aortic pressure of 202 mmHg, the descending aortic pressure of 115 mmHg, and left ventricular end-diastolic volume of 33.5 ml (90% of normal). Whole ascending aorta except sinus Valsalva was severely hypoplastic, so called diffuse type of supravalvular aortic stenosis. The ascending aorta was only 6.3 mm in diameter, whereas the diameter of the aortic annulus was 20.6 mm. The ascending aortic reconstruction of Doty's type was performed from the aortic root to the distal aortic arch with a equine pericardium reinforced by Dacron velour using selective perfusion to the right bracheocepharic artery, the left common carotid artery and the right femoral artery to avoid circulatory arrest. Postoperative course was uneventful and post operative catheterization revealed left ventricular pressure of 128 mmHg, the ascending aortic pressure of 126 mmHg and the descending aortic pressure of 90 mmHg. Mild residual pressure gradient was probably due to hypoplastic descending aorta. In conclusion, patch aortic reconstruction for ascending aorta under selective cerebral perfusion for a six-year old boy can be performed without postoperative neurological complication.

[Color M-mode Doppler analysis of left ventricular inflow in pediatric patients].

This study evaluated the clinical usefulness of analyzing left ventricular (LV) filling by color M-mode Doppler echocardiography in pediatric patients. The LV-filling patterns of color M-mode Doppler echocardiography were obtained by LV inflow in the apical 4-chamber or long-axis view, and the time difference between the occurrence of peak velocity at the mitral tip and in the apical region (M-AP) was calculated. The peak velocity at each depth was determined by adequate selection of the Nyquist limit by shifting the zero point after freezing the color M-mode. LV volume and posterior wall motion velocity were obtained simultaneously. The catheter-derived data were compared with echo-derived data in 7 patients (mean age 12.0 years). The M-AP correlated positively with the time constant of LV relaxation (tau; r = 0.83, p < 0.05), pulmonary capillary wedge pressure (r = 0.83, p < 0.05), and negatively with peak diastolic posterior wall motion velocity (r = -0.78, p < 0.05). The M-AP was compared with other echo-derived data between Group N (35 children with normal cardiac function, mean age 4.3 years) and Group F (12 children with LV ejection fraction less than 40%, mean age 9.5 years). The M-AP was significantly longer in Group F (53.3 +/- 14.0 vs 116.5 +/- 30.5 msec; p < 0.001), but there was no significant difference in the E/A or deceleration time of E between the 2 groups. In Group N, the E/A correlated to LV end-diastolic volume and heart rate, but the M-AP showed no correlation. In Group F, the M-AP correlated with the percentages of normal LV end-diastolic volume (r = 0.76, p < 0.01) and LV ejection fraction (r = -0.58, p < 0.05). The M-AP was not influenced by LV size or heart rate and could easily differentiate normal heart from failing heart, and thus this is a useful parameter for evaluating diastolic function in pediatric patients.

A follow up study of myocardial involvement in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).

OBJECTIVE: To investigate cardiac function in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and clarify the clinical features of cardiomyopathy in MELAS. PATIENTS: 11 consecutive patients with MELAS (mean age at initial examination 11.3 years, range 4 to 16 years) were enrolled in the study. Six were followed for more than five years. RESULTS: On echocardiographic examination, three patients showed increased left ventricular end diastolic posterior wall thickness (LVPWTd), exceeding 140% of the normal value. Four patients, including these three, had an ejection fraction of less than 50%, and two also had increased left ventricular end diastolic volume (LVEDV) exceeding 140% of the normal value (%N). The LVPWTd%N was correlated positively with the LVEDV%N (R = 0.669, p < 0.05) and negatively with the ejection fraction (R = -0.6701, p < 0.05). One patient died of heart failure aged 22 years. CONCLUSIONS: The cardiomyopathy in MELAS is characterised by an abnormally thick left ventricular wall with progressive dilatation and poor left ventricular contraction developing over several years, indicating hypertrophic cardiomyopathy advancing to dilated cardiomyopathy.

[Total cavopulmonary connection for grown diminutive pulmonary artery after staged Blalock-Taussig shunt].

We report a two-year-old girl with asplenia, [A, L, L] DORV, pulmonary atresia, common AV valve, PDA, and TAPVC, who successfully underwent total cavo pulmonary connection (TCPC). Deep cyanosis was pointed out since birth. Cardiac catheterization performed on the sixth day after birth revealed a diminutive pulmonary artery tree of which PA index was 41 mm2/m2. Left modified Blalock-Taussig shunt was created at 27 days of age. The PA index increased to 282 mm2/mm2, but disparity in diameter between the left and the right pulmonary artery was yielded by PDA subsidence. Therefore additional contralateral B-T shunt was made at one year of age. Follow-up cardiac catheterization at 28 months of age showed well developed pulmonary artery; PA index of 460 mm2/m2, right pulmonary resistance (Rp) of 3.49 units, left Rp of 2.33 units, and estimated total Rp was 1.39. According to study, bidirectional Glenn procedure or TCPC was indicated. Considering necessity of urgent repair of common pulmonary vein obstruction, regurgitation of the common atrio-ventricular valve and pulmonary artery stenosis, TCPC was performed with concomitant repair of the associated lesions. Severe butterfly-figure stenosis of the central PA was augmented by anastomosing both the left SVC and the left-sided atrium. In conclusion, diminutive pulmonary artery could be adequately grown by phase-in Blalock-Taussig shunts. Pulmonary blood flow scintigraphy was thought to be useful for estimation of pulmonary resistance in such cases with different pulmonary resistance between right and left PA.

[An experience of the modified Norwood's operation for hypoplastic left heart syndrome with aberrant origin of right subclavian artery and persistent left superior vena cava--the procedure without total circulatory arrest and cardiac arrest].

We reported a successful case of the modified Norwood operation for a 21-day-old neonate with hypoplastic left heart syndrome (MS and AS) associated with an aberrant right subclavian artery and a persistent left superior vena cava. The modified Norwood operation was performed without total circulatory arrest and Cardiac arrest. A 4 mm Gore-Tex graft, which was anastomosed between the right carotid artery and the right pulmonary artery for systemic-pulmonary shunt, was used for cerebral perfusion during aortic arch reconstruction. Coronary perfusion was performed with a small cannula placed on the relatively large ascending aorta during anastomosis between the main pulmonary artery and the ascending aorta. Equine pericardial patch was used for aortic arch reconstruction and the ascending aorta was directly anastomosed to a part of the main PA. Postoperative course was uneventful and postoperative MRI revealed no stenosis of the aortic arch and the pulmonary artery.

[A successful Konno's operation for subaortic stenosis progressed after total correction of partial atrioventricular septal defect associated with polysplenia].

Konno's operation was successfully performed on a small infant, weighing 3.8 kg. She underwent pulmonary artery banding on the 29th day of life under the diagnosis of partial atrioventricular septal defect with a small left ventricle, associated with polysplenia. Intracardiac repair was subsequently performed on the 45th day of life, which included atrial partition and mitral valvuloplasty. Eleven months after the second operation, wedge resection on the narrow subaortic fibrous lesion was done concomitant with mitral revalvuloplasty. However, repeated echocardiac study disclosed progression of subaortic stenosis. Cardiac catheterization performed at 2 years of age showed the pressure gradinet of 90 mmHg between the aorta and the LV. The aortic annulus and the subaortic lesion measured 10 mm and 4 mm in diameter respectively. Severe subaortic stenosis was created by protrusion of abnormal mitral tissue to the LV outflow, in addition by secondary circumferential fibrous tissue growth and hypertrophy of the ventricular septum. Konno's operation using on 18A Carbomedics valve was chosen for the certain relief of the subaortic stenosis. Although the operation required extensive ventriculotomy and septostomy because of the small aortic annulus, the postoperative course was uneventful. Two months after the operation echocardiography showed good LV function and low RV pressure of about 40 mmHg.

[Repair of D-transposition of the great arteries associated with double aortic arch].

We report a case of D-transposition of the great arteries associated with double aortic arch. An aortic root angiogram revealed that the left-sided aortic arch was anterior and smaller than the right one and the descending thoracic aorta located on the left side of the spine. Balloon atrial septostomy was performed at one day of age. The patient underwent a simultaneous arterial switch procedure and division of the vascular ring at the isthmus of the left aortic arch through a median sternotomy incision at the age of 16 days. There was persistent postoperative difficulty in weaning the patient from the ventilator. Magnetic resonance images showed re-formation of pseudovascular ring by the connective tissue grown around the divided arch. At the age of 23 days, resection of the remnant of left aortic arch including the left subclavian artery and the diverticulum concomitant with vascular suspension procedure was performed through a left lateral thoracotomy. The patient was subsequently extubated without difficulty and was discharged from the hospital. It is though that a vascular suspension procedure and resection of the subclavian artery are necessary to avoid respiratory obstruction when the great arteries are in an anteroposterior position and Lecompte procedure is performed.

[Right atrial flap method for repair of partial anomalous pulmonary venous drainage into the high superior vena cava--case report].

We report an alternative method of repairing partial anomalous pulmonary venous return (PAPVR) wherein anomalous veins drain into the high portion of superior vena cava (SVC). A six year old girl, weighing 19 kg underwent cardiac catheterization for cardiomegaly. The study showed sinus venous defect and pulmonary veins anomalously drained from the right upper and middle lobe into the high SVC. Under cardiopulmonary bypass with aortic and bicaval direct cannulation, a 2-cm-wide pedicled flap made from the middle part of the right atrium (RA), was pulled into the SVC. The atrial flap divided the SVC from the ostium of the uppermost pulmonary vein (PV) to the ASD. This posterior tunnel drained anomalous PV blood into the left atrium. Postoperative echocardiogram and magnetic resonance imaging showed adequate space in the SVC and the PV channel. The patient maintained normal sinus rhythm after surgery. The advantage of this method is to minimize the risk of injuring the sinus node or sinus node artery, and to easily reconstruct both the SVC and PV channel without using prosthetic materials, even in patients with small RA.

Validation of the proximal isovelocity surface area method for assessing mitral regurgitation in children.

The proximal isovelocity surface area (PISA) method for calculating volume flow through the regurgitant orifice has attracted significant attention. A number of in vitro studies and clinical studies in adults suggest that the method is accurate. However, when applying the method to children it must be noted that the absolute regurgitation volume is small, and the range of body sizes is wide. This study investigated the accuracy of the PISA method for quantitative assessment of the severity of mitral regurgitation in children. Twenty children aged 7 months to 12 years (average 4.7 years) with mitral regurgitation but without interventricular shunt or aortic stenosis were selected for this study. Underlying cardiac diseases included atrioventricular septal defects in nine, isolated mitral regurgitation in five, and association with other heart defects in six. The PISA radius (r) and the duration of regurgitation (T) were measured on color M-mode recordings, with the M line passing through the center of the PISA. Assuming that the PISA is a hemisphere, maximal regurgitant flow rate (MFR: ml/s) was calculated as MFR = 2pi x r2 x V (r = maximal radius, V = aliasing velocity), and regurgitant stroke volume (RSVpisa) as RSVpisa = 2pi x MSR x V x T (MSR = mean square of the PISA radius during regurgitation). As a validating standard, total stroke volume (TSV) using two-dimensional echocardiography determined by the area-length volumetry method and forward stroke volume (FSV) by the pulsed Doppler method were measured, and regurgitant stroke volume (RSVD: RSVD = TSV - FSV) and regurgitant fraction (RF: RF = RSVD/TSV) were calculated. A linear correlation was found between MFR, RSVpisa, and RSVD (X) (MFR = 4.2X + 54.0, r = 0.84. RSVpisa = 1. 0X + 9.8, r = 0.90), and both RSVpisa and MFR divided by body surface area (BSA: m2) revealed a significant correlation with regurgitant fraction (X) by nonlinear regression analysis (RSVpisa/BSA = 26.2 x X/(1 - X) + 16.8, r = 0.85. MFR/BSA = 121.8 x X/(1 - X) + 92.2, r = 0.79). It is concluded that maximal regurgitant flow rate, regurgitant stroke volume, and regurgitant fraction can be accurately predicted in children using the PISA method by Doppler echocardiography.

[Surgical treatment for tetralogy of Fallot with pulmonary atresia right ventricular outflow tract reconstruction with autologous pulmonary tissue and concomitant extensive pulmonary angioplasty].

Eight consecutive patients with tetralogy of Fallot associated with pulmonary atresia successfully underwent corrective surgery without using an extracardiac conduit at a mean age of 2 years 4 months. Each of these patients had undergone a classical or modified Blalock-Taussig shunt at a mean age of 55 days. In 6 cases, central PA was fully mobilized and pulled forward. An autologous flap was made from the rudimentary PA trunk or right PA, then it was anastomosed to the endocardium of RV infundibulum as a posterior wall of the outflow tract. In 7 cases, concomitant extensive pulmonary angioplasty was performed on stenotic and under-developed lesions which were caused by tissue contraction of the PDA. During follow up period from 11 to 25 months, all patients have remained in good condition without restenosis of the RVOT. The mean pressure ratio of RV over LV measured 0.42 in 5 patients who underwent catheterization after operation. We conclude that these procedures are useful for early corrective surgery of tetralogy of Fallot with pulmonary atresia.

Measurement of ventricular volumes by cine magnetic resonance imaging in complex congenital heart disease with morphologically abnormal ventricles.

This study assessed the validity of cine magnetic resonance imaging (MRI) for measuring right and left ventricular volumes by using Simpson's rule in children with complex congenital heart disease. Forty-five patients with complex congenital heart disease (average age 2.6 years) and 10 controls (average age 2.3 years) were evaluated. The whole heart was encompassed by contiguous transverse sections. Ventricular volumes were calculated by adding luminal areas determined in each section at end diastole and end systole. End-diastolic and end-systolic volumes by MRI in both groups correlated well with those by ventriculography (r>0.89). Comparison of the ejection fraction in both ventricles in both groups yielded a good correlation between MRI and ventriculography (r>0.67). MRI technique in both groups had low intraobserver and interobserver variation (<6%). Cine MRI provides a suitable noninvasive means of quantifying ventricular volume in children with complex congenital heart disease.

Thrombocytopenia: a risk factor for acute myocardial infarction during the acute phase of Kawasaki disease.

BACKGROUND: We report on 10 patients with Kawasaki disease and thrombocytopenia who were found to have a high incidence of coronary artery aneurysm and acute myocardial infarction. The clinical features of these patients, the cause of their thrombocytopenia and the relationship between cardiovascular pathology and thrombocytopenia were analyzed. METHODS: The clinical features of 10 patients with Kawasaki disease found to have thrombocytopenia (group A: mean age 8.0 +/- 7.0 months) and those of 293 patients with Kawasaki disease (group B, controls: mean age 13 +/- 20 months) were analyzed. Coagulation studies and bone marrow aspiration were performed to ascertain the cause of the thrombocytopenia in nine out of 10 subjects in group A. RESULTS: The minimum platelet count was 4-12 x 10(4)/mm3 (average day of illness, 10.3) and platelet counts were elevated to the baseline value within 1-2 weeks of onset of the illness. Low fibrinogen concentrations, high levels of fibrin degradation products, and low erythrocyte sedimentation rates with high C-reactive protein levels were observed in seven patients. In two other patients, immature megakaryocytes with normal coagulation values were observed. The differences in the incidence of coronary artery aneurysm and acute myocardial infarction between groups A and B were highly significant (coronary artery aneurysm: 60% in group A, 8.9% in group B; acute myocardial infarction: 40% in group A, 0.3% in group B). CONCLUSIONS: In many patients with Kawasaki disease and thrombocytopenia, the thrombocytopenia appears to be a result of intravascular coagulation, and to be one of the risk factors for acute myocardial infarction.

Magnetic resonance imaging of heterotaxia in infants.

OBJECTIVES: This study assessed the usefulness and safety of magnetic resonance imaging (MRI) for systematically diagnosing heterotaxia in infants. BACKGROUND: Although it is important to diagnose and treat infants with heterotaxia, which is associated with viscerobronchial cardiovascular anomalies, systematic diagnosis of these anomalies by a single imaging technique is difficult. METHODS: Twenty patients with heterotaxia were evaluated. The infants ranged in age from 21 days to 12 months (average 5.2 months, average body weight 4.3 kg). Electrocardiographically gated MRI was performed by spin echo imaging techniques operating at 0.5 tesla. RESULTS: In all 20 patients, MRI results were sufficient to evaluate these anomalies without serious complications. In 17 patients, neither a spleen nor splenules were detected, but in 3 patients, a polymorphous spleen was visualized. In all 20 patients, bronchial anatomies were clearly visualized (bilateral eparterial bronchi in 14 patients, bilateral hyparterial bronchi in 2 and normal bronchial patterns in 4). Additionally, in a comparison of 149 observations of cardiovascular anatomy by MRI with those by angiography, discrepancies were found in only 10 observations (6.7%). CONCLUSIONS: Magnetic resonance imaging was found to be safe and very useful for the systematic diagnosis of heterotaxia in infants.

[Echocardiographic manifestations of excessive pulmonary artery banding in patients with transposition of the great arteries without ductal or ventricular shunt].

Recently, pulmonary arterial banding (PAB) and the Blalock-Taussig shunting operation (B-T) have been performed as a preparatory procedure for Jatene's operation for patients with complete transposition of the great arteries (TGA) without patent ductus arteriosus (PDA) or ventricular septal defect (VSD). We reviewed the echocardiographic findings of 29 patients after PAB and B-T. Four cases had abnormal catheterization data after PAB and B-T (Group 1). Twenty-five control cases with successful two-stage Jatene's operation exhibited normal data (Group 2). We studied 1) the grade of distortion of the interventricular septum as the a/b ratio on two-dimensional echocardiogram (2-DE), 2) the left ventricular (LV) shortening fraction (LVSF), 3) the thickening fraction (ThF), 4) the LV posterior wall thickness in diastole (LVPWTd) on M-mode echocardiogram, and 5) the LV inflow tract (LVIT) flow pattern on pulsed Doppler echocardiogram. In Group 1, all cases revealed LVSF less than 0.19 (control group: 0.40-0.56), ThF less than 0.18 (control group: 0.43-0.81), the a/b ratio higher than 0.88 (control group: 0.53-0.79), and LVPWTd thicker than 0.67 cm (control group: 0.45-0.59 cm). These data are markedly deviated from the range of the control data (p < 0.01). All cases in Group 1 had LVIT flow lacking the rapid filling phase, which was recognized in the control group. These abnormal echocardiographic findings suggest LV failure in adaptation against excessive after-load due to very tight PAB, and these figures are very different from the control group. These unusual postoperative cardiac abnormalities can be detected noninvasively using 2-DE and Doppler echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Anomalous origin of both pulmonary arteries from the ascending aorta with a nonbranching main pulmonary artery arising from the right ventricle.

A 3-month-old boy, mildly cyanosed and tachypneic, was found by cineangiography to have a nonbranching main pulmonary artery arising from the right ventricle and connecting to the descending aorta via a large persistent ductus arteriosus. The left and right pulmonary arteries arose as a common "trunk," before branching, from the ascending aorta. Complete surgical correction was performed at 7-months of age. Subsequent cardiac catheterization has demonstrated normal pressures and blood oxygen saturation in all right-heart chambers and the great arteries.

Ventricular volume characteristics in double-inlet left ventricle before and after septation.

Septation is one of the surgical choices for double-inlet left ventricle, yet postoperative hemodynamics have not been well defined. We studied ventricular volume characteristics in 10 patients with double-inlet left ventricle before and after septation. Preoperative end-diastolic volume (EDV) of the ventricle was 291 +/- 111% (+/- SD) of normal and ejection fraction (EF) was 0.59 +/- 0.07. Postoperatively, EDV of the right-sided ventricle (RV) was 82 +/- 24%, and EDV of the left-sided ventricle (LV) was 153 +/- 41%. Ejection fraction of the RV was 0.77 +/- 0.10, and LVEF was 0.49 +/- 0.13. On the short-axis view of two-dimensional echocardiography, fractional change of the cross-sectional area was 0.65 +/- 0.16 for the RV and 0.23 +/- 0.11 for the LV. Fractional shortening of the septum-to-ventricular free wall axis was 0.51 +/- 0.17 in the RV and -0.05 +/- 0.09 in the LV. Analysis of the curvature of the new septum during cardiac cycle on two-dimensional echocardiography revealed that the septum shifted to the right side during systole in all patients in whom the systolic LV/RV pressure ratio was larger than 1.0. The septum shifted toward the LV during diastole in eight patients in whom end-diastolic pressure in the RV was higher than or equal to that in the LV, whereas it remained in the right side in two patients with higher left-side pressure. The cardiac index of these two patients was 2.4 and 2.6 l/min/m2, respectively, whereas it averaged 4.4 +/- 1.0 l/min/m2 in the other eight patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Criteria for two-staged arterial switch operation for simple transposition of great arteries.

We analyzed hemodynamic variables in patients with transposition of the great arteries with intact ventricular septum (simple transposition) after pulmonary artery banding and Blalock-Taussig anastomosis to establish the criteria for two-staged arterial switch operation. The study included 35 patients who underwent the switch operation after banding and anastomosis; two died shortly after surgery, and one died of tachycardia 31 days after the operation. The left-to-right ventricular pressure ratio was above 0.83 in all surviving patients, 0.68 and 0.63 in the two operative deaths, and 0.84 in the other death. In the 32 surviving patients, angiographically determined left ventricular (LV) end-diastolic volume and ejection fraction averaged 147 +/- 46(SD)% of normal and 0.64 +/- 0.12, respectively. We also measured LV mass using angiographic LV semiaxes and end-diastolic LV posterior wall thickness obtained from an echocardiogram. These variables of the patients who died were not different from those of the surviving patients. The wall thickness was greater than 4 mm in the surviving patients, while it was 3.5 mm in the two patients who died early and 5 mm in the patient who died later. From the semiaxes, the wall thickness, and aortic diastolic pressure, all of which were obtained before the anatomic repair, we calculated the predictive LV wall stress. This wall stress would indicate the LV wall stress at the time of aortic valve opening immediately after the arterial switch operation. Predictive wall stress was less than 120 x 10(3) dynes/cm2 in all but one of the surviving patients, whereas it was 151, 153, and 186 x 10(3) dynes/cm2 in the three patients who died.(ABSTRACT TRUNCATED AT 250 WORDS)