Resynthesis of sternal dehiscence with autologous bone graft and autologous platelet gel.

Postoperative management of sternal dehiscence requires the organised effort of a multidisciplinary medical team, including orthopaedic surgeons, plastic surgeons, microbiologists, critical care nurses and rehabilitation experts. Clinical care of this complication impacts heavily on health-care costs, length of hospital stay, and the time to full recovery and return to regular work activity. There are various surgical approaches to sternal resynthesis, but they are often unsuccessful. In this paper, we describe the case of a 67-year-old male complaining of chronic pain due to sternal dehiscence after coronary artery bypass grafting surgery. We first report a technique for sternal resynthesis, performed in the cardiac surgery setting, using a combination of autologous bone graft and autologous platelet-derived gel (APG), and describe its postoperative management and outcome. The four-month follow-up was uneventful and a CT scan confirmed full healing of the nonunion site with solid bridging bone.

A critical review of the efficacy and safety in the use of low-molecular-weight heparin in acute ST-elevation myocardial infarction: a Bayesan approach.

BACKGROUND: ST segment elevation myocardial infarction (STEMI) is an important risk factor of death worldwide. Significant clinical research has been done to assess ideal reperfusion strategies in the setting of STEMI, including the role of the antithrombin agents: unfractionated heparin (UFH) and low molecular weight heparin (LMWH). Given the evidence that LMWH may be safer than UFH in the treatment of other thrombotic disorders, its role in the management of STEMI needs to be more defined. OBJECTIVE: To assess the safety and efficacy of LMWH compared to UFH and/or placebo for the treatment of STEMI. MATERIALS AND METHODS: The Cochrane Library, MedLine and EMABASE databases were searched for randomized controlled trials pertinent to the study objective. Selection criteria included all randomized controlled trials comparing LMWH to either UFH or placebo in the treatment of STEMI through December 2010. Two Authors performed the search independently.After identifying appropriate studies, a random effect model and Bayesian sensitivity analysis were used to combine results from original trials and assess the consistency of results. RESULTS: We identified 13 studies that met the described selection criteria; 8 comparing LMWH to UFH and 5 to placebo in STEMI patients. The combined Odd's ratio was 0.79 with a 95% confidence interval of 0.67-0.94 for all studies and 0.74 (0.54-1.02) for those comparing LMWH to UFH only. A trend toward more frequent hemorrhagic events was identified in the LMWH group (Odd's ratio 1.40) which did not meet statistical significance (95% confidence interval 0.80-2.47). Sensitivity analysis demonstrated clinical benefits of 6% and 12.5% with probabilities of 99% and 95% respectively. CONCLUSION: Compared to placebo or UFH, LMWH is effective as a first line treatment of STEMI patient with no significant increase in major hemorrhagic events.

Evaluation of ear function after cardiopulmonary bypass with otoacoustic emissions: a pilot study.

OBJECTIVES: During extracorporeal circulation (ECC) there is a great hemodynamic stress with possible impact on the microcirculation, including cochlear one. Previous studies have evaluated the effect of ECC on inner ear with contrasting results. The aim of this study is to evaluate possible modifications of the outer hair cells (OHC) function after open heart surgery (OHS) under ECC with transient evoked (TEOAEs) and distortion product otoacoustic emissions (DPOAEs). METHODS: Ten patients (5 F and 5 M), undergoing OHS with ECC, were subjected to an audiological assessment pre- and postoperatively. We compared the pre-operative and post-operative mean auditory thresholds, mean TEOAEs reproducibility and amplitude, and mean DPOAEs amplitude. Student's t-test was used to compare different values. RESULTS: No significant differences were found between pre- and post-operative audiological assessment both in hearing level and in otoacoustic emissions. CONCLUSION: OHC function seems to be not affected by hemodynamic stress induced by ECC. Further studies on a larger scale will be necessary to confirm our preliminary data.

Apoptosis and autoimmunity induced by clodronate in systemic lupus erythematosus mononuclear circulating cells.

The aim of this study is to evaluate the effect of clodronate on apoptosis of human systemic lupus erythematosus circulating mononuclear cells and to analyze possible correlations with changes in autoantibody production in vitro. Lympho-monocytes from 20 SLE patients were isolated and incubated with or without addition of 1 microM clodronate for 72 hours. Apoptosis and release of genomic material was assessed by immunofluorescent detection of cleaved caspase-3 and by Cell-Death-Detection ELISAPLUS kit (Roche). Anti-Nucleosome IgG and anti-dsDNA IgM and IgG autoantibody levels were determined in supernatants by commercially available ELISA kits. Clodronate induced apoptosis in monocytes as confirmed by cleaved caspase-3 immunostaining and by quantification of cleaved nucleosome in the supernatants (treated 0.22+/-0.05 O.D. vs untreated 0.09+/-0.04 O.D.; P less than 0.001). This finding was coupled with a significant increasing in supernatants of IgG anti-Nucleosome (treated 6.5+/-1.1 vs untreated 5.5+/-0.6 IU/mL; p=0.001) and IgM (treated 3.0+/-1.3 vs 2.2+/-0.9 IU/mL; p=0.02) and IgG (treated 4.0+/-1.8 vs untreated 2.8+/-1.5 IU/mL; p=0.02) anti-dsDNA autoantibody levels. Our findings stressed the pro-apoptotic activity of clodronate, as well as its potential autoimmunity induction in SLE mononuclear circulating cells. Clinical studies could clarify the role of bisphosphonates on autoantibody production and worsening of disease activity.

Apoptotic molecular mechanisms implicated in autoimmune diseases.

Apoptosis is a programmed cell death that represents a normal component of the development, differentiation and health of multicellular organisms leading to an adequate cellular turnover and homeostasis. In autoimmune diseases, the immune system recognizes various autoantigens causing damage in target organs. Dead cells represent an important source of autoantigens that, in particular conditions, can represent a stimulus for an autoimmune response. A large number of studies reported the impairment of the apoptosis regulatory mechanisms in immune cells as a pivotal element in the pathogenesis and evolution of autoimmune disorders. Several pathogenetic pathways have been claimed to account for autoimmunity development during apoptotic processes. In fact, interestingly abnormalities potentially leading to immune disorders have been described as occurring in each step involved in apoptosis, from the very beginning to the post death phenomena. In this extent we propose a systematic review of the molecular mechanisms strictly leading to apoptosis with particular interest to their alterations, potentially causing tissue specific and/or systemic autoimmunity.

Usefulness of the axillary artery as vascular access for cardiopulmonary bypass.

AIM: In this paper we report our clinical experience with extended utilization of axillary artery cannulation for cardiopulmonary bypass (CPB) and discuss the indications and the results of the procedure in terms of complications and usefulness. METHODS: Between January 1999 and May 2004, 26 patients underwent right axillary artery cannulation for CPB. Fifteen patients presented acute type A aortic dissection and were operated urgently. Axillary cannulation was also used in 11 elective cases: 3 reoperative coronary surgery, 3 valve redo-operations and 5 cases of aortic valve regurgitation+aneurysm of the ascending aorta. RESULTS: All axillary artery cannulations were successful (21 direct and 5 with a side graft) without neurologic or vascular injuries to the right upper extremities. Hospital mortality was 7.7% and included 2 patients operated in an emergency procedure because of acute type A aortic dissection. In all cases, this cannulation site provided adequate perfusion, with a range of peak flows from 4.1 to 5.7 L/min. CONCLUSION: Our preliminary results demonstrate that the right axillary artery may be considered an alternative cannulation site for achieving full CPB and providing antegrade flow, thus avoiding complications related to retrograde flow when femoral artery perfusion is performed. This safe and useful method may be used not only in aortic surgery but in other such complex cardiac procedures as redo-operations.

Prognostic significance of endothelial dysfunction in hypertensive patients.

BACKGROUND: Forearm endothelial dysfunction, characterized by an impaired vasodilating response to acetylcholine (ACh), may be associated with several cardiovascular risk factors, including essential hypertension. Although the prognostic value of coronary endothelial dysfunction has been demonstrated, that of forearm endothelial dysfunction is still unknown. Methods and Results-- Endothelium-dependent and -independent vasodilation was investigated in 225 never-treated hypertensive patients (age, 35 to 54 years) by intra-arterial infusion of increasing doses of ACh and sodium nitroprusside. Patients were divided into tertiles on the basis of their increase in ACh-stimulated forearm blood flow (FBF) from basal: group 1, from 30% to 184%; group 2, from 185% to 333%; and group 3, from 339% to 760% increase from basal. During a mean follow-up of 31.5 of months (range, 4 to 84 months), there were 29 major adverse events at the cardiac (n=19), cerebrovascular (n=9), or peripheral vascular (n=1) level. Events included myocardial infarction, angina, coronary revascularization procedures, stroke, transient cerebral ischemic attack, and aortoiliac occlusive disease. Event rate per 100 patient-years was 8.17, 4.34, and 2.02 in the first, second, and third tertiles of peak percent increase in FBF during ACh infusion. The excess risk associated with an FBF increase in the first tertile was significant (relative risk, 2.084; 95% CI, 1.25 to 3.48; P=0.0049) after controlling for individual risk markers, including 24-hour ambulatory blood pressure. CONCLUSIONS: Our data suggest that forearm endothelial dysfunction is a marker of future cardiovascular events in patients with essential hypertension.

Nitric oxide modulation of neutrophil-endothelium interaction: difference between arterial and venous coronary bypass grafts.

OBJECTIVES: This study sought to evaluate the relation between the pattern of neutrophil-endothelial adhesion in saphenous vein (SV) and internal mammary artery (IMA) grafts and the endothelial production of nitric oxide (NO). BACKGROUND: Autologous IMA and SV grafts (SVGs) are increasingly used as conduits for coronary bypass grafting. Previous studies have demonstrated a greater production of endothelial-derived relaxing factor (NO) from IMA than from SVGs. Because of the well known role of NO in modulating the adhesion of polymorphonuclear leukocytes to the endothelium, we studied the pattern of neutrophil adhesion to the endothelium of IMA and SVs under basal conditions and after inhibition of NO synthesis. METHODS: Segments of IMA and SVs were obtained from 20 patients undergoing coronary artery bypass graft surgery. We evaluated the adhesion of both unstimulated and activated neutrophils to the endothelial surface of IMA and SVs in both basal conditions and after inhibition of NO synthesis with Nomega-nitro-L-arginine methyl ester. RESULTS: Under basal conditions, no difference in unstimulated neutrophil adhesion to endothelium was observed between the two vessel conduits. After neutrophil activation, a significantly (p < 0.05) greater adhesion of neutrophils was observed in the SV than in the IMA. After inhibition of NO release, the adhesion of activated neutrophils increased in both vessels, and no significant difference between them was observed. The increased adhesion was attenuated by both L-arginine and sodium nitroprusside. CONCLUSIONS: The lesser neutrophil adhesion to the endothelium of the IMA is a consequence of enhanced release of NO at this level; this effect could be responsible for the better early and long-term patency of this conduit over the SVG in coronary bypass grafting.

Calcium antagonist isradipine improves abnormal endothelium-dependent vasodilation in never treated hypertensive patients.

OBJECTIVE: To examine whether middle (two months) and long-term (six months) isradipine sustained-release treatment improves endothelium-dependent vasodilation in never treated hypertensive patients. METHODS: The responses of the forearm vasculature to acetylcholine (7.5, 15 and 30 micrograms/min) and sodium nitroprusside (0.8, 1.6, 3.2 micrograms/min) were evaluated in 12 normotensive controls (seven men and five women, aged 25 to 49 years), and in 12 hypertensives (eight men and four women, aged 20 to 47 years) at baseline and after two and six months of isradipine sustained-release treatment. Drugs were infused into the brachial artery, and forearm blood flow was measured by strain-gauge plethysmography. RESULTS: At baseline, the response to acetylcholine was significantly lower in hypertensives vs controls: at the highest dose (30 micrograms/min), forearm blood flow was 28.6 +/- 2.4 ml/100 ml of tissue per min in the controls vs 8.9 +/- 1.0 ml/100 ml of tissue per min in hypertensive (p < 0.0001). Similarly, vascular resistance was significantly (p < 0.0001) higher in hypertensives: 4.8 +/- 0.5 units (controls) vs 15.1 +/- 1.7 units (hypertensives). After isradipine treatment, the forearm blood flow in hypertensive patients changed from 8.9 +/- 1.0 ml/100 ml of tissue per min to 16.0 +/- 1.2 ml/100 ml of tissue per min (two months; p < 0.0001) and 15.2 +/- 1.4 ml/100 ml of tissue per min (six months; p < 0.0001). Isradipine treatment did not modify the vasodilating effect of sodium nitroprusside. CONCLUSIONS: Our data demonstrate for the first time that the calcium antagonist isradipine improves acetylcholine-induced vasodilation in hypertensives.

Hypertensive left ventricular remodeling and ACE-gene polymorphism.

OBJECTIVE: To evaluate the relationship between ACE-gene polymorphism and left ventricular geometry in never treated hypertensives. METHODS: We enrolled 200 hypertensive outpatients that underwent clinical and ambulatory blood pressure measurements, echocardiographic evaluation and analysis for insertion (I)/deletion (D) polymorphism by PCR. Patients with normal or increased (> 125 g/m2 in males and > 110 g/m2 in females) left ventricular mass were considered to have concentric remodeling or concentric left ventricular hypertrophy if their relative wall thickness was > or = 0.45. RESULTS: The left ventricular mass index values (g/m2) were 136 +/- 30 in DD genotype, 124 +/- 26 in ID genotype, and 116 +/- 20 in II genotype (DD vs. ID P < 0.005; DD vs. II P < 0.05), and were unrelated to blood pressure. Ninety-six patients presented left ventricular hypertrophy (48.0%): 51 with concentric and 45 with eccentric hypertrophy. The eccentric left ventricular hypertrophy was detected in 32 (36.8%) DD patients, in ten (10.5%) ID patients (P < 0.05), and in three (16.6%) II patients. The relative septal thickness was 0.43 +/- 0.09 in DD genotype, 0.45 +/- 0.08 in ID genotype, and 0.43 +/- 0.10 in II genotype. In DD and ID genotypes, the relative posterior wall thickness (0.37 +/- 0.07 vs. 0.41 +/- 0.07; P < 0.0001) and the end-diastolic left ventricular internal dimension (52.8 +/- 3.3 mm vs. 48.3 +/- 2.8 mm; P < 0.0001) were statistically different. CONCLUSIONS: The DD genotype of the ACE-gene is associated with an increased left ventricular mass and with a significantly higher prevalence of eccentric left ventricular hypertrophy, when compared to ID genotype.

Effects of atorvastatin and vitamin C on endothelial function of hypercholesterolemic patients.

We tested the effects of vitamin C and atorvastatin treatment on endothelium-dependent and endothelium-independent vasodilation in 18 hypercholesterolemic patients (ten men and eight women, aged 20-46 years) in comparison with 12 normal volunteers (seven men and five women, aged 20-45 years). The responses of the forearm blood flow (FBF) to acetylcholine (ACh) (7.5, 15 and 30 microg/min), sodium nitroprusside (SNP) (0.8, 1.6, 3.2 microg/min) and L-NMMA (2, 4, 8 micromol/min) were evaluated at baseline and after 1 month of atorvastatin (10 mg/day) treatment. Drugs were infused into the brachial artery and FBF was measured by strain-gauge plethysmography. At baseline, the response to ACh was significantly attenuated in hypercholesterolemics versus controls: at the highest dose (30 microg/min), FBF was 27.0+/-3.4 versus 11.5+/-1.9 ml.100 ml tissue(-1).min(-1) respectively (P<0.0001). No significant differences were found between groups during SNP infusion. The atorvastatin treatment significantly improved ACh-stimulated FBF: at highest dose the FBF increased to 14.9+/-1.5 ml.100 ml tissue(-1). min(-1) (P<0.0001). Similarly, the L-NMMA endothelial effects were significantly enhanced by lipid-lowering treatment, supporting the improvement of basal nitric oxide. Vitamin C increased ACh-vasodilation in the same way before and after atorvastatin treatment. In conclusion, the endothelial dysfunction in hypercholesterolemics is due to an oxidative stress and atorvastatin rapidly improves both basal and stimulated endothelium-dependent vasodilation.

Emergency thoracoabdominal aortic aneurysm repair: clinical outcome.

OBJECTIVE: Emergency repair of thoracoabdominal aortic aneurysm remains a formidable operation with high morbidity and mortality. Although advanced surgical and perioperative care techniques have reduced the risks in elective repair of these aneurysms, the mortality rate has remained high when emergency surgery is performed. We have evaluated the outcome of patients undergoing emergency repair of thoracoabdominal aortic aneurysm. METHODS: Of 47 consecutive patients with thoracoabdominal aortic aneurysm observed from January 1993 to September 1998, 19 required an emergency operation. Twelve had a ruptured aneurysm and 7 an acute dissection. Twelve type I, 3 type II, 1 type III, and 3 type IV thoracoabdominal aortic aneurysms (Crawford's classification) were diagnosed. All patients were operated on via a thoracolaparotomy with partial femoral-femoral extracorporeal circulation. The cerebrospinal fluid pressure was monitored, and the aorta was replaced with a vascular graft. Patent intercostal arteries were reimplanted when feasible. RESULTS: The early (30-day) mortality was 42.1%; there were 2 late deaths. Complications in the 11 surviving patients are summarized as follows: paraplegia/paraparesis, 3 cases; renal, 4 cases; pulmonary, 4 cases; cardiac, 1 case; cerebrovascular, 1 case; and reexploration for bleeding, 1 case. Hemodialysis and aortic dissection were predictive factors of hospital mortality. CONCLUSIONS: Our surgical experience in emergency repair of thoracoabdominal aortic aneurysm must be considered encouraging in terms of late outcome despite the in-hospital mortality of 42.1% and serious postoperative complications in the surviving patients. Moreover, our results show that acute aortic dissection and the need for hemodialysis are predictive factors for mortality.

Inhibition by dipyridamole of neutrophil adhesion to vascular endothelium during coronary bypass surgery.

BACKGROUND: Release of reactive oxygen radicals by activated neutrophils and neutrophil adhesion to endothelial cells have been observed after cardiopulmonary bypass. The aim of the present study was to evaluate the effects of preoperative dipyridamole treatment on neutrophil superoxide anion generation and endothelial cell-neutrophil interactions. METHODS: Two groups of patients scheduled for elective coronary artery bypass grafting were randomized to receive oral dipyridamole or a placebo. Nitro blue tetrazolium scores of circulating neutrophils, neutrophil CD11b/CD18 expression, and their adhesion to human umbilical vein endothelial cells were assayed before anesthesia, 30 minutes after the beginning of cardiopulmonary bypass, at the end of bypass, and 60 minutes postoperatively. RESULTS: In both groups, cardiopulmonary bypass resulted in a significant increase in nitro blue tetrazolium scores in circulating neutrophils as well as a significant increase in both neutrophil CD11b/CD18 expression and neutrophil adhesion to endothelial cells. The extent of neutrophil superoxide anion generation was higher in the control group; a significant (p < 0.01) reduction in neutrophil adhesion to endothelial cells was observed 1 hour postoperatively in the dipyridamole group. In 5 patients treated with dipyridamole, the incubation of activated polymorphonuclear leukocytes with adenosine deaminase significantly increased their adhesion to endothelial cells (p < 0.05). CONCLUSIONS: Our study demonstrated that preoperative treatment with oral dipyridamole significantly reduces both neutrophil superoxide anion generation and extent of neutrophil adhesion to endothelial cells after coronary bypass grafting procedures with cardiopulmonary bypass. The mechanism is probably mediated by endogenous adenosine.

Intermittent warm blood cardioplegia preserves myocardial beta-adrenergic receptor function.

BACKGROUND: Left ventricular dysfunction is frequently observed in patients after hypothermic cardioplegic arrest, and often inotropic intervention is necessary for patients to be successfully weaned from cardiopulmonary bypass (CPB). A myocardial beta-adrenergic receptor (beta AR) desensitization has been noted to occur after hypothermic CPB in patients undergoing coronary artery bypass grafting. This randomized study was undertaken to determine the effect of cardioplegic solution temperature on cardiac beta ARs. METHODS: Two groups of patients (20 patients in each) scheduled for elective coronary artery bypass grafting underwent CPB with either intermittent warm or cold blood cardioplegia. The density of the beta ARs, the proportion of beta 1- to beta 2-adrenergic receptors, and the beta AR coupling capacity to adenylate cyclase were determined in specimens of the right atrial tissue at baseline, during CPB, and after discontinuation of CPB. Plasma concentrations of catecholamines were also measured in both arterial and coronary sinus samples. RESULTS: In both cardioplegia groups, no significant modification in either the beta AR density or the proportion of beta 1- to beta 2-adrenergic receptors was detected. However, a significant decrease in adenylate cyclase activity after stimulation with isoproterenol was observed in the cold blood cardioplegia group during CPB (p < 0.01) and 30 minutes after its discontinuation (p < 0.05). Moreover, a significant decrease in adenylate cyclase activity during CPB was detected in this group after stimulation with sodium fluoride (p < 0.05), but this pattern was found to be completely reversed by 30 minutes after discontinuation of CPB. No modification in the basal or stimulated adenylate cyclase activity was observed in the warm blood cardioplegia group during or after CPB. CONCLUSIONS: Our results confirm the finding from previous studies of a cardiac beta AR desensitization after hypothermic cardioplegic arrest, and provide evidence of the advantages of intermittent warm blood cardioplegia in preserving the autonomic sympathetic function of the heart.

Protection by coenzyme Q10 from myocardial reperfusion injury during coronary artery bypass grafting.

To evaluate the effect of coenzyme Q10 in reducing postoperative cardiac complications after ischemia and reperfusion, we randomly divided 40 patients undergoing elective coronary artery bypass into two groups: patients in group 1 received coenzyme Q10 (150 mg/day) for 7 days before operation, and those in group 2 were the control group. Concentrations of thiobarbituric acid-reactive substances (malondialdehyde), conjugated dienes, and cardiac isoenzymes of creatine kinase were measured in samples from both arterial and coronary sinus sites. Serial sampling was performed 5 minutes after heparin administration, at 10 and 30 minutes during cardiopulmonary bypass, 15 and 30 minutes after aortic cross-clamp removal, and 5 minutes after protamine administration. The concentrations of malondialdehyde, conjugated dienes, and creatine kinase in group 1 were significantly lower than those in group 2. The decrease in plasma malondialdehyde concentrations correlated positively with the decrease in creatine kinase levels in the coronary sinus. The treatment group showed a significantly lower incidence of ventricular arrhythmias during the recovery period than did the control group (p < 0.05). Although the percentage of patients requiring inotropic agents was not significantly different between the two groups, the mean dosage of dopamine required to maintain stable hemodynamics was significantly lower in patients of group 1 than in those of group 2 (p < 0.01). Our findings suggest that pretreatment with coenzyme Q10 may play a protective role during routine bypass grafting by attenuating the degree of peroxidative damage.

Magnetic resonance imaging and abdominal wall hernias in aortic surgery.

BACKGROUND: The aim of this study was to evaluate the incidence of abdominal wall hernias (AWH) in patients operated on for abdominal aortic aneurysm (AAA) compared with patients treated for aortoiliac occlusive disease. The efficacy of MRI in early diagnosis of AWH also was studied. STUDY DESIGN: One hundred fourteen patients operated for either AAA (51 patients, group A) or aortoiliac occlusive disease (63 patients, group B) constitute the study. The presence of AWH onset was evaluated by clinical observation followed by ultrasonography. Data acquired by ultrasonography were compared with those obtained by MRI to determine the efficacy of this diagnostic tool in all 114 patients. The prevalence of inguinal hernias in both groups also was determined. RESULTS: A significant difference was found in the incidence of AWH. AWH developed in 31.7% (16 of 51) of group A patients and 17.4% (11 of 63) of group B patients (p < 0.03). A significant prevalence ofinguinal hernias was detected in group A (p < 0.01). The Cox hazard regression analysis revealed as independent predictors of postoperative AWH only the presence of AAA and a history of laparotomy. CONCLUSIONS: Ours and other studies recall collagen synthesis disorders to explain the statistical association observed among AAA, inguinal hernias, and AWH. MRI, especially in patients at risk, appears to be an effective diagnostic approach to early detection of AWH.

Collagen network remodelling and left ventricular function in constrictive pericarditis.

OBJECTIVE: To investigate whether patients with constrictive pericarditis have changes in collagen content and architecture that could influence left ventricular function. DESIGN: Cohort study. SETTING: University teaching hospital. PATIENTS: Biopsy specimens of myocardium from 13 patients admitted consecutively for treatment of chronic constrictive pericarditis were compared with normal heart tissue taken at necropsy from 15 patients free of cardiac disease. INTERVENTION: Pericardiectomy through median sternotomy. Biopsy specimens (4 or 5) were taken from the left ventricular free wall. MAIN OUTCOME MEASURES: Biochemical and histological assessment of total collagen content, relative proportion of type I and III collagen, and amount of orthogonal collagen fibre meshwork (crosshatching) in the left ventricular tissue. RESULTS: There was more collagen in the myocardium of patients with constrictive pericarditis than in controls when measured either biochemically by hydroxyproline content (89.4 v 50.4 mg/g dry weight) or by histological measurement of the collagen fraction of the myocardium (2.4% v 7.0%). Neither of these measurements, however, correlated with left ventricular ejection fraction, pulmonary wedge pressure, or right ventricular end diastolic pressure. The thickness of the fibrous trabeculae in the myocardium was, however, inversely related to both left ventricular ejection fraction (r = -0.76) and deceleration time (r = -0.68). Trabecular thickening was also related to NYHA class, with those in class III and IV having the greatest thickening. CONCLUSION: Changes in collagen content and architecture may contribute to impaired ventricular function in patients with chronic constrictive pericarditis.

Improved beta-adrenergic receptor function after coronary artery bypass grafting in patients with congestive heart failure.

BACKGROUND: To evaluate whether coronary artery bypass grafting (CABG) in patients with congestive heart failure (CHF) modifies beta-adrenergic receptor dysfunction, we measured lymphocytic beta-adrenergic receptor density and function, and plasma catecholamine levels in patients with congestive ischaemic disease scheduled for CABG. METHODS: Assays were performed on 20 patients with CHF at admission and 6 months following CABG; 20 age-matched healthy subjects served as the control group. RESULTS: Preoperative lymphocyte beta-adrenergic receptor density was significantly reduced in patients with CHF compared with the control group. Similarly, basal adenylyl cyclase as well isoproterenol- and NaF-stimulated adenylyl cyclase activity was significantly reduced in lymphocytic membranes of patients with CHF compared with controls. Conversely, no difference was found in forskolin-stimulated adenylyl cyclase activity between the two groups of patients. Preoperatively, plasma levels of both noradrenaline and adrenaline were significantly higher in patients with CHF compared with the control group. CABG was associated with clinical and haemodynamic improvement in all patients. Lymphocyte beta-adrenergic receptor density and function were also improved. Basal beta-adrenergic receptor density improved from 39.2 +/- 1.7 to 46 +/- 1.5 fmol/mg protein. Basal adenylyl cyclase activity increased from 33.1 +/- 2.6 40 +/- 2.4 pmol/mg protein per min; a significant increase in activity stimulated by isoproterenol (from 41.5 +/- 3.1 to 61 +/- 3.8 pmol/mg protein per min) and by NaF (from 71.8 +/- 2.7 to 85.3 +/- 3.5 pmol/mg protein per min) was also observed. Although postoperative plasma catecholamine levels tended to decrease, the difference compared with preoperative values was not significant. CONCLUSION: The results of our study indicate that CABG in patients with CHF is accompanied by the restoration of an almost normal functional state of the lymphocytic beta-adrenergic receptor system.

Pseudoaneurysm of the thoracic aorta in patients with human immunodeficiency virus infection.

Arterial pseudoaneurysm has been reported as a possible complication of immunodeficiency virus infection. We report two cases of HIV-positive patients with a pseudoaneurysm at the level of the descending thoracic aorta. The first patient refused surgery and has been followed up to 14 months, whereas the second patient underwent successful surgical repair. The importance of magnetic resonance imaging in the diagnosis of thoracic aorta pseudoaneurysm is also discussed.

Suppressed fibrinolysis after administration of low-dose aprotinin: reduced level of plasmin-alpha2-plasmin inhibitor complexes and postoperative blood loss.

Various clinical investigation have shown that aprotinin therapy reduces bleeding after open-heart operations. In this study low-dose aprotinin, 30,000 KIU/kg in the cardiopulmonary bypass (CPB) priming volume and 7,500 KIU/kg intravenously each hour during CPB, was used in ten patients undergoing primary myocardial revascularization or surgery for valvular diseases. Another ten patients served as controls. Blood loss, platelet count and plasma levels of hemoglobin, antithrombin III, fibrinogen, fibrinogen degradation products (FDP), total plasmin inhibitor and alpha2-plasmin inhibitor-plasmin complexes were evaluated at nine preoperative, intraoperative and postoperative points. Intraoperative and postoperative blood loss was significantly reduced in the aprotinin group. There was no significant difference between the two groups in platelet count and levels of hemoglobin and antithrombin III. A significant increase in FDP during CPB in the control group indicated hyperfibrinolysis. The levels of plasmin inhibitor were significantly reduced during CPB in the control group. The alpha 2-plasmin inhibitor-plasma complex levels, indicating the plasmin activity, were significantly reduced in the aprotinin group. These results confirmed that low-dose aprotinin reduced blood loss with the prevention of hyperfibrinolysis during CPB and demonstrated improved hemostasis.