Chronotropic incompetence in Chagas disease: effectiveness of blended sensor (volume/minute and accelerometer)

Introduction

Technological progress of pacemakers has allowed the association of two or more sensors in one heart rate system response. The accelerometer sensor measures the intensity of the activity; it has a relatively rapid response to the beginning of it, however, it may present insufficient response to less strenuous or of less impact exercise. The minute ventilation sensor changes the pacing rate in response to changes in respiratory frequency in relation to tidal volume, allowing responses to situations of emotional stress and low impact exercises.

Objective

To evaluate the cardiorespiratory response of the accelerometer with respect to the blended sensor (BS=accelerometer sensor+minute ventilation sensor) to exercise in chagasic patients undergoing cardiopulmonary exercise test.

Methods

This was a prospective, observational, randomized, cross-sectional study. Patients who met the inclusion criteria were selected. The maximum heart rate of the sensor was programmed by age (220-age). The results were analyzed through t test with paired samples (P<0.05).

Results

Sample was comprised of 44 patients, with a mean age of 66±10.4 years, 58% were female, 54% as first implant, in 74% were functional class I and 26% were functional class II, left ventricular ejection fraction was 58±7. As for the cardiopulmonary test, maximum expected heart rate and VO2 were not achieved in both the accelerometer sensor and the blended sensor, however, metabolic equivalent in the blended sensor was higher than the expected, all data with P<0.001.

Conclusion

Even though the maximal heart rate was not reached, the blended sensor provided a physiological electrical sequence when compared to the accelerometer sensor, providing better physical fitness test in cardiopulmonary hemodynamics and greater efficiency.     

Short-term inspiratory muscle training potentiates the benefits of aerobic and resistance training in patients undergoing CABG in phase II cardiac rehabilitation program

Objective

To investigate the efficiency of short-term inspiratory muscle training program associated with combined aerobic and resistance exercise on respiratory muscle strength, functional capacity and quality of life in patients who underwent coronary artery bypass and are in the phase II cardiac rehabilitation program.

Methods

A prospective, quasi-experimental study with 24 patients who underwent coronary artery bypass and were randomly assigned to two groups in the Phase II cardiac rehabilitation program: inspiratory muscle training program associated with combined training (aerobic and resistance) group (GCR + IMT, n=12) and combined training with respiratory exercises group (GCR, n=12), over a period of 12 weeks, with two sessions per week. Before and after intervention, the following measurements were obtained: maximal inspiratory and expiratory pressures (PImax and PEmax), peak oxygen consumption (peak VO₂) and quality of life scores. Data were compared between pre- and post-intervention at baseline and the variation between the pre- and post-phase II cardiac rehabilitation program using the Student''s t-test, except the categorical variables, which were compared using the Chi-square test. Values of P<0.05 were considered statistically significant.

Results

Compared to GCR, the GCR + IMT group showed larger increments in PImax (P<0.001), PEmax (P<0.001), peak VO₂ (P<0.001) and quality of life scores (P<0.001).

Conclusion

The present study demonstrated that the addition of inspiratory muscle training, even when applied for a short period, may potentiate the effects of combined aerobic and resistance training, becoming a simple and inexpensive strategy for patients who underwent coronary artery bypass and are in phase II cardiac rehabilitation.     

Surgical Management of Boerhaave's Syndrome in a Tertiary Oesophagogastric Centre

INTRODUCTION

The aim of this study was to review the management and outcome of patients with Boerhaave''s syndrome in a specialist centre between 2000–2007.

PATIENTS AND METHODS

Patients were grouped according to time from symptoms to referral (early, < 24 h; late, > 24 h). The effects of referral time and management on outcomes (oesophageal leak, reoperation and mortality) were evaluated.

RESULTS

Of 21 patients (early 10; late 11), three were unfit for surgery. Of the remaining 18, immediate surgery was performed in 8/8 referred early and 6/10 referred late. Four patients referred late were treated conservatively. Oesophageal leak (78% versus 12.5%; P < 0.05) and mortality (40% versus 0%; P < 0.05) rates were higher in patients referred late. For patients referred late, mortality was higher in patients managed conservatively (75% versus 17%; not significant).

CONCLUSIONS

The best outcomes in Boerhaave''s syndrome are associated with early referral and surgical management in a specialist centre. Surgery appears to be superior to conservative treatment for patients referred late.     

Mortality risk is dose-dependent on the number of packed red blood cell transfused after coronary artery bypass graft

Introduction

Transfusions of one or more packed red blood cells is a widely strategy used in cardiac surgery, even after several evidences of increased morbidity and mortality. The world''s blood shortage is also already evident.

Objective

To assess whether the risk of mortality is dose-de>pendent on the number of packed red blood cells transfused after coronary artery bypass graft.

Methods

Between June 2009 and July 2010, were analyzed 3010 patients: transfused and non-transfused. Transfused patients were divided into six groups according to the number of packed red blood cells received: one, two, three, four, five, six or more units, then we assess the mortality risk in each group after a year of coronary artery bypass graft. To calculate the odds ratio was used the multivariate logistic regression model.

Results

The increasing number of allogeneic packed red blood cells transfused results in an increasing risk of mortality, highlighting a dose-dependent relation. The odds ratio values increase with the increased number of packed red blood cells transfused. The death''s gross odds ratio was 1.42 (P=0.165), 1.94 (P=0.005), 4.17; 4.22, 8.70, 33.33 (P<0.001) and the adjusted death''s odds ratio was 1.22 (P=0.43), 1.52 (P=0.08); 2.85; 2.86; 4.91 and 17.61 (P<0.001), as they received one, two, three, four, five, six or more packed red blood cells, respectively.

Conclusion

The mortality risk is directly proportional to the number of packed red blood cells transfused in coronary artery bypass graft. The greater the amount of allogeneic blood transfused the greater the risk of mortality. The current transfusion practice needs to be reevaluated.     

Risk factors for transient dysfunction of gas exchange after cardiac surgery

Objective

A retrospective cohort study was preformed aiming to verify the presence of transient dysfunction of gas exchange in the postoperative period of cardiac surgery and determine if this disorder is linked to cardiorespiratory events.

Methods

We included 942 consecutive patients undergoing cardiac surgery and cardiac procedures who were referred to the Intensive Care Unit between June 2007 and November 2011.

Results

Fifteen patients had acute respiratory distress syndrome (2%), 199 (27.75%) had mild transient dysfunction of gas exchange, 402 (56.1%) had moderate transient dysfunction of gas exchange, and 39 (5.4%) had severe transient dysfunction of gas exchange. Hypertension and cardiogenic shock were associated with the emergence of moderate transient dysfunction of gas exchange postoperatively (P=0.02 and P=0.019, respectively) and were risk factors for this dysfunction (P=0.0023 and P=0.0017, respectively). Diabetes mellitus was also a risk factor for transient dysfunction of gas exchange (P=0.03). Pneumonia was present in 8.9% of cases and correlated with the presence of moderate transient dysfunction of gas exchange (P=0.001). Severe transient dysfunction of gas exchange was associated with patients who had renal replacement therapy (P=0.0005), hemotherapy (P=0.0001), enteral nutrition (P=0.0012), or cardiac arrhythmia (P=0.0451).

Conclusion

Preoperative hypertension and cardiogenic shock were associated with the occurrence of postoperative transient dysfunction of gas exchange. The preoperative risk factors included hypertension, cardiogenic shock, and diabetes. Postoperatively, pneumonia, ventilator-associated pneumonia, renal replacement therapy, hemotherapy, and cardiac arrhythmia were associated with the appearance of some degree of transient dysfunction of gas exchange, which was a risk factor for reintubation, pneumonia, ventilator-associated pneumonia, and renal replacement therapy in the postoperative period of cardiac surgery and cardiac procedures.     

Incidence of stroke and acute renal failure in patients of postoperative atrial fibrillation after myocardial revascularization

Introduction

Postoperative atrial fibrillation is the most common arrhythmia in cardiac surgery, its incidence range between 20% and 40%.

Objective

Quantify the occurrence of stroke and acute renal insufficiency after myocardial revascularization surgery in patients who had atrial fibrillation postoperatively.

Methods

Cohort longitudinal bidirectional study, performed at Portuguese Beneficent Hospital (SP), with medical chart survey of patients undergoing myocardial revascularization surgery between June 2009 to July 2010. From a total of 3010 patients were weaned 382 patients that presented atrial fibrillation preoperatively and/or associated surgeries. The study was conducted in accordance with national and international following resolutions: ICH Harmonized Tripartite Guidelines for Good Clinical Practice - 1996; CNS196/96 Resolution, and Declaration of Helsinki.

Results

The 2628 patients included in this study were divided into two groups: Group I, who didn''t show postoperative atrial fibrillation, with 2302 (87.6%) patients; and group II, with 326 (12.4%) who developed postoperative atrial fibrillation. The incidence of stroke in patients was 1.1% without postoperative atrial fibrillation vs. 4% with postoperative atrial fibrillation (P<0.001). Postoperative acute renal failure was observed in 12% of patients with postoperative atrial fibrillation and 2.4% in the group without postoperative atrial fibrillation (P<0.001), that is a relation 5 times greater.

Conclusion

In this study there was a high incidence of stroke and acute renal failure in patients with postoperative atrial fibrillation, with rates higher than those reported in the literature.     

Effects of Resistance Exercise Applied Early After Coronary Artery Bypass Grafting: a Randomized Controlled Trial

OBJECTIVE

To evaluate the effects of resistance exercise applied early after coronary artery bypass grafting.

METHODS

It is a randomized controlled trial with 34 patients undergoing coronary artery bypass grafting between August 2013 and May 2014. Patients were randomized into two groups by simple draw: a control group (n=17), who received conventional physical therapy and an intervention group (n=17), who received, additionally, resistance exercise. Pulmonary function and functional capacity were evaluated in preoperative period and hospital discharge by spirometry and the six-minute walk test. For statistical analysis, we used the following tests: Shapiro-Wilk, Mann-Whitney, Student''s t and Fisher''s exact. Variables with P<0.05 were considered significant.

RESULTS

Groups were homogeneous in terms of demographic, clinical and surgical variables. Resistance exercise exerted no effect on pulmonary function of intervention group compared to control group. However, intervention group maintained functional capacity at hospital discharge measured by percentage of predict distance in 6MWT (54.122.7% vs. 52.515.5%, P=0.42), while control group had a significant decrease (59.211.1% vs. 50.69.9%, P<0.016).

CONCLUSION

Our results indicate that resistance exercise, applied early, may promote maintenance of functional capacity on coronary artery bypass grafting patients, having no impact on pulmonary function when compared to conventional physical therapy.     

Pediatric and congenital heart transplant: twenty-year experience in a tertiary Brazilian Hospital

Introduction

Cardiac transplantation remains the gold standard for end-stage cardiomyopathies and congenital heart defects in pediatric patients.

Objective

This study aims to report on 20 years of experience since the first case and evaluate our results.

Methods

We conducted a retrospective analysis of the database and outpatient follow-up. Between October 1992 and April 2012, 109 patients underwent 114 transplants. 51.8% of them being female. The age of patients ranged from 12 days to 21 years with a mean of 8.8±5.7 years and a median of 5.2 years. The underlying diagnosis was dilated cardiomyopathy in 61.5%, congenital heart disease in 26.6% and restrictive cardiomyopathy in 11.9%. All patients above 17 years old had congenital heart disease.

Results

Survival rate at 30 days, 1, 5, 10, 15, and 20 years were 90.4%, 81.3%, 70.9%, 60.5%, 44.4% and 26.7%, respectively. Mean cold ischemic time was 187.9 minutes and it did not correlate with mortality (P>0.05). Infectious complications and rejection episodes were the most common complications (P<0.0001), occurring, respectively, in 66% and 57.4% of the survivors after 10 years. There was no incidence of graft vascular disease and lymphoproliferative disease at year one, but they affected, respectively, 7.4% and 11% of patients within 10 years.

Conclusion

Twenty-year pediatric heart transplant results at our institution were quite satisfactory and complication rates were acceptable.     

Use of EuroSCORE as a predictor of morbidity after cardiac surgery

Objective

To evaluate the use of the EuroSCORE as a predictor of postoperative morbidity after cardiac surgery.

Methods

We retrospectively analyzed the charts of 900 patients operated on and admitted to the intensive care unit postoperatively at the Royal Portuguese Hospital of Recife. We included all patients with complete medical records, excluding those who died during surgery, underwent transplantation or correction of congenital heart disease. We evaluated the development of respiratory infection, cerebrovascular accident, and dialysis-dependent renal failure, and the EuroSCORE was compared in terms of the three complications using the Mann-Whitney test. The calibration model for predicting the morbidities being studied was evaluated using the test set of Homer-Lemeshow goodness. The accuracy of the model was assessed using the area under the ROC curve (AUROC).

Results

The model showed good calibration in predicting respiratory infection, acute renal failure and stroke (P=0.285, P=0.789, P=0.45, respectively), with good accuracy for respiratory infection (AUROC=0.710 and P<0.001) and dialysis-dependent renal failure (AUROC=0.834 and P<0.001), but no accuracy to predict stroke (AUROC=0.519). The high-risk patients were more likely to develop respiratory infection (OR=9.05, P<0.001) and dialysis-dependent renal failure (OR=39.6, P<0.001). The probability of developing respiratory infection and dialysis-dependent renal failure was less than 10% with EuroSCORE up to 7 and more than 70% with EuroSCORE greater than 15.

Conclusion

EuroSCORE proved to be a good predictor of major postoperative morbidity in cardiac surgery: respiratory and dialysis-dependent renal failure.     

Mitral annulus morphologic and functional analysis using real time tridimensional echocardiography in patients submitted to unsupported mitral valve repair

Introduction

Mitral valve repair is the treatment of choice to correct mitral insufficiency, although the literature related to mitral valve annulus behavior after mitral repair without use of prosthetic rings is scarce.

Objective

To analyze mitral annulus morphology and function using real time tridimensional echocardiography in individuals submitted to mitral valve repair with Double Teflon technique.

Methods

Fourteen patients with mitral valve insufficiency secondary to mixomatous degeneration that were submitted to mitral valve repair with the Double Teflon technique were included. Thirteen patients were in FC III/IV. Patients were evaluated in preoperative period, immediate postoperative period, 6 months and 1 year after mitral repair. Statistical analysis was made by repeated measures ANOVA test and was considered statistically significant P<0.05.

Results

There were no deaths, reoperation due to valve dysfunction, thromboembolism or endocarditis during the study. Posterior mitral annulus demonstrated a significant reduction in immediate postoperative period (P<0.001), remaining stable during the study, and presents a mean of reduction of 25.8% comparing with preoperative period. There was a significant reduction in anteroposterior and mediolateral diameters in the immediate postoperative period (P<0.001), although there was a significant increase in mediolateral diameter between immediate postoperative period and 1 year. There was no difference in mitral internal area variation over the cardiac cycle during the study.

Conclusion

Segmentar annuloplasty reduced the posterior component of mitral annulus, which remained stable in a 1-year-period. The variation in mitral annulus area during cardiac cycle remained stable during the study.     

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.     

Chronic stress and coping among cardiac surgeons: a single center study

Introduction

Cardiac surgeons stress may impair their quality of life and professional practice.

Objective

To assess perceived chronic stress and coping strategies among cardiac surgeons.

Methods

Twenty-two cardiac surgeons answered two self-assessment questionnaires, the Trier Inventory for Chronic Stress and the German SGV for coping strategies.

Results

Participants mean age was 40±14.1 years and 13 were male; eight were senior physicians and 14 were residents. Mean values for the Trier Inventory for Chronic Stress were within the normal range. Unexperienced physicians had significantly higher levels of dissatisfaction at work, lack of social recognition, and isolation (P<0.05). Coping strategies such as play down, distraction from situation, and substitutional satisfaction were also significantly more frequent among unexperienced surgeons. "Negative" stress-coping strategies occur more often in experienced than in younger colleagues (P=0.029). Female surgeons felt more exposed to overwork (P=0.04) and social stress (P=0.03).

Conclusion

Cardiac surgeons show a tendency to high perception of chronic stress phenomena and vulnerability for negative coping strategies.     

Evaluation of the influence of pulmonary hypertension in ultra-fast-track anesthesia technique in adult patients undergoing cardiac surgery

Objective

To evaluate the influence of pulmonary hypertension in the ultra-fast-track anesthesia technique in adult cardiac surgery.

Methods

A retrospective study. They were included 40 patients divided into two groups: GI (without pulmonary hypertension) and GII (with pulmonary hypertension). Based on data obtained by transthoracic echocardiography. We considered as the absence of pulmonary hypertension: a pulmonary artery systolic pressure (sPAP) <36 mmHg, with tricuspid regurgitation velocity <2.8 m/s and no additional echocardiographic signs of PH, and PH as presence: a sPAP >40 mmHg associated with additional echocardiographic signs of PH. It was established as influence of pulmonary hypertension: the impossibility of extubation in the operating room, the increase in the time interval for extubation and reintubation the first 24 hours postoperatively. Univariate and multivariate analyzes were performed when necessary. Considered significant a P value <0.05.

Results

The GI was composed of 21 patients and GII for 19. All patients (100%) were extubated in the operating room in a medium time interval of 17.58±8.06 min with a median of 18 min in GII and 17 min in GI. PH did not increase the time interval for extubation (P=0.397). It required reintubation of 2 patients in GII (5% of the total), without statistically significant as compared to GI (P=0.488).

Conclusion

In this study, pulmonary hypertension did not influence on ultra-fast-track anesthesia in adult cardiac surgery.     

Relationship between occupation, social class and time taken off work following a whiplash injury

INTRODUCTION

Little has been published about occupational and social factors in relation to time off work following a whiplash injury.

PATIENTS AND METHODS

We analysed 800 medicolegal case sheets from a consultant orthopaedic surgeon''s practice.

RESULTS

Of those injured, 596 were working and 204 were unemployed or retired. The working group was further analysed. Severity of injury was estimated by analysing velocity of injury combined with vehicular damage. Mean time off work for a minor injury was 10.6 days, moderate 12.1 days, severe 13.8, and very severe 24.9 (P < 0.05). Looking at work categories as previously described in the literature, 20.5 days were taken off by heavy manual workers, light manual 15.7, driving 13.9, secretarial 9.2 and sedentary 12.8 (P < 0.05). Analysing as per social class showed that professionals required 7.0 days, intermediate 14.7 days, skilled non-manual 16.1 days, skilled manual 34.2 days, semi-skilled manual 33.2 days, and unskilled manual 11.5 days (P < 0.05). Nearly a third (31.2%) required no time off work, after 4 days off, 52.1% had returned to work and 90.1% were back at work after 30 days. Time off lasting more than 12 weeks occurred in 29 cases (4.9%).

CONCLUSIONS

Job style, severity of injury and social class have a bearing on time taken off work after road traffic accidents causing whiplash injury.     

A propose of pulmonary dysfunction stratification after valve surgery by physiotherapeutic assistance level

Objective

a) to propose and implement an evaluation system; b) to classify the pulmonary involvement and determine levels of physical therapy; c) to check the progress postoperatively.

Methods

Patients underwent physiotherapy assessment preoperatively, postoperatively and after 5 days of intervention. They were classified into three levels of care: level 1 - low risk of complication; Level 2 - medium risk; Level 3 - high risk. We used analysis of variance and Kruskal-Wallis and analysis of variance for repeated measures or Friedman. Chi-square test or Fisher for proportions. We considered statistical significance level P<0.05.

Results

We studied 199 patients, 156 classified within level 1, 32 at level 2 and 11 at level 3. Thoracoabdominal motion and auscultation changed significantly postoperatively, persisting at levels 2 and 3 (P<0.05). Oxygenation and respiratory rate changed at levels 2 and 3 postoperatively (P<0.05) with recovery at the end. Significant decrease in lung volumes occurred in three levels (P<0.05) with partial recovery at level 1, lung collapse occurred at all levels, with recovery by 56% at level 1, 47% at level 2, 27% at level 3.

Conclusion

The proposed assessment identified valve surgery patients who require differentiated physical therapy. Level 1 patients had rapid recovery, while the level 2 showed significant changes with functional gains at the end. Level 3 patients, more committed and prolonged recovery, should receive greater assistance.     

Predictors of mortality in cardiac surgery: brain natriuretic peptide type B

Objective

We evaluated whether the preoperative serum concentration of brain natriuretic peptide (BNP) is a predictor of in-hospital mortality in patients that underwent cardiac surgery.

Methods

We continuously evaluated 488 patients that underwent cardiac valve surgery or coronary artery bypass grafting (CABG) between January of 2009 and July of 2012. Follow up of these patients were done prospectively for 30 days postoperatively.

Results

Data analysis showed that the overall mortality rate was equal to 9.6%, Receiver Operating Charactheristic (ROC) curve analysis found the optimal cut-off value of BNP equal to 382 pg/mL for overall mortality (AUC=0.73, 95% CI=0.66 to 0.81, P<0.001). Multivariate analysis showed that the value of BNP higher than 382 pg/mL (P=0.033, HR=2.05, 95% CI=1.6 to 3.98) was an independent predictor of overall mortality at 30 days postoperatively.

Conclusion

We concluded that the preoperative serum concentration of BNP is an independent predictor of mortality in patients undergoing valve surgery or coronary artery bypass graft.     

Impact of type of procedure and surgeon on EuroSCORE operative risk validation

Objective

EuroSCORE has been used in cardiac surgery operative risk assessment, despite important variables were not included. The objective of this study was to validate EuroSCORE on mortality prediction in a Brazilian cardiovascular surgery center, defining the influence of type of procedure and surgical team.

Methods

Between January 2006 and June 2011, 2320 consecutive adult patients were studied. According to additive EuroSCORE, patients were divided into low risk (score<2), medium risk (3 - 5), high risk (6 - 11) and very high risk (>12). The relation between observed mortality (O) and expected mortality (E) according to logistic EuroSCORE was calculated for each of the groups, types of procedures and surgeons with > 150 operations, and analyzed by logistic regression.

Results

EuroSCORE correlated to the observed mortality (O/E=0.94; P<0.0001; area under the curve 0.78). However, it overestimated the mortality in very high risk patients (O/E=0.74; P=0.001). EuroSCORE tended to overestimate isolated myocardial revascularization mortality (O/E=0.81; P=0.0001) and valve surgery mortality (O/E=0.89; P=0.007) and it tended to underestimate combined procedures mortality (O/E=1.09; P<0.0001). EuroSCORE overestimated surgeon A mortality (O/E=0.46; P<0.0001) and underestimated surgeon B mortality (O/E=1.3; P<0.0001), in every risk category.

Conclusion

In the present population, EuroSCORE overestimates mortality in very high risk patients, being influenced by type of procedure and surgical team. The most appropriate surgical team may minimize risks imposed by preoperative profiles.     

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.