HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Martti V.K. Lepojärvi Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Penttilä, H. J. Articles by Peuhkurinen, K. J. Search for Related Content PubMed PubMed Citation Articles by Penttilä, H. J. Articles by Peuhkurinen, K. J.

Ann Thorac Surg 1999;67:683-688
© 1999 The Society of Thoracic Surgeons

---

Original Articles

Myocardial metabolism and hemodynamics during coronary surgery without cardiopulmonary bypass

^a Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
^b Department of Thoracic Surgery, Oulu University Hospital, Oulu, Finland
^c Department of Internal Medicine, Kuopio University Hospital, Kuopio, Finland

Accepted for publication August 12, 1998.

Address reprint requests to Dr Penttilä, Department of Anesthesiology, Oulu University Hospital, Kajaanintie 50, 90220 Oulu, Finland
e-mail: hannu.penttila{at}oulu.fi

Presented at the Annual Meeting of the European Association of Cardiothoracic Anaesthesiologists, Bergen, Norway, June 17–20, 1998.

	Abstract

Top Abstract Introduction Material and methods Results Comment References

 
Background. Although renewed interest has recently been shown in coronary artery bypass grafting without cardiopulmonary bypass, no reports are available on myocardial metabolism and hemodynamics during temporary coronary occlusion and rotation of the contracting heart.

Methods. Changes in myocardial energy metabolism and hemodynamics were monitored in 12 patients undergoing elective coronary artery bypass grafting without cardiopulmonary bypass, and the postoperative efflux of creatine kinase-MB mass and troponin T were also determined.

Results. There was a significant increase in myocardial production of ATP degradation products (p = 0.026) and lactate (p = 0.004) during the operation. Myocardial oxygen extraction decreased (p = 0.012) in correlation with use of the short-acting ß-blocker, esmolol (r = -0.71). Apart from a decrease in mean arterial blood pressure (p = 0.002), there were no significant hemodynamic changes during the operation. The overall postoperative troponin T and creatine kinase-MB mass changes remained nonsignificant during the first two postoperative days. One patient had a myocardial infarction, diagnosed by electrocardiography, on the second postoperative day, but otherwise there were no major complications.

Conclusions. Coronary artery bypass grafting without cardiopulmonary bypass seems to be well tolerated as only minor changes in myocardial energy metabolism and hemodynamics are observed during the operation.

	Introduction

Top Abstract Introduction Material and methods Results Comment References

 
Before the era of cardiopulmonary bypass (CPB) in the late 1950s and early 1960s, coronary endarterectomy and coronary artery bypass grafting (CABG) were performed with the heart beating. Since 1968, the widespread adoption of CPB and cardioplegia has greatly facilitated coronary artery operations, and further efforts to operate on the beating heart have almost been forgotten [1]. However, CPB is reported to be harmful in many ways. Interaction between the blood and foreign surfaces activates the complement system and neutrophils, with inflammatory responses [2], and CPB adversely affects both the platelet count and platelet function [3, 4]. The incidence of postoperative neurologic deficits has increased at the same time as overall mortality has declined [5]. Myocardial protection during the aortic cross-clamp period may sometimes be difficult. The subendocardium may be inadequately perfused during CPB [6], and septal function abnormalities have been observed after the use of cardioplegia that are not seen after CABG without CPB [6–8].

Although the adverse effects of CPB are mostly minor and reversible, patients with significant preoperative functional impairments of various organ systems may not tolerate the deleterious effects of CPB. Therefore renewed interest in CABG without extracorporeal circulation has arisen lately, and several series of CABG operations without CPB have been reported [7–13]. Some advantages, such as lower morbidity and mortality, shorter hospital stays with lower costs [7, 9, 10], decreased need for blood transfusions [9], and fewer perioperative myocardial infarctions and low output states [10], have been reported. Decreased graft patency with early recurrence of angina is the main disadvantage reported [11, 12], but the results in this respect are controversial [7, 13].

The coronary artery to be grafted is usually occluded during suturing of the distal anastomosis when CABG is performed with the beating heart. Evidence from studies of major coronary artery occlusion in the dog show that the safe coronary artery occlusion time is about 15 to 20 minutes [14]. We set out to evaluate changes in myocardial energy metabolism and hemodynamics during temporary occlusion of the coronary arteries and occasional rotation of the contracting heart.

	Material and methods

Top Abstract Introduction Material and methods Results Comment References

 
Patients
Twelve nonemergency coronary artery disease patients considered suitable for CABG without CPB were included in the series after written informed consent had been obtained. The exclusion criteria were ongoing ischemia, acute myocardial infarction less than 1 month previously, ejection fraction less than 0.40, diabetes, serum creatinine level higher than 150 µmol/L, symptomatic internal carotid artery stenosis, chronic atrial fibrillation, and aortic valvular disease. The study was approved by the Ethical Committee of Oulu University Hospital.

Anesthesia and hemodynamic care
All the patients were anesthetized by two experienced cardiac anesthesiologists (H.J.P. and P.K.K.). All medications except salicylates were allowed without interruption until the day of the operation. Salicylates were withdrawn 2 weeks before the operation except in one case of unstable angina. Premedication consisted of oral diazepam (10 to 15 mg) and intramuscular morphine (8 to 12 mg). The left radial artery was cannulated and a Swan-Ganz pulmonary artery catheter was introduced. Anesthesia was induced with fentanyl (3.8 to 7.7 µg/kg) and propofol (0.9 to 2.4 mg/kg). Muscle relaxation was achieved with pancuronium (0.09 to 0.13 mg/kg). The patients were ventilated with 40% oxygen in air, and anesthesia was maintained with propofol (2.0 to 5.3 mg/kg per hour), alfentanil (1.7 to 5.9 µg/kg per hour), and sevoflurane (0.3 to 1.3 MAC).

The patients were heparinized with an initial heparin dose of 1 mg/kg, and additional heparin was given when needed. The activated coagulation time was maintained for 250 seconds, and heparinization was reversed with protamine sulfate (30 to 100 mg). To reduce heart rate and the amplitude of ventricular wall movement, most of the patients were given boluses or a continuous infusion of esmolol. Mean arterial blood pressure was maintained greater than 50 mm Hg with phenylephrine hydrochloride.

Myocardial ischemia was evaluated by continuous automatic monitoring of the ST segment in the modified leads V₅ and II and by observing the appearance of a v wave in the pulmonary artery wedge pressure curve. Ischemia, if present, was treated with intravenous nitroglycerin.

Surgical technique
All operations were performed by the same experienced cardiac surgeon (M.V.K.L). A conventional midline sternum-splitting incision was used, and a coronary sinus catheter (Pediatric RCSP Cannula, Grand Rapids, MI) was introduced through the right atrial wall. Pericardial traction sutures were used to ease visibility and access, and elevating gauze pads were used to rotate the heart if necessary to obtain an unobstructed view of either the left side (left anterior descending, diagonal, and obtuse marginal coronary artery branches) or the right side (right coronary artery and its peripheral branches). Hemostatic silastic loops (Retract-O-Tape, Quest Medical Inc, Allen, TX) were used to obstruct the coronary artery proximal and distal to the anastomosis. Proximal anastomoses of vein grafts were finished with the aid of a partially occluding aortic side clamp.

Hemodynamic parameters
The deepest shift in the ST segments of both leads (V₅ and II) was recorded, heart rate, mean arterial pressure, and cardiac output by the thermodilution technique were measured, and the cardiac index was calculated in the operation theater before coronary artery bypass grafting, at the end of preparing the first and second distal anastomoses, and 5 and 15 minutes after completing the proximal anastomoses.

Laboratory data
Blood samples were withdrawn simultaneously from the arterial and pulmonary arterial lines and the coronary sinus catheter before the anastomoses, when releasing the occlusion of the native coronary artery immediately after the completion of the first and second distal anastomoses, and 5 and 15 minutes after the last proximal anastomosis had been completed and the side clamp removed.

Oxygen and carbon dioxide tensions, pH, and oxygen saturation of hemoglobin were determined with a 288 blood gas system (Ciba-Corning, Medfield, MA), and oxygen content was calculated as 1.39 hemoglobin concentration x oxygen saturation + 0.003 oxygen tension. Myocardial and systemic oxygen extractions were calculated from the values for oxygen content. Lactate was assayed using an electrode-based lactate analyzer (YSI model 1500; Yellow Springs Instrument Co, Inc, Yellow Springs, OH), and transcardiac and systemic differences were calculated. To measure plasma levels of adenosine triphosphate (ATP) degradation products (adenosine, inosine, hypoxanthine, and xanthine), blood samples of 5 mL were withdrawn simultaneously from the arterial line and coronary sinus catheter in a syringe containing 1 mL of dipyridamole solution (1.1 mg/mL), centrifuged directly, and the acidified plasma (3 mL of plasma in 0.5 mL of 60% perchloric acid) was neutralized with 2 mol/L KOH, 0.5 mol/L triethanolamine hydrochloride. The extracts were stored at -20°C for later analysis by high-pressure liquid chromatography as described by Nissinen and coworkers [15] and Raatikainen and associates [16]. Transcardiac concentration differences of ATP degradation products were calculated.

Postoperative follow-up
Electrocardiogram (ECG) and the mass of isoenzyme MB in creatine kinase (CK-MBM) were measured 2, 4, 6, and 12 hours after removal of the side clamp and on the next two mornings. Creatine kinase-MBM was analyzed using the microparticle enzyme immunoassay technology (AxSYM, Abbott Laboratories, Abbott Park, IL). Troponin T (TnT) was obtained and ECG recorded 2 and 6 hours after side clamp removal and on the next two mornings. Troponin T was analyzed by a manual version of an enzyme-linked immunosorbent assay specific for cardiac TnT (Boehringer Mannheim, Mannheim, Germany). The ECGs were evaluated by the same experienced cardiologist (K.J.P), who was blinded to the perioperative course of the patients. Perioperative myocardial infarction was defined as the appearance of a significant new Q wave, left bundle-branch block, or poor R wave progression and a significant elevation of TnT levels. Morbidity and mortality were recorded during the first postoperative week.

Statistics
The statistical analyses were performed using the Statistica package program, version 5.1 (StatSoft, Tulsa, OH). Analysis of variance was used to test time-dependent changes. When the F values indicated significance, Scheffe’s post-hoc test was used. Pearson’s correlation was used to measure the relation between two or more variables. The data are presented as means and 95% confidence intervals (CI). Significance was assumed when the p value was less than 0.05.

	Results

Top Abstract Introduction Material and methods Results Comment References

 
Patients
Of the 12 patients admitted to the series, 11 were stable and one was considered unstable. Ten of the patients were men and 2 women, and the average age was 58.4 years (CI, 52.3 to 64.5 years) and body mass index 26.1 kg/m² (CI, 23.9 to 28.2 kg/m²). All of them were receiving ß-blocking agents and long-acting nitrates or intravenous nitroglycerin infusion preoperatively. Four patients received calcium-blocking agents and one an angiotensin-converting enzyme inhibitor. Demographic data on the patients are presented in Table 1.

View larger version (30K): [in this window] [in a new window]   Fig 1. Myocardial lactate production (A) and oxygen extraction (B) (median, 25% and 75% percentiles, and range) before grafting (I), after completion of the first (II) and second (III) distal anastomoses, and 5 (IV) and 15 (V) minutes after the last proximal anastomosis was completed. *p = 0.02 compared with initial value (Scheffé’s test). p = 0.004 and p = 0.01 for overall changes in lactate production and oxygen extraction, respectively, by analysis of variance.

ECG changes during operation
During coronary occlusion and suturing of the distal anastomoses 4 patients had an ST-segment elevation of more than 0.5 mV in lead II and 2 of those also in lead V₅. Only 1 patient had ST-segment depression. Three patients showed a transient ST-segment elevation of several minutes in lead V₅ immediately after restoring the perfusion of the left anterior descending coronary artery by left internal mammary artery bypass grafting. Two patients were considered to be ischemic when preparing the distal anastomoses and received medication with intravenous nitroglycerin.

Hemodynamic changes
Seven patients of the 12 received esmolol to control ventricular ejection during preparation of the distal anastomoses. There was no significant change in heart rate, but mean arterial pressure decreased (p = 0.002) from 74 mm Hg (CI, 66 to 82 mm Hg) to 58 mm Hg (CI, 52 to 63 mm Hg) during preparation of the distal anastomoses. The decrease was not correlated with the dose of esmolol. The cardiac index was 2.6 L · min^-1 · m^-2 (CI, 2.2 to 2.9 L · min^-1 · m^-2) initially, 1.9 L · min^-1 · m^-2 (CI, 1.5 to 2.3 L · min^-1 · m^-2) during preparation of the distal anastomoses, and 2.5 L · min^-1 · m^-2 (CI, 2.1 to 2.9 L · min^-1 · m^-2) after side clamp removal. The changes were not statistically significant and did not correlate with the esmolol dose. Two patients developed atrial fibrillation after the sternotomy, probably as a consequence of manipulation of the atria. In the first case it was converted to sinus rhythm by defibrillation at 10 J with surface electrodes before preparing the anastomoses, but in the second case it could not be converted to sinus rhythm in spite of three defibrillations with 10 to 20 J. Sinus rhythm was eventually restored with one defibrillation of 20 J after completing the anastomoses.

There were no significant changes in systemic oxygen extraction or arteriovenous pH differences. Mixed venous oxygen saturation of hemoglobin remained higher than 60% and no systemic lactate production was recorded during or after the operation.

Postoperative course
The highest mean TnT value, of 0.31 µg/L (range, 0.03 to 2.5 µg/L), was observed on the first postoperative morning (Fig 2). The mean value of CK-MBM was also highest on the first postoperative morning, 13.4 µg/L (CI, 1.3 to 25.4 µg/L) (Fig 2). The highest single values recorded of TnT and CK-MBM were 2.5 and 57 µg/L, respectively. The patient with atrial fibrillation who received four DC shocks before and after finishing the anastomoses had the highest TnT and CK-MBM values. The hemodynamics in this particular patient remained satisfactory, however, without any need for inotropic medication, and there were no ischemic changes or signs of myocardial infarction in the ECG. When excluding this patient the highest mean values of TnT and CK-MBM were 0.12 and 9.0 µg/L, respectively.

View larger version (27K): [in this window] [in a new window]   Fig 2. Plasma levels of CK-MB mass (CK-MBM; A) at 2 (I), 4 (II), 6 (III), and 12 (IV) hours postoperatively and on the next two mornings (V, VI), and Troponin T (TnT; B) at 2 (I) and 6 (II) hours postoperatively and on the first (III) and second (IV) postoperative mornings.

During the follow-up, which lasted until the first postoperative morning, hemodynamics remained satisfactory, with 5 patients receiving dopamine for 4.7 to 17.5 hours, the highest infusion rate being 8.3 µg/kg per minute. Dopamine was used mainly for treatment of hypotension, which was modest in every case. No other inotropic agents were needed. Two patients were given intravenous ß-blockers to control hyperdynamic circulation and 1, sodium nitroprusside to control high blood pressure. One patient received intravenous nitroglycerin because of ST-segment elevation and 2, amiodarone hydrochloride to convert atrial fibrillation, 1 receiving medication for several days and also needing repeated DC shocks. Tracheal extubation took place 6.0 hours (CI, 4.0 to 8.0 hours) after the operation. One patient was reoperated on after 4 hours because of bleeding. Apart from one postoperative myocardial infarction, there were no major complications during the 1-week follow-up period.

	Comment

Top Abstract Introduction Material and methods Results Comment References

 
The transcardiac differences with concentrations of adenosine and its metabolites show a negative correlation with cellular ATP levels, and can be used to monitor changes in the myocardial energy state during coronary angioplasty and CABG with cardioplegia [15–17]. Adenosine is rapidly metabolized or taken up by red blood cells, and its half-life in human plasma has been estimated to be on the order of 0.6 to 1.5 seconds [18]. Therefore, measures were taken to prevent adenosine metabolism in vitro similar to the earlier studies [15, 16]. There was net production of ATP degradation products during the operation, suggesting worsening of the average myocardial energy state. Peuhkurinen and colleagues [17] studied changes in myocardial energy metabolism during coronary angioplasty in patients with one-vessel disease and found that net efflux of ATP degradation products with considerably shorter occlusion times was about one fourth of that observed in this series. Nissinen and coworkers [15] studied patients undergoing CABG receiving intermittent cold antegrade blood cardioplegia and found a net efflux of myocardial ATP degradation products that was more than twice that recorded here. Raatikainen and associates [16] studied patients undergoing CABG receiving near-continuous normothermic or mild hypothermic retrograde blood cardioplegia. In the mild hypothermic group the net efflux of ATP degradation products was approximately the same as that found by Nissinen and colleagues [15], but in the warm group it was considerably higher. Although these patient groups are not strictly comparable the average myocardial energy state during CABG performed on a beating heart seems to be at least as well maintained as during CABG with CPB and blood cardioplegia, regardless of the route or the temperature of the cardioplegia delivered.

In the angioplasty study of Peuhkurinen and associates [17], lactate extraction was converted to net production of 0.10 mmol/L during the short coronary occlusions, this being of the same magnitude as in the present series (0.17 mmol/L). Moreover, the changes in transcardiac pH differences in these two series were similar (0.05 versus 0.07). Raatikainen and colleagues [16] observed a similar myocardial lactate production in their mild hypothermic group, but it was significantly higher in the normothermic group.

Continuous ST-segment monitoring of the modified leads V₅ and II revealed a wide variance in ST-segment behavior. Three patients showed transient ST-segment elevation lasting for several minutes in lead V₅ after restoring blood flow to the left anterior descending coronary artery with the left internal mammary artery. The exact reason for this is hard to tell, but could perhaps be regarded as some kind of reperfusion phenomenon.

The transient decreases in the mean arterial pressure to 50 mm Hg and in the cardiac index to less than 2.0 L · min^-1 · m^-2 were well tolerated, although systemic extraction of oxygen tended to increase slightly. Mixed venous oxygen saturation of hemoglobin remained above the 60% level, however, which was regarded as a threshold for satisfactory circulation. The almost constant levels of systemic pH and lactate also indicate sufficient circulation.

Because of its short half-life, esmolol was often used to control the hemodynamics during preparation of the distal anastomoses. Esmolol was effective in reducing the amplitude of ventricular wall movements and making suturing easier, but it did not otherwise affect heart rate or hemodynamics. Esmolol reduced myocardial oxygen extraction, probably because of decreased myocardial oxygen consumption. The results are in accordance with the well-known myocardial protective effects of ß-blocking agents.

There were no significant increases in TnT and CK-MBM levels during the follow-up period of 2 days, demonstrating an absence of significant myocardial damage. For the most part the TnT levels remained less than 0.2 µg/L, which in our hospital is the lowest value for acute myocardial infarction in patients not undergoing an operation. None of the TnT measurements exceeded 3.5 µg/L, which has been considered the threshold value for perioperative myocardial infarction on patients operated on with CPB and crystalloid cardioplegia [19]. One patient had large inferior and anterior Q waves on the second postoperative morning, however, indicating postoperative myocardial infarction, but unfortunately the TnT and CK-MBM levels were no longer being monitored in this particular patient. In this case the left anterior descending coronary artery was bypassed with a thin left internal mammary artery, and the left anterior descending coronary artery beyond the stenosis was of a satisfactory caliber (1.5 to 2.0 mm) according to the operation report. There was some suspicion of proximal left anterior descending coronary artery thrombosis formation as a consequence of difficulties in connection with probing the artery. Hemodynamically, the patient recovered uneventfully and was transferred from the ward according to the normal routine of the hospital.

We conclude that the changes in myocardial energy metabolism during bypass grafting are mild and transient in nature and comparable to those observed during coronary angioplasty with shorter vessel occlusion times. Coronary artery occlusions were hemodynamically well tolerated, and CABG without CPB seems to be a safe operation for properly selected patients. Our study was, however, small, and larger randomized, comparative trials are needed.

	References

Top Abstract Introduction Material and methods Results Comment References

 

1. Westaby S., Benetti F.J. Less invasive coronary surgery: consensus from the Oxford meeting. Ann Thorac Surg 1996;62:924-931.[Free Full Text]
2. Butler J., Rocker G.M., Westaby S. Inflammatory response to cardiopulmonary bypass. Ann Thorac Surg 1993;55:552-559.[Abstract]
3. Woodman R.C., Harker L.A. Bleeding complications associated with cardiopulmonary bypass. Blood 1990;76:1680-1697.[Abstract/Free Full Text]
4. Zilla P., Fasol R., Gronscurth P., Klepetko W., Reichenspurner H., Wolner E. Blood platelets in cardiopulmonary bypass operations: recovery occurs after initial stimulation, rather than continual activation. J Thorac Cardiovasc Surg 1989;97:379-388.[Abstract]
5. Gill R., Murkin M. Neuropsychologic dysfunction after cardiac surgery: what is the problem?. J Cardiothorac Vasc Anesth 1996;10:91-98.[Medline]
6. Steed D, Follette D, Foglia R, Buckberg G. Unavoidable subendocardial underperfusion during bypass, especially in infants [Abstract]. Circulation 1977;56(Suppl 3):III 248.
7. Benetti F.J., Naselli G., Wood M., Geffner L. Direct myocardial revascularization without extracorporeal circulation: experience in 700 patients. Chest 1991;100:312-316.[Abstract/Free Full Text]
8. Akins C.W., Bouchar C.A., Pohost G.M. Preservation of interventricular septal function in patients having coronary artery bypass grafts without cardiopulmonary bypass. Am Heart J 1984;107:304-309.[Medline]
9. Buffolo E., Andrade J.C.S., Branco J.N.R., Aguiar L.F., Ribeiro E.E., Jatene A.D. Myocardial revascularization without extracorporeal circulation. Eur J Cardiothorac Surg 1990;4:504-508.[Abstract]
10. Pfister A.J., Zaki M.S., Garcia J.M., et al. Coronary artery bypass without cardiopulmonary bypass. Ann Thorac Surg 1992;54:1085-1092.[Abstract]
11. Archer R., Ott D.A., Parravicini R., et al. Coronary artery revascularization without cardiopulmonary bypass. Tex Heart Inst J 1984;11:52-57.
12. Moshkovitz Y., Lusky A., Mohr R. Coronary artery bypass without cardiopulmonary bypass: analysis of short-term and mid-term outcome in 220 patients. J Thorac Cardiovasc Surg 1995;110:979-987.[Abstract/Free Full Text]
13. Buffolo E., Andrade J.C.S., Succi J., Leão L.E.V., Gallucci C. Direct myocardial revascularization without cardiopulmonary bypass. Thorac Cardiovasc Surgeon 1985;33:26-29.[Medline]
14. Murry C.E., Jennings R.B., Reimer K.A. Preconditioning with ischemia: a delay of lethal cell injury in ischemic myocardium. Circulation 1986;74:112-136.
15. Nissinen J., Raatikainen M.J.P., Karlqvist K., Peuhkurinen K.J. Efflux of adenosine and its catabolites during cold blood cardioplegia. Ann Thorac Surg 1993;55:1546-1552.[Abstract]
16. Raatikainen P., Kaukoranta P., Lepojärvi M., Nissinen J., Peuhkurinen K. Myocardial energy metabolism and functional recovery in coronary bypass surgery: a comparative study between continuous retrograde warm and mild hypothermic blood cardioplegia. Int J Angiol 1997;6:91-98.
17. Peuhkurinen K., Ikäheimo M., Airaksinen J., Huikuri H., Linnaluoto M., Takkunen J. Changes in myocardial energy metabolism in elective coronary angioplasty. Cardiovasc Res 1991;25:158-163.[Abstract/Free Full Text]
18. Möser G.H., Schrader J., Deussen A. Turnover of adenosine in plasma of human and dog blood. Am J Physiol 1989;256:C799-C806.[Abstract/Free Full Text]
19. Mair P., Mair J., Seibt I., et al. Cardiac troponin T: a new marker of myocardial tissue damage in bypass surgery. J Cardiothorac Vasc Anesth 1993;7:674-678.[Medline]

This article has been cited by other articles:

				A. H Olivencia-Yurvati, N. Wallace, S. Ford, and R. T Mallet Leukocyte filtration and aprotinin: synergistic anti-inflammatory protection Perfusion, January 1, 2004; 19(1_suppl): S13 - S19. [Abstract] [PDF]

				H. J. Penttila, M. V.K. Lepojarvi, P. K. Kaukoranta, K. T. Kiviluoma, K. V. Ylitalo, and K. J. Peuhkurinen Ischemic preconditioning does not improve myocardial preservation during off-pump multivessel coronary operation Ann. Thorac. Surg., April 1, 2003; 75(4): 1246 - 1252. [Abstract] [Full Text] [PDF]

				K.-B. Kim, C. H. Kang, W.-I. Chang, C. Lim, J. H. Kim, B. M. Ham, and Y. L. Kim Off-pump coronary artery bypass with complete avoidance of aortic manipulation Ann. Thorac. Surg., October 1, 2002; 74(4): S1377 - 1382. [Abstract] [Full Text] [PDF]

				P. Gersbach, C. Imsand, L. K. von Segesser, A. Delabays, P. Vogt, and F. Stumpe Beating heart coronary artery surgery: is sternotomy a suitable alternative to minimal invasive technique? Eur. J. Cardiothorac. Surg., October 1, 2001; 20(4): 760 - 764. [Abstract] [Full Text] [PDF]

				K.-B. Kim, C. Lim, C. Lee, I.-H. Chae, B.-H. Oh, M.-M. Lee, and Y.-B. Park Off-pump coronary artery bypass may decrease the patency of saphenous vein grafts Ann. Thorac. Surg., September 1, 2001; 72(3): S1033 - 1037. [Abstract] [Full Text] [PDF]

				K.-B. Kim, C. Lim, H. Ahn, and J.-K. Yang Intraaortic balloon pump therapy facilitates posterior vessel off-pump coronary artery bypass grafting in high-risk patients Ann. Thorac. Surg., June 1, 2001; 71(6): 1964 - 1968. [Abstract] [Full Text] [PDF]

				E. Kilger, B. Pichler, F. Weis, A. Goetz, P. Lamm, A. Schutz, D. Muehlbayer, and L. Frey Markers of myocardial ischemia after minimally invasive and conventional coronary operation Ann. Thorac. Surg., December 1, 2000; 70(6): 2023 - 2028. [Abstract] [Full Text] [PDF]

				V. Piriou, A. Aouifi, and J.J. Lehot Interet des beta-bloquants en medecine perioperatoire. Deuxieme partie: indications therapeutiques Can J Anesth, July 1, 2000; 47(7): 664 - 672. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Martti V.K. Lepojärvi Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Penttilä, H. J. Articles by Peuhkurinen, K. J. Search for Related Content PubMed PubMed Citation Articles by Penttilä, H. J. Articles by Peuhkurinen, K. J.