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Case Report, A 51-year-old man who had undergone a modified Carpentier procedure at age 32 years for Ebstein anomaly later developed chronic heart failure due to severe tricuspid regurgitation and atrial flutter with right heart dysfunction. Findings from indocyanine green fluorescence angiography were helpful in avoiding an unnecessary additional procedure of one and one half ventricle repair. At a 6-month follow-up examination, the patient was asymptomatic and had a normal sinus rhythm without administration of an antiarrhythmic agent.

We report a rare case of type A dissection involving a right-sided aortic arch with an aberrant left subclavian artery originating from Kommerell’s diverticulum in a 76-year-old woman. Endovascular treatment for Kommerell’s diverticulum including intimal tear of the dissection was performed. At the 5-year follow-up, the patient was doing well, with no endoleak or dilatation of the Kommerell’s diverticulum.

Case Report, A 64-year-old woman was admitted for weakness and coldness in her right upper arm. She had undergone a right mastectomy for breast carcinoma 32 years before presentation and radiotherapy for clavicular metastasis of breast cancer 3 years before presentation. After thorough investigation, post-radiotherapy axillary artery occlusion was diagnosed. She underwent right external carotid-brachial artery bypass and was discharged without postoperative cerebral complications. Herein, we describe treatment for post-radiotherapy axillary artery occlusion.

A 52-year-old male patient with a history of total arch replacement using the elephant trunk technique for acute aortic dissection 4 years before visited our hospital with the chief complaint of persistent fever. Chest computed tomography (CT) suggested prosthetic vascular graft infection, which was treated surgically after chemotherapy. The first surgery consisted of debridement of an abscess around the vascular graft and in the aorta around the elephant trunk, and thoracic descending aorta replacement and vacuum-assisted closure (VAC) in view of the risk of bleeding from the peripheral region of the elephant trunk. One week later, omental filling was performed as the second step. This is a very rare case of aortic abscess around the elephant trunk that could successfully be managed by graft-conserving treatment.

Purpose To determine whether a dynamic cultured biograft can positively affect the function of the damaged heart. Methods We ligated the coronary artery (LAD) of rats to generate a model of myocardial infarction (MI) and then implanted them with the following grafts comprising vascular smooth muscle cells (VSMCs) derived from the rat aorta and seeded onto biodegradable patches (patch replacement therapy; (PRTx)): control without PRTx, PRTx without seeded cells, PRTx with static cultured VSMCs, PRTx with dynamic cultured VSMCs and sham-operated. Cultured VSMCs were labeled with PKH26 for identification after implantation, and the centre of the MI site was excised and replaced with an implanted biograft. Cardiac performance was monitored for 12 weeks thereafter and followed by a histological study. Results Although the ejection fraction of the damaged heart improved in all groups that were transplanted with grafts, remodeling was prevented only in groups with a dynamic or static cultured patch. More cells were α-SMA-positive in the group with the dynamic, rather than the static cultured patch. Cells were positive for PKH26 in the biograft and in the infarcted myocardium. Conclusions Dynamic cultured biografts improved the function of the infarcted myocardium more than statically cultured biografts or those without cells.

To avoid stenotic conduit events, 2 modifications were added to Norwood reconstruction with a right ventricle-to-pulmonary artery conduit: open-square insertion of a proximal conduit end and use of a pre-cuffed, spiral-ringed conduit. Three consecutive patients treated with this technique successfully underwent bidirectional Glenn with no stenotic events. These modifications are beneficial and safe.

Background: Tissue engineering with cell seeded biodegradable material has attracted attention as a novel means of treating the severely impaired heart. Here, we consider optimal preparation of a durable biograft using dynamic and static cultures.Methods: Vascular smooth muscle cells (VSMCs) derived from the rat aorta were seeded onto biodegradable material P (LA/CL) (poly-L-lactide-e-caprolactone copolymer) and cultured as follows: a) Static culture (n = 11), b) dynamic culture (n = 12), c) 0 h pre-seeding (n = 12), d) 24 h pre-seeding (n = 5) and e) 1 week pre-seeding (n = 12). Dynamic culture: Cells were cultured in spinner flasks. Pre-seeding: Static cell seeding and culture before dynamic culture. Evaluation: The conditions of the P (LA/CL) in the five groups were evaluated as cell proliferation and by histological studies.Results: VSMCs proliferated both in and on the biodegradable materials. The quality of the dynamic culture cell with pre-seeding increased. Although the duration of pre-seeding exerted no significantly different effects, cell attachment and proliferation were widely scattered in the 0 h pre-seeding group, whereas cells proliferating on the front of the scaffold obstructed proliferation inside the biodegradable material in the 1 week pre-seeding group.Conclusions: Dynamic cell culture with 24 h pre-seeding is effective for constructing ideal biografts.

症例は75歳，男性．約6カ月前から発熱を繰り返し改善認めないため，当院に紹介となった．心エコーにて大動脈弁に疣贅，僧帽弁前尖に肥厚を認め，血液培養にてEnterococcus faeciumが検出された．感染性心内膜炎の診断で化学療法施行し，炎症反応陰転化した後に手術を施行した．術前の経食道心超音波にてAortomitral continuityから僧帽弁前尖左室側に，膿瘍形成を疑わせるmass echoを認めた．手術は上行大動脈を切開し，大動脈弁を切除した．Aortomitral continuityから僧帽弁前尖左室側に膿瘍が自潰したと思われる10mm径の潰瘍形成を認めた．経大動脈的に自己心膜パッチにて潰瘍を閉鎖し，CE 21mmにて大動脈弁置換術を施行した．術後の経食道超音波にて僧帽弁左室側の潰瘍部分が良好に修復され，僧帽弁の動きに制限はなく術前同様の軽度の逆流を認めるのみであった．

Cardiopulmonary bypass (CPB) induces numerous systemic reactions. This study examined the efficacy of heparin-bonded CPB circuits on inflammatory responses and postoperative status in children.Thirty-four infants undergoing elective cardiac surgery were randomly divided into two groups: a heparin-bonded CPB group (n = 17) and a non-heparin-bonded group (n = 17). Plasma levels of the inflammatory cytokines were measured before, during, and after CPB, and postoperative status was determined by examining the respiratory index, blood loss, and the post- and preoperative body weight percent ratio.Significant differences in tumor necrosis factor-alpha, interleukin-6, and interleukin-8 patterns were observed during and after CPB between the two groups (p0.01, p0.01, p0.05, respectively). All cytokines measured were significantly lower in the heparin-bonded group just after CPB (p0.05). There were no differences in duration of intubation, intensive care unit or hospital stay, or postoperative blood loss, but the respiratory index 3 hours after CPB and body weight percent ratio 24 and 48 hours after CPB were significantly reduced in the bonded group (p0.05, p0.01, p0.05, respectively).Our findings suggest that heparin bonding of the bypass circuits affects early postoperative status and reduces cytokine responses in pediatric cardiac surgery.

今回われわれは,本態性血小板血症(essential thrombocythemia: ET)を合併した冠動脈バイパス術(CABG)を経験した.症例は73歳の男性,狭心症精査入院でLMT(左主幹部)を含む3枝病変を認め,CABGを予定したが血液データ上,3系統の血球異常を認め,ETと診断された.ETは慢性骨髄増殖性疾患に分類され血小板異常による出血傾向,血栓傾向の両面を併せもつ疾患である.ETを合併する虚血性心疾患は血栓による心筋梗塞の例が多く,狭心症で冠動脈の血行再建を要する症例は少ない.ETを合併する症例に対するCABGでは周術期の出血と術後のグラフト閉塞が問題となる.DNA合成阻害剤であるヒドロキシカルバミドを用い血小板数,機能をコントロールし,CABGを施行し良好な経過を得た.術後7年を経過した今も心事故およびETによる合併症もなく元気に社会生活を営んでおり,若干の文献的考察を加え報告した.

Background: Antegrade cardioplegic delivery may be impaired by coronary occlusions, whereas retrograde delivery of cardioplegic solution may be inhomogeneous, leading to an accumulation of lactate and hydrogen ions, the products of anaerobic metabolism. Integrated cardioplegia using continuous retrograde cardioplegia and antegrade infusions into completed vein grafts washes out metabolites accumulated in regions inadequately perfused by retrograde cardioplegia alone. To determine the flow rates required to achieve the greatest washout, we compared a high flow rate (200 ml/min) to a low flow rate (100 ml/min). Methods: Twenty patients scheduled for isolated coronary bypass surgery were prospectively randomized to compare two flow rates for integrated cardioplegic protection using tepid (29° C) blood cardioplegia. Arterial and coronary sinus blood samples were collected to evaluate myocardial metabolism. After antegrade arrest, cardioplegic solution was delivered by coronary sinus perfusion and simultaneous infusions into each completed vein graft at either high or low flow. Results: Increasing from low to high flow increased the washout of lactate and hydrogen ions during the aortic crossclamp period. Two hours after crossclamp removal, ventricular function was better in the high flow group. Conclusions: Tepid retrograde cardioplegia resulted in an accumulation of toxic metabolites. The addition of antegrade vein graft infusions at a flow rate of 100 ml/min resulted in a washout of these metabolites. A flow rate of 200 ml/min further improved this washout and resulted in improved ventricular function. An integrated approach to myocardial protection using a flow rate of 200 ml/min may improve the results of coronary bypass surgery. (J Thorac Cardiovasc Surg 1998;115:226–35)

The artery and vein of the transplanted kidney are generally anastomosed to the external iliac artery and vein, respectively. Therefore, in open abdominal artery aneurysm (AAA) repair in renal transplant patients, kidney ischemia due to a proximal aortic clamp is a serious problem. We successfully performed endovascular aneurysm repair (EVAR) of AAA without aortic clamping in two renal transplant recipient cases. The two patients were diagnosed with large AAAs following the renal transplant, and EVAR was performed. To protect the renal function, we used N-acetylcysteine premedication and hydration before the operation, and we could then reduce the iodine contrast medium by using echography of the artery during the operation. In this report, a case where EVAR with renal function protection is a useful treatment for renal transplant recipients with AAA is described.

A 49-year-old man was diagnosed with an interrupted aortic arch (IAA), a massive saccular thoracic collateral aneurysm, ischemic renal insufficiency, and multiple abdominal collateral aneurysms. A bypass from the left subclavian artery to the descending aorta and thoracic collateral aneurysmectomy proceeded simultaneously through a posterolateral thoracotomy. The pressure gradient between upper and lower extremities disappeared and renal function was normalized. Thoracic collateral aneurysmectomy and a simultaneous bypass from the left subclavian artery to the descending aorta with postoperative normalization of ischemic renal insufficiency are extremely rare in adult patients with IAA, and the remaining abdominal collateral aneurysms require careful monitoring.

To determine whether a dynamic cultured biograft can positively affect the function of the damaged heart.We ligated the coronary artery (LAD) of rats to generate a model of myocardial infarction (MI) and then implanted them with the following grafts comprising vascular smooth muscle cells (VSMCs) derived from the rat aorta and seeded onto biodegradable patches (patch replacement therapy; (PRTx)): control without PRTx, PRTx without seeded cells, PRTx with static cultured VSMCs, PRTx with dynamic cultured VSMCs and sham-operated. Cultured VSMCs were labeled with PKH26 for identification after implantation, and the centre of the MI site was excised and replaced with an implanted biograft. Cardiac performance was monitored for 12 weeks thereafter and followed by a histological study.Although the ejection fraction of the damaged heart improved in all groups that were transplanted with grafts, remodeling was prevented only in groups with a dynamic or static cultured patch. More cells were α-SMA-positive in the group with the dynamic, rather than the static cultured patch. Cells were positive for PKH26 in the biograft and in the infarcted myocardium.Dynamic cultured biografts improved the function of the infarcted myocardium more than statically cultured biografts or those without cells.

Abdominal pseudoaneurysm is an extremely rare disease entity. Precise preoperative diagnosis is mandatory for the treatment of this disease and an accurate surgical approach that minimizes ischemia of the visceral organs has long since been needed according to origin. A 40-year-old woman with an abdominal injury was treated by blocking the abdominal artery to occlude the aneurysmal foramen between the celiac artery and superior mesenteric artery using a balloon catheter for intra aortic balloon pumping (IABP) under hypothermia. Postoperative course was uneventful. The patient was discharged from the hospital, and currently under follow-up observation.

In order to prevent a harmful influence of leukocyte in whole blood transfusion, leukocyte depleted red cell (LDR) was used for infant cardiopulmonary bypass, and its clinical features were evaluated. Subjects were 87 children undergoing cadiac surgery with cardiopulmonary bypass (CPB). In 37 out of 87 children (LDR group) LDR was used for CPB priming, and in 50 children (control group) fresh whole blood was used for CPB priming. After the operation GOT and GPT levels did not change significantly between LDR and control groups. Only one child in control group evidenced transient liver dysfunction. Number of leukocytes increased postoperatively in LDR group. It means that transfused leukocytes depressed postoperative reaction in control group. The count of platelets decreased significantly in LDR group, because the filter used in LDR group removed platelets with leukocytes. Then, in LDR group, bleeding volume on the first day after the operation was measured more than in control group. But total bleeding volume after the operation did't show any significant difference. Neither controlled time under respirator nor administration days of antibiotics was significantly different.It is suggested that LDR for CPB priming prevents a harmful potency of transfused leukocyte without clinical disadvantages.

A 52-year-old man with Leriche syndrome with a high aortic occlusion, in which the abdominal aorta proximal to the origin of the renal artery was thrombosed, is reported. The patient was admitted to the hospital because of intermittent claudication and sexual impotence. On aortogram the abdominal aorta just from the infrarenal portion to bilateral common iliac arteries occluded completely and the orifice of right renal artery was slightly stenotic. Operation was performed under hypothermia at 30°C of rectal temperature, and a wide operative field was secured through a modified spiral skin incision and extraperitoneal approach (by Stoney et al., 1973). Through a longitudinal aortotomy, thrombus was found locating from the proximal to the renal arteries to bilateral common iliac arteries. The orifice of the right renal artery was thrombosed, too. The long segmental thrombus was removed carefully. Aorta was reconstructed with Y-shaped Dacron graft from the infrarenal portion to bilateral common iliac arteries. The postoperative course was uneventful without renal dysfunction. On postoperative aortogram blood flow was sufficient along the prosthetic graft. In conclusion the spiral skin incision with extraperitoneal approach under systemic hypothermia is a preferable and appropriate procedure for this disease.

A 74-year-old female patient with left main trunk (LMT) and triple vessel disease underwent coronary artery bypass graft (CABG) surgery. The patient began to experience exertional dyspnea. A coronary artery angiogram confirmed a severe stenosis in the proximal side of the saphenous vein graft (SVG). The patient had impending infarction immediately after the unsuccessful attempt for percutaneous coronary intervention, which resulted in an emergent CABG procedure. A left thoracotomy at the 4th intercostal space was made with the patient in the right lateral position. We then interrupted the use of intra-aortic balloon pumping (IABP), confirmed on transesophageal echocardiography (TEE) that the balloon was in a position distal to the target anastomosis site, and made a proximal anastomosis using the PAS-Port system (Cardica, Redwood City, CA, USA). After its successful deployment, IABP was repositioned back and resumed. The distal anastomosis was made to the previously bypassed graft. The patient had no postoperative myocardial damage or complications and was discharged on postoperative day 21. A redo CABG for post-CABG acute coronary syndrome patient was thought to be an extreme high risk; however, the operative time could be minimized by using the PAS-Port system, which enabled a safe redo CABG with left thoracotomy.

Reported herein is a patient with valvular dysfunctions due to thorombosis developed 14 years after mitral valve prosthesis with Bjork-Shiley valve, who could be rescued by emergency operation. A 44-year-old woman was admitted to the hospital because of hemorrhagic gastric ulcer. There was a history of mitral valve prosthesis with Bjork-Shiley valve for mitral insufficiency in 1976, and subsequent anti-coagulation therapy on an ambulant basis, after admission her symptoms of heart failure were aggravated. She was diagnosed as dysfunction of the artificial valve and underwent an emergency operation for reconstruction of the valve with 29 mm of St. Jude Medical valve. The findings at the operation revealed that a newly formed thrombosis at the minor-strut area had been inhibiting the motility of the valve.After the operation, her condition was improved and she was discharged at Day 20 of illness. This case was thus identified as having causative factors of nutritive infusion and administration of hemostatic agent upon suspending the anticoagulation therapy due to hemorrhagic gastric ulcer after 14 years of the term with no complaint of heart failure. It was also diagnosed as dysfunction of artificial valve decisively induced by a newly formed thrombosis which was assumed to becaused by the increased blood coagulation.

Cell preservation is essential for successful cell transplantation and/or tissue engineering. We examined the effects of cryopreservation on the transplantation of human heart cells.Cells isolated from human atrial tissues were cultured for 15 days (control group), cryopreserved for 1 week, and rapidly thawed and cultured for 15 days. Proliferation was compared among control and cryopreserved cells or tissues by constructing growth curves. Growth factors, cytokines, biochemical features, and cell cycle phase were measured immediately before and after cryopreservation, and immunogenicity was evaluated from growth curves generated from heart cells after 7 days in mixed-lymphocyte culture. Control or cryopreserved cells were transplanted into rat connective tissues and evaluated histologically 2 weeks later.Cryopreserved cells proliferated more effectively than control cells. Levels of basic fibroblast growth factor and transforming growth factor-β1 were significantly higher, and those of interleukin (IL)-6 and IL-8 were significantly lower after cryopreservation. Fewer peripheral blood lymphocytes were produced in cryopreserved cells than in noncryopreserved cells, and the cell cycle phase of cryopreserved heart cells shifted primarily to G2 + M from G1 + G0. Noncryopreserved and cryopreserved cells both survived in connective tissue.Human atrial cells can be cultured, cryopreserved, and transplanted. Cryopreservation might increase the proliferation of human cells and tissues and also reduce the immunogenicity of heart cells.

The patient was a 59-year-old female. Because of massive hemoptysis, she was brought to our emergency center by ambulance. Thoracic computed tomography led to a diagnosis of an infectious thoracic aortic pseudoaneurysm accompanied by an aortobronchopulmonary fistula. Emergency surgery followed. Also noted was an advanced hepatic dysfunction, assessed as Child-Pugh score B, caused by an alcoholic liver disease. A localized affected area made it possible for us to perform an aneurysmectomy using a temporary bypass rather than assisted circulation. A patch plasty using expanded polytetrafluoroethylene completed the procedure. Streptococcus agalactiae (GBS) was detected in a sample obtained during the surgery from an abscess located in the aneurysm. The patient made satisfactory postoperative progress and left the hospital walking unaided on the 36th postoperative day.

The occurrence of mediastinitis following synthetic vascular replacement surgery is still associated with an unfavorable prognosis in the treatment of thoracic aortic diseases. This time we report a Bentall procedure that we re-performed to treat an aortic root pseudoaneurysm, which developed after a postoperative mediastinitis. This followed the first Bentall procedure, which was treated by debridement of the focus of infection, continuous lavage, and a two-step rectus abdominis muscle flap implantation. Implantation of a rectus abdominis muscle flap is effective in controlling infection in the treatment of mediastinitis after heart surgery. However, after synthetic vascular replacement surgeries have been performed to treat aortic diseases, especially after aortic root reconstruction surgery, which puts stress on the anastomotic site, consideration should be given regarding the development of hemorrhages and pseudoaneurysms as a result of infection-induced tissue fragilization.

We assessed potential limitations of retrograde continuous tepid blood cardioplegia (RCTBC) for myocardial remodeling, represented by hypertrophied and/or dilated myocardium in patients with severe cardiomyopathy following single aortic valve replacement.The study was conducted on 91 patients who underwent initial single aortic valve replacement with tepid cardiopulmonary bypass (CPB) and RCTBC. Based on the postoperative maximum creatine phosphokinase (max CPK)-MB level, the patients were allocated to Group H (/=100 IU/mL) with severe cardiomyopathy or Group L (100 IU/mL) to make intergroup comparisons of preoperative, intraoperative, and postoperative parameter values.Preoperative measurements were as follows: pressure gradient between left ventricle and aorta (DeltaPG), 92.8+/-46.2 mmHg in Group H and 57.9+/-41.6 mmHg in Group L (p0.01); implanted valve size, 21.0+/-2.2 mm in Group H and 22.8+/-2.2 mm in Group L (p0.01); left ventricular end-diastolic volume (LVEDV), 155.7+/-73.3 mL in Group H and 224.3+/-101.5 mL in Group L (p0.01). The rate of RCTBC flow rate increase did not differ between the groups (17.6% in Group H and 20.7% in Group L), while the rate of concomitant use of optional antegrade coronary perfusion was significantly lower in Group H (25%) than in Group L (37%) (p0.05). Pre- and post-perfusion lactic acid levels in the myocardial protection solution measured every 30 min after aortic cross clamping were higher in Group H than in Group L.The study suggests preoperative high DeltaPG, small aortic root diameter, and low LVEDV, namely, concentrically hypertrophied myocardium, as risk factors for severe cardiomyopathy after RCTBC. RCTBC in patients with any risk factor should be accompanied by an increase in initial continuous perfusion flow and/or aggressive use of intermittent antegrade coronary perfusion.

An emergency off-pump coronary artery bypass (OPCAB) was performed successfully in an aged patient with acute coronary syndrome (ACS). The patient, an 80-year-old woman residing in a nursing home, suddenly lost consciousness during lunch. The electrocardiogram (ECG) showed ventricular fibrillation (Vf) but defibrillation successfully recovered the sinus rhythm. The patient was brought to our hospital as an emergency. She underwent emergency cardiac catheterization. Coronary angiography demonstrated severe three vessel disease with left main coronary trunk (LMT) stenosis. Even during intra-aortic balloon pumping (IABP), the hemodynamic state was unstable, with repeated development of ventricular tachycardia and fibrillation. An emergency coronary artery bypass without a cardiopulmonary bypass was performed. Saving her life was of primary importance and revascularization of the left anterior descending artery (LAD) branch, was performed. Thanks to the advances made in various devices, safe and reliable anastomoses have become possible in OPCAB applied to ACS. OPCAB for ACS have become safe and reliable anastomoses following development of various devices. We think that OPCAB is an effective surgical technique for coronary revascularization for emergency or serious cases involving elderly patients.

Two cases of pancreatic pseudocyst successfully resected by pancreatoduodenectomy are reported. Neither case revealed malignancy on the histopathological examination performed during surgery; however, pancreatoduodenectomy was carried out because of the thickness of the cyst wall, intense inflammatory adhesion and stenosis of the common bile duct or duodenum. Up to now, extirpation of pseudocyst and drainage operation have been performed as the usual surgical treatment, but, considering the recent advances in patient care and surgical techniques, pancreatoduodenectomy seems to be indicated more frequently, depending on the condition of the pseudocyst.

During the past 8 years from 1975 to 1982, 75 cases (19.3%) with macroscopical invasion into surrounding organs out of 387 cases of gastric cancer were experienced. They were divided into two groups a nonresectable groups of 41 cases (54.7%) and a resectable group of 34 cases (45.3%). In the nonresectable group, there were 21 cases (51.2%) with the tumor in the antrum and 25 cases (61%) with pancreatic invasion. On the other hand, in the resectable group there were 14 cases (41.2%) with the tumor in the middle part. The invaded surrounding organs were pancreas in 19 cases (55.9%), transverse colon in 12 cases (35.3%) and liver in 2 cases (5.9%). The operation methods were total gastrectomy in 10 cases (29.4%), subtotal gastrectomy in 17 cases (50%), partial gastrectomy in 6 cases (17.6%) and a modified Child's in procedure in 1 case (2.9%). Combined resection of the stomach and one organ was performed in 9 cases (26.5%) and with two organs in 7 cases (20.6%). Eighteen patients (54.5%) in the resectable group have survived more than 1 year and 4 (12.1%) of these for more than 5 years. If the general condition of the patients is such as to enablec them to tolerate the operation, the invaded surrounding organs should be resected with the stomach, and lymph node dissection also should be performed en-block over a wide range.

Impaired myocardial metabolism after cardioplegic arrest results in persistent anaerobic lactate production. Insulin may protect the heart from ischemia and reperfusion by enhancing myocardial metabolic recovery. However, the stimulation of glycolysis during ischemia may be detrimental because of an accumulation of metabolic end-products. We examined the effect of insulin on quiescent human ventricular cardiomyocytes subjected to simulated cardioplegic ischemia and reperfusion. Methods: Primary cardiomyocyte cultures were established from patients undergoing corrective repair of tetralogy of Fallot. Cells were exposed to varying concentrations of glucose and insulin during 30 minutes of stabilization in 10 mL of phosphate-buffered saline solution. Ischemia was simulated by exposing the cells to a low volume (1.5 mL) of deoxygenated phosphate-buffered saline solution for 90 minutes followed by 30 minutes of simulated reperfusion in 10 mL of normoxic phosphate-buffered saline solution. Cell viability was assessed by trypan blue exclusion. The activity of mitochondrial pyruvate dehydrogenase was measured in 3 states: stabilization, ischemia, and reperfusion. In addition intracellular lactate, adenine nucleotides, extracellular lactate, pyruvate, and acid release were measured. Results: Higher ambient glucose concentrations resulted in greater cellular injury although insulin-treated cells displayed less injury after ischemia and reperfusion. Insulin increased the pyruvate dehydrogenase activity by 31% in cardiomyocytes and reduced extracellular lactate production by 40%. Intracellular adenosine triphosphate was improved by 75% in cells exposed to high glucose concentrations in the presence of insulin. Conclusions: Insulin protected human ventricular cardiomyocytes from ischemia and reperfusion. This protection may be due to a stimulation of pyruvate dehydrogenase activity which resulted in improved aerobic metabolism. (J Thorac Cardiovasc Surg 1998;116:485-94)