Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

Introduction

We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery.

Methods

Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time.

Results

In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series.

Conclusion

Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries.     

Comparative analysis of the patency of the internal thoracic artery in the CABG of left anterior descending artery: 6-month postoperative coronary CT angiography evaluation

Objective

To assess the patency of the pedicled right internal thoracic artery with an anteroaortic course and compare it to the patency of the left internal thoracic artery , in anastomosis to the left anterior descending artery in coronary artery bypass grafting by using coronary CT angiography at 6 months postoperatively.

Methods

Between December 2008 and December 2011, 100 patients were selected to undergo a prospective coronary artery bypass grafting procedure without cardiopulmonary bypass. The patients were randomly divided by a computer-generated list into Group-1 (G-1) and Group-2 (G-2), comprising 50 patients each, the technique used was known at the beginning of the surgery. In G-1, coronary artery bypass grafting was performed using the left internal thoracic artery for the left anterior descending and the free right internal thoracic artery for the circumflex, and in G-2, coronary artery bypass grafting was performed using the right internal thoracic artery pedicled to the left anterior descending and the left internal thoracic artery pedicled to the circumflex territory.

Results

The groups were similar with regard to the preoperative clinical data. A male predominance of 75.6% and 88% was observed in G-1 and G-2, respectively. Five patients migrated from G-1 to G-2 because of atheromatous disease in the ascending aorta. The average number of distal anastomoses was 3.48 (SD=0.72) in G-1 and 3.20 (SD=0.76) in G-2. Coronary CT angiography in 96 re-evaluated patients showed that all ITAs, right or left, used in situ for the left anterior descending were patent. There were no deaths in either group.

Conclusion

Coronary artery bypass grafting surgery involving anastomosis of the anteroaortic right internal thoracic artery to the left anterior descending artery has an outcome similar to that obtained using the left internal thoracic artery for the same coronary site.     

On-pump beating-heart versus conventional coronary artery bypass grafting for revascularization in patients with severe left ventricular dysfunction: early outcomes

Background

We sought to evaluate the effects of on-pump beating-heart versus conventional coronary artery bypass grafting techniques requiring cardioplegic arrest in patients with coronary artery disease with left ventricular dysfunction.

Methods

We report the early outcomes associated with survival, morbidity and improvement of left ventricular function in patients with low ejection fraction who underwent coronary artery bypass grafting between August 2009 and June 2012. Patients were separated into 2 groups: group I underwent conventional coronary artery bypass grafting and group II underwent an on-pump beating-heart technique without cardioplegic arrest.

Results

In all, 131 patients underwent coronary artery bypass grafting: 66 in group I and 65 in group II. Left ventricular ejection fraction was 26.6% ± 3.5% in group I and 27.7% ± 4.7% in group II. Left ventricular end diastolic diameter was 65.6 ± 3.6 mm in group I and 64.1 ± 3.2 mm in group II. There was a significant reduction in mortality in the conventional and on-pump beating-heart groups (p < 0.001). Perioperative myocardial infarction and low cardiac output syndrome were higher in group I than group II (both p < 0.05). Improvement of left ventricular function after the surgical procedure was better in group II than group I.

Conclusion

The on-pump beating-heart technique is the preferred method for myocardial revascularization in patients with left ventricular dysfunction. This technique may be an acceptable alternative to the conventional technique owing to lower postoperative mortality and morbidity.     

Epidemiology of coronary artery bypass grafting at the Hospital Beneficência Portuguesa,S?o Paulo

Introduction

The knowledge of the prevalence of risk factors and comorbidities, as well as the evolution and complications in patients undergoing coronary artery bypass graft allows comparison between institutions and evidence of changes in the profile of patients and postoperative evolution over time.

Objective

To profile (risk factors and comorbidities) and clinical outcome (complications) in patients undergoing coronary artery bypass graft in a national institution of great surgical volume.

Methods

A retrospective cohort study of patients undergoing coronary artery bypass graft in the hospital Beneficência Portuguesa de São Paulo, from July 2009 to July 2010.

Results

We included 3,010 patients, mean age of 62.2 years and 69.9% male. 83.8% of patients were hypertensive, 36.6% diabetic, 44.5% had dyslipidemia, 15.3% were smokers, 65.7% were overweight/obese, 29.3% had a family history of coronary heart disease. The expected mortality calculated by logistic EuroSCORE was 2.7%. The isolated CABG occurred in 89.3% and 11.9% surgery was performed without cardiopulmonary bypass. The most common complication was cardiac arrhythmia (18.7%), especially acute atrial fibrillation (14.3%). Pneumonia occurred in 6.2% of patients, acute renal failure in 4.4%, mediastinites in 2.1%, stroke in 1.8% and AMI in 1.2%. The in-hospital mortality was 5.4% and in isolated coronary artery bypass graft was 3.5%. The average hospital stay was 11 days with a median of eight days (3-244 days).

Conclusion

The profile of patients undergoing coronary artery bypass graft surgery in this study is similar to other published studies.     

Effects of intraoperative diltiazem infusion on flow changes in arterial and venous grafts in coronary artery bypass graft surgery

Objective

This study aimed to show the effects of intra-operative diltiazem infusion on flow in arterial and venous grafts in coronary artery bypass graft surgery.

Methods

Hundred fourty patients with a total of 361 grafts [205 (57%) arterial and 156 (43%) venous] underwent isolated coronary surgery. All the grafts were measured by intraoperative transit time flow meter intra-operatively. Group A (n=70) consisted of patients who received diltiazem infusion (dose of 2.5 microgram/kg/min), and Group B (n=70) didn''t receive diltiazem infusion.

Results

Mean graft flow values of left internal mammary artery were 53 ml/min in Group A and 40 ml/min in Group B (P<0.001). Pulsatility index (PI) values of left internal mammary artery for Group A and Group B were 2.6 and 3.0 respectively (P<0.001). No statistically significant difference was found between venous graft parameters.

Conclusion

We recommend an effect of diltiazem infusion in increasing graft flows in coronary artery bypass graft operations.     

Triple coronary artery revascularization on the stabilized beating heart: initial experience

Objective

To decrease health costs and morbidity related to extracorporeal circulation, surgeons have modified the coronary artery bypass (CAB) technique so that it can be completed without the use of extra-corporeal circulation. This study summarizes initial experience with direct coronary artery revascularization on the beating heart using a coronary stabilizer.

Design

A case series.

Setting

The Montreal Heart Institute, a university-affiliated centre, specializing in the treatment of cardiac illnesses.

Patients

Ten patients underwent CAB by this technique. They presented with double or triple coronary artery disease with no intramyocardial, heavily calcified, diffused atheromatous coronary vessels, or left main coronary disease.

Intervention

CAB grafting in the beating heart. The anterior wall was grafted in all patients, the inferior wall in 7 and the posterior wall in 7.

Main outcome measures

Patient survival and graft patency.

Results

One patient died of multiple organ failure not related to the grafting technique itself, and 1 patient suffered a non-Q myocardial infarction. Early coronary angiography performed on 8 patients showed 100% graft patency, most with excellent distal runoff (21/22 grafts).

Conclusion

In patients with adequate anatomy, performance of CAB without extracorporeal circulation can achieve excellent early results provided there is appropriate mechanical stabilization of the beating heart.     

Effect of using pump on postoperative pleural effusion in the patients that underwent CABG

Objective

The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting.

Methods

A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden) heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11.

Results

The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump) as compared to Group 2 (off-pump). But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893), P>0.05 for bilateral pleural effusion (P=0.780)]. Left pleural effusion was encountered to be lower in Group 2 (off-pump). The difference was found to be statistically significant (P<0.05, P=0.006).

Conclusion

Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.     

Comparison of two surgical techniques for creating an acute myocardial infarct in rats

Objective

To perform a comparative assessment of two surgical techniques that are used creating an acute myocardial infarc by occluding the left anterior descending coronary artery in order to generate rats with a left ventricular ejection fraction of less than 40%.

Methods

The study was completely randomized and comprised 89 halothane-anaesthetised rats, which were divided into three groups. The control group (SHAM) comprised fourteen rats, whose left anterior descending coronary artery was not occluded. Group 1 (G1): comprised by 35 endotracheally intubated and mechanically ventilated rats, whose left anterior descending coronary artery was occluded. Group 2 (G2): comprised 40 rats being manually ventilated using a nasal respirator whose left anterior descending coronary artery was occluded. Other differences between the two techniques include the method of performing the thoracotomy and removing the pericardium in order to expose the heart, and the use of different methods and suture types for closing the thorax. Seven days after surgery, the cardiac function of all surviving rats was determined by echocardiography.

Results

No rats SHAM group had progressed to death or had left ventricular ejection fraction less than 40%. Nine of the 16 surviving G1 rats (56.3%) and six of the 20 surviving G2 rats (30%) had a left ventricular ejection fraction of less than 40%.

Conclusion

The results indicate a tendency of the technique used in G1 to be better than in G2. This improvement is probably due to the greater duration of the open thorax, which reduces the pressure over time from the surgeon, allowing occlusion of left anterior descending coronary artery with higher accuracy.     

Graft pathology at the time of harvest: impact on long-term survival

Objective

This study aims to present the graft pathology at the time of harvest and its impact on long-term survival.

Methods

The remnants of the bypass grafts from 66 consecutive patients with coronary artery disease receiving a coronary artery bypass grafting were investigated pathologically, and pertinent predictive risk factors and survival were analyzed.

Results

Medial degenerative changes with or without intimal proliferation were present in 36.8%, 37.8% and 35.6% of left internal mammary artery (IMA), radial artery and saphenous vein grafts. There were 2 (3.0%) hospital deaths and 9 (14.1%) late deaths. Multinomial logistic regression revealed left IMA pathological changes, dyslipidemia, history of percutaneous transluminal coronary angioplasty/stent deployment and Y-graft were significant predictive risk factors negatively influencing the patients’ long-term survival. Kaplan-Meier survival analysis revealed that the long-term survival of patients with left IMA pathological changes were significantly reduced compared with those without (74.1% vs. 91.4%, P=0.002); whereas no differences were noted in long-term survivals between patients with and without pathological changes of the radial arterial or saphenous vein grafts.

Conclusion

Pathological changes may be seen in the bypass graft at the time of harvest. The subtle ultrastructural modifications and the expressions of vascular tone regulators might be responsible for late graft patency. The pathological changes of the left IMA at the time of harvest rather than those of the radial artery or saphenous vein graft affect significantly longterm survival. Non-traumatic maneuver of left IMA harvest, well-controlled dyslipidemia and avoidance of using composite grafts can be helpful in maintaining the architecture of the grafts.     

Incidence of postoperative atrial fibrillation in patients undergoing on-pump and off-pump coronary artery bypass grafting

Objective

To determine the incidence of postoperative atrial fibrillation in patients undergoing on-pump and off-pump coronary artery bypass grafting.

Methods

A retrospective study with analysis of 230 medical records between January 2011 and October 2013 was conducted.

Results

Fifty-six (24.3%) out of the 230 patients were female. The average age of patients undergoing on-pump coronary artery bypass grafting was 59.91±8.62 years old, and off-pump was 57.16±9.01 years old (P=0.0213). The average EuroSCORE for the on-pump group was 3.37%±3.08% and for the off-pump group was 3.13%±3% (P=0.5468). Eighteen (13.43%) patients who underwent off-pump coronary artery bypass grafting developed postoperative atrial fibrillation, whereas for the onpump group, 19 (19.79%) developed this arrhythmia, with no significant difference between the groups (P=0.1955).

Conclusion

Off-pump coronary artery bypass grafting did not reduce the incidence of atrial fibrillation in the postoperative period. Important predictors of risk for the development of this arrhythmia were identified as: patients older than 70 years old and presence of atrial fibrillation in perioperative period in both groups, and non-use of beta-blockers drugs postoperatively in the on-pump group.     

Association of pre and intraoperative variables with postoperative complications in coronary artery bypass graft surgery

Objective

To associate the pre- and intraoperative variables with postoperative complications of patients undergoing coronary artery bypass graft surgery.

Methods

The pre- and intraoperative risk factors of individuals of both genders with diagnosis of coronary insufficiency undergoing coronary artery bypass graft have been studied.

Results

Fifty-eight individuals with median age 62 ± 10 year-old were included in the study, 67% of whom were male. Fourteen (24.1%) patients were smokers, 39 (67.2%) had previous myocardial infarction history, 11 (19%) had undergone coronary angioplasty, 74% had hypertension, 27% had diabetes mellitus, 64% had dyslipidemia and 15.5% had chronic obstructive pulmonary disease. Eighteen (31%) patients presented postoperative complications, most frequent being: infection in surgical incision, difficulties in deambulation, dyspnea, urinary infection and generalized weakness. Male patients had fewer complications than females (P=0.005). Patients with chronic obstructive pulmonary disease remained hospitalized for longer time periods (P=0.019). Postoperative complications occurred in 50% of the patients with creatinine increased, while only 27.1% of the patients with normal value of creatinine had complications (P=0.049). In addition, complications occurred in 50% of the patients with diabetes mellitus, while only 23.8% of patients without diabetes mellitus had complications (P=0.032). The intraoperative factors showed no statistically significant differences.

Conclusion

The preoperative factors are associated with postoperative complications in patients undergoing coronary artery bypass graft surgery.     

Anomalous origin of coronary artery: taxonomy and clinical implication

Objective

Anomalous origin of coronary artery is uncommon. The taxonomies of anomalous origin of coronary artery are inconsistent and complex. Conceptual and therapeutic debates remain. The aim of the present study is to reappraise the concept of anomalous origin of coronary artery and to discuss the potential hazards and treatment rationale of this anomaly on basis of literature review.

Methods

A comprehensive literature review was made in terms of the taxonomies including “simple”, “multiple” and “complex” types of anomalous origin of coronary artery.

Results

Anomalous origin of coronary artery can be simply categorized according to the ectopically originated coronary artery. There are a couple of complex anatomical variants: “multiple” type, involving more than one coronary artery or branch, which can be subdivided into 2 subtypes, A) more than one coronary arteries or branches arising from one place; and B) two coronary arteries/branches arising from separate ectopic sites; and “complex” type, associated with acquired heart disease, or congenital heart defects.

Conclusion

Sudden cardiac death in anomalous origin of coronary artery is associated with the anatomical features including abnormal coursing, acute angle take-off and ostial abnormalities. Atherosclerosis is prone to be in the right-sided ectopic and retroaortic coursing coronary artery. Surgical treatment is a definitive therapy. Simple coronary artery bypass grafting is not recommended due to the potential hazards of coronary steal phenomenon and poor patency of mammary arterial grafts, and modified maneuvers such as coronary ostial reimplantation, impinged coronary segment unroofing and coronary stent deployment are advocated instead.     

Sex Differences in Mortality After CABG Surgery

INTRODUCTION

Numerous studies have shown that women undergoing coronary artery bypass graft surgery present higher mortality rate during hospitalization, and often complications when compared to men.

OBJECTIVE

To compare the mortality of men and women undergoing coronary artery bypass graft surgery and identify factors related to differences occasionally found.

METHODS

Retrospective cohort study conducted with 215 consecutive patients who underwent coronary bypass surgery.

RESULTS

Women had a higher average age. Low body surface and dyslipidemia were more prevalent in women (1.65 vs. 1.85, P <0.001: 53% vs. 30%, P =0.001), whereas history of smoking and previous myocardial infarction were more prevalent in men (35% vs.14.7%, P =0.001; 20% vs. 2.7%, P =0.007). Regarding complications in the postoperative period, there was a higher rate of blood transfusions in women. The overall mortality rate was 5.6%, however there was no statistically significant difference in mortality between men and women. It was observed that among the patients who died, the average body surface area was lower than that of patients who did not have this complication.

CONCLUSION

There was no difference in mortality between the sexes after coronary artery bypass graft in this service.     

Anterior opening wedge high tibial osteotomy: the effect of increasing posterior tibial slope on ligament strain

Background

Although a previous study showed that anterior opening wedge high tibial osteotomy (HTO) for sagittal plane correction induced no increased strain in the anterior cruciate ligament (ACL), we hypothesized that other ligamentous restraints of the knee may be subjected to increased strain.

Methods

We mounted 6 cadaveric knees at 15° flexion in a testing apparatus that provided compressive and anterior loading. We measured the strain in the ACL, posterior (PCL), medial (MCL) and lateral (LCL) ligaments for 6 randomized loading combinations and 3 conditions: intact, after anterior opening wedge HTO with a 5-mm plate and with a 10-mm plate.

Results

The mean ACL strain decreased from 0.84% (standard deviation [SD] 1.50%) at baseline to −6.28% (SD 5.40%) with a 5-mm anterior opening wedge osteotomy and to −6.77% (SD 4.79%) with a 10-mm osteotomy. Stepwise regressions yielded no significant effect of compression, anterior loading or osteotomy on PCL, MCL or LCL strain.

Conclusion

Increasing the posterior slope via HTO did not increase strain in the PCL, MCL or LCL.     

EuroSCORE II and the importance of a local model,InsCor and the future SP-SCORE

Introduction

The most widely used model for predicting mortality in cardiac surgery was recently remodeled, but the doubts regarding its methodology and development have been reported.

Objective

The aim of this study was to assess the performance of the EuroSCORE II to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution.

Methods

One thousand consecutive patients operated on coronary artery bypass grafts or valve surgery, between October 2008 and July 2009, were analyzed. The outcome of interest was in-hospital mortality. Calibration was performed by correlation between observed and expected mortality by Hosmer Lemeshow. Discrimination was calculated by the area under the ROC curve. The performance of the EuroSCORE II was compared with the EuroSCORE and InsCor (local model).

Results

In calibration, the Hosmer Lemeshow test was inappropriate for the EuroSCORE II (P=0.0003) and good for the EuroSCORE (P=0.593) and InsCor (P=0.184). However, the discrimination, the area under the ROC curve for EuroSCORE II was 0.81 [95% CI (0.76 to 0.85), P<0.001], for the EuroSCORE was 0.81 [95% CI (0.77 to 0.86), P<0.001] and for InsCor was 0.79 [95% CI (0.74-0.83), P<0.001] showing up properly for all.

Conclusion

The EuroSCORE II became more complex and resemblance to the international literature poorly calibrated to predict mortality in patients undergoing coronary artery bypass grafts or valve surgery at our institution. These data emphasize the importance of the local model.     

Factors related to caregiving for individuals with spinal cord injury compared to caregiving for individuals with other neurologic conditions

Context/objective

To compare outcomes among caregivers of adults with spinal cord injuries (SCIs) to caregivers of adults with other neurological conditions, and determine if caregiving for SCI is associated with poor health status and chronic conditions.

Design

Secondary data analysis of 2009/2010 Behavioral Risk Factor Surveillance System survey.

Participants

Informal caregivers of adults with neurological conditions.

Outcome measures

Sociodemographics, caregiving factors (e.g. role, emotional support, life satisfaction), lifestyle behaviors, chronic conditions, and health status.

Results

Demographics and lifestyle behaviors did not differ in caregivers of adults with SCI vs. caregivers of adults with other neurological conditions (except younger age of SCI caregivers). Greater proportions of caregivers of adults with SCI had coronary heart disease (CHD) (12% vs. 6%, P = 0.06) and were obese (43% vs. 28%, P = 0.03). Frequent physical distress was reported by 20% of caregivers of persons with SCI (vs. 12% of other caregivers, P = 0.09), but mental health did not differ between caregiver groups. A greater proportion of caregivers of adults with SCI experienced insufficient sleep (47% vs. 30%, P = 0.008) and more days without enough sleep (13 vs. 9 days, P = 0.008). Odds of being younger, caregiver of a spouse, having CHD, and being obese were associated with being a caregiver of an adult with SCI.

Conclusion

Caregivers of adults with SCI report similar mental health status, but more poor sleep, and have increased odds of CHD and obesity. Interventions to address physical distress, improve sleep, and address CHD and obesity are needed in this cohort.     

Effects of Cardiopulmonary Bypass on Mediastinal Drainage and the Use of Blood Products in the Intensive Care Unit in 60- to 80-Year-Old Patients Who Have Undergone Coronary Artery Bypass Grafting

OBJECTIVE

The present study consisted of patients who underwent on-pump coronary artery bypass grafting (CABG) and off-pump CABG and investigated effect of using cardiopulmonary bypass (CPB) on the amount of postoperative drainage and blood products, red blood cell (RBC), free frozen plasma (FFP) given in the intensive care unit in 60-80-year-old patients who underwent CABG.

METHODS

The present study comprises a total of 174 patients who have undergone coronary artery bypass graft (off-pump or on-pump CABG) surgery in our clinic in between 2012-2015 year.

RESULTS

It was observed that the amount of drainage in the first 24 postoperative hours was lower in the on-pump CABG group (Group 1) when compared to off-pump group (Group 2) (Group 1 vs. Group 2; 703.5±253.8 ml vs. 719.6±209.4 ml; P =0.716). However, the amount of drainage in the second 24 hours was statistically significantly lower in the off-pump CABG group (Group 1 vs. Group 2; 259.8±170.6 ml vs. 190.1±129.1 ml; P =0.016). With regard to the amount of overall drainage, no statistically significant difference was observed between the two groups. Group 1 needed RBC transfusion higher than Group 2 (Group 1 vs. Group 2; 2.2±1.3 bag vs. 1.2±0.9 bag; P <0.001).

CONCLUSION

We can say that CPB influences the amount of second 24-hour drainage which indexed body surface area. In addition, CPB decreases hct, hb, thrombocyte count in ICU arrived, after 24 hours in postoperative period. Reduced thrombocyte counting effect can be appeared after 48 hours in the postoperative period of CPB.     

Twenty four hour imaging delay improves viability detection by Tl-201 myocardial perfusion scintigraphy

Objective

Since twenty-four-hour imaging by Tl-201 myocardial perfusion scintigraphy has been introduced as an effective additional procedure, the aim of this study was to compare this method''s result with only rest redistribution procedure in the diagnosis of myocardial viability.

Methods

Thirty patients (Seven female, 23 male; mean: 59.8 ± 10.7, 55.8-63.8 years old) with diagnosis of coronary artery disease were involved in this study. All patients had anamnesis of previous myocardial infarction and/or total occlusion of any main artery in the coronary angiography. Myocardial perfusion scintigraphy with Tl-201 with rest four hour (early) redistribution and 24 hour delayed redistribution protocol were performed to all of the patients. The images were evaluated according to 17 segment basis by an experienced nuclear medicine physician and improvement of a segment by visual interpretation was considered as viable myocardial tissue.

Results

Viability was found at 52 segments in the early redistribution images and additional 18 segments in the 24 hour delayed redistribution images on segment basis in the evaluation of 510 segments of 30 patients. On per patient basis, among the 26 patients who had viable tissue, 14 (54%) had additional improvement in 24 hour delayed images. Three (12%) patients had viable tissue in only 24 hour delayed images.

Conclusion

Delayed imaging in Tl-201 MPS is a necessary application for the evaluation of viable tissue according to considerable number of patients with additional improvement in 24 hour images in our study, which is restricted to the patients with myocardial infarct.