International Cardiovascular Research Journal
Volume:1 Issue: 3, Mar 2008

Several studies reported during recent years showed some new possible advantages of the three-dimensional echocardiography in daily practice. Real-time three dimensional echocardiography (RT3DE) is the only on-line 3D method based on real time volumetric scanning, as compared with other 3D imaging techniques such as computed tomography and magnetic resonance imaging, which are based on post-acquisition reconstruction and not on volumetric scanning. The aim of this study is to give a brief review of the development of the technology of RT3DE and its clinical application.

Chronic heart failure is a clinical syndrome and the final common pathway of different cardiac diseases. A rising incidence is reported all over the world, leading to enormous cost and spending of health care resources. Although medical therapy with beta blockers, ACE-inhibitors and spironolactone has proved to be efficacious, mortality remains high. Therefore the introduction of supplemental methods is very welcome and indeed, electrical therapies with implanted devices become increasingly important in this regard. Besides the implanted cardioverter defibrillator (ICD), cardiac resynchronisation therapy (CRT) has recently been shown not only to improve exercise tolerance, but also to prolong survival in patients with heart failure and cardiac asynchrony. Therefore, an overview of cardiac resynchronisation therapy, including additional CRT-ICD capabilities, is given herein according the literature. This includes current guidelines, our own implantation experience, and follow-up data of 500 patients during 1999 – 2007.

To define right atrial appendage functional parameters and comparing them with those of left atrial appendage. A consecutive series of 154 patients (76 males and 78 females) with mean age of 42 years were referred for transesophageal echocardiography. Ejection and filling velocities of right and left atrial appendages were measured at 120 and 70 degrees respectively. The left and right ventricles size and function, right atrial size, tricuspid regurgitation severity, and pulmonary artery systolic pressure were prospectively measured and calculated during transthoracic echocardiography. Mean right and left atrial appendages velocities were 42 ± 18 cm/s and 50 ± 26 cm/s respectively (PV<0.001). Statistically significant positive association (PV<0.001) was found between right atrial appendage velocity and right ventricle ejection fraction and statistically negative relationship was observed between right atrial appendage velocity and smoke pattern (PV<0.001). Also, the results suggested marginally significant associations between right atrial appendage velocity and right atrium size (PV = 0.05) and pulmonary artery systolic pressure (PV = 0.07). It was also found that right atrial appendage measures were relatively independent on right ventricle size and tricuspid regurgitation severity. Our study showed right atrial appendage measures were relatively dependent on right ventricle function, right atrium size and pulmonary artery systolic pressure and relatively independent on right ventricle size and tricuspid regurgitation severity. In patients with right atrium smoky pattern right atrial appendage velocity was significantly reduced.

Right ventricular apical (RVA) pacing has been reported to induce several deleterious effects particularly in the presence of structural heart disease but can also involve patients with normal left ventricular (LV) function. Left atrial (LA) enlargement is one of these effects, but the majority of studies have measured LA dimension rather than volume. The present prospective study was designed to assess the effect of RVA pacing on LA volume in patients with normal LV function.Patients and The study comprised 41 consecutive patients with LV ejection fraction ≥ 45% and LV end diastolic dimension ≤ 56 mm who underwent single-or dual- chamber pacemaker implantation in RVA and followed for LA volume measurement and pacemaker analysis at least during the ensuing 4.2 months. In all, 21 patients were excluded from the study due to five spontaneous wide QRS complex (≥120msec), one recent acute coronary syndrome,one significant valvular heart disease, three pacing frequency <90%, eight death or losing follow up in three cases. In remaining 20 patients, LA volume ragned from 21 to 54 mm3 with mean of 37.3±9.7 mm3 prior to pacemaker implantation that increased to 31 to 103 mm3 (54.3±17.0) during follow-up (P<0.001). RVA pacing might lead to an increase in LA volume even in patients with normal LV function.

Surgical treatment of active infective endocarditis (IE) requires not only homodynamic repair, but also, special emphasis on the eradiation of the infection to prevent recurrence. This study was undertaken to examine the outcome of surgery for active infective endocarditis in a cohort of patients.Patients and One hundred and sixty-four consecutive patients underwent valve surgery for active IE in Madani heart centre (Tabriz, Iran) from 1996 to 2006. The patients with diagnosis of IE (according to Duke Criteria) were eligible for the study. The mean age of patients was 36.3 ± 16 years, with 34.6±17.5 yrs for native valve endocarditis and 38.6±15.2 yrs for prosthetic valve endocarditis (p= 0.169). Ninety-one (55.5%) of patients were males. The infected valve was native in 112 (68.3%) of patients and prosthetic in 52 (31.7%). There was no predisposing heart disease in 61 (37%) of patients. The aortic valve was infected in 78(47.6%), the mitral valve in 69 (42.1%), and multiple valves in 17 (10.3%) of patients. Active culture-positive endocarditis was present in 81 (49.4%) whereas 83(50.6%) patients had culture-negative endocarditis. Staphylococcus aureus was the most common isolated microorganism. Ninety patients (54.8%) were in NYHA classes III and IV. Mechanical valves were implanted in 69 patients (42.1%) and bioprostheses in 95 (57.9%), including homograft in 19 (11.5%) cases. There were 16 (9%) operation-related deaths, but only 1 death in patients undergoing aortic homograft replacement. Reoperation was required in 18 (10.9%) cases.Based on multivariate logistic regression analysis, Staphylococcus aureus infection (p= 0.008), prosthetic valve endocarditis (p=0.01), paravalvular abscess (p=0.001) and left ventricular ejection fraction less than 40% (p=0.04) were independent predictors of hospital mortality. Surgery for infective endocarditis continues to be challenging and associated with high operation-related mortality and morbidity. Prosthetic valve endocarditis, impaired ventricular function, paravalvular abscess and Staphylococcus aureus infection associated with hospital mortality. Also we found that aortic valve replacement with an aortic homograft could be performed with acceptable hospital mortality and provided satisfactory results.

Unfractioned heparin (UFH) is the standard antithrombotic agent in elective percutaneous coronary intervention (PCI), but has its own limitations. Several studies have suggested intravenous enoxaparin as a safe and effective alternative but most of them are uncontrolled. Our main goal was to evaluate the safety of enoxaparin over UFH in PCI patients undergoing coronary stenting by drug eluting stents (DES). We randomly assigned 195 patients undergoing PCI using DES to receive either 0.75 mg enoxaparin per kilogram of body weight or 10000 IU unfractioned heparin. The primary end point was the incidence of major or minor bleeding. The secondary end point was the incidence of acute coronary events (ST-elevation myocardial infarction, non ST-elevation myocardial infarction,and unstable angina) in the first 24 hours after PCI. The rate of major and minor bleedings was similar in the first 24 hours after procedure between enoxaparin group and UFH group (P value>0.05). The incidence of acute coronary events and mortality was also similar between two arms. In DES based PCI, a single intravenous bolus of 0.75 mg of enoxaparin per kilogram is associated with similar rate of bleeding as compaired with UFH. Also the rates of ischemic events are not different for enoxaparin and UFH however larger trials are needed for definit conclusion.

There is considerable evidence that vascular fluid dynamics plays an important role in the development and prevalence of atherosclerosis which is one of the most widespread disease in humans. The onset and prevalence of atherosclerosis hemodynamic parameter are largely affected by geometric parameters. If any obstacle interferes with the blood flow, the above parameters change dramatically. Most of the arterial diseases, such as atherosclerosis, occur in the arteries with complex patterns of fluid flow where the blood dynamics plays an important role. Arterial stenosis mostly occurs in an area with a complex pattern of fluid flow, such as coronary artery, aorta bifurcation, carotid and vessels of lower limbs. During the past three decades, many experimental studies have been performed on the hemodynamic role of the blood in forming sediment in the inner wall of the vessels. It has been shown that forming sediment in the inner wall of vessels depends on the velocity of fluid and also on the amount of wall shear stress. We have examined the effect on the blood flow of local stenosis in carotid artery in numerical form using the incompressible Navier-Stockes equations. The profile of the velocity in different parts and times in the pulsatile cycle, separation and reattachment points on the wall, the distance stability of flow and also alteration caused by the wall shear stress in entire vessel were shown and compared with two behaviors flow (Newtonian and Non-Newtonian).Finally we describe the influence of the severity of the stenosis on the separation and reattachment points for a Non-Newtonian fuid. In the present study, we have pointed very low and high oscillating WSS (Wall Shear Stress) values play a significant role in the development of forming sediment in the inner wall of vessels. Also, we obtain this probability is higher for Newtonian than Non-Newtonian fluid behavior. Based on our results, the possibility of the endothelium destruction is greater with the Newtonian fluid behavior and in the regions where WSS are beyond the range of 10-420 dyne/cm2.

The dominant role of percutaneous transluminal coronary angioplasty (PTCA), especially with drug-eluting stent is obvious in alleviating symptoms and improving life quality of patients with coronary artery disease.Patients and We analyzed a total 2267 angioplasty cases (906 women, and 1361 men) in six public and private catheterization centers in Shiraz, from January 2006 to January 2007. A) Pure old balloon angioplasties were performed only in 12 cases (0.52 %)B) Drug-eluting stents (53.7 %) were placed more frequently than Bare-metal stents (46.3 %). There was 13% increase in placing drug-eluting stent during 2005. C) Drug-eluting stents were used in 50.0 % and 54.9 % of patients in public and private hospitals, respectively. D) In Shiraz centers, Cypher model was used more often than other models (29.1 %). E) Single-vessel disease PTCA were done in 65.5 % of patients followed by two (27.0 %), and three-vessel diseases (7.5 %). We recommend the increasing use of drug-eluting stents especially in patients with three-vessel disease. However, the use of first generation of drug-eluting stents would increase the chance of subacute thrombosis. It is also essential to carry out especial surveys about drug-eluting stents in Iran and Middle East.

The most common fungal organism to cause endocarditis is Candida which is followed by Aspergillus. Aspergillus endocarditis can occur in either the native or prosthetic heart valves, usually occurring post operatively after cardiac surgery on implanted valves. The usual route of infection for invasive aspergillosis is through inhalation of organism into the lungs. Diagnosis is difficult because blood culture usually remains negative even with extensive disease. Long term survival is limited even with surgical intervention.Herein, we present a 49-year-old man with previous history of coronary artery bypass graft and aortic valve endocarditis which was diagnosed as Aspergillus endocarditis after the valve surgery. Unfortunately the patient died because of late occurrence of progressive aortic invasion caused by Candida and Enterococci.

A2B negative is one of rare subgroups of ABO blood group system. Herein, we report a 59-year-old male patient who was candidate for coronary artery bypass grafting surgery (CABG) due to coronary artery stenosis. The patient`s blood group was reported as AB negative in routine laboratory, and because of doubtful result, a complementary test confirmed his blood group as A2B negative. The consultant hematologist recommended reserving either negative A2B packed red blood cell (PRBC) or if unavailable O- blood group. After induction of anesthesia three units of patient’s own blood were collected and replaced by colloid solution. The patient underwent CABG with hypothermic cardiopulmonary bypass. The collected autologous blood units were transfused at the end of operation. The patient received one unit of A2B- homologous PRBC in the postoperative period, and was discharged without any reaction to transfusion.

A case of aortic valve replacement (AVR) with St. Jude Medical (SJM) Regent® valve no 21, that was fractured intraoperatively and replaced with a SJM Regent® valve no 19, is reported here.The fracture point was ring part of the valve that has not been reported yet.