Adiponectin--its potential to predict and prevent coronary artery disease.

BACKGROUND: Recent evidence suggests that epicardial adipose tissue may contribute locally to the pathogenesis of coronary artery disease (CAD). We investigated how local and systemic adiponectin, an adipokine with anti-inflammatory and insulin sensitizing properties, is related to the presence of CAD and cardiovascular risk factors. METHODS: Serum and adipose tissue samples from subcutaneous and pericoronary depots were collected from sixty consecutive patients with CAD who required coronary artery bypass grafting or patients without CAD who underwent cardiac surgery for aortic valve replacement. Western blot, ELISA and PCR were used to detect and determine the adiponectin concentrations and expression in the samples. RESULTS: Adiponectin concentrations in the serum and pericoronary fat of patients without CAD were significantly higher than in patients with CAD ( P < 0.01). However, the expression of adiponectin mRNA did not differ in any instances. Male gender, BMI > 30 and type 2 diabetes were significantly correlated to decreased serum adiponectin ( P < 0.03). CONCLUSION: Pericoronary fat specifically secretes metabolically active adiponectin. Its local and systemic concentrations are inversely correlated to the presence of coronary artery disease, indicating its anti-atherogenic effects. As for patients with CAD, adiponectin might be a promising marker for intra-individual monitoring of cardiovascular risk factors and thus a course of secondary prevention. Further evaluation is necessary to elucidate whether a novel therapeutic option could be derived against the onset and progression of CAD.

Unchanged heat-shock protein 70 expression in myocardium of patients with permanent atrial fibrillation.

AIM: Cardiomyocytes respond to permanent atrial fibrillation (AF) with an increase in mitochondrial heat shock proteins (Hsp). The aim of our study was to test if there is a cytoplasmic response to stress by investigating the expression of Hsp70. METHODS: Right atrial samples from 18 patients undergoing elective cardiac surgery were excised and immediately frozen in liquid nitrogen. Eight patients had permanent AF (> 3 months) and 10 patients were in sinus rhythm (SR). Hsp70 was determined by SDS-PAGE, Western blot and quantified with optical densitometry. RESULTS: We found no increase in Hsp70 expression in myocardial samples from patients with permanent AF. CONCLUSION: The unchanged expression of Hsp70 may indicate that the cytoplasmic stress response in permanent AF is exhausted.

[Thoracic alterations after surgical closure of the ductus arteriosus botallo in preterm infants]. / Thoraxveränderungen nach operativem Ductus-arteriosus-Botallo-Verschluss bei Frühgeborenen.

BACKGROUND: Left-sided thoracotomy for ligation of patent ductus arteriosus (PDA) dissects the musculus latissimus dorsi and notches a small part of the musculus trapezius. After ductal closure the 4 (th) and 5 (th) rib are adapted. This follow-up study investigated if mid- or long-term consequences on the thorax occur after this procedure. PATIENTS AND METHODS: Status of the thoracic scar, functionality of the shoulder and presence of scapulata alata or scoliosis was evaluated at median age of 6 years (range: 2.9-11.9) in 57 pre-term infants (30 male; gestational age 26 weeks (24-32); birth weight 805 g (450-2140)). RESULTS: Scoliosis was diagnosed in 1 patient (=1.8%) with Rubinstein-Taybi syndrome. The length of the thoracic scar (13.8 cm; 9.4-25.5) correlated with the patient's age (r=0.61; p=0.001). The scar was relocatable except for one case. The distance of the ventral end of the scar to the nipple was 2 cm or less in 22% of the female patients. None of the patients showed impaired function of the shoulder. Scapula alata was found in 16 (28%) patients. CONCLUSION: Thoracotomy for PDA ligation was not associated with an increased risk for scoliosis or disturbed function of the shoulder. One quarter of all infants developed scapula alata which meant an aesthetic issue for some parents.

Chronic atrial fibrillation: decreased actin expression in patients with chronic atrial fibrillation.

AIM: Chronic atrial fibrillation (AF) is characterized by a severe contractile dysfunction and myolysis, which develops progressively. Myolysis and the remodelling of the cellular ultrastructure is associated with the replacement of sarcomeres by glycogen. The aim of our study was to determine if myolysis is characterized by a reduction in actin concentration. METHODS: Right atrial samples from 18 patients undergoing elective cardiac surgery were excised and immediately frozen in liquid nitrogen. Eight patients had chronic AF (>3 months) and 10 patients were in sinus rhythm (SR). Actin concentration was determined by sodium dodecyl sulfate-polycrylamide gel electrophoresis (SDS-PAGE), Western blot and quantified by optical densitometry. RESULTS: Immunoblot analysis demonstrated actin expression in all hearts. In myocardial samples from patients with chronic AF we found a 2.1 fold reduction in actin expression. (P<0.001) CONCLUSION: The decrease in actin concentration via myolysis, might decrease energy consumption and be an additional mechanism for contractile dysfunction in chronic AF.

Increased endothelin release by cultured human smooth muscle cells from atherosclerotic coronary arteries.

OBJECTIVES: Endothelin, a 21-amino acid peptide initially purified from the medium of cultured endothelial cells, is a potent vasoconstrictor exerting its effects predominantly in a paracrine or autocrine manner. Recent data indicate that endothelin is also synthesized by cultured vascular smooth muscle cells and that endothelin is an effective stimulator of smooth muscle cell proliferation. This study aimed to investigate the endothelin release of cultured human smooth muscle cells, isolated from coronary plaques and from normal coronary tunica media, and to determine circulating endothelin concentrations in patients with coronary artery disease compared to control subjects. METHODS: Coronary plaque material was extracted by thrombendarterectomy during aorto-coronary bypass grafting (n = 19). Segments of normal coronary arteries were obtained at autopsy (n = 33). Cells were isolated by enzymatic disaggregation and identified as smooth muscle cells with antibodies against smooth muscle alpha-actin. Venous blood samples were drawn from patients with coronary artery disease undergoing cardiac catheterization (n = 32) and from control subjects (n = 38). Endothelin concentrations in culture medium and in plasma samples were measured by radioimmunoassay after Sep Pak C18 extraction. RESULTS: Cultured smooth muscle cells, isolated from coronary plaques, released a significantly (P < 0.001) higher amount of immunoreactive endothelin into the culture medium (39.2 +/- 3.9 pg/10(4) cells, mean +/- s.e.m., 31 supernatant samples) than smooth muscle cells from normal coronary tunica media (3.9 +/- 0.8 pg/10(4) cells, 28 samples). Circulating endothelin concentrations were slightly elevated (P < 0.01) in patients with coronary artery disease (3.8 +/- 0.2 pg/ml) compared to control subjects (3.0 +/- 0.2 pg/ml). CONCLUSIONS: These data suggest that the endothelin production is markedly increased in smooth muscle cells of coronary atherosclerotic plaques. The enhanced endothelin release may stimulate smooth muscle cell proliferation in a paracrine or autocrine manner and thus may contribute to the development or progression of coronary artery disease.

Cardiomyoplasty to improve myocardial collateral blood supply as an alternative to transplantation in intractable angina.

In diffuse small-vessel coronary heart disease, heart transplantation may be indicated for intractable angina. As an alternative, a free striated muscle flap can constitute a source of neovessels. Those extraintracardial collaterals develop only 4 weeks after transplantation of the flap as shown by the following experiments with seven dogs. In those animals a myocardial infarction of the anterior wall was selectively produced by the Judkins technique for the injection of Sephadex microspheres. Four weeks later a free pectoralis muscle flap was transplanted onto the anterior wall of the heart. Arterial blood supply was achieved by anastomosis with the internal mammary artery. The venous flow was directed into the right atrium. Six weeks after surgery the patency of the anastomosis was studied by angiography, which showed patency in all animals. Pathologic examination of the hearts revealed a prominent capillary network penetrating into the underlying myocardium. Corrosion cast preparations showed even further penetration of the capillary network into the noninjured parts of the myocardium. Thus myocardial revascularization could be achieved by transplantation of a skeletal muscle on the heart.

Endocarditis after nipple piercing in a patient with a bicuspid aortic valve.

Piercing the skin for cosmetic reasons can be dangerous in young adults who have previously undergone surgery for congenital defects of the heart. We report the case of a 24-year-old man in whom coarctation of the aorta had been corrected 15 years earlier. Two months after piercing his left nipple without antibiotic prophylaxis, he developed a local mastitis, followed by bacterial endocarditits that required replacement of the aortic valve.

Leaflet escape in a TEKNA and an original duromedics bileaflet valve.

We report a case of leaflet escape in an Edwards-TEKNA bileaflet valve, in the mitral position. The examination findings of the explanted valve are compared with a similar case of leaflet escape in an original Edward-Duromedics prosthesis. Based on our findings alone, it is not certain whether the TEKNA valve continues to have a higher risk for fracture.

Modulation of Ca2+-activated K+ channels in human vascular cells by insulin and basic fibroblast growth factor.

Insulin and basic fibroblast growth factor (bFGF) play an important role in the pathogenesis of atherosclerosis and have been shown to have vasodilatory effects. Since modulation of vascular ion channels determines membrane potential and thereby influences essential Ca2+-dependent intracellular pathways, we have investigated the effect of insulin and bFGF on Ca2+-activated K+ channels (BKCa) in human umbilical vein endothelial cells (HUVEC) and smooth muscle cells. The latter were obtained from either atherosclerotic plaques (SMCP) or from media segments (SMCM) of human coronary arteries. Using the patch-clamp technique, insulin (100 microU/ml) caused a significant increase in BKCa open-state probability in SMCP and HUVEC, whereas no significant changes were observed in SMCM. Basic FGF (30 ng/ml) revealed a significant increase in BKCa activity in HUVEC and a significant decrease in the BKCa open-state probability in SMCP, but caused no changes in SMCM. Thus, growth factors modulate vascular BKCa in a cell-type specific manner, which may be of importance concerning vasoactive and atherogenic effects of growth factors.

New aspects concerning the regulation of the post-operative acute phase reaction during cardiac surgery.

During a cardio-pulmonary bypass, as well as post-operatively, high levels of endotoxin, interleukin-6 (Il-6) and C-reactive protein (CRP) were measured in 30 patients. A significant increase in endotoxin plasma level occurred during surgery, culminating in a peak during reperfusion. Plasma levels of endotoxin continued to be slightly raised until the fifth day after surgery, whereas those of Il-6 rose at the time the operation came to an end and were at their highest 6 h later. CRP levels were also high, post-operatively, and were markedly raised on day 2. A definite, statistically significant correlation between the plasma levels of endotoxin and Il-6 during the operation was established, leading us to conclude that the endotoxin liberated during cardiac surgery acts as the main trigger in the release of Il-6 and thus induces the post-operative acute phase reaction. There was no evidence of a correlation between CRP and endotoxin or Il-6 plasma levels.

Effects of vasoactive drugs on postoperative coronary bypass flow: a new technique.

OBJECTIVE: This study aimed to investigate the influence of vasoactive drugs, including a calcium channel blocker, nitroglycerine, and a beta-blocker, often used after coronary artery bypass grafting (CABG). Measurements were taken using a new, completely implantable, mini-Doppler system. The probes were implanted during CABG, led outside through the thoracic wall, and removed 3 days after the operation by a simple pull. RESULTS: The mean Doppler flow increased dramatically in the calcium channel blocker and the nitroglycerine groups (P = 0.002) and decreased slightly in the beta-blocker group (P = 0.015). Mean arterial pressure decreased significantly in all three groups. Heart rate decreased in the beta-blocker group (P = 0.002). Changes in the other hemodynamic variables measured were not significant; there were no changes in the control group. Doppler sonographic monitoring of bypass diameters did not show any changes. CONCLUSION: This is the first study to measure the influence of vasoactive drugs directly and online after CABG. From our experience of more than 40 implantations, we conclude that our method is easy to use and reliable and will help improve the therapeutic regimen for patients after CABG.

The in-vitro effect of antineoplastic agents on proliferative activity and cytoskeletal components of plaque-derived smooth-muscle cells from human coronary arteries.

BACKGROUND: Restenosis after successful percutaneous transluminal coronary angioplasty remains the major clinical problem limiting the long-term efficacy of the treatment. Recent advances in the understanding of the biology of restenosis indicate that its cause is predominantly a multifactorial stimulation of smooth-muscle cell proliferation. The aim of this study was to investigate the in-vitro effect of antineoplastic agents on smooth-muscle cells isolated from human coronary plaque material. METHODS: Atherosclerotic tissue from coronary arteries was extracted from 15 patients of both sexes by thrombendarterectomy. Cells were isolated using enzymatic disaggregation and identified to be smooth-muscle cells with fluorescent antibodies for smooth-muscle-specific alpha-actin. The antineoplastic agents cytarabine (500-0.005 micrograms/ml), doxorubicin (50-0.0005 micrograms/ml), and vincristine (10-0.0001 micrograms/ml) were added to the cultures. Six days after seeding, the cells were trypsinized and then counted. RESULTS: All three antineoplastic agents had a strong dose-dependent antiproliferative effect on cultured smooth-muscle cells. After the application of cytostatic agents, cells either became rounded or underwent complete lysis. Cytoskeletal elements, such as actin, microtubules, and vimentin, were largely altered. CONCLUSION: This investigation examined the potential role of antineoplastic therapy in the prevention of restenosis after coronary angioplasty. The development of new intravascular delivery systems, such as coated stents, may open the way for local antiproliferative strategies in interventional cardiology.

Expression of intercellular adhesion molecule-1 in human coronary endothelial and smooth muscle cells after stimulation with tumor necrosis factor-alpha.

BACKGROUND: The intercellular adhesion molecule-1 (ICAM-1) is one of several human cell adhesion molecules that play a critical role in the early stages of postangioplasty restenosis. In this study, the in-vitro expression of ICAM-1 in human coronary endothelial cells and human coronary smooth muscle cells (SMC) after stimulation with tumor necrosis factor-alpha (TNF-alpha) was investigated. METHODS AND RESULTS: SMC were isolated from the media of normal human coronary arteries (n = 26) up to 10 h post mortem (HCMSMC) and from human atherosclerotic coronary arteries (HCPSMC) that were extracted by thrombendarterectomy (n = 25). Endothelial cells of human coronary arteries (HCAEC) were purchased from Clonetics (Cell System, Remagen, Germany), and endothelial cells from human umbilical cord veins (HUVEC) were isolated after vaginal delivery. For investigations of the effect of TNF-alpha (2.5, 5, 10, and 20 ng/ml) on the proliferative activity of HUVEC, HCAEC, HCPSMC, and HCMSMC, serum-free media was used. After 24 h cell number and cell size distribution were measured in a cell analyzer system. The proliferation of HCPSMC and HCMSMC was increased by TNF-alpha; however, significant differences compared with controls were not reached. The proliferation of HUVEC and HCAEC was significantly reduced by TNF-alpha. For investigations of the effect of TNF-alpha (2.5, 5, 10, and 20 ng/ml) on the surface expression of ICAM-1, monoclonal anti-ICAM-1 antibodies (84H10) were used. The expression of ICAM-1 was analyzed using an immunofluorescence microscope. For flow cytometry analysis, 5 x 10(3) cells (100% gated) were analyzed using a fluorescence-activated cell sorter. In control cultures with no stimulation, the expression of ICAM-1 was positive in HCAEC, HCPSMC, HCMSMC, and HUVEC. TNF-alpha stimulated the expression of ICAM-1 in a time- and dose-dependent manner. After maximal stimulation with TNF-alpha (20 ng/ml for 24 h), the expression of ICAM-1 was stronger in HCMSMC than in HCPSMC. CONCLUSIONS: These results suggest that the cytokine TNF-alpha regulates the expression of ICAM-1 in both human coronary endothelial cells and SMC, and could therefore play an important role in the pathophysiology of inflammatory and immune processes in restenosis after angioplasty.

High-dose diltiazem prevents migration and proliferation of vascular smooth muscle cells in various in-vitro models of human coronary restenosis.

BACKGROUND: Restenosis after coronary angioplasty is considered to be caused mainly by increased migration and proliferation of smooth muscle cells (SMC). The concept of local, site-specific delivery of pharmacologic therapies has opened the door for new, high-dose drug regimes. METHODS AND RESULTS: SMC were isolated by enzymatic disaggregation with collagenase/elastase from human coronary plaque tissue of 29 patients (pSMC) and post mortem from the coronary media of 33 corpses (mSMC). Endothelial cells were isolated from human umbilical veins by enzymatic disaggregation with collagenase/dispase. By positive reaction with antibodies against smooth muscle alpha-actin and von Willebrand factor cells were identified as SMC or endothelial cells. In proliferation studies 5-150 micrograms/ml diltiazem was added to the culture media of pSMC, mSMC and endothelial cells. After 5 days there was a significant dose-dependent inhibition of cell proliferation (for pSMC with > 50 micrograms/ml, for mSMC with > 25 micrograms/ml, and for endothelial cells with > 5 micrograms/ml). In migration studies the effect of 5-150 micrograms/ml diltiazem on the velocity of migration of pSMC was investigated over a period of 48 h. Administration of diltiazem at concentrations of 100 and 150 micrograms/ml caused a significant inhibition of the migration of pSMC. The cytoskeletal components smooth muscle alpha-actin, vimentin, and alpha-tubulin of pSMC and the expression of von Willebrand factor of endothelial cells were investigated after an incubation period of 5 days with 50 and 150 micrograms/ml diltiazem. In the transfilter coculture model the effect of 50 micrograms/ml diltiazem on mSMC was investigated after mechanical injury of cocultured endothelial cells. Administration of diltiazem at a concentration of 50 micrograms/ml inhibited the development of a neointimal proliferate in the transfilter coculture model significantly (P < 0.001). CONCLUSIONS: A high dose of diltiazem inhibited the migratory and proliferative activities of coronary SMC significantly. In further experimental studies the effect of locally applied high doses of diltiazem on postangioplasty restenosis should be elucidated.

Sex steroids in cardiopulmonary bypass.

BACKGROUND: Sex steroids have immunomodulatory effects. No data exist on alterations of sex steroids during cardiopulmonary bypass (CPB). Cardiac surgery with CPB releases an immunological response with complement and cytokine activation. RESULTS: Plasma estradiol and progesterone levels before and immediately after CPB were measured in 11 patients. During CPB, mean estradiol levels decreased from 29 to 15 pg/ml and progesterone levels rose from 0.13 to 0.90 ng/ml. These changes were statistically significant. CONCLUSIONS: These are the first preliminary results evaluating plasma levels of sex steroids during CPB. Whether alterations in estradiol and progesterone levels influence complement and cytokine activation during bypass or vice versa is currently being investigated.

Intermediate follow up of the TEKNA bileaflet valve.

BACKGROUND AND AIM OF THE STUDY: The study aim was to collect intermediate clinical data on the TEKNA bileaflet valve. METHODS: This nine-center clinical study involved 884 patients implanted between June 1990 and October 1993. The population consisted of 522 (59.0%) males and 362 (41.0%) females. Mean age at implant was 59.1 +/- 11.8 years (range: 14.7 to 88.4 years). Indication for valve replacement was dependent on the position: stenosis was the predominant reason in the aortic position; regurgitation was more pronounced for the mitral position. A total of 261 (29.5%) patients underwent concomitant procedures. Mean follow up is 2.7 +/- 1.2 years; total follow up is 2386.1 patient-years (pt-yr). RESULTS: Total operative (< or = 30 days postoperative) mortality rate was 3.7%; seven patients (0.8%) died due to valve-related causes. Total postoperative (> 30 days postoperative) mortality rate was 2.5%/pt-yr and included a valve-related mortality rate of 1.1%/pt-yr. The following valve-related complication rates (%/pt-yr) were reported for the long-term postoperative period: thromboembolism 0.6; valve thrombosis 0.3; bleeding events 1.5; non-structural deterioration 0.6; and endocarditis 0.4. No structural valve deterioration was reported. Actuarial freedom at four years was: overall survival rate 86.9 +/- 1.4%; valve-related survival rate 94.7 +/- 1.0%; freedom from thromboembolism 96.8 +/- 0.9%; valve thrombosis 99.3 +/- 0.3%; endocarditis 98.5 +/- 0.5%; bleeding events 94.3 +/- 1.0%; and non-structural deterioration 98.2 +/- 0.6%. CONCLUSIONS: The data indicate that observed mortality is due mainly to non-valve-related disorders. Risk of thromboembolic and bleeding events was low (0.9%/pt-yr and 1.5%/pt-yr, respectively). We conclude that this valve is safe and efficacious for use.

Indirect myocardial revascularization--an experimental study in the dog.

It has been shown in previous studies that grafting a free skeletal muscle flap onto the heart of the dog produces myocardial revascularization. In order to evaluate the functional aspect of these neovessels, an Ameroid constrictor was implanted into the LADs (left anterior descending coronary artery) of five dogs. At the same time, the free muscle flap was grafted onto the anterior wall of the heart. The arterial anastomosis was achieved with the internal mammary artery. Venous flow was drained into the right atrium. About 12 months later, the regional myocardial blood flow was evaluated adopting the radioactive microsphere technique. This was carried out with the LAD occluded by the Ameroid constrictor and the circumflex artery (CX) open (control conditions). Then the CX was occluded in order to exclude collateral blood flow. Afterwards another occlusion of the CX was performed ("preconditioning") to produce maximal opening of the anatomical collaterals. It was found that regional myocardial blood flow was unchanged in the antero-lateral parts of the hearts despite complete occlusion of the coronaries supplying this area. In the parts supplied by the CX, though, flow was minimal. "Preconditioning" positively influenced the perfusion of this region only in the epicardial parts. Histologically large sinusoid-like blood conductors connected the graft and the heart. Thus, grafting a free skeletal muscle flap onto the heart in the dog produces functional myocardial revascularization in the dog.

Aprotinin in elective primary bypass surgery. Graft patency and clinical efficacy.

The proteinase inhibitor aprotinin is used in open heart surgery to reduce intraoperative and postoperative blood loss and transfusion requirements. To investigate a possible influence on graft patency, a randomized double-blind group comparison study was carried out in male patients elected for primary bypass surgery. One hundred ten (55/55) patients received either placebo treatment or aprotinin according to the Hammersmith scheme (2 Mio KIU as loading dose before sternotomy, followed by an infusion of 0.5 Mio KIU/h until the end of surgery; 2 Mio KIU added to the priming volume additionally). Graft patency was evaluated by angiography in 44 aprotinin and 35 placebo patients between the 18th and 35th days postoperatively. There was no difference in the overall graft occlusion: in the aprotinin group 89.5% (111/124) grafts were found patent compared to 87.2% (89/102) in the placebo group. Of the aprotinin patients 72.7% (32/44) and 71.4% (25/35) of the placebo patients had all grafts patent. Venous grafts were occluded in 16% (7/44) of aprotinin patients and in 29% (10/35) of placebo patients. On the other hand 5/27 patients in the aprotinin group vs 0/27 in the placebo group had occluded internal mammary artery (IMA) grafts (P = 0.0511%). Graft occlusions were not accompanied by signs of myocardial infarction in any case. Fifty-one patients in the aprotinin group and 47 patients in the placebo group were valid for parameters of clinical efficacy: blood loss within 6 h postoperatively was reduced by 58.5% in the aprotinin group (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The CardioOP-Data Clas (CDC). Development and application of a thesaurus for content management and multi-user teleteaching in cardiac surgery.

OBJECTIVES: Self-directed and customized medical education programs are gaining importance in health care instruction. We prototypically implemented a repository-driven online computer system (CardioOP) for teleteaching in Heart Surgery. It supports authoring and multiple re-use of multimedia data for different user groups in different instructional applications and therefore requires a process of content management. METHODS: We defined objectives for a terminological system to support semantic, cross-media type annotation and retrieval of learning objects: domain completeness, German (natural) language processing, multi-user concepts, extensibility and maintenance, content based annotation and technical implementation. Existing terminologies (ICD10, READ V3, Snomed III, UMLS 1997, MESH) have been analysed according to these objectives. RESULTS: We found that the analysed terminologies did not meet our criteria sufficiently. Therefore, we developed a domain-specific thesaurus, the CardioOP-DataClas (CDC). The application of the CDC within a database-driven authoring process using specifically developed tools is reported. CONCLUSIONS: Metadata play an important role in the effective discovery and search, access, integration and management of educational multimedia data in medicine but so far, there is no terminology to support content management for instructional multimedia. We prototypically designed and applied a thesaurus for the CardioOP educational system. Additional work is needed to evaluate the system in terms of user-friend-liness, concept coverage and information retrieval performance.

Heat shock protein 60 expression in patients undergoing cardiac operations.

AIM: Cardiomyocytes respond to stress with the expression of different heat shock proteins (HSP). The mitochondrial HSP60 is known to be expressed by various stress factors, including ischemia and reperfusion. The aim of this study was to investigate if HSP60 is increased in human myocardium after cardiac surgery. METHODS: To determine if heat shock protein 60 accumulated in the myocardium of patients undergoing car-diac operations, right atrial samples before and after extracorporeal circulation were excised and immediately frozen in liquid nitrogen. PATIENTS: we obtained 10 sequential right atrial specimens from 5 male patients in sinus rhythm undergoing elective cardiac surgery. MEASURES: the HSP60 protein level was determined by SDS-PAGE, Western blot and quantified by optical densitometry according to the immunoreactive bands of actin. RESULTS: The HSP60 concentration was unchanged in hearts after a single episode of hypothermic ischemia and reperfusion. Immunoblot analysis demonstrated HSP60 expression in all hearts. There was no correlation with the endurance of cardiopulmonary bypass or reperfusion time. CONCLUSION: These findings indicate that myocardial HSP60 of patients undergoing cardiac operations is not increased after an obligatory period of ischemia, cardioplegic arrest and reperfusion. This might reflect an effective cardioprotection during ECC.