Prevalence of arrhythmias and their risk factors mid- and long-term after the arterial switch operation.

Early results of the arterial switch operation (ASO) for transposition of the great arteries (TGA) are good, but there are few mid- and long-term data on postoperative arrhythmias, especially in Japan. In this study, clinical data on 624 1-year survivors who had an ASO between 1976 and 1995 were collected from six institutes in Japan up to October 2002. Sixty (9.6%) 1-year survivors had significant arrhythmias. Bradycardia occurred in 22 patients, including complete atrioventricular block (CAVB) in 12, sick sinus syndrome (SSS) in 6, and second-degree atrioventricular block in 4. Syncope developed in 2 with CAVB and 2 with SSS. Ten patients with bradycardia underwent permanent pacemaker implantation. Supraveutricular tachycardia (SVT) was seen in 25 patients, including paroxysmal supraventricular tachycardia in 16, atrial flutter in 7, and atrial fibrillation in 2. Six patients with SVT received antiarrhythmic medication. SVT was transient in 20 and persistent in 5. Ventricular arrhythmias occurred in 13 patients, including nonsustained ventricular tachycardia in 5, paroxysmal ventricular contractions with couplets in 5, ventricular flutter in 2, and sustained ventricular tachycardia in 1. Four patients with ventricular arrhythmias received antiarrhythmic medication. Of the study patients, 8 died 1 year or more after ASO. Death was directly related to arrhythmia in 1 patient and was due to nonsustained ventricular tachycardia with severe congestive heart failure. The presence of a ventricular septal defect (VSD) was a risk factor for postoperative arrhythmia. Patients with TGA and VSD had more arrhythmias than those with TGA and an intact ventricular septum (13.7 vs 8.7%, p < 0.05), and this was especially true for CAVB (3.9% vs 1.0%, p < 0.05). In 36 patients clearly documented time onset of postoperative arrhythmia arrhythmia developed in 18 (50%) after less than 1 year and in 15 (42%) after more than 5 years. In summary serious arrhythmias after ASO were uncommon, but postoperative arrhythmias, such as unpaced CAVB, SSS, and VT, were related to morbidity and mortality. VSD was a risk factor for postoperative arrhythmia, especially CAVB. Approximately half of the arrhythmias developed late. Lifelong monitoring with respect to arrhythmia is needed for patients after ASO.

Risk factors for arrhythmia and late death in patients with right ventricle to pulmonary artery conduit repair--Japanese multicenter study.

BACKGROUND: Arrhythmia and late cardiac deaths are thought to be major complications in patients after right ventricle (RV) to pulmonary artery (PA) conduit repair, although the incidence and predictors of these complications remain unknown. The aim of this study was to clarify the incidence and risk factors for arrhythmia and late deaths in patients with the RV to PA conduit repair through a Japanese multicenter study. METHODS: Three hundred fifty-one hospital survivors who underwent the RV to PA conduit repair before 1995 were studied. RESULTS: Survival rate after repair was 92% at 10 years, 88% at 20 and 25 years, respectively. Late death was observed in 30 (8.5%) including 4 patients with sudden death (SD). Higher right ventricular pressure (p = 0.02), larger cardio-thoracic ratio after repair (p = 0.02) and higher incidence of brady- or tachy-arrhythmia and SD (9/30) were associated with late death. Six (1.7%) patients developed ventricular tachycardia or ventricular fibrillation (VT/Vf). There were 22 patients who had 23 new-onset supraventricular tachy-arrhythmia (SVT). Right ventricular hypertension (p = 0.04) was associated with VT/Vf or SD. Male sex (p < 0.01), absence of previously aorto-pulmonary shunt (p < 0.05), older age at repair (p < 0.01) or longer length of follow-up (p < 0.01) were associated with SVT. CONCLUSION: Arrhythmia and late sudden death are relatively common late after the RV to PA conduit repair. Our data support recent surgical strategies of earlier primary operation and timely reoperation for progressive right ventricular outflow stenosis that may reduce the incidence of late arrhythmias and SD.

Outcome of right ventricle-to-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome: a multi-institutional study.

BACKGROUND: To evaluate the developing surgical technique of a modified Norwood procedure using a right ventricle-to-pulmonary artery shunt, we analyzed data obtained from 73 infants who underwent first-stage palliation for hypoplastic left heart syndrome between 1998 to 2002 at three centers in Japan. METHODS: Procedures performed included an aortopulmonary neoaortic reconstruction and a nonvalved polytetrafluoroethylene shunt between a small right ventriculotomy and a distal stump of the main pulmonary artery. The size of the shunt used was 4 mm in 6 patients, 5 mm in 41, and 6 mm in 26. Continuous cerebral perfusion was used in all patients and an additional descending aortic perfusion was used in 39. Postoperative management was basically the same as that for infants undergoing other types of operations. RESULTS: There were 61 hospital survivors (84%), including 5 of 6 patients weighing less than 2 kg, with 8 late deaths. Risk factors for hospital mortality include preoperative treatment without ventilatory support and surgeon's experience (first 10 cases). Three patients underwent a primary Fontan operation at 5, 9, and 10 months of age, with one late death. Forty-one patients underwent the bidirectional Glenn shunt after a mean interval of 6.9 months, and 19 of them completed the Fontan operation at median age of 2.1 years. Overall survivals were 65% at 1 year and 63% at 2 years. CONCLUSIONS: Improved survival for patients after first-stage palliation of hypoplastic left heart syndrome is reproducible for many centers by an application of the modified Norwood procedure with the right ventricle-to-pulmonary artery shunt.

Hypoplasia of the small pulmonary arteries in total anomalous pulmonary venous connection with obstructed pulmonary venous drainage.

OBJECTIVE: Preoperative pulmonary venous obstruction has been reported to be a risk factor negatively impacting survival in total anomalous pulmonary venous connection. We examined lung tissue from total anomalous pulmonary venous connection patients with pulmonary venous obstruction and demonstrated hypoplasia of small pulmonary arteries to elucidate the mechanism underlying the poor outcome. METHODS: Ten total anomalous pulmonary venous connection patients with preoperative pulmonary venous obstruction between the ages of 2 days and 10 months were studied. As histological parameters, we assessed the size of small pulmonary arteries in relation to the size of accompanying bronchioles to identify small pulmonary artery underdevelopment. Other parameters, such as the radial alveolar count, which reflects alveolar maturity, intimal lesions, lymphangiectasia, and the medial thickness of small pulmonary arteries and small pulmonary veins, were also examined. As a control group, we examined 24 autopsy cases with no congenital heart or pulmonary disease. RESULTS: When the radius of the accompanying bronchiole was 100 microm, the radius of small pulmonary artery in the control group was found to enlarge for the first 2 months and then remain stable at approximately 80 microm from 2 to 10 months. In total anomalous pulmonary venous connection with preoperative pulmonary venous obstruction, the radius was significantly lower than in the control (47.0 +/- 21.8 microm versus 75.9 +/- 9.8 microm, P <.001), and the difference between dead and surviving patients was significant at P <.001 (33.0 +/- 14.6 microm versus 68.2 +/- 9.2 microm). Examination of the alveoli yielded an radial alveolar count of 4.6 +/- 1.5 in the control group and 4.4 +/- 0.8 in the total anomalous pulmonary venous connection patients, and the difference was not significant (P =.71). CONCLUSIONS: The small pulmonary arteries of total anomalous pulmonary venous connection patients with preoperative pulmonary venous obstruction were underdeveloped compared with controls but their alveolae were not hypoplastic. These results suggested that the small pulmonary artery hypoplasia may be responsible for the poor outcome of these patients.

Arrhythmias late after repair of tetralogy of fallot: a Japanese Multicenter Study.

BACKGROUND: Arrhythmia is a major late complication in adults with repaired tetralogy of Fallot, although a large-scale study has not been carried out in Japan. METHODS AND RESULTS: A nationwide multicenter study with 512 operative survivors was performed. Actuarial survival rate at 30 years (maximum follow-up) was 98.4%. Fifty-four patients (10.5%) had clinically important arrhythmias, including 23 patients with bradycardia caused by sick sinus syndrome or atrioventricular block (AVB). A patient with complete AVB (CAVB) without pacemaker implantation (PMI) died later. Two patients had sustained ventricular tachycardia (VT) and syncope was reported in 18 patients with ventricular arrhythmias (VA). Atrial tachyarrhythmias were observed in 13 patients. Older age at operation was a risk factor for atrial fibrillation/flutter, longer postoperative survival duration for VA, and QRS duration >120 ms for VT. Perimembranous ventricular septal defect was related to CAVB. Right ventricular outflow patch was not a risk factor. Importantly, 60% of the subjects had QRS duration <120 ms. CONCLUSION: The prevalence of serious arrhythmias is low in Japanese TOF patients as compared with the results from Western countries. CAVB without PMI and VT are the major risk factors for late morbidity and mortality. The excellent result could be related to the narrow QRS after surgery.

Surgical treatment of coronary sinus orifice atresia with hypoplastic left heart syndrome after total cavo-pulmonary connection.

Atresia of the coronary sinus orifice is rare. We describe the surgical treatment of coronary orifice atresia in an infant with a persistent left superior vena cava after total cavo-pulmonary connection for hypoplastic left heart syndrome. The diagnosis was made by cardiac catheterization after total cavo-pulmonary connection at 8 months of age. After surgery, cardiac performance deteriorated. At reoperation, the coronary sinus was fenestrated to the left atrium. The patient survived surgical treatment of coronary sinus ostial atresia unroofed to the left atrium, guiding the placement of the fenestration with a probe placed through the open cardiac end of left superior vena cava.