Quantitative estimation of infarct size by simultaneous dual radionuclide single photon emission computed tomography: comparison with peak serum creatine kinase activity

To test the hypothesis that simultaneous dual energy single photon emission computed tomography (SPECT) with technetium-99m (99mTc) pyrophosphate and thallium-201 (201TI) can provide an accurate estimate of the size of myocardial infarction and to assess the correlation between infarct size and peak serum creatine kinase activity, 165 patients with acute myocardial infarction underwent SPECT 3.2 +/- 1.3 (SD) days after the onset of acute myocardial infarction. In the present study, the difference in the intensity of 99mTc-pyrophosphate accumulation was assumed to be attributable to difference in the volume of infarcted myocardium, and the infarct volume was corrected by the ratio of the myocardial activity to the osseous activity to quantify the intensity of 99mTc-pyrophosphate accumulation. The correlation of measured infarct volume with peak serum creatine kinase activity was significant (r = 0.60, p less than 0.01). There was also a significant linear correlation between the corrected infarct volume and peak serum creatine kinase activity (r = 0.71, p less than 0.01). Subgroup analysis showed a high correlation between corrected volume and peak creatine kinase activity in patients with anterior infarctions (r = 0.75, p less than 0.01) but a poor correlation in patients with inferior or posterior infarctions (r = 0.50, p less than 0.01). In both the early reperfusion and the no reperfusion groups, a good correlation was found between corrected infarct volume and peak serum creatine kinase activity (r = 0.76 and r = 0.76, respectively; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Chylothorax developed after cardiac surgery in children: a report of three cases]

Two children developed chylothorax after median sternotomy and a third child developed chylothorax after a Blalock-Taussig operation under the left thoracotomy. The first patient had a closure of ASD and a pulmonary valvotomy and then later developed chylothorax. The thoracic duct was ligated 10 cm just above the diaphragm at 28 days after the first operation because of unsuccessful conservative treatment. The second patient had a Blalock-Taussig operation and the third patient had radical operation for ECD and both developed chylothorax. The latter two patients were cured with conservative treatments such as the administration of Medium Chain Triglyceride or total parenteral nutrition with thoracic drainage. Children who developed chylothorax after cardiac surgery should be treated conservatively for at least the early postoperative period when circulatory and/or respiratory conditions are still unstable.

Growth of tracheal anastomoses: advantage of absorbable interrupted sutures

Growth of the trachea after complete transection and anastomosis was studied in four groups of 1-month-old New Zealand white rabbits. The trachea was transected at the fifth cartilaginous ring and then anastomosed with continuous 6-0 polypropylene (Prolene) (group 1), interrupted 6-0 polypropylene (group 2), continuous 6-0 polydioxanone (PDS) (group 3), or interrupted 6-0 PDS (group 4). The animals were followed up for 90 to 103 days (mean follow-up, 95 days). At the time the animals were killed, body weight had increased 125% (1.2 to 2.7 +/- 0.18 kg). Growth of the trachea was assessed at the time of death. Results from this study suggest that growth of a tracheal anastomosis is retarded in a growing animal model. The degree of resultant stenosis was significantly less when an absorbable suture material (PDS) and an interrupted suturing technique were used.

Concentration of Mn-superoxide dismutase in serum in acute myocardial infarction

Serum concentrations of manganese-containing superoxide dismutase (Mn-SOD; EC 1.15.1.1), a mitochondrial enzyme present in high concentrations in the heart, were measured successively by enzyme immunoassay in 18 patients with acute myocardial infarction (AMI) and in eight with angina pectoris. Results were compared with creatine kinase (EC 2.7.3.2) isoenzyme MB (CK-MB) concentrations in the same specimens. The mean (and SD) serum Mn-SOD concentration in 120 healthy adults was 77.5 (18) micrograms/L. Mn-SOD concentrations exceeding 150 micrograms/L (greater than mean + 4 SD) were considered above-normal. In patients with AMI, the Mn-SOD concentration was 80 (16.8) micrograms/L on admission and increased gradually after the first hospital day. The peak, 260 (109) microgram/L, occurred on the fourth hospital day, at which time the Mn-SOD concentrations in all AMI patients were above normal. Thereafter the Mn-SOD concentration decreased slowly, but still was above normal in 14 of 18 patients on the seventh hospital day. On the other hand, in patients with angina pectoris, the Mn-SOD concentration was 78 (11) micrograms/L on admission and did not increase significantly [peak value 97.5 (42) micrograms/L on the fourth hospital day]. The serum concentration of Mn-SOD is a potentially useful marker for estimating cardiac mitochondrial damage and for diagnosing AMI, especially in the late phase.

Evaluation of a new calcium containing cardioplegic solution in the isolated rabbit heart in comparison to a calcium-free, low sodium solution

Isolated perfused rabbit hearts were studied to compare the effects of 3 hour ischemic arrest following either calcium-free or calcium-containing cardioplegia, on the recovery of isovolumic function of the left ventricle, coronary flow, release of creatine phosphokinase and myocardial water content. The hearts perfused with the calcium-containing solution (Ca 0.5 mmol/L) showed better recovery of the developed pressure in the left ventricle, and its first derivative and compliance. Coronary flow at a constant perfusion pressure was better restored during reperfusion in the hearts with calcium-containing solution. The release of less CPK and a lower water content were also observed in the hearts reperfused with calcium-containing solution. We concluded that calcium-containing cardioplegic solution with a high concentration of magnesium (10 mmol/L) was superior to calcium-free solution for myocardial protection.

[Centrifugal pump as right ventricular assist pump in the treatment of right ventricular failure following resection of left atrial myxoma]

A 31-year-old woman had a left atrial myxoma associated with severe pulmonary hypertension and respiratory failure because of incarceration of the tumor to the mitral valve. Emergency surgery was performed, but the patient could not be weaned from cardiopulmonary bypass because of right ventricular failure. A Biomedicus centrifugal pump was used as a right ventricular assist pump. The result was a successful termination of cardiopulmonary bypass. With the support of an intra-aortic balloon pump, the right ventricular assist pump was removed 38 hours after the operation, and the intra-aortic balloon pump was terminated 2 days later. The centrifugal pump is very useful at the majority of centers where the pneumatically activated bi-valved ventricular assist device is unavailable. The Biomedicus centrifugal pump can be easily applied for treatment of perioperative right ventricular failure and is very useful for short-term use without systemic anticoagulants.

Peripheral vascular permeability following a thermal injury to the airway

Effects of thermal injury to the airway on the vascular permeability in the region of head and neck, were studied in the canine models. The thermal airway injury was produced by an inhalation of a gas burner's flame through the metallic tracheostomy cannula. The changes in vascular permeability were evaluated by calculating the reflection coefficient, which was obtained by the protein washdown technique into lymph. The reflection coefficient after the flame inhalation did not show any increases, while it increased significantly after a histamine infusion into the carotic artery. We concluded, that the vascular permeability in the unburned area does not increase at least in the first 3 hr after a thermal injury to the airway.

Immunomodulator, LZ-8, prevents antibody production in mice

LZ-8, a new and recently discovered immunomodulator from Ganoderma lucidum, has been shown to have immunosuppressive activity in vivo and to be a member of the immunoglobulin superfamily. In this paper we examined the in vivo effect of LZ-8 on antibody production using the hepatitis B surface antigen (HBs Ag) in mice. LZ-8 had mitogenic activity in vitro towards spleen cells of C57BL/10 (B10) and C57BL/10BR (B10BR) as previously shown towards those of DBA/2 mice. B10 and B10BR mice produced anti-HBs Ag antibody by the twice sensitization of the antigen while intraperitoneal administration of LZ-8 twice weekly into the mice (8 and 12 mg/kg) greatly prevented the production of antibody to HBs Ag (83.3-96.8% inhibition). We further examined the effect of LZ-8 administration on mitogen responsibility of spleen cells and on the T-cell subset population in both the spleen and lymph node but no significant differences were observed between the LZ-8 treated and untreated mice. These results suggest that the immunosuppressive activities of LZ-8, previously shown, such as the prevention of systemic anaphylaxis and the Arthus reactions, were caused by the blocking of antigen-specific antibody production.

[A successful removal of a left atrial massive ball thrombus caused by mitral stenosis]

A 66-year-old female with a mitral stenosis and a left atrial massive ball thrombus is presented. She was admitted due to a transient right hemiplegia and a speech disturbance. This thrombus had been detected preoperatively by an echocardiogram and a left atriography. A mitral valve replacement using a Björk-Shiley valve 27 mm, accompanied with the removal of the thrombus was performed. The ball thrombus was dark red, 55 x 35 x 32 mm in size and 15 g in weight. After the surgery, the patient progressed well. Because of the high frequency of peripheral embolism and of sudden death, a left atrial ball thrombus should be removed immediately.

[Legionellosis]

Although increasing attention is being given to Legionella pneumonia in Japan, reports of solitary onset of this disease are scant in Japan. The patient, from whom L. dumoffii was isolated, was a 59-year-old male with no underlying disease. He visited our hospital because of fever and cough, and was admitted to our department for X-ray findings consistent with pneumonia. After admission, pulmonary lesions spread rapidly, and based on the suspicion of Legionella pneumonia, drugs such as EM, RFP and MINO were used. However, the patient died on the 26th hospital day. L. dumoffii was isolated from specimens obtained by airway aspiration before death and specimens of lung abscess and airway discharge obtained during autopsy (7 specimens in total). In addition, the L. dumoffii antibody titer in the serum became elevated. This is the first case of L. dumoffii pneumonia reported in Japan. The other case was in an 81-year-old male with underlying disease. He was admitted urgently with suspected pneumonia but died on the following day. L. pneumophila serogroup 5 was isolated from autopsied lung tissue. Fatality is high for this disease, making early diagnosis and treatment with appropriate antibiotics essential. Physicians should bear in mind the possibility of this disease and request the necessary laboratory tests in suspected cases without delay.

[A surgical case of aortic regurgitation with Behçet disease]

A case of Behçet disease associated with aortic valve regurgitation treated with aortic valve replacement is reported. The patient was treated successfully with special surgical techniques for prevention of post operative paravalvular leakage and occurrence of pseudo aneurysm because the patient was under long-term steroid therapy for Behçet disease.

Rescue of a patient with fulminant myocarditis by percutaneous extracorporeal bypass

A previously well 53-year-old man with fulminant myocarditis is presented. Cardiogenic shock and medically refractory low cardiac output syndrome were unsuccessfully treated using an intraaortic balloon pump. A percutaneous extracorporeal bypass system improved hemodynamics, DIC and other multiorgan injuries following acute myocarditis.

[Three operated cases of LMT-lesion with chief complaint of syncopal attack]

An urgent aorto-coronary bypass operation (AC-bypass) was made in three patients with unstable angina pectoris, suffering from stenosis of the left main trunk (LMT). All patients were admitted with chief complaints of chest discomfort and syncopal attack. Case 1 was a 71 year-old man who suffered with chest discomfort and syncopal attack. He was admitted to our emergency room by ambulance 40 minutes after the syncopal attack, on January 11, 1989. His blood pressure was 140/96; pulse 84 and regular. The electrocardiogram (ECG) showed right bundle branch block, ST elevation in aVR, aVL and ST depression in all other leads. Coronary arteriogram (CAG) was made urgently and showed 80% stenosis in LMT. The emergency AC-bypass operation was successfully carried out about 3 hours and 10 minutes after the onset of symptoms. Case 2 was a 51 year-old man who suffered from precordial oppression and syncopal attack. He was admitted to our emergency room by ambulance about 1 hour after the attack, on January 17, 1989. His blood pressure was 94/74; pulse 120 and irregular. Chest radiography showed a cardiothoracic ratio of 58% and the ECG disclosed atrial fibrillation, ST elevation in aVR and ST depression in I, II, III, aVF, V1-6. The echocardiogram revealed hypokinetic motion in the antero-lateral wall of the left ventricle. CAG was carried out without delay, and showed 70% stenosis with slit in LMT. An emergency AC-bypass operation was successfully carried out about 3 hours and 50 minutes after the onset of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

[Valvuloplasty for acute mitral insufficiency caused by torn chordae (Carpentier method): report of a case]

A 66-year-old female was admitted to our hospital with acute heart failure (NYHA III), and diagnosed as an MR + Tr. The cause of MR was torn chordae of the posterior leaflet of the mitral valve. A prolapse part of the posterior leaflet was resected and sutured by McGoon's method. Valvuloplasty was performed by using a Carpentier ring. Postoperative course was uneventful. She recovered well after the operation. Histological examination of the valve showed myxomatous degeneration.

[Significance of measuring Cu, Zn-superoxide dismutase (SOD) levels in open heart surgery]

Cu, Zn-SOD levels, free hemoglobin (Hb) and CPK-MB were measured in 18 patients undergoing open heart surgery. In order to evaluate the serum level of Cu, Zn-SOD, the ratio of Cu, Zn-SOD/free Hb was used to eliminate an influx of Cu, Zn-SOD released from erythrocytes during cardiopulmonary bypass. The value of Cu, Zn-SOD/free Hb was decreased significantly 30 minutes after aortic declamping and the minimal value was indicated 1 hour after the termination of cardiopulmonary bypass compared with the preoperative status. We thought that the decrease was due to the consumption of SOD competing against free radical generation. The correlation between the minimal value of Cu, Zn-SOD/free Hb and the ischemic time was apparent but the correlation between the minimal value of Cu, Zn-SOD/free Hb and the value of peak CPK-MB was not determined. It was suggested that the serum free radicals were not only derived from the heart but also from the lung or other parts of the body during open heart surgery.

Clinical trial of nicardipine cardioplegia in pediatric cardiac surgery

To clarify the effectiveness of nicardipine, one of the dihydropyridine calcium-channel blockers, for myocardial protection during cold potassium cardioplegic arrest in pediatric cardiac surgery, a clinical trial of nicardipine (0.25 mg/L) added to potassium cardioplegic solution was performed in children undergoing surgical repair of congenital heart diseases. Twenty patients were selected to receive nicardipine cardioplegia and 13 patients received a standard potassium cardioplegia, serving as a control group. Nicardipine cardioplegia provided better cardiac performance in the early postoperative period and reduced release of the MB isozyme of creatine kinase, as determined during a 48-hour postoperative period. These results suggest that nicardipine added to cold potassium cardioplegic solution offers additional protection for the myocardium during ischemia and postischemic reperfusion in pediatric cardiac surgery.

[Noonan syndrome associated with atrial septal defect, ventricular septal defect and pulmonary stenosis--a case report]

A 10 year old girl with diagnosis of Noonan syndrome was admitted to our hospital because of easy fatiguability and cardiac murmur. She had a peculiar face with hypertelorism, saddle nose, webbed neck and kyphosis. Chromosomal analysis demonstrated normal 46 XX pattern. Associated cardiac anomalies in this case were atrial septal defect, ventricular septal defect and pulmonary stenosis caused by pulmonary valvular dysplasia. The cardiac anomalies were corrected successfully and postoperative clinical course was uneventful.

Detection of cardiac allograft rejection and myocyte necrosis by monoclonal antibody to cardiac myosin

Indium 111-labeled monoclonal antibody to cardiac myosin was examined for efficacy in the detection of cardiac graft rejection and rejection-related myocyte necrosis. Heterotopic heart transplants were performed in isogenic and allogenic groups of rats (n = 56). At selected intervals posttransplant, uptake of injected antibody in the donor and native hearts was determined by gamma scintillation scanning. Indium uptake was compared to histologic results graded for the severity of rejection and the presence of myocyte necrosis. The donor heart uptake of labeled antibody was significantly greater in both moderate rejection and severe rejection than in lesser degrees of rejection (P = 0.05). The donor/native heart antibody uptake ratio (AUR) in both severe and moderate rejection were significantly different from no or mild rejection (P = 0.05). In pooled grafts without myocyte necrosis, both the absolute donor heart antibody uptake and the donor/native heart AUR were significantly greater in grafts with moderate or severe rejection than in those with no or mild rejection (P less than 0.001). Among grafts with moderate or severe rejection, those with myocyte necrosis had greater donor heart antibody uptakes and greater donor/native heart AUR than grafts without myocyte necrosis (P less than 0.001). The grade of rejection and the presence of histologic myocyte necrosis appear to be closely related but independent variables, both of which influence antibody uptake. It is concluded that monoclonal antibody to cardiac myosin may be a useful noninvasive tool that could distinguish moderate or severe rejection from lesser degrees of rejection and that could detect the presence of myocyte necrosis.

[Legionella dumoffii and Legionella pneumophila serogroup 5 isolated from 2 cases of fulminant pneumonia]

We encountered two cases of legionella pneumonia which ran a dramatic course and isolated Legionella dumoffii from one patient and Legionella pneumophila serogroup 5 from the other patient. The patient from whom L. dumoffii was isolated was a 59-year-old male with no basic disease. He presented chill, fever, coughing and other symptoms, starting on July 3, 1986, his disease was diagnosed as pneumonia at the clinic of his company. The patient was then introduced and admitted to our hospital. On admission chest radiography disclosed zonal pneumonia with an unclear border in the right superior lobe of the lung; a beta-lactam preparation was administered, but no effect was obtained and the lung lesion showed a rapid advance. From this condition, we suspected legionella pneumonia and changed the therapy to treatment with erythromycin and rifampicillin. Despite this, no improvement occurred and the patient died on the 26th hospital day. Colonies like Legionella colonies were separated from a total of seven specimens of biopsy aspirated matter from the airway and autopsy collected lung abscess and tracheal secretions, and the bacterium was identified L. dumoffii based on the biochemical and serological properties. In addition, the patient's serum was found to have an increased antibody titer against L. dumoffii. Based on these findings, the patient's disease was diagnosed as pneumonia as caused by L. dumoffii, a relatively rare bacterium as a member of the genus Legionella. The patient from whom Legionella pneumophila serogroup 5 was isolated was an 81-year-old man with basic diseases such as heart failure, anemia and hypothyroidism. He presented fever, general fatigue, anorexia and other symptoms, starting around June 2, 1987; pneumonia was suspected and the patient was urgently admitted to our hospital. The patient died of pneumonia of unknown cause on the second hospital day. To clarify the cause, autopsy was conducted; a large number of colonies like Legionella colonies were noted in the lung tissue. Identification test was then conducted and the bacterium was identified as L. pneumophila; we concluded that the patient's pneumonia had been caused by the identified bacterium L. pneumophila. The isolate was further subjected to slide agglutination test and identified as L. pneumophila serogroup 5.

[Growth of tracheal anastomoses in growing animals]

Growth of the trachea after complete transection and anastomoses was studied in four equal groups (N = 7) of young New Zealand white rabbits (mean weight 1.19 +/- 0.19 kg). The trachea was transected below the 5th cartilagenous ring and immediately anastomosed. Suture materials and sewing techniques used for comparison were continuous 6-0 polypropylene, interrupted 6-0 polypropylene, continuous 6-0 polydioxanone (PDS) or interrupted 6-0 PDS. The animals were electively sacrificed between 95 and 98 days after surgery. Mean body weight increased to 2.7 +/- 0.18 kg. Mean cross sectional area (CSA) of the trachea at sacrifice at the anastomosis (A) and an average of CSA 5 mm above and below the anastomosis (B) were compared. The ratios (A/B) of each groups were 0.52 (continuous polypropylene), 0.62 (interrupted polypropylene), 0.58 (continuous PDS) and 0.80 (interrupted PDS), respectively. One way of analysis of variance revealed that growth of the tracheal anastomoses in interrupted PDS was significantly better (p less than 0.005) than other combinations. It was concluded that growth of the trachea following complete transection and anastomosis in a growing animal was significantly better with absorbable suture material and interrupted suturing technique.

Effect of reperfusion on the cardiac acetylcholine and norepinephrine contents in rat hearts

The effects of ischemia, reperfusion and hypoxia on the cardiac acetylcholine, choline, norepinephrine and cyclic AMP contents were investigated in isolated, spontaneously beating rat hearts perfused under constant pressure (100 cm H2O) with Krebs-Henseleit solution gassed with 95% O2-5% CO2. Acetylcholine, choline and norepinephrine were determined by high performance liquid chromatography with electrochemical detection. Cyclic AMP was determined by radioimmunoassay. One min reperfusion following 15 min ischemia (termination of perfusion) caused a significant decrease in both cardiac acetylcholine (P less than 0.05) and norepinephrine (P less than 0.01) contents, but had no significant effect on the cardiac norepinephrine/acetylcholine content ratio, or choline or cyclic AMP content. By contrast, 16 min ischemia did not significantly affect the cardiac acetylcholine, norepinephrine, choline or cyclic AMP content. Also, 16 min hypoxia (perfusion with Krebs Henseleit solution gassed with 95% N2 5% CO2) decreased the cardiac norepinephrine content significantly (P less than 0.01) and norepinephrine/acetylcholine content ratio slightly but not significantly. However, hypoxia had no significant effect on the cardiac acetylcholine, choline or cyclic AMP content. Pre-treatment with 10 microns atropine sulfate prevented the decrease in the cardiac acetylcholine content caused by reperfusion but caused a significant depletion in the cardiac norepinephrine content in the control (P less than 0.01) and ischemia (P less than 0.05) groups and a significant decrease in the norepinephrine/acetylcholine content ratio in all three groups (all, P less than 0.05). Extending the reperfusion period to 5 and 10 min following 15 min ischemia also caused a significant decrease in both cardiac acetylcholine and norepinephrine contents compared with the control groups. However, no significant difference in these contents was found between 1 min reperfusion group and 5 or 10 min reperfusion group. Twenty or 25 min ischemia alone did not significantly affect these contents. These findings suggest that reperfusion disturbs both the sympathetic and parasympathetic nervous systems in the heart and that pre-treatment with atropine adversely affects the balance of the autonomic nervous system.

Cardiac transplantation without cardiopulmonary bypass: experimental model to study growth of the transplanted heart

An experimental model using surface-induced (20 degrees C) deep hypothermia and total circulatory arrest instead of cardiopulmonary bypass was developed for the study of growth of the transplanted heart. Autotransplantation of the heart was performed in 42 young dogs weighing from 4.4 to 9.0 kg (mean, 6.9 kg). Time of ischemia ranged from 26.0 to 60 minutes (mean, 43.4 minutes). Return of satisfactory cardiac function occurred in all but one animal. An early high mortality rate was due primarily to pulmonary complications, but with modifications to the technique, long-term survival increased to 70%. Early deaths (5 days to 13 weeks) of five dogs during preliminary trials were due to pleural effusion (2), sepsis (1), endocarditis (1), and ascites (1). There have been 14 long-term survivors (range, 194 to 498 days; mean, 264 days). Long-term survivors appear well, are active, and show satisfactory growth. This experimental model eliminates the need for heparinization and reduces the potential for complications associated with cardiopulmonary bypass in the dog. It avoids cannulations that might impinge on anastomotic sites. This model appears to be suited for studying growth of the transplanted heart.

Experimental validation of Doppler echocardiographic measurement of volume flow through the stenotic aortic valve

In aortic stenosis, evaluation of aortic valve area by the continuity equation assumes that the volume of flow through the stenotic valve can be measured accurately in the left ventricular outflow tract. To test the accuracy of Doppler volume-flow measurement proximal to a stenotic valve, we developed an open-chest canine model in which the native leaflets were sutured together to create variable degrees of acute aortic stenosis. Left ventricular and aortic pressures were measured with micromanometer-tipped catheters. Volume flow was controlled and varied by directing systemic venous return through a calibrated roller pump and back to the right atrium. Because transaortic volume flow will not equal roller pump output when there is coexisting aortic insufficiency (present in 67% of studies), transaortic flow was measured by electromagnetic flowmeter with the flow probe placed around the proximal descending thoracic aorta, just beyond the ligated arch vessels. In 12 adult, mongrel dogs (mean weight, 25 kg), the mean transaortic pressure gradient ranged from 2 to 74 mm Hg, and transaortic volume flow ranged from 0.9 to 3.2 l/min. In four dogs, electromagnetic flow that was measured distal to the valve was accurate compared with volume flow determined by timed collection of total aortic flow into a graduated cylinder (n = 24, r = 0.97, electromagnetic flow = 0.87 Direct +0.13 l/min). In eight subsequent dogs, electromagnetic flow was compared with transaortic cardiac output measured by Doppler echocardiography in the left ventricular outflow tract as circular cross-sectional area [pi(D/2)2] x left ventricular outflow tract velocity-time integral x heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

[Levels of plasma cyclic AMP in cardiac surgery]

The actions of hormones such as catecholamines, vasopressin and growth hormones are mediated by a common intracellular second messenger, cyclic AMP (adenosine 3',5'-monophosphate). The effects of cardiac surgery on plasma cyclic AMP were studied in 32 adults patients with aorta-coronary bypass or with valvular disease. Blood specimens were obtained before operation, at the beginning and at the end of the cardiopulmonary bypass, 1, 3, 6, 9, 12, 24, 48, 72, 168 hours after surgery. The plasma cyclic AMP level during cardiac operation was elevated above the preoperative level. High levels of plasma cyclic AMP were found both in the aorta-coronary bypass and in the valvular disease immediately after the end of cardiopulmonary bypass. The plasma cyclic AMP level in patients undergoing aorta-coronary bypass with aortic clamping time more than 60 minutes was 38.6 +/- 11.7 pmol/ml, compared to 25.6 +/- 6.6 pmol/ml with aortic clamping time less than 60 minutes immediately after the end of cardiopulmonary bypass. In patients undergoing valve replacement and/or commissurotomy with aortic clamping time more than 60 minutes, the plasma cyclic AMP level immediately after the end of cardiopulmonary bypass was 113 +/- 63.3 pmol/ml, compared to 45.4 +/- 10.3 pmol/ml with aortic clamping time less than 60 minutes (p less than 0.01, Student's t test). During 24 hours after cardiac surgery, the plasma cyclic AMP concentration returned to normal range. It is considered that the plasma cyclic AMP level reflects the risk of cardiac surgery in response to homeostatic derangement.