The Journal of Tehran University Heart Center
Volume:3 Issue: 4, Oct 2008

Atrial fibrillation is the most prevalent permanent arrhythmia. It may be associated with other cardiac pathologies which need surgical treatment. Various types of surgery including the traditional cut-sew operations and operations using different energy sources are currently in use. In comparison with medical treatment, surgery is safe, effective, and has reliable results.

Angiogenesis gene therapy has long been sought as a novel alternative treatment for restoring the blood flow and improving the contractile function of the ischemic heart in selected clinical settings. Angiogenic fibroblast growth factor-1 (FGF-1) is a promising candidate for developing a promising gene therapy protocol due to its multipotent ability to stimulate endothelial cell (EC) growth, migration, and tube formation. Despite these advantages, however, FGF gene therapy has suffered setbacks mainly due to the inefficient delivery rate of the growth factor in vivo. Given the potent angiogenic effect of FGF-1, we reasoned that constitutively synthesized minute quantities of this polypeptide hormone, when empowered with the ability to escape the cellular constraint, could freely act in a paracrine/autocrine fashion on nearby existing capillary plexuses and lead to neovascularization and restoration of the blood flow to ischemic tissues for reparative purpose.

We report the direct gene transfer of a retroviral-based mammalian expression vector encoding a secreted form of FGF-1 (sp-FGF-1) for the purpose of therapeutic angiogenesis into the porcine myocardium subjected to the surgical placement of an ameroid occluder to induce the chronic coronary occlusion of the left circumflex coronary artery (LCx) and regional myocardial ischemia. Coronary angiography, performed 3 weeks after surgery, confirmed the interruption of the blood flow in the LCx distal to the site of ameroid placement.

Immunohistochemical analysis using antibody specific to von Willebrand factor (vWF), an endothelial marker, showed a significant increase (p<0.05) in myocardial vascularity in the sp-FGF-1 hearts compared to the control (vector alone).Importantly, an assessment of the cardiac function by echocardiography, performed 3 weeks after surgery, demonstrated improved cardiac contractility due to increased left ventricular free wall contraction in the sp-FGF-1-treated animals only.

These results suggest that the intramyocardial delivery of our chimeric secretory FGF-1 gene can enhance vascularity and improve cardiac contractility in a chronic ischemic heart. This protocol may serve useful for developing reparative angiogenesis strategies aimed at improving the pumping function of the ischemic hearts in human patients.

Prosthetic valve endocarditis (PVE) is an important cause of morbidity and mortality associated with heart valve replacement surgery. The aim of the present study was to describe the early outcome of treatment in patients with PVE in a single center. The data of all the episodes of PVE registered at our institution between 2002 and 2007 were collected and analyzed retrospectively. The patients were assessed using clinical criteria defined by Durack and colleagues (Duke criteria). The analysis included a detailed study of hospital records. The continuous variables were expressed as mean ± standard deviation, and the discrete variables were presented as percentages. Thirteen patients with PVE were diagnosed and treated at our center during the study period. In all the cases, mechanical prostheses were utilized. The patients'' mean age was 46.9±12.8 years. Women made up 53.8% of all the cases. Early PVE was detected in 6 (46.2%) patients, and late PVE occurred in 7 (53.8 %). Eleven (84.6%) patients were treated with intravenous antimicrobial therapy, and the other two (15.4%) required surgical removal and replacement of the infected prosthesis in addition to antibiotic therapy. Blood cultures became positive in 46.2% of the patients. Mortality rate was 15.4% (2 patients). It seems that in selected cases with PVE, i.e. in those who remain clinically stable and respond well to antimicrobial therapy, a cure could be achieved by antimicrobial treatment alone with acceptable morbidity and mortality risk.

The recent developments in tissue Doppler imaging (TDI) now more than ever permit the quantification of the myocardial function. In the current systems, tissue tracking or displacement curves are generated from color tissue Doppler data through the instantaneous temporal integral of velocity-time curves. The purpose of the present study was to assess regional myocardial displacement via spectral TDI. Maximum myocardial velocities were extracted from spectral pulsed tissue Doppler images using a developed computer program and were integrated throughout the cardiac cycle. Spectral tissue Doppler echocardiography was performed to evaluate longitudinal and radial functions in 20 healthy men, and the calculated end-systolic displacements were subsequently compared with the displacements measured from the same areas via color tissue tracking. According to the Bland-Altman analysis between spectral tissue tracking and color tissue tracking, the significant arithmetic mean was 7.34 mm with SD mean differences of ±2.24 mm in all of the evaluated segments. Despite significant differences (p<0.001), there was a good significant correlation between the two methods (r=0.79, p<0.001). A verification study showed that the proposed approach had the ability to assess regional myocardial displacement using spectral TDI, which can be used in a wider range of equipment than is currently possible.

Elderly patients (>75 years) have constituted the fastest growing portion of the coronary artery bypass grafting (CABG) patient population over the last two decades. Of the goals that surgical care for the elderly pursues, cure may be an unfeasible one; nevertheless, palliation and comfort warrant sufficient importance.The present study sought to examine the postoperative course and events in elderly patients undergoing CABG with or without other procedures and to compare the results with those in younger patients. Demographic, mortality, morbidity, and resource utilization data were collected from the records of the patients undergoing CABG between January 2005 and July 2007 in Imam Khomeini Medical Center, Tehran, Iran. The mean time to extubation was 9.3 and 6.3 hours in the elderly and non-elderly patients, respectively (p<0.01). Blood transfusion was required in 87.8% of the elderly compared to 58.5% of the non-elderly subjects (p<0.01). The mean Intensive Care Unit stay was 2.1 days for the elderly and 1.4 days for the non-elderly patients (p<0.001). In-hospital mortality was 9% for the elderly patients vs. 2.8% for the younger group (p<0.001). The elderly patients undergoing CABG had a significantly higher morbidity rate, with an increased incidence of postoperative renal failure, neurological complications, and in-hospital mortality.

Discrete subaortic stenosis (DSS) is a progressive condition. Controversy still rumbles on as to whether the subaortic membrane causes aortic regurgitation (AR) and whether membrane resection reduces AR severity. We investigated the association between the left ventricular outflow tract peak gradient (LVOT-PG) and AR severity preoperatively and changes in AR severity and obstruction recurrence after surgery in DSS patients. Twenty patients were evaluated before and after surgery for DSS (mean follow-up time: 13.60±9.61 months). The patients were evaluated via transthoracic echocardiography and transesophageal echocardiography, if necessary. The cut-off point for surgery was LVOT-PG ≥50 mmHg or the presence of progressive AR. The mean age of the patients was 28.55±15.23 years, and 35% of them were male. LVOT-PG decreased from a mean of 80.83±42.72 mmHg preoperatively to 19.14±14.03 mmHg postoperatively and to 25.47±16.10 at follow-up. AR was identified in 15 (75%) patients preoperatively: mild in 8 (40%) and moderate in 7 (35%). The postoperative change in AR severity was insignificant. The correlation between preoperative LVOT-PG and the incidence and severity of preoperative AR was not significant. AR severity had no correlation with age. Membrane recurrence occurred in 25% of the patients. Our results indicated no relationship between AR severity and LVOT-PG and the patient’s age. Patient selection for surgery can, therefore, be carried out on the basis of LVOT-PG or AR severity separately. Subaortic resection may reduce AR severity in some patients, but this reduction is not significant. Future studies are required to elucidate whether or not the presence of the AR is an indication for surgery.

Coronary angiography is frequently applied for diagnostic purposes in patients with coronary artery disease. Be that as it may, there is still no consensus about the optimal time for the ambulation of patients following femoral arterial puncture. We sought to compare 6 hours of complete bed rest and 2 hours of complete bed rest in patients after angiography. This randomized quasi–experimental study was performed in 120 patients candidated for coronary angiography. The patients were divided into experimental and control groups randomly. Primarily demographic data were obtained from both groups before intervention was carried out for them. The arterial sheath was removed immediately after the procedure. Hemostasis was achieved by manual compression and maintained with sandbags. Early ambulation was attempted after two hours of supine bed rest following sheath removal. The incidence of bleeding and insertion site complications was documented at 24 hours and subsequently at 30 days post-procedure. Our findings were indicative of no significant difference between the two groups in terms of gender, age, body mass index, catheter size, total procedure duration, total hemostasis time, history of anticoagulant drug use, and coagulation tests before angiography. Pre-ambulation bleeding occurred in 2 patients in each of the two groups. Post-ambulation bleeding occurred in 2 patients in the control group and 1 in the experimental group. Whereas there was no incidence of large pre-ambulation hematoma in the control group, there was one case in the experimental group. There was no case of post-ambulation hematoma, however, in either group, and nor was there any late bleeding or vascular complication. Ambulation 2 hours after angiography via the femoral site is feasible and safe with the same incidence of insertion site complication as that of 6 hours of bed rest. Therefore, an early ambulation protocol can shorten hospital stay without significant vascular complications.

Congenital left ventricular diverticulum is a rare cardiac malformation. Two categories of congenital ventricular diverticulum have been identified with regard to their localization: apical and non-apical. Apical diverticula are always associated with midline thoraco-abdominal defects and other heart malformations. Non-apical diverticula are always isolated defects. Diagnosis is established by imaging studies such as echocardiography, magnetic resonance imaging, or left ventricular angiography. Mode of treatment has to be individually tailored and depends on clinical presentation, accompanying abnormalities, and possible complications. We report a 10-month-old girl with left ventricular apical diverticulum, large atrial septal defect, two small muscular ventricular septal defects, and pulmonary hypertension, associated with epigastric hernia. This patient underwent total surgical repair for intra-cardiac defects as well as diverticular resection.