Histopathologic analysis of atrial tissue in patients with atrial fibrillation: comparison between patients with atrial septal defect and patients with mitral valvular heart disease.

BACKGROUND: Atrial fibrillation (AF) in adult patients with atrial septal defect (ASD) accompanies an enlarged right atrium (RA) with a less enlarged left atrium (LA), which is the opposite situation in patients with AF and mitral valvular disease. This study was to compare the histopathological change in the atrium of patients with AF of two different etiologies: ASD and mitral disease. METHODS: Twenty-four patients were enrolled. Group 1 included patients with ASD (8), Group 2 included patients with ASD with AF (6), and Group 3 included patients with mitral disease with AF (10). Preoperative atrial volumes were measured. Atrial tissues were obtained during surgical procedures and stained with periodic acid-Schiff, smooth muscle actin, Sirius red, and Masson's trichrome to detect histopathologic changes compatible with AF. The severity of histopathological changes was represented with "positivity" and "strong positivity" after analyzing digitalized images of the staining. We investigated the relationship between the degree of atrial dilatation and severity of histopathological changes according to the groups and tissues. RESULTS: Group 2 and Group 3 patients showed a tendency toward an enlarged RA volume and enlarged LA volume, respectively, compared with each others. However, in the histopathologic analysis, "positivity" and "strong positivity" showed no significant positive correlations with the degree of atrial volume in special staining. CONCLUSIONS: A similar degree of histopathologic changes was observed in both atria in patients with AF (Group 2 and 3) regardless of the degree of dilatation of atrial volume and disease entities.

Anti-alpha-Gal antibody response following xenogeneic heart valve implantation in adults.

BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the xenoreactive immune response directed at Galalpha1, 3-Galbeta1-4GlcNAc-R (alpha-Gal) which is known to be a major barrier in xenotransplantation, and to identify factors such as age, gender, ABO group and type of implanted tissue that might affect the anti-alpha-Gal immune response in adults subjected to bioprosthetic heart valve (BHV) implantation. METHODS: A total of 103 early survivors aged > 20 years who underwent cardiac surgery using cardiopulmonary bypass was enrolled. Among the patients (45 males, 58 females; mean age 62.8 years), 66 who underwent BHV implantation were assigned as a study group, while the remainder were assigned to a control group. Serum samples were obtained from all patients on three occasions: before surgery (TO); on postoperative day 1 (T1); and on postoperative day 14 or at discharge (T2). A serum sample was also obtained from 31 patients in the study group at the out-patient clinic (T3) at a mean of 38 days after surgery. RESULTS: Anti-alpha-Gal antibody reactivity at TO was higher in patients aged < 65 years. Anti-alpha-Gal IgM and IgG reactivity at T2 was higher in the study group when compared to that in controls. In the study group, anti-alpha-Gal IgM and IgG reactivities were decreased at T1, but then increased at T2 when compared to that at TO. Anti-alpha-Gal IgG reactivity remained elevated at T3, but the IgM reactivity declined in the study group. None of the factors, including age, gender, ABO group and type of implanted tissue, had any effect on the anti-alpha-Gal immune response after BHV implantation. CONCLUSION: BHV implantation in adults elicits an increased formation of anti-alpha-Gal antibodies, with different patterns for each isotype. Based on the study results, host factors including age, gender and blood type might be less important in the anti-alpha-Gal immune response following BHV implantation in adults.

A case of partial congenital pericardial defect presenting as acute coronary syndrome.

Congenital pericardial defects are rare and asymptomatic for both partial and complete defects. However, some patients can experience syncope, arrhythmia, and chest pain. When a patient experiences a symptom, it may be caused by herniation and dynamic compression or torsion of a heart structure including the coronary arteries. Diagnosis of a congenital pericardial defect may be difficult, especially in old patients with concomitant coronary artery disease. The clinical importance of congenital pericardial defect has not been stressed and congenital pericardial defects are regarded as benign, but in this case, pericardial defect was responsible for myocardial ischemia. The authors report a case of partial congenital pericardial defect causing herniation and dynamic compression of the coronary arteries, presenting as an acute coronary syndrome in an old man, with an emphasis on the unique features of the coronary angiogram that support the diagnosis of partial pericardial defects.

Surgical treatment of chronic atrial fibrillation combined with rheumatic mitral valve disease: Effects of the cryo-maze procedure and predictors for late recurrence.

OBJECTIVE: The aim of this study was to evaluate the effects of the modified maze procedure using cryoablation for treating chronic atrial fibrillation (AF) associated with rheumatic mitral valve disease and to assess the risk factors for late failure of sinus rhythm restoration. METHODS: Between March 2000 and June 2004, 170 consecutive patients, who underwent the modified maze procedure using cryoablation concomitant with mitral valve surgery for atrial fibrillation associated with rheumatic mitral valve disease, were divided into two groups based on the type of right-sided maze: the modified Cox-maze III (CM group, n=93) and modified Kosakai-maze (KM group, n = 77) procedures. The postoperative and mid-term follow-up results were analyzed and compared between the two groups. Both univariate and multivariate analyses were used to assess the risk factors for late recurrence of atrial fibrillation. RESULTS: There were three in-hospital deaths, including two in the CM group (2.2%) and one in the KM group (1.3%), and there were no significant differences in the incidence of postoperative complications between the two groups. The cardiopulmonary bypass and aortic cross-clamp times were significantly shorter in the KM group than the CM group. At discharge, the sinus rhythm rate was 70% in the CM group and 74% in the KM group (p = 0.55). Follow-up was completed in 97% of the patients, with a mean time of 26.6+/-15.2 months. At the latest follow-up, one death occurred in the CM group (0.6%). Sinus rhythm was documented in 141 (84%) out of all the patients, including 76 (84%) in the CM group and 65 (86%) in the KM group (p=0.72). The 4-year actuarial survival free from stroke was 90.3+/-5.9% for the CM group and 96.4+/-3.5% for the KM group (p = 0.68), and 4-year event-free survival was 81.2+/-7.4% for the CM group and 96.4+/-3.5% for the KM group (p = 0.078). Using a multivariate analysis, a left atrial dimension >65 mm (p = 0.011) and repair for rheumatic mitral valve disease (p = 0.038) were independent risk factors for a late recurrence of AF. CONCLUSIONS: The modified maze procedures using cryoablation are safe and effective in treating chronic atrial fibrillation associated with rheumatic mitral valve disease.

Alternative Fontan connection for apicocaval juxtaposition.

We present an alternative technique to the modified Fontan procedure used in a 3-year-old boy who had complex heart defects with bilateral superior vena cava and apicocaval juxtaposition. The left superior vena caval pathway was used behind the ventricle to connect the inferior vena cava to the pulmonary artery. We proved the technical feasibility of this with good midterm results at the 5-year follow-up angiography.

Commissural malalignment of aortic-pulmonary sinus in complete transposition of great arteries.

BACKGROUND: Translocation of the coronary artery to the neoaorta is essential in the arterial switch operation. The goal of this study is to investigate (1) the frequency of commissural malalignment in complete transposition of the great arteries, (2) the usefulness of echocardiography in diagnosis of commissural malalignment, and (3) the impact of commissural malalignment on surgery. METHODS: We retrospectively reviewed the medical records of 28 patients with complete transposition of the great arteries who underwent an arterial switch operation from February 2000 to August 2001. RESULTS: Commissural malalignment was expected preoperatively in 11 patients by echocardiography and was confirmed in 13 patients intraoperatively. Four patterns of commissural malalignment were present: (1) sinus-facing of the pulmonary valve, (2) sinus-facing of the aortic valve, (3) sinus-facing of both valves, and (4) bicuspid pulmonary valve (functionally sinus-facing). Two patterns of severity were present: major and minor. To avoid torsion and stretching of the coronary arteries during surgery, various methods were needed: more extensive dissection of the coronary artery, trap door incision, supracommissural or juxtacommissural transfer, both coronary transfer to the same sinus, tube reconstruction of the coronary artery, and neoaorta dextrorotation anastomosis. One patient who had severe commissural malalignment died during the operation, and the cause of death was probably stretching or torsion of the coronary artery. CONCLUSIONS: The recognition of malalignment of the facing sinus in transposition of the great arteries can be detected preoperatively by echocardiography. The surgical procedure of the arterial switch operation is influenced by the presence of commissural malalignment. Preoperative awareness of commissural malalignment seems to be helpful for surgeons to predict the need for an alternative operational procedure.

Aortic arch reconstruction using regional perfusion without circulatory arrest.

OBJECTIVES: Deep hypothermic circulatory arrest during repair of aortic arch anomalies may induce neurological complications or myocardial injury. Regional cerebral and myocardial perfusion may eliminate those potential side effects. METHODS: From March 2000 to March 2002, 48 neonates or infants with complex arch anomaly were operated on using the regional perfusion technique. Thirty-three patients were male and the median age was 24 days (range 5-301 days). Preoperative diagnosis consisted of coarctation or interruption of the aorta associated with ventricular septal defect (group I, n = 26) and arch anomaly with complex intracardiac defects such as hypoplastic left heart syndrome or its variants (group II, n = 22). Arterial cannula was inserted through the innominate artery and the flow rate was regulated to about 50-100 ml/kg per min during regional perfusion. Simultaneous myocardial perfusion was maintained using a Y-connected infusion line. Cardioplegia was applied during intracardiac repair. RESULTS: Cardiopulmonary bypass and aortic cross-clamp times were 154 +/- 49 and 39 +/- 34 min, respectively. Temporary circulatory arrest for intracardiac procedures was performed in eight patients. However, the mean arrest time was minimized (range 1-18 min). The descending aorta clamping time was 33 +/- 16 min. Operative mortality rates in each group were 0 and 18.2% (0/26 and 4/22). Late mortality rates were 0 and 11.1% (0/26 and 2/18) during 9.1 months of follow-up. Complications consisted of low cardiac output in eight cases, transient neurological problems in two cases, and transient renal insufficiency in two cases, respectively. CONCLUSIONS: Regional perfusion is feasible and can be used with acceptable results. It may reduce potential complications following aortic arch reconstruction using circulatory arrest. However, repair of aortic arch in the patients with complex intracardiac defects still imposes a significant rate of mortality and morbidity.