Risk stratification scores for predicting mortality in coronary artery bypass surgery.

BACKGROUND: Four risk-stratification scores (RSSs - Euro, French, CCS/Higgins, Parsonnet) were tested as predictors of mortality in coronary artery bypass grafting (CABG) surgery. METHODS: From March to April 2000, the perioperative courses of 245 consecutive CABG patients were compared to the predictions according to the RSSs. Sensitivity and specificity were determined with receiver operating characteristics (ROC) curves. RESULTS: CCS/Higgins uses the most easily acquired patient data, and rates emergency conditions as high-risk. Euro focuses on advanced age and septal rupture. French uses the smallest number of patient parameters and rates rare critical situations as high-risk. Parsonnet is partially based on the physician's subjective assessment of a "catastrophic state," making the scoring arbitrary. All RSSs gave similar (not significant) areas under the ROC curves regarding mortality (Euro 0.826 +/- 0.080, French 0.783 +/- 0.094, CCS/Higgins 0.820 +/- 0.060, Parsonnet 0.831 +/- 0.042). Predicted risk levels for the 11 patients who died differed between the RSSs--Higgins placed these patients in 3 of 5 risk levels with ascending distribution. The other RSSs placed these patients in the highest risk level except for one and two patients, respectively, who were placed in the lowest Euro and French risk level. Euro and Parsonnet placed about half of all patients with non-lethal outcome in the highest risk level. CONCLUSIONS: All RSSs satisfactorily estimated the group risk for mortality. No RSS expressed sufficient validity to predict individuals with lethal outcome. In clinical use, CCS/Higgins proved the most practicable.

Continuous antegrade blood cardioplegia: cold vs. tepid.

BACKGROUND: Continuous antegrade blood cardioplegia (CABCP) is used at different temperatures. We investigated the consequences of CABCP at 6 degrees C (COLD) vs. 28 degrees C (TEPID). METHODS: Anesthetized open-chest pigs (25 +/- 2 kg) were placed on cardiopulmonary bypass (CPB). The hearts were arrested for 30 min by 6 degrees C cold or 28 degrees C tepid CABCP (n = 8 each). After an initial 3 min antegrade application of high potassium (20 mEq) cold (6 degrees C) blood cardioplegia, the hearts were arrested for a subsequent 27 min by normokalemic blood delivered antegrade at either 6 degrees C or 28 degrees C. After this, the hearts underwent perfusion with warm systemic blood for an additional 30 min on CPB. Biochemical cardiac data (MVO2 [ml/min/100 g], release of creatine kinase [CK U/min/100 g] and lactate [mg/min/100 g]) were measured during CPB. Total tissue water content (%) and left ventricular stroke work index (SWI g x m/kg) were determined 30 min after discontinuation of CPB and compared to pre-CPB controls. RESULTS: Cold CABCP kept all hearts continuously arrested. The COLD hearts showed no biochemical or functional disturbance. The TEPID hearts intermittently fibrillated and required additional high potassium BCP shots. The TEPID hearts showed a marked CK leakage (2.6 +/- 0.4 vs. 0.7 +/- 0.4), lactate production (4.0 +/- 1.6 vs. extraction from the COLD group) despite the non-ischemic protocol, an impaired initial oxygen consumption (4.2 +/- 1.3 vs. 7.1 +/- 1.6) at the end of cardiac arrest, the formation of myocardial edema (79.5 +/- 1.0 vs. 77.0 +/- 0.8), and a depressed recovery of SWI (0.69 +/- 0.15 degrees vs. 1.41 +/- 0.13). *p < 0.05 for comparison of TEPID vs. COLD hearts using Student's t-test for unpaired data; degrees p < 0.05 for intergroup-comparison of TEPID vs. COLD vs. controls using ANOVA adjusted for repeated measures. CONCLUSIONS: Uninterrupted cardioplegia can be safely performed with cold normokalemic CABCP. In contrast, tepid normokalemic CABCP leads to fibrillation, jeopardizes the heart, and should be avoided.UND

Extent of myocardial tissue damage during transmyocardial laser revascularization with the CO2 Heart Laser.

OBJECTIVE AND BACKGROUND: Transmyocardial laser revascularization (TMR) is the only surgical treatment for patients with severe diffuse coronary artery disease, who are not candidates for bypass grafting or percutaneous angioplasty. However, vaporization of tissue during the creation of channels leads to a certain loss of viable myocardium during every TMR procedure. METHODS: We analyzed serum levels of creatine kinase and creatine kinase MB subtype in 163 patients after sole TMR with a CO2 laser (wave length 10.6 microm, 800-watt power). The control group consisted of 35 consecutive CABG patients and 30 consecutive redo-CABG patients. Additionally, in the TMR group we measured echocardiographically the left ventricular ejection fraction before and after TMR. We recorded the total amount of laser energy applied, average and maximum energy per channel, and the number of created channels, in order to calculate the correlation between these parameters and postoperative enzyme levels or changes in the LVEF. RESULTS: After TMR, we measured higher creatine kinase levels compared to those in CABG patients (607.8+/-558.4 U/L vs. 285.0+/-292.3 U/L, p < 0.01). The relative proportion of CK-MB of total CK, however, was significantly lower after TMR, compared to that of the control group (4.5+/-3.0% vs. 10.1+/-6.4%, p < 0.01). Patients with a pronounced postoperative increase in CK-MB levels or a higher percentage of CK-MB of total CK also after TMR operations show a decline in left ventricular contractility. In the laser group, the maximum enzyme levels were detected significantly later than in the control group (25.0+/-19.4 h postoperatively vs. 8.7+/-9.1 h, p < 0.01). There was no significant correlation between the technical laser parameters or the number of created channels and the percentage of CK-MB of total CK or changes in left ventricular ejection fraction. CONCLUSIONS: CO2 laser TMR does not result in significant injury to the myocardium. Cardiac enzymes play an important role in the detection of perioperative myocardial infarction in TMR patients.

Risk scores currently used in German heart surgery.

BACKGROUND: Risk scores (RS) in heart surgery assess mortality and morbidity and mirror the degree of severity of disease of the patients when presented for surgery. We examined the use and dissemination of RS in Germany. MATERIAL AND METHODS: Our survey included 79 German heart surgery institutes in Fall 1999 and Winter 2000. RESULTS: Four institutes did not respond. Out of 75 (ad 100 %) responders 56 (75 %) institutes did not use RS, 17 (22 %) institutes used one RS method and 2 (3 %) institutes used two RS methods. The most frequently applied RS methods were the Cleveland Clinic Score and the Euro Score (n = 7, each) followed by institution-specific, internally developed RS methods (n = 5), Parsonnet's RS (n = 1) and the RS from the STS database (n = 1). Fourteen institutes used RS for internal quality control. Of these, 2 institutes publish their RS data for external quality control. The patient-related individual procedure risk was used in 6 institutes. CONCLUSIONS: A quarter of the German heart surgery institutes use one or more RS methods. The most commonly used were the Cleveland Clinic Score and the Euro Score, followed by internally developed RS methods. RS methods were most frequently used for internal quality control. The degree of the severity of disease of the patients who presented for surgery could only be compared between a small number of institutes using the same RS.

Cold continuous antegrade blood cardioplegia: high versus low hematocrit.

OBJECTIVE: Cold continuous antegrade blood cardioplegia (CCABCP) is used with different hematocrit values. We investigated the consequences of CCABCP with low hematocrit (LH: 20-25%) versus high hematocrit (HH: 40-45%). METHODS: Anesthetized open chest pigs (25 kg) were placed on cardiopulmonary bypass (CPB). The hearts were arrested for 30 min by 6 degrees C CCABCP with either LH or HH (n=8, each): After an initial 3 min application of high potassium (20 mEq) BCP the hearts were arrested for subsequent 27 min by normokalemic 6 degrees C cold blood delivered continuously antegradely. Thereafter the hearts underwent perfusion with warm systemic blood for an additional 30 min on CPB. Biochemical cardiac data (MVO(2) (ml min(-1)100 g(-1)), release of creatine kinase (CK; units min(-1)100 g(-1))) and lactate (mg min(-1)100 g(-1))) and the coronary vascular resistance index (CVRI (mmHg ml(-1)ming)) were measured during CPB. Total tissue water content (%) and left and right ventricular stroke work indices (LV-and RV-SWI (g m kg(-1))) were assessed 30 min after discontinuation of CPB and compared to pre-CPB controls. RESULTS: The hearts of the LH group had no biochemical or functional disturbance. The HH group showed marked CK leakage (0.6+/-0.2* vs. 0.1+/-0.1, *P<0.05 for comparison of LH vs. HH with Student's t-test for unpaired data), impaired initial oxygen consumption (4+/-1* vs. 7+/-1) after cardiac arrest, an increased CVRI (82+/-12* vs. 50+/-8), the formation of myocardial edema (81.0+/-1.3* vs. 77.5+/-1.2), and poor functional recovery (LVSWI 0.2+/-0.1* vs. 1.0+/-0.1; RVSWI 0.1+/-0.1* vs. 0.5+/-0.1). The absence of lactate production in both groups was in accord with the non-ischemic protocol. CONCLUSIONS: CCABCP with a low hematocrit of 20-25% is cardioprotective. In contrast, CCABCP with a high hematocrit of 40-45% jeopardizes the heart despite avoiding ischemic periods, and should be avoided.

[Metastasizing malignant germ cell tumor of the testis with infiltration of the thoracic aorta--a case for metastasis surgery]. / Metastasierender maligner Keimzelltumor des Hodens mit Infiltration der Aorta thoracica--Kasuistik zur Metastasenchirurgie.

HISTORY AND FINDINGS: A 33-year-old man was admitted 7 years after a testicular teratomatous carcinoma had first been diagnosed, treated by a right orchiectomy and two-stage radical retroperitoneal lymphadenectomy. Five years later the first mediastinal metastases were treated with high-dosage chemotherapy and autologous germ-cell transplantation, and remaining paraaortic--mediastinal tumour tissue was resected. Two years later another tumour at that site was only partially resected. A curing treatment seemed impossible, because the aortic wall had been invaded. TREATMENT AND COURSE: Five months after re-thoracotomy the metastasis and the invaded aortic segment were resected, the latter replaced by a vascular prosthesis. Histology indicated metastasis of a malignant teratoma of intermediate type. There has been no evident recurrence in the last 20 months. CONCLUSION: Combined orchidectomy, lymphadenectomy, high-dosage chemotherapy with cisplatin and autologous germ-cell transplantation at present constitute the standard treatment of malignant testicular germ-cell tumour. In case of metastatic infiltration of vital structures, such as the aortic wall, special operative procedures can prolong the period of remission when the success of a standard treatment seems limited.

Batista procedure: elliptical modeling against spherical distention.

OBJECTIVE: Batista's cardio-reduction of mass and diameter changes the geometry of the left ventricle (LV). This in vivo study explores the LV changing from spherical distention to elliptic modeling. METHODS: Nineteen pigs were connected to cardio-pulmonary bypass (CPB), five of them without cardiac alteration (controls). The LV of the other fourteen pigs was incised between the left anterior descending and the circumflex arteries. Myocardial protection with the beating open method was used. In seven pigs, the LV incision was closed by direct suture to assess the surgical trauma of the Batista procedure (incision). In the other seven pigs a pericardial patch was placed for spherical distention of the LV as a model of heart failure (sphericalization). Patch removal and LV closure restored the normal cardiac geometry (elliptical modeling). Ventricular function was evaluated with Frank-Starling curves (stroke work index, SWI), with endsystolic elastance (EES) and diastolic compliance (beta(-1)) by impedance catheter, and with ejection fraction (EF) by transesophageal echocardiogram. Data were recorded after ventriculotomy, after sphericalization and after elliptical modeling (before and 30 min after discontinuation of CPB). RESULTS: CPB did not significantly alter controls' hemodynamic. Ventriculotomy decreased cardiac function (as % vs. post CPB-controls: SWI* 63 +/- 4; EES 93 +/- 2; beta(-1)* 86 +/- 5). Sphericalization additionally impaired the function (as % vs. ventriculotomy: SWI* 57 +/- 4; EES* 60 +/- 7; beta(-1)* 45 +/- 8). The elliptical modeling greatly improved ventricular performance (as % vs. sphericalization: SWI** 156 +/- 5; EES** 162 +/- 8; beta(-1)** 177 +/- 7; EF** 216 +/- 5) (P < 0.05 for Student's unpaired* and paired** t-test). CONCLUSIONS: Spherical distention of the left ventricular dimensions causes cardiac decompensation. The surgical trauma of the Batista procedure impairs the LV performance. However, the spherically distended LV benefits from Batista's cardio-reduction by elliptical modeling.

Hypocalcemia in piglets reduces cardiac and pulmonary vascular disturbance after hypoxemia and reoxygenation during cardiopulmonary bypass.

BACKGROUND: Placing cyanotic newborns on cardiopulmonary bypass (CPB) and performing abrupt reoxygenation affects myocardial performance. This study tests the hypothesis that hypocalcemia is beneficial in this circumstance of reoxygenation. METHODS: Twenty-one newborn piglets (anesthetized, open-chests) were placed for one hour on CPB. Seven piglets under normoxic and normocalcemic conditions were the controls. The other piglets underwent hypoxemia and subsequent reoxygenation, for periods of 30 minutes each, under normo-calcemic (Normo-Ca++, n= 7) or hypocalcemic conditions (Hypo-Ca++, n=7). Thirty minutes after discontinuation of CPB, the hemodynamic function was assessed taking into account stroke work indices (SWI), end systolic elastance (EES), pulmonary vascular resistance index (PVRI), cardiac release of conjugated dienes (CD) and creatine phosphokinase (CK), and myocardial oxygen consumption (MVO2). These parameters were expressed as a percentage of the pre-CPB value. The endogenous antioxidant reserve capacity (AORC) of ventricular wall specimens was determined by in-vitro lipid peroxidation forming malondealdehyde (nmol MDA/g protein). RESULTS: After one hour of CPB the cardiac performance returned to normal range without any functional or metabolic disturbance. The normocalcemic condition resulted in a hardly impaired cardiac performance (42%**SWI; 67%**EES), an augmented PVRI (more than 4-fold**), and highly elevated release of CD and CK (3-fold** each). The Normo-Ca++ group's MVO2 (95 +/- 14%) was unaltered. The hypocalcemic condition improved the myocardial function to near control value (85% SWI; 91 % EES) and attenuated the augmentation of the PVRI (n.s. vs. Control group) down to 64% of the Normo-Ca++ group's level. The release of CD and CK in the Hypo-Ca++ group (both n. s. vs. Control group) only minimally increased. The Hypo-Ca++ group's MVO2 improved (137+/-8%*). The MDA formation was worse (344+/-38**) in the Normo-Ca++ group, but unaltered in the Hypo-Ca++ group (203+/-9; n.s. vs. Control group (218+/-20)). * =p<0.05 vs. Controls and Normo-Ca++, ** =p<0.05 vs. Controls and Hypo-Ca++, using ANOVA. CONCLUSIONS: Hypocalcemia during hypoxemia and subsequent reoxygenation highly attenuates myocardial and pulmonary vascular disturbance in newborn piglets. This condition of low blood calcium protects cardiac function and metabolism as well as the pulmonary vascular tone due to diminished myocyte membrane damage, reduced cellular membrane lipid peroxydation, and improved endogenous antioxidant reserve capacity.

Influence of different routes of flush perfusion on the distribution of lung preservation solutions in parenchyma and airways.

OBJECTIVE: The present study was performed to investigate the influence of different routes of perfusion on the distribution of the preservation solutions in the lung parenchyma and upper airways. METHODS: Pigs were divided into four groups: control (n = 6), pulmonary artery (PA) (n = 6), simultaneous PA + bronchial artery (BA) (n = 8), and retrograde delivery (n = 6). After preparation and cannulation, cardioplegia solution and Euro-Collins solution (ECS) for lung preservation were given simultaneously. After removal of the heart, the double lung bloc was harvested. Following parameters were assessed: total and regional perfusion (dye-labeled microspheres), tissue water content, PA, aorta, left atrial and left ventricular pressures, cardiac output and lung temperature. RESULTS: Our data show that flow of the ECS in lung parenchyma did not reach control values (9.4+/-1.0 ml/min per g lung wet weight) regardless of the route of delivery (PA 6.3+/-1.5, PA + BA 4.8+/-0.9, retrograde 2.7+/-0.9 ml/min per g lung wet weight). However, flow in the proximal and distal trachea were significantly increased by PA + BA delivery (0.970+/-0.4, respectively, 0.380+/-0.2 ml/min per g) in comparison with PA (0.023+/-0.007, respectively, 0.024+/-0.070 ml/min per g), retrograde (0.009+/-0.003, respectively, 0.021+/-0.006 ml/min per g) and control experiments (0.125+/-0.0018, respectively, 0.105+/-0.012 ml/g per min). Similarly the highest flow rates in the right main bronchus were achieved by PA + BA delivery (1.04+/-0.4 ml/min per g) in comparison with 0.11+/-0.03 in control, 0.033+/-0.008 in PA, and 0.019+/-0.005 ml/min per g in retrograde group. Flows in the left main bronchus were 0.09+/-0.02 ml/min per g in control, 0.045+/-0.012 ml/min per g in PA, and 0.027+/-0.006 ml/min per g in retrograde group. The flow rates were significantly (P = 0.001) increased by PA + BA delivery of the storage solution (0.97+/-0.3 ml/min per g). CONCLUSIONS: Our data show that the distribution of ECS for lung preservation is significantly improved in airway tissues (trachea and bronchi) if a simultaneous PA + BA delivery is used.

Restoring the remodeled enlarged left ventricle: experimental benefits of in vivo porcine cardioreduction in the beating open heart.

Conceptual models have been used to assess the efficacy of cardioreduction (i.e., Batista procedure) because in vivo models were not available. This study reproduces an experimental angiographic model of heart failure by placing a large pericardial patch to sphericalize the left ventricle. Patch removal restored an elliptical normal cardiac shape. Cardioreduction was evaluated in 20 mini-pigs on cardiopulmonary bypass. Myocardial protection with a beating open method was used and cardioplegia was not used. Studies were made after an LV incision (i.e., circumflex marginal artery occlusion with the Batista incision). A large pericardial patch sphericalized the left ventricle, and LV closure by patch removal restored normal cardiac shape (ellipse). Ventricular function was evaluated by inscribing Starling curves to fill the heart systolic elastance (Ees, conductance catheter), and surface echocardiogram for fiber shortening. After defining LV function in normal hearts on bypass only, an LV incision to divide the median ramus circumflex artery was made. This ventriculotomy reduced stoke work (SW) 37% +/- 4%, but did not change elastance (Ees) or SW/end-diastolic volume (EDV) significantly. Using the LV incision function as control, patch placement reduced SW 33% +/- 4%, Ees 40% +/- 3%, and SW/EDV 44% +/- 7% and decreased fiber shortening 43% +/- 5% by echocardiogram. Patch removal restored stroke work, SW/EDV, and Ees, and echocardiograms returned to normal values after LV incision. Ventricular function after patch removal was unchanged when the beating open cardioprotective technique was used. We conclude that sphericalization of left ventricular dimensions by pericardial patch placement causes cardiac failure that is relieved by restoring the ellipsoid shape by patch removal. These findings support the value of restoration of an elliptical shape by surgical cardioreduction, when the beating open ventricle is used for myocardial protection.

Endothelial stunning and myocyte recovery after reperfusion of jeopardized muscle: a role of L-arginine blood cardioplegia.

Ischemia and reperfusion may damage myocytes and endothelium in jeopardized hearts. This study tested whether (1) endothelial dysfunction (reduced nitric oxide release) exists despite good contractile performance and (2) supplementation of blood cardioplegic solution with nitric oxide precursor L-arginine augments nitric oxide and restores endothelial function. Among 30 Yorkshire-Duroc pigs, 6 received standard glutamate/aspartate blood cardioplegic solution without global ischemia. Twenty-four underwent 20 minutes of 37 degrees C global ischemia. Six received normal blood reperfusion. In 18, the aortic clamp remained in place 30 more minutes and all received 3 infusions of blood cardioplegic solution. In 6, the blood cardioplegic solution was unaltered; in 6, the blood cardioplegic solution contained L-arginine (a nitric oxide precursor) at 2 mmol/L; in 6, the blood cardioplegic solution contained the nitric oxide synthase inhibitor L-nitro arginine methyl ester (L-NAME) at 1 mmol/L. Complete contractile and endothelial recovery occurred without ischemia. In jeopardized hearts, complete systolic recovery followed infusion of blood cardioplegic solution and of blood cardioplegic solution plus L-arginine. Conversely, contractility recovered approximately 40% after infusion of normal blood and blood cardioplegic solution plus L-NAME. Postischemic nitric oxide production fell 50% in the groups that received blood cardioplegic solution and blood cardioplegic solution plus L-NAME but was increased in the group that received blood cardioplegic solution L-arginine. In vivo endothelium-dependent vasodilator responses to acetylcholine recovered 75% +/- 5% of baseline in the blood cardioplegic solution plus L-arginine group, but less than 20% of baseline in other jeopardized hearts. Endothelium-independent smooth muscle responses to sodium nitroprusside were relatively unaltered. Myeloperoxidase activity (neutrophil accumulation) was similar in the blood cardioplegic solution (without ischemia) and blood cardioplegic solution plus L-arginine groups (0.01 +/- 0.002 vs 0.013 +/- 0.003 microgram/gm tissue). Myeloperoxidase activity was raised substantially to 0.033 +/- 0.002 microgram/gm after exposure to normal blood and to 0.025 +/- 0.003 microgram/gm after infusion of blood cardioplegic solution and was highest at 0.053 +/- 0.01 microgram/gm with exposure to blood cardioplegic solution plus L-NAME in jeopardized hearts. The discrepancy between contractile recovery and endothelial dysfunction in jeopardized muscle can be reversed by adding L-arginine to blood cardioplegic solution.

Submitral left ventricular tuberculoma.

A 62-year-old woman suffered from increasing dyspnea and an impaired general condition. Chest roentgenograms and echocardiogram showed a dense mass at the left atrioventricular junction resulting in the preoperative working diagnosis of a myocardial myxoma. Intraoperatively, an isolated tuberculoma was found caudal to the posterior leaflet of the mitral valve. This case report describes the successful surgical and postoperative medical treatment of an isolated myocardial tuberculoma.

Distribution of lung preservation solutions in parenchyma and airways: influence of atelectasis and route of delivery.

BACKGROUND: Bronchial healing remains one of the dominant issues in lung transplantation. Among other factors the quality of airway protection during lung procurement may contribute to improve bronchial healing. METHODS: Thirty-three pigs were divided into four groups: controls (n = 6), those receiving antegrade delivery of Euro-Collins solution with (n = 4) and without prostacyclin (n = 9), and those receiving retrograde delivery of Euro-Collins solution (n = 14). In addition, the atelectatic and nonatelectatic regions of the lungs from all groups were compared. After preparation and cannulation, cardioplegic solution and Euro-Collins solution for lung preservation were given simultaneously. After removal of the heart the double-lung bloc was harvested. During each experiment lungs were assessed by the following methods: dye-labeled microspheres for total and regional lung perfusion, tissue water content, pulmonary artery, left atrial and left ventricular pressures, cardiac output, lung temperature, and microscopic examination. Data were expressed as mean +/- standard error of the mean. RESULTS AND CONCLUSIONS: Our data show that (1) injection of modified dye-labeled microspheres is a useful method to determine absolute flow in lung parenchyma and airways, (2) determination of tissue water content is a simple and reproducible method to investigate the distribution of hyperosmolar lung preservation solutions, (3) atelectasis leads to a significant maldistribution of lung preservation solutions regardless of the route of delivery (0.7 +/- 0.2 versus 6.5 +/- 1.0 ml/min/gm lung wet weight, p = 0.0001) and a severe increase in water content (80.6% +/- 0.4% versus 79.0% +/- 0.5%, p = 0.024), (4) prostacyclin added to the pulmonary artery flush solution results in only a slight improvement in the distribution, and (5) retrograde delivery of Euro-Collins solution through the left atrium is technically feasible and seems to improve flow to the airways even without the addition of prostacyclin.

Circulating endothelin in patients undergoing coronary artery bypass grafting.

Increased synthesis of endothelin, (a powerful physiological vasoconstrictor), is a uniform response to endothelial injury and has been associated with myocardial ischemia and reperfusion. This study tests the hypothesis that coronary artery bypass grafting (CABG) affects endothelin plasma concentrations in various vascular beds. Twenty-four CABG patients were included in this study. Endothelin was determined in multiple plasma specimens obtained from superior vena cava, aortic root and coronary sinus (CS). Venous endothelin plasma concentrations collected in CABG patients before surgery were 1.16 +/- 0.18 pg/ml. They increased after sternotomy (1.71 +/- 0.12 pg/ml) and during (2.97 +/- 0.27 pg/ml) and after cardiopulmonary bypass (CPB, 2.72 +/- 0.21 pg/ml). There is no net release of endothelin from the coronary circulation before (aorta 2.26 +/- 0.13 pg/ml vs CS 2.44 +/- 0.17 pg/ml, not significant (n.s.), during (cardioplegia 2.55 +/- 0.17 pg/ml vs CS 2.45 +/- 0.15 pg/ml, n.s.), and after aortic cross-clamping (aorta 2.95 +/- 0.23 pg/ml vs coronary sinus 2.71 +/- 0.18 pg/ml, n.s.). Pulmonary endothelin clearance is preserved on partial bypass (aorta 2.26 +/- 0.13 pg/ml vs vena cava 2.86 +/- 0.18 pg/ml, P < 0.003), but remains inhibited even 10-30 min after release of the aortic cross-clamp (aorta 2.95 +/- 0.23 pg/ml vs vena cava 2.97 +/- 0.27 pg/ml, n.s.). Two out of 24 patients had severe myocardial ischemia. These patients showed particularly high endothelin concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

[An isolated tuberculoma in the left ventricle]. / Isoliertes myokardiales Tuberkulom im linken Ventrikel.

In the course of 8 weeks, a 62-year-old woman with chronic bronchitis developed increasing dyspnoea on effort and reduced well-being. The chest radiograph revealed a round focus, 2 x 3 cm, in the region of the left ventricle which, from the results of echocardiography and left-heart catheterization, suggested myxoma. At open-heart surgery under extracorporeal circulation an encapsulated tumour was found on the mural leaflet of the mitral valve, directly caudal of the atrioventricular plane. On opening, the capsule contained dough- or paste-like, yellowish-white substance with scattered polygonal granules, typical of a tuberculoma. The entire contents and capsule were excised. Immediately after operation tuberculostatic treatment was initiated (three times daily ethambutol, 400 mg, and once daily rifampicin, 600 mg, and isoniazid, 300 mg), even though acid-fast rods were not demonstrated histologically and by culture. Polymerase chain reaction, however, established the presence of Mycobacterium tuberculosis in the resected material. There was no evidence of florid tuberculosis in the subsequent course.

Alpha-adrenoceptor mediated facilitation of acetylcholine release in the rat perfused heart.

Rat hearts were isolated with the vagus nerves intact and perfused, and the neuronal acetylcholine stores were pulse labeled with [14C]choline. The overflow of [14C]choline/acetylcholine evoked by extrinsic vagus nerve stimulation (3 Hz and 720 pulses or 10 Hz and 1200 pulses) was determined by liquid scintillation spectrometry and used as a measure for acetylcholine release. The postjunctional changes in atrial contraction and beating frequency were also recorded. Compared to controls, oxymetazoline and xylometazoline [but not clonidine, (3,4-dihydroxyphenyl-amino)-2-imidazoline), methoxamine and norepinephrine] enhanced the evoked overflow of 14C-activity in a concentration-dependent manner without changing the ratio between choline and acetylcholine determined by paper chromatography. Norepinephrine (10 mumol/l) inhibited the evoked overflow in the presence of propranolol plus yohimbine. The oxyme-tazoline-induced increase in evoked overflow was unaffected by rauwolscine (1 mumol/l), idazoxan (0.3 and 5 mumol/l), and yohimbine (0.3 and 5 mumol/l), but significantly reduced by phentolamine (5 mumol/l), prazosin (0.03 mumol/l), the (-)-enantiomer of WB 4101 (0.1 mumol/l) and SK&F 104078 (3 mumol/l). The overflow of 14C-activity evoked by field stimulation was increased by oxymetazoline the absence and presence of hemicholinium-3. The results are compatible with an alpha-1 adrenoceptor-mediated facilitation of exocytotic acetylcholine release from the rat heart in vitro. The increase in evoked neurotransmitter overflow, however, was not accompanied by an increase in postjunctional heart responses to vagus stimulation due to nonselective blocking properties of the facilitating agonists.