Evaluation of ventricular arrhythmias late after coronary artery bypass graft surgery--relation to clinical variables

This study was undertaken to evaluate ventricular arrhythmias (VA) using ambulatory ECG monitoring in 150 patients 33 +/- 22 months (mean +/- SD) after successful CABG in relation to severity of coronary artery disease (LS: Leaman score, Circulation 1981), revascularization ratio (RI: preop. LS-postop.LS/preop.LS), preoperative myocardial infarct size (Selvester score: SQS, Circulation 1982), LV function and other variables. They were divided into two groups according to the Lown classification; 42 patients with serious VA (group A: grade 4 to 5), and 108 without them (group B: grade 0 to 3). Group A was older than group B (60 +/- 5 vs. 57 +/- 9; p less than 0.05). There were no significant differences in follow-up period, coronary risk factors, LS and RI between the groups. Group A had significantly higher SQS (7.5 +/- 3.2 vs. 2.6 +/- 1.9; p less than 0.01), LVEDP (preop.: 14 +/- 7 vs. 11 +/- 5 mmHg; p less than 0.05, postop.: 14 +/- 7 vs. 11 +/- 5 mmHg; p less than 0.05), LVESVI (preop.: 53 +/- 27 vs. 31 +/- 17 ml/M2; p less than 0.01, postop.: 53 +/- 35 vs. 30 +/- 14 ml/M2; p less than 0.01), LVEDVI (preop.: 93 +/- 28 vs. 72 +/- 22 ml/M2; p less than 0.01, postop.: 90 +/- 36 vs. 74 +/- 21 ml/M2; p less than 0.01), and lower LVEF (preop.: 44 +/- 15 vs. 58 +/- 11%; p less than 0.01, postop.: 44 +/- 15 vs. 60 +/- 10%; p less than 0.01) than group B.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simplified Parsonnet risk scale identifies limits to early patient discharge

BACKGROUND: Fast-track recovery after coronary artery bypass surgery has influenced patient care positively. Predicting patients who fall off track and require prolonged (> or =7 days) hospitalization remains uncertain. The Parsonnet risk assessment score is effective in predicting length of stay, but is limited by inaccurate subdivision of risk categories. We simplified the Parsonnet risk scale to better identify patients eligible for fast-track recovery. METHOD: The cases of 604 consecutive patients who underwent isolated coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) were reviewed retrospectively. A rapid recovery protocol emphasizing reduced CPB time, preoperative intra-aortic balloon pump (IABP) criteria, and atrial fibrillation prophylaxis was applied to all patients. The five original divisions of the Parsonnet risk scale were reduced to three risk categories: Low (0-10; Group A), Intermediate (11-20; Group B), High (> 20; Group C). Comparisons of progressive risk categories were analyzed to identify predictive factors associated with fast-track outcomes. RESULTS: The thirty-day operative mortality for the entire group was 3.6%. Three clinical features were identified that distinguished risk progression-female gender, reoperative CABG, and increased age. Additionally, the presence of diabetes (p < 0.05), congestive heart failure (p < 0.01), and peripheral vascular disease (p < 0.001) distinguished Groups A and B, while acute myocardial infarction (p < 0.05) influenced outcomes in Group C. Group A (48%) mean risk score 5.9+/-3.2 was compared to Group B (34%) 14.8+/-2.6, which was further compared to Group C (18%) 26.4+/-2.8. The mean length of stay for Group A (5.3+/-4.1 days) was notably less than Group B (6.1+/-4.7 days; p < 0.05); however, both groups responded favorably to fast-track techniques. Group C did not respond comparably (9.2+/-9.2 vs 6.1+/-4.7 days; p < 0.001) and experienced prolonged recovery. The simplified Parsonnet risk scale did not identify differences in operative mortality and revealed only pneumonia (p < 0.05) and atrial fibrillation (p < 0.01) to be greater in Group C. As risk increased, significantly less revascularization was performed (Group A 3.6+/-1.2 grafts/patient vs Group B 3.3+/-1.2 [p < 0.01]; Group B 3.3+/-1.2 vs Group C 2.5+/-1.0 [p < 0.001]). CONCLUSION: A simplified Parsonnet risk scale (three categories) is an effective tool in identifying factors limiting fast-track recovery. Low- and intermediate-risk patients represent the majority (82%) and respond well to fast-track methods. High-risk patients (18%) are limited by a greater percentage of female patients, reoperative CABG, and the very elderly, resulting in fast-track failure. Strategies to improve recovery in high-risk patients may include evolving off-pump techniques.     

Quantitative assessment of myocardial viability following coronary artery bypass grafting using exercise thallium-201 myocardial single photon emission computed tomography and left ventricular regional wall motion

Using exercise thallium-201 myocardial single photon emission computed tomography (SPECT) and % radial shortening (%RS), 58 patients were evaluated before and after coronary artery bypass grafting (CABG) to quantitatively assess myocardial viability and the effect of CABG. The patient was classified, according to redistribution pattern, as group I with only complete redistribution (20 cases) and group II with including incomplete redistribution (22 cases) and group III with no redistribution (16 cases). 1. Group I was expected complete improvement of ischemic myocardium after CABG but regional left ventricular wall motion was unchanged (sigma i%RS: 142.5 +/- 54.7----138.4 +/- 39.6, sigma a%RS: 201.2 +/- 51.1----238.2 +/- 68.2). 2. Group II was expected to diminish ischemic size after CABG and left ventricular regional wall motion was significantly improved (sigma i%RS: 68.8 +/- 25.9----154.9 +/- 42.6 p less than 0.01, sigma a%RS: 108.4 +/- 62.3----178.9 +/- 77.6, p less than 0.05). 3. Group III was no significant change of ischemic size and left ventricular wall motion after CABG (sigma i%RS: 67.8 +/- 24.1----83.9 +/- 19.2, sigma a%RS: 86.0 +/- 29.0----94.0 +/- 33.9). The present study suggests that quantitative assessment of myocardial viability using exercise thallium-201 myocardial SPECT and %radial shortening was useful method to determine the indication and to assess the effect of CABG.     

Comparison of midazolam and flunitrazepam as premedication administered rectally in infants

The present study aimed to assess the pharmaco-clinical profile of infants premedicated with rectal midazolam. The results were compared with those of a reference drug, flunitrazepam. Infants undergoing minor surgery were divided into three groups: group A (n = 30), with a mean age of 15.8 +/- 13.2 months and a mean weight of 8.6 +/- 3.3 kg, receiving 0.33 mg X kg-1 flunitrazepam; group B (n = 15), with a mean age of 11.2 +/- 10.7 months and a mean weight of 9.3 +/- 3.1 kg, receiving 0.3 mg X kg-1 midazolam; and group C (n = 30), with a mean age of 15.5 +/- 9.1 months and a mean weight of 10.7 +/- 2.5 kg, receiving 0.4 mg X kg-1 midazolam. An aqueous solution of each drug was administered with atropine sulfate (0.02 mg X kg-1) 20 min prior to induction of anaesthesia. The drug was well tolerated in 84% of cases. Statistically significant haemodynamic changes consisted of: a 9 c X min-1 decrease in heart rate (p less than 0.05) and a 12 mmHg decrease in systolic and diastolic blood pressures (p less than 0.05) in group C; a 6 mmHg decrease in systolic blood pressure (p less than 0.05) in group B. The tranquilizer action was either excellent or good in 93% of groups B and C compared with only 40% in group A (p less than 0.001 in both cases). Somnolence was attained in 60% of group A, 26.6% of group B and 30% of group C. A mask was much better accepted in group C (86.6%) than in group B (66.6%; p less than 0.05) or in group A (36.6%; p less than 0.01). Therefore, midazolam given rectally at 0.4 mg X kg-1 was better than flunitrazepam, because of a greater therapeutic effect for an equivalent rate of side effects.     

Concomitant carotid endarterectomy and coronary artery bypass grafting versus staged carotid stenting followed by coronary artery bypass grafting

AIM: Significant carotid stenosis (>or=70%) in patients undergoing coronary artery bypass grafting (CABG) can increase the risk of perioperative cerebral vascular accident (CVA). In this study, we compared the results of two common operative strategies: concomitant carotid endarterectomy and CABG versus carotid stenting and CABG. METHODS: This cohort study was conducted from January 2001 to September 2006. Significant carotid artery stenosis was detected in patients who were candidates for CABG at the Tehran Heart Center. The stenosis was detected by carotid Doppler screening and was confirmed by magnetic resonance angiography. Reluctant patients or those with previous major CVA, significant bilateral carotid stenosis and intracranial lesions were excluded. Patients were divided into 2 groups. Group A underwent concomitant carotid endarterectomy and CABG (n=19), while carotid stenting and CABG were done in group B (n=28). RESULTS: The mean age in group A was 67.37+/-7.09 years and 65.57+/-8.13 years in group B. The mean hospital stay (days) was 18.68+/-7.95 in group A and 26.35+/-77.04 in group B (P=0.01). The median charge was dollars 252.79 in group A and dollars 2206.66 in group B (P <0.0001). There was a significant difference in frequency of hypotension and bradycardia between the 2 groups (P <0.05). There were 2 cases of in-hospital mortality in each group (10.5% and 7.1%, respectively). Two postoperative strokes occurred in group A and 3 in group B (10.5% and 10.7%, respectively). CONCLUSION: Concomitant carotid endarterectomy and CABG is as safe as carotid stenting and CABG, with fewer neurologic events and less hypotension, bradycardia, cost and shorter hospital stay.     

Multiglycosidorum tripterygii, a new immunosuppressant, supresses coronary arteriosclerosis after heart transplantation.

BACKGROUND: Graft coronary arteriosclerosis is the major limiting factor for long-term survival after heart transplantation. In this study, we investigate the effect of multiglycosidorum tripterygii on graft coronary arteriosclerosis and platelet-derived growth factor A mRNA expression of transplanted hearts. METHODS: Three groups of Lewis rats (n = 7/Group) underwent heterotopic heart transplantation from Wistar-King donors and were treated with cyclosporine A (10 mg/ kg/day) for 60 days (Group A) or with multiglycosidorum tripterygii (30 mg/kg/day) for 60 days (Group B) or with cyclosporine A for the first 30 days and followed by multiglycosidorum tripterygii for another 30 days (Group C). Histological evaluations of rejection and coronary arteriosclerosis, as well as Northern blot analysis on graft platelet-derived growth factor A mRNA expression were made 60 days after transplantation. RESULTS: Morphometric results indicated no significant difference in rejection among three groups. However, the extent of graft coronary arteriosclerosis in Group B (1.12 +/- 0.21) and Group C (1.41 +/- 0.19) was significantly less than that seen in Group A (1.72 +/- 0.18) (p < 0.01 andp < 0.05, respectively). Furthermore, the incidence of diseased vessels was significantly less in Group B (29.5% +/- 7.8%) and Group C (42% +/- 9.1%) compared with Group A (69.1% +/- 11%) (p < 0.01 and p < 0.05, respectively). The expression of platelet-derived growth factor A mRNA of cardiac allograft was also significantly suppressed in Group B (25.4 +/- 6.2) and Group C (39.8 +/- 9.4), when compared with Group A (62.2 +/- 12.9) (p < 0.01 and p < 0.05, respectively). CONCLUSION: Multiglycosidorum tripterygii is superior to cyclosporine in prevention and attenuation of graft coronary arteriosclerosis and this efficacy is probably associated with the depressed expression of graft platelet-derived growth factor A mRNA in the multiglycosidorum tripterygii-treated groups.     

Echanges gazeux per- et postopératoires : hyperventilation isocapnique versus normoventilation

The effects of isocapnic hyperventilation (A) and normoventilation (B) on PaCO2, PaO2 and A-aDO2 were compared in 102 patients undergoing elective surgery, randomized into two comparable groups A and B. Cases for thoracic, high abdominal and intracranial surgery were excluded, as well as patients with clinically evident pulmonary pathology. A volumetric ventilator was used in association with three different breathing systems (A: Bain system and circle system without CO2 absorption; B: circle system with CO2 absorption). The groups were comparable, except for percentage of overweight: 75% in group A and 56% in group B. Overweight was defined as weight above the mean ideal weight of 100%, and obesity as a weight above 120% the mean ideal weight. Blood gases were sampled 1) preoperatively, 2) 15 min and 3) 60 min after the beginning of mechanical ventilation, 4) postoperatively, 90 min after extubation, without supplemental oxygen. The preoperative mean PaO2 values were 79 +/- 11.4 mmHg (A) and 82.5 +/- 13.2 mmHg (B); the PaCO2 were 37.2 +/- 3.7 mmHg (A) and 37.2 +/- 3.8 mmHg (B). During surgery, PaO2 was distinctly higher (p less than 0.01) in group A than in group B (on average 15-20 mmHg higher), indicating the favourable effect of great tidal volumes on gas exchange. Correspondingly, the A-aDO2 was less increased in group A than in group B (p less than 0.01). At 15 min, 33% of the patients were hypocapnic (PaCO2 less than 35 mmHg): one case in group A and three in group B could be classed as severe hypocapnia (PaCO2 = 25-30 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)     

The mechanisms and prevention of intravascular fluid loss after occlusion of the supraceliac aorta in dogs

Mechanisms of intravascular fluid depletion after temporary occlusion of the supraceliac aorta were investigated in a canine model. During ischemia and reperfusion, hemodynamic parameters, superior mesenteric artery flow, intestinal mucosal perfusion, and mucosal permeability were monitored. After 12 hours of reperfusion, the volumes of intravenous electrolyte fluid required to maintain hemodynamic stability and fluid lost into the gastrointestinal tract and peritoneal cavity were measured. The distribution of total body water was analyzed by use of radionuclide dilution techniques. Group A animals underwent laparotomy only, group B had the supraceliac aorta occluded for 45 minutes, group C had superoxide dismutase administered after 45 minutes of aortic occlusion, and group D animals were exposed to mild hypothermia during a similar ischemia and reperfusion period. No significant difference was found in mean superior mesenteric artery flow or mucosal perfusion during ischemia among groups B, C, and D. During reperfusion superior mesenteric artery flow returned to values similar to control in all groups. Aortic occlusion increased mucosal permeability most significantly in group B (p less than 0.01). Mean intravenous fluid requirements (ml/mg) were the following: group A, 80 +/- 5; group B, 201 +/- 9 (p less than 0.01); group C, 116 +/- 7 (p less than 0.05); group D, 245 +/- 24 (p less than 0.05). Mean gastrointestinal fluid loss was highest in the hypothermic group and smallest if superoxide dismutase was given. Mean intracellular fluid volume was increased in groups B and D compared with group A (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary artery bypass surgery in octogenarian

Between May 1992 and December 1997, 14 parents aged 80 or older underwent CABG with cardiopulmonary bypass. (Group A: mean age 82.1 +/- 1.73). This group was compared with 127 patients aged 70s. (Group B: mean 73.3 +/- 0.70). Left main trunk stenosis was more frequent in group A (p < 0.05), and number of patient who had old myocardial infarction was also frequent (p < 0.05). Emergency operation and preoperative use of intra aortic balloon pump was frequent in group A (p < 0.05). While there was no significant change in the number of graft per patient and used number of internal thoracic artery between the two groups, postoperative complications such as atrial arrhythmia and respiratory failure was appeared more frequently in group A (p < 0.05). The hospital mortality did not differ between the groups (21.4% for group A and 14.2% for group B). In group A, 11 patients are alive without recurrence of angina. In conclusion, while there is many problems pre and post operative term, CABG in over 80 years patients of age was satisfactory result, so we should not exclude octogenarian because of age alone.     

Risk of thrombosis in prolonged catheterization of the radial artery: comparison of 2 types of catheters

The thrombosis rate after long-term cannulation of the radial artery was assessed prospectively in 48 intensive care patients randomly assigned to groupe A (polyethylene Leader-Cath 115-09 catheter; n = 50, aged 55 +/- 20 years, 74% male patients) or groupe B (Teflon Viggo Floswitch 4441 catheter; n = 48, aged 58.6 +/- 16 years, 73% male patients). Bedside angiography was carried out with 10 to 15 ml Hexabrix before removal of the catheter. The two groups were similar with regard to anthropometric parameters, used drugs, pathological events during the stay in ICU, arterial cannulation technique and its duration. There was no case of clinically significant ischaemia. The rate of X-ray total arterial thrombosis was 20% in group A, and 2% in group B (p less than 0.01). There was no difference in the rate of partial thrombosis (54% vs. 41.7% respectively, NS) and of lack of thrombosis (26% vs. 56.3% respectively, NS). The overall rate of thrombosis was greater in group A than in group B, but not significantly (74% vs. 43.7% respectively). The duration of arterial cannulation did not influence the rate of thrombosis. However it was higher in males of Group A than in those of Group B (p less than 0.01), when heparin was not given (p less than 0.05); when vaso-active drugs were used (p less than 0.05); and when the time required for cannula insertion was greater than 5 min (p less than 0.01). It is concluded that Teflon catheters are more biocompatible than polyethylene catheters.     

Left ventricular performance in patients with thermal injury or multiple trauma: a clinical study with echocardiography.

Left ventricular (LV) contractile and diastolic performance was evaluated in patients with thermal injury or multiple trauma using precordial and transesophageal echocardiography. Thirty-nine patients were divided into four groups: group B1 (within 24 hours after thermal injury); group B2 (from 24 to 72 hours after thermal injury); group M (multiple trauma); and a control group (outpatients). Left ventricular contractile indices, including ejection fraction, mean velocity of circumferential fiber shortening, and the ratio of systolic blood pressure to LV end-systolic dimension, were not impaired in any of the experimental groups. The ratio of LV filling volume during rapid filling to stroke volume, obtained from M-mode echocardiography as an index of LV distensibility, was significantly decreased in groups B1 (44.5% +/- 8.8%) and B2 (46.8% +/- 8.5%) compared with controls (61.9% +/- 7.4%) (p less than 0.05). The ratio of the peak velocity in the atrial contraction phase to that in the rapid filling phase, obtained using pulsed Doppler echocardiography, also showed significant impairment of LV distensibility in groups B1 (1.08 +/- 0.12) and B2 (1.09 +/- 0.07) compared with controls (0.71 +/- 0.12) (p less than 0.01). Group M showed no significant impairment of these diastolic indices. A profound depression of LV diastolic function thus occurs following thermal injury but not following multiple trauma.     

Myocardial temperature mapping in patients with left main coronary artery disease

Two consecutive groups of high risk patients with left main coronary disease (greater than 50% stenosis) undergoing aortocoronary bypass grafting using different cardioplegia delivery methods were compared retrospectively for perioperative myocardial infarction (MI) and mortality. Group I (July 1979 to June 30, 1982, n = 53) received an initial 1000 ml aortic root cardioplegia infusion from a pressure regulated (85-100 mmHg) delivery system. Regional mid-myocardial wall temperatures determined the distal anastomoses sequence (with the warmest region bypassed first) followed by additional 400 ml cardioplegia infusions. Group II patients (March 1976 to June 30, 1979, n = 47) had their cardioplegia administered by a hand-held syringe without regional temperature mapping. The volume injected varied and was based on cessation of electrical activity or a septal temperature less than 20 degrees C. Background data were similar except that Group I was significantly older than Group II (63.4 +/- 1.4 years vs 57.1 +/- 1.5 years, p less than 0.01). Despite this, there was only 1 (2%) perioperative MI in Group I vs 6 (13%) in Group II (p less than 0.05). There was also a marked reduction in cardiac mortality with 1 (2%) cardiac death in Group I vs 5 (11%) in Group II (p = 0.09). These data suggest that the delivery of adequate volumes of cardioplegia, in conjunction with myocardial temperature directed bypass grafting, can improve myocardial preservation in high risk patients.     

Experimental and clinical study of cardiopulmonary hemodynamics under one-lung ventilation during transthoracic esophagectomy]

Cardiopulmonary hemodynamics in pre- and postoperative period after transthoracic esophagectomy under one-lung ventilation (OLV) was investigated in experimental and clinical studies. In experimental study, 30 mongrel dogs were assigned to one of the groups: Group 1 (n = 10): 2 hour right thoracotomy alone under one (n = 5)- or two-lung ventilation (TLV) (n = 5), Group 2 (n = 10): thoracotomy + esophagectomy, Group 3 (n = 10): esophagectomy + right thoracic vagotomy. For further evaluation of the effect of vagotomy on increase of extravascular lung water (EVLW) on 3rd POD, the following 2 groups were designed as Group 4-1) (n = 5): thoracotomy + right thoracic vagotomy and Group 4-3) (n = 5): esophagectomy + left thoracic vagotomy. In clinical study, 30 patients underwent transthoracic esophagectomy were randomly divided into either OLV or TLV group. Cardiopulmonary hemodynamics and postoperative complications were investigated in pre- and up to 3 POD. 1. Cardiopulmonary parameters and EVLW except PaO2 and shunt ratio were not different between OLV and TLW groups in experimental study. PaO2 of OLV group dropped from the pre-thoracotomy value of 577 +/- 75 mmHg to 98 +/- 47 mmHg. This decrease was significant in comparison with TLV (582 +/- 85 mmHg to 215 +/- 132 mmHg) (p less than 0.05). Shunt ratio increased in the OLV group from 10 +/- 11% to 37 +/- 13%. This increase was also significant in comparison with TLV (24 +/- 10% from 9 +/- 9%) (p less than 0.05). However, both PaO2 and shunt ratio returned to the pre-thoracotomy value after stopping of OLV and showed no difference compared with TLV. 2. EVLW per kg was not different between 5 groups. Values of right to left lung ratio of EVLW in Group 3 and Group 4-3), 1.77 +/- 0.26 and 1.82 +/- 0.26, were greater than that in Group 1, 1.39 +/- 0.17 (p less than 0.05). This difference seems to be caused by increase of permeability of pulmonary capillaries. 3. Cardiopulmonary parameters and postoperative complications were not different between OLV and TLV groups in clinical study. In conclusion, OLV is a desirable procedure, not only for good exposure of the operative filed, but also for its safety regarding the cardiopulmonary hemodynamics. Transthoracic esophagectomy plus vagal branch denervation, which is necessary for aggressive lymphadenectomy around the trachea, increases EVLW and subsequent pulmonary edema compared with thoracotomy alone.     

A clinical study of cerebral perfusion during pulsatile and nonpulsatile cardiopulmonary bypass

The purpose of this study was to determine the effect of pulsatile flow on cerebral perfusion under cardiopulmonary bypass (CPB). Twenty-three patients who underwent cardiac operations were divided into two comparable groups: Group A (N = 11) had standard nonpulsatile flow, while in Group B (N = 12), a pulsatile pump was used. The blood flow of left common carotid artery and radial arterial pressure were continuously monitored during cardiac operation in both groups and cerebral vascular resistance was calculated. In Group B, the perfusion pressure of left common carotid artery was monitored and compared with that of radial artery. Arterial and internal jugular venous blood were sampled and the difference of cerebral A.V O2 contents and cerebral oxygen consumption was calculated. Cerebral vascular resistance in Group B (54.0 +/- 11.2% of the value of before-CPB) significantly decreased compared to that in Group A (72.2 +/- 11%) at the end of CPB (p less than 0.05). Pulse pressure following pulsatile CPB flow was 15.1 +/- 5.8 mmHg monitored in radial artery and it reduced to 8.5 +/- 5 mmHg in left common carotid artery. Although there was no significant difference in cerebral oxygen consumption of both groups during and just after CPB, the difference of cerebral A-V O2 contents of Group B was greater than Group A just after CPB. These data suggest that pulsatile flow may minimize the cerebral microcirculatory shunt during CPB, resulting from the reduction of cerebral vascular resistance.     

Influence of combined zero-balanced and modified ultrafiltration on the systemic inflammatory response during coronary artery bypass grafting.

OBJECTIVE: To evaluate whether combined zero-balanced and modified ultrafiltration affects the systemic inflammatory response in coronary artery bypass graft (CABG) patients. DESIGN: Randomized and controlled. SETTING: University-affiliated heart center. PARTICIPANTS: Forty-three patients scheduled for elective CABG. INTERVENTIONS: In the ultrafiltration group (UF group; n = 21), zero-balanced ultrafiltration was performed during rewarming and modified ultrafiltration immediately after the end of cardiopulmonary bypass (CPB). A control group of patients (n = 22) was treated identically to the treatment group except no ultrafiltration process was performed. MEASUREMENTS AND MAIN RESULTS: Immediately after CPB (ie, after zero-balanced ultrafiltration), and again after the modified ultrafiltration, the concentrations of interleukin-6 and interleukin-8 were significantly less (p < 0.05) in the UF group compared with the control group. Both proinflammatory cytokine levels peaked at 2 and 4 hours after CPB, at which time no difference between the two groups could be observed. The levels of measured anti-inflammatory mediators (interleukin-10 and interleukin-1 receptor antagonist) did not show any difference between the two groups. Intrapulmonary shunt fraction decreased in the course of the modified ultrafiltration from 31% +/- 1.2% to 25% +/- 1.3% (p < 0.01), whereas mean arterial pressure increased (69 +/- 1.8 to 80 +/- 2.8 mmHg; p < 0.01); neither parameter changed in the control group. Time to extubation was shorter in the UF group (6.1 +/- 0.5 v 8.6 +/- 0.7 hours; p < 0.05). CONCLUSION: It was concluded that the use of ultrafiltration diminished inflammatory response in a very limited time period immediately after CPB and, probably as a consequence, slightly improved clinical parameters.     

A comparison of the myocardial metabolic and haemodynamic changes produced by propofol-sufentanil and enflurane-sufentanil anaesthesia for patients having coronary artery bypass graft surgery

The purpose of this study was to compare propofol-sufentanil with enflurane-sufentanil anaesthesia for patients undergoing elective coronary artery bypass graft (CABG) surgery with respect to changes in (1) haemodynamic variables; (2) myocardial blood flow and metabolism; (3) serum cortisol, triglyceride, lipoprotein concentrations and liver function; and (4) recovery characteristics. Forty-seven patients with preserved ventricular function (ejection fraction greater than 40%, left ventricular end diastolic pressure less than or equal to 16 mmHg) were studied. Patients in Group A (n = 24) received sufentanil 0.2 microgram.kg-1 and propofol 1-2 mg.kg-1 for induction of anaesthesia which was maintained with a variable rate propofol (50-200 micrograms.kg-1.min-1) infusion and supplemental sufentanil (maximum total 5 micrograms.kg-1). Patients in Group B (n = 23) received sufentanil 5 micrograms.kg-1 for induction of anaesthesia which was maintained with enflurane and supplemental sufentanil (maximum total 7 micrograms.kg-1). Haemodynamic and myocardial metabolic profiles were determined at the awake-sedated, post-induction, post-intubation, first skin incision, post-sternotomy, and pre-cardiopulmonary bypass intervals. Induction of anaesthesia produced a larger reduction in systolic blood pressure in Group A (156 +/- 22 to 104 +/- 20 mmHg vs 152 +/- 26 to 124 +/- 24 mmHg; P less than 0.05). No statistical differences were detected at any other time or in any other variable including myocardial lactate production (n = 13 events in each group), time to tracheal extubation and time to discharge from the ICU. We concluded that, apart from hypotension on induction of anaesthesia, propofol-sufentanil anaesthesia produced anaesthetic conditions equivalent to enflurane-sufentanil anaesthesia for CABG surgery.     

The mid-term outcome of geometric endoventricular repair for the patients with ischemic left ventricular dysfunction.

OBJECTIVE: Recent studies have suggested that increased left ventricular (LV) size is a risk factor for perioperative mortality in patients with low ejection fraction (EF) undergoing coronary artery bypass surgery (CABG). We previously presented a new method of LV reconstruction, called geometric endoventricular repair (GER) as representing a physiologically effective repair. The aim of this study is to assess whether GER confers benefits compared to patients undergoing CABG alone. METHODS: Between July 1996 and July 2001, 110 patients with a low EF of less than 35% documented by radionuclide ventriculogram (RNVG) underwent CABG in Austin Hospital, Australia, and were divided into two groups. Group I consisted of 52 patients undergoing isolated CABG. Group II comprised 58 patients undergoing CABG and GER. We compared the two groups in terms of EF, NYHA class, incidence of recurrent heart failure, and mortality. RESULTS: Preoperative EF was 27.7+/-6.1% in group I and 27.4+/-5.7% in group II, respectively (NS), with significant improvement in both groups (33.8+/-13.0% in group I, 35.1+/-13.3% in group II). NYHA class was also significantly improved postoperatively (from 3.3 to 1.8 in group I, and 3.6 to 1.7 in group II). There were 15 patients (28.8%) hospitalized for heart failure in group I, postoperatively, compared to seven patients (10.9%) in group II (p=0.026). Cardiac event-free survival rate at 28 months (mean follow-up) was also significantly higher in group II (88.9% in group II vs. 70.6% in group I, p=0.05). The actuarial survival rate at 31 months (mean follow-up) was 88.2% in group I and 95.3% in group II, respectively (NS). CONCLUSIONS: LV reconstruction along with CABG for ischemic ventricular dysfunction may provide symptomatic and cardiac event free survival benefits, compared to CABG alone.     

Should Mild‐to‐Moderate and Moderate Ischemic Mitral Regurgitation Be Corrected in Patients with Impaired Left Ventricular Function Undergoing Simultaneous Coronary Revascularization?

INTRODUCTION: Mitral valve regurgitation (MR) occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction predicts poor outcome. This study assessed the feasibility of mitral valve (MV) surgery concomitant with coronary artery bypass grafting (CABG) in patients with mild-to-moderate and moderate ischemic MR and impaired LV function. MaTERIALS AND METHOD: From January 1996 to July 2000, 49 patients (group 1) and 50 patients (group 2) with grade II and grade III ischemic MR and LV ejection fraction (EF) between 17% and 30% underwent combined MV surgery and CABG (group 1) or isolated CABG (group 2). LVEF (%), LV end-diastolic diameter (EDD) (mm), LV end-diastolic pressure (EDP) (mmHg), and LV end-systolic diameter (ESD) (mm) were 27.5 +/- 5, 67.7 +/- 7,27.7 +/- 4, and 51.4 +/- 7, respectively in group 1 versus 27.8 +/- 4, 67.5 +/- 6, 27.5 +/- 5, and 51.2 +/- 6, respectively in group 2. Groups 1 and 2 were divided into Groups 1A and 2A with mild-to-moderate MR (22 [45%] and 28 [56%] patients, respectively) and groups 1B and 2B with moderate MR (27 [55%] and 22 [46%], respectively). In group 1, MV repair was performed in 43 (88%) patients and MV replacement in 6 (12%) patients. RESULTS: Preoperative data analysis did not reveal any difference between groups. Five (10%) patients in group 1 died versus 6 (12%) in group 2 (p = ns). Within 6 months after surgery, LV function and its geometry improved significantly in group 1 versus group 2 (LVEF, p < 0.001; LVEDD, p = 0.002; LVESD, p = 0.003; and LVEDP (p < 0.001) improved significantly in group 1 instead of a mild improvement in Group 2). The regurgitation fraction decreased significantly in group 1 patients after surgery (p < 0.001). There was an inverse strong correlation between postoperative forward cardiac output and regurgitation fraction (p < 0.001). LVEF and LVESD improved significantly in group 1 versus group 2 patients (p = 0.04 and p = 0.02, respectively). The cardiac index increased significantly in group 1 and 2 (p < 0.001 and p = 0.03, respectively). LV function and geometry improved significantly postoperatively in group 1B versus group 2B (LVEDD, p = 0.027; LVESD, p = 0.014; LVEDP, p = 0.034; and LVEF, p = 0.02), instead of a mild improvement in group 1A versus group 2A (LVESD, p = 0.015; LVEF, p = 0.046; and LVEDD and LVEDP, p = 0.05). At follow-up, 4 (67%) of 6 patients undergoing MV replacement died versus 5 (11.5%) of 43 patients undergoing MV repair in group 1 (p = 0.007). The overall survival at 3 years in Group 2 was significantly lower than group 1 (p < 0.009). Conclusion: MV repair and replacement-preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcomes in terms of morbidity and survival. Surgical correction of mild-to-moderate and moderate MR in patients with impaired LV function should be taken into consideration since it yields better survival and improved LV function.     

Comparison of alternative cardioplegic techniques

Cold potassium cardioplegia provides adequate protection for coronary bypass operations, but severe coronary stenoses limit cardioplegic delivery to ischemic regions. The traditional technique delivers cardioplegic solution into the aortic root during the performance of distal anastomoses. The proposed alternative technique constructs proximal as well as distal anastomoses during a prolonged cross-clamp period, but permits more uniform cooling. The two techniques were compared in a prospective concurrent trial of 45 patients undergoing elective coronary bypass grafting. The traditional technique was employed in 26 patients (Group A) and the alternative technique in 19 patients (Group B). In both groups, 700 to 1,000 ml of a crystalloid cardioplegic solution was infused into the aortic root after application of the aortic cross-clamp. In Group A (traditional technique), 500 ml was infused into the aortic root after each distal anastomosis. In Group B (alternative technique), cardioplegic solution was administered through the vein graft after each distal anastomosis, and a proximal anastomosis was constructed after distal anastomoses to the most ischemic regions to permit continued cardioplegic delivery to these regions. The cross-clamp period was shorter in Group A than in Group B (44 +/- 15 versus 60 +/- 18 minutes, p less than 0.01), but the mean temperature in the most ischemic region was warmer (Group A, 19 degrees +/- 3 degrees C; Group B, 15 degrees +/- 3 degrees C, p less than 0.05). The postoperative CK-MB was higher in Group A (Group A, 47 +/- 36; Group B, 21 +/- 9 IU/L, p less than 0.01). Cardiac lactate production persisted longer in Group A (Group A, 4 +/- 1; Group B, 1 +/- 1 hours postoperatively, p less than 0.05). Volume loading 4 hours postoperatively produced a similar increase in left atrial pressure and cardiac index in both groups. In response to volume loading, Group A patients produced lactate, but Group B patients extracted lactate (change in cardiac lactate extraction: Group A, -1.7 +/- 2.3; Group B, +2.5 +/- 5.1 mg/dl, p less than 0.05). The construction of proximal as well as distal anastomoses during a prolonged cross-clamp period permits more uniform cooling and immediate reperfusion. This alternative technique resulted in less injury (CK-MB release) and more rapid recovery of myocardial metabolism.     

Preventive effect of post-ischemic reperfusion injury by terminal Nicorandil-Mg cardioplegia

In this study, we evaluated the preventive effect of post-ischemic reperfusion injury by Nicorandil-Mg cardioplegia (Nic: 8 mg/l, Mg: 20 mEq/l) given just prior to reperfusion as "terminal cardioplegia". Nineteen dogs were placed on cardiopulmonary bypass and the aorta was cross-clamped for 90 min under hypothermic (17-19 degrees C) cardioplegic arrest. The hearts of ten dogs were reperfused without terminal cardioplegia (Group A). In the other nine dogs, terminal cardioplegia was given for 2 min prior to reperfusion (Group B). During and after a period of ischemia, myocardial tissue calcium ion (t-Ca) and PCO2 (t-PCO2) were continuously monitored by ISFET (ion sensitive filed effective transistor) sensor. Myocardial tissue blood flow, oxygen consumption and lactate flux were calculated at 5, 10, 20, 40 min of reperfusion. And myocardial function was evaluated at 45 min of reperfusion. In the initial reperfusion period, Group B showed an improved myocardial tissue blood flow compared to group A (at 5 min of reperfusion in group A: 29.4% of control, in group B: 42.7% of control, p less than 0.025). T-Ca and T-PCO2 in Group B were rapidly and significantly decreased at 5 min of reperfusion (t-Ca in group A: 2.8 +/- 0.5 mM----1.7 +/- 0.5 mM, in group B: 3.1 +/- 0.6----1.2 +/- 0.4, p less than 0.05; t-PCO2 in group A: 117.5 +/- 23.0 mmHg----82.5 +/- 17.4 mmHg, in group B: 127.5 +/- 22.5----42.5 +/- 9.7, p less than 0.001), and group B had better metablic recovery evaluated by myocardial oxygen consumption and lactate flux.(ABSTRACT TRUNCATED AT 250 WORDS)