Right ventricular function during weaning from mechanical ventilation after coronary artery bypass grafting: effect of volume loading

The inter-incisal distance and dimension of the interdental papilla between the mandibular incisors were examined in cyclosporin A (CSA) fed rats over 6 weeks. Rats in the test group received CSA daily in mineral oil by gastric feeding (30 mg/kg body weight); the control group received mineral oil only. The inter-incisal distance and gingival dimensions, including bucco-lingual width and vertical height, were assessed biweekly from alginate impressed stone models. Animals were sacrificed at the end of the study and tissue sections were obtained from the anterior region of the mandible for histopathological evaluation. Both the inter-incisal distance and the dimension of the interdental papilla were significantly greater in CSA-exposed animals compared to control. The significant alteration appeared earlier in the papillary dimensions than that in the interdental distance. Particular histopathological alterations of the soft and hard tissues of the periodontium were observed in CSA-exposed animals. Within limitations of the study, we suggest that the CSA-induced gingival overgrowth may offer an active force contributing to observed tooth movement, however, remarkable alveolar remodeling should be considered as an undetermined factor for the movement.     

Managing pain after coronary artery bypass surgery

From June 1992 to May 1993, rotaviruses were detected by an immunoenzymatic assay in 159 (49.5%) of 321 children admitted to the hospital with acute diarrhea. Of the 159 cases ELISA positive, 80 samples were chosen at random to investigate subgroups and serotypes of group A human rotavirus. By the ELISA test 9 (11.3%) of the strains were subgroup I, 46 (57.5%) were subgroup II, and 25 (31.3%) could not be grouped. The serotype G1 was identified in 52 cases (65%), G2 in 11 cases (13.8%), G3 in 1 case (1.2%), and 7 cases (8.8%) showed more than one serotype. By electrophoretic analysis of viral RNA, 137 (42.7%) of the samples exhibited an RNA pattern. The long pattern (59.1%) prevailed over the short pattern (35.8%), and by coelectrophoresis 8 different electropherotypes were found throughout the period of study. These results illustrate the great variety of rotavirus strains in this region of the country.     

PET scan predicts recovery of left ventricular function after coronary artery bypass operation

BACKGROUND: Viable but hypocontractile myocardium can show functional improvement after revascularization (hibernation). It is sometimes difficult, however, to predict viability and recovery in patients with severe left ventricular function. This study sought to identify possible predictive factors of recovery of cardiac function after revascularization in patients with three-vessel disease. METHODS: Positron emission tomography (fluoro-18-deoxyglucose uptake for metabolism; nitrogen 13-labeled ammonia for flow) and equilibrium-gated nuclear angiography (for the global ejection fraction) were performed in 59 patients with three-vessel disease before and after undergoing coronary artery bypass grafting. The positron emission tomographic data were expressed as match normal (flow and metabolism normal), mismatch (low flow, high metabolism), match viable (moderate decrease in flow and metabolism), and match necrosis (low flow and metabolism). RESULTS: Stepwise logistic regression analysis showed that only mismatch regions played a significant role in predicting postoperative improvement in function (p = 0.019). There were 1.7 +/- 1.5 mismatch regions in 31 patients who showed an improvement in their ejection fraction (0.47 +/- 0.14 versus 0.58 +/- 0.11; mean +/- standard deviation) versus 0.8 +/- 1.0 mismatch regions (p = 0.017) in patients who did not show recovery. There was more pronounced functional improvement with increasing numbers of mismatch regions, and patients with at least one mismatch region had a high likelihood of recovery (p < 0.001). In patients with a very low preoperative ejection fraction and two or more mismatch regions, there was early significant recovery (0.27 +/- 0.08 versus 0.46 +/- 0.06; p = 0.009). CONCLUSIONS: At least one mismatch region must be present for there to be a postoperative functional benefit. When a low left ventricular ejection fraction is associated with mismatch, early recovery is substantial.     

Long-term outcome when major complications follow coronary artery bypass graft surgery. Recovery after complicated coronary artery bypass graft surgery

OBJECTIVE: To determine whether information available 1 week after surgery correlates with long-term function in patients who suffer major complications after coronary artery bypass graft (CABG) surgery. DESIGN: An inception cohort study. SETTING: A 526-bed community teaching hospital. PATIENTS: All 67 patients who required at least 7 days of CT-ICU care following 2,751 consecutive CABG operations. MAIN OUTCOMES: Hospital survival, long-term survival, and functional ability at long-term follow-up. RESULTS: Forty-three patients survived hospitalization (64%), while 24 died 37 +/- 45 days (range, 7 to 190 days) after surgery. When 42 patients were surveyed 22 +/- 9 months after surgery, 21 of the survivors enjoyed excellent, independent function, 7 were moderately impaired but living at home, 6 were institutionalized with severe limitations, and 8 had died. Patients with very severe cardiac or neurologic dysfunction 1 week after surgery had an extremely poor outcome. When mechanical ventilation was required for causes other than primary failure of the respiratory system, long-term function and hospital survival were poor. Twelve of 14 patients with pulmonary complications survived hospitalization, and all 12 were alive at long-term follow-up. CONCLUSION: More than half of patients requiring 7 days or more of ICU treatment after CABG surgery survive, and many enjoy excellent long-term function. However, those with very severe cardiac or neurologic dysfunction 1 week after surgery have little chance for independent recovery.     

Predicting the occurrence of adverse events after coronary artery bypass surgery

Approximately 15% of patients with mitral valve disease will experience left atrial thrombosis and its consequences. The etiology and diagnosis of left atrial thrombosis are reviewed, stressing the importance of blood stagnation as the most important etiologic factor. Atrial fibrillation, a left atrial diameter greater than 60 mm and absence of significant mitral regurgitation are predictors of left atrial thrombosis in mitral stenosis. Left atrial thrombus can be detected in 50% of patients with all three factors; all influence blood stagnation. Smoke-like echoes in the left atrium, detected by echocardiography, provide a semi-quantitative assessment of left atrial blood stagnation. The incidence of thrombi in patients with well marked smoke-like echoes is 60%, while in those without this echocardiographic finding it is only 9%. Smoke-like echoes provide an early warning system of conditions in the left atrium likely to lead to thrombosis unless the patient is anticoagulated.     

Potential advantages of treatment of transplanted saphenous vein aorto-coronary artery bypass grafts with beta irradiation to prevent graft occlusion

Intimal proliferation or Neointimal hyperplasia (NIH) is a vascular lesion that often arises in arteries after balloon angioplasty or other vessel wall injuries. FIH is a vascular lesion that develops in autologous saphenous vein grafts (SVG) after transplantation into the aorto-coronary circulation or the peripheral vascular circulation. FIH shares elements of smooth muscle migration, proliferation and fibrous tissue deposition in common with nibrointimal proliferation (NIH). Either NIH of a coronary artery or FIH of a SVG obstruct the vascular lumen and result in myocardial dysfunction. Local radiotherapy has been used for several decades to reduce the post-operative recurrence of the fibrovascular proliferations of pterygia and keloids. Similarly, in animal and human experiments, endovascular radiotherapy has been shown to reduce arterial smooth muscle proliferation. Consideration of the similarities of vascular smooth muscle cell proliferation in NIH and FIH leads one to suggest that endovascular beta irradiation can reduce FIH as well as it reduces NIH. The goal of such treatment is to achieve a clinically significant decrease in the morbidity and mortality resulting from SVG occlusions. The potential for large reduction of the consequences of SVG occlusion, the very large number of patients at risk, and the simplicity of the proposed intervention encourages prompt scientific evaluation of this technique.     

Short- and long-term prognosis after coronary artery bypass grafting in relation to smoking habits

A study was conducted to determine the conditions needed to achieve the equilibrium concentration for the epimerization of d-lysergic acid diethylamide (LSD) to iso-LSD. The reaction was followed by integration of the C-9 resonance of LSD and iso-LSD by proton nuclear magnetic resonance (NMR). The C-9 resonance of LSD and iso-LSD appear as singlets at 6.35 and 6.27 ppm respectively. Starting with pure LSD, the conversion to iso-LSD is attained at temperatures above 37 degrees C and pH levels over 7.0. At a pH of 7.0 or higher, the LSD/iso-LSD ratio of 9:1 is achieved after one week at 45 degrees C or two weeks at 37 degrees C. Starting with iso-LSD, the conversion to LSD requires more vigorous conditions. The 9:1 LSD/iso-LSD ratio is attained only after 6 weeks at a temperature of 45 degrees C and a pH of 9.7. At lower pH levels, the reaction proceeds more slowly. The 9:1 LSD/iso-LSD ratio is achieved whether the starting material is LSD or iso-LSD and therefore represents an equilibrium concentration (K = 9). In addition, the more vigorous conditions needed to achieve equilibrium of iso-LSD to LSD demonstrate the difficulty in extraction of the epimerizable proton of iso-LSD. This study is the first to quantitate the epimerization of LSD by NMR techniques and establishes the conditions needed to induce epimerization in solution.     

Two cases of total arch replacement after coronary artery bypass surgery with internal mammary artery graft

We report two successful cases of total arch replacement after coronary artery bypass surgery (CABG) using internal mammary artery graft (ITA). Case 1 had a true aneurysm of the distal aortic arch occurring 7 years after CABG using left ITA, and case 2 had a dissecting aneurysm of DeBakey II occurring 10 months after CABG using right ITA. This patient was also complicated by a preexisting true aneurysm of the proximal descending aorta. Both cases were managed by repeat midsternal incision, selective cerebral perfusion (SCP) and retrograde cardioplegia. In both cases, functioning ITAs were dissected out easily without injury, and an operative filed for total arch replacement was well obtained under the cardioplegia and brain protection mentioned above.     

Effects of age on activity patterns after coronary artery bypass surgery

By screening for new seed color mutations, we have identified a new gene, pale aleurone color1 (pac1), which when mutated causes a reduction in anthocyanin pigmentation. The pac1 gene is not allelic to any known anthocyanin biosynthetic or regulatory gene. The pac1-ref allele is recessive, nonlethal, and only reduces pigment in kernels, not in vegetative tissues. Genetic and molecular evidence shows that the pac1-ref allele reduces pigmentation by reducing RNA levels of the biosynthetic genes in the pathway. The mutant does not reduce the RNA levels of either of the two regulatory genes, b and c1. Introduction of an anthocyanin structural gene promoter (a1) driving a reporter gene into maize aleurones shows that pac1-ref kernels have reduced expression resulting from the action of the a1 promoter. Introduction of the reporter gene with constructs that express the regulatory genes b and c1 or the phlobaphene pathway regulator p shows that this reduction in a1-driven expression occurs in both the presence and absence of these regulators. Our results imply that pac1 is required for either b/c1 or p activation of anthocyanin biosynthetic gene expression and that pac1 acts independently of these regulatory genes.     

Thrombogenic and atherogenic lipid modifications in plasma and patients with coronary artery disease and after coronary artery bypass surgery

BACKGROUND: Although multiple studies have shown that the left ventricular assist device (LVAD) improves distorted cardiac geometry, the pathological mechanisms of the "reverse remodeling" of the heart are unknown. Our goal was to determine the effects of LVAD support on cardiac myocyte size and shape. METHODS AND RESULTS: Isolated myocytes were obtained at cardiac transplantation from 30 failing hearts (12 ischemic, 18 nonischemic) without LVAD support, 10 failing hearts that received LVAD support for 75+/-15 days, and 6 nonfailing hearts. Cardiac myocyte volume, length, width, and thickness were determined by use of previously validated techniques. Isolated myocytes from myopathic hearts exhibited increased volume, length, width, and length-to-thickness ratio compared with normal myocytes (P<0.05). However, there were no differences in any parameter between myocytes from ischemic and nonischemic cardiomyopathic hearts. Long-term LVAD support resulted in a 28% reduction in myocyte volume, 20% reduction in cell length, 20% reduction in cell width, and 32% reduction in cell length-to-thickness ratio (P<0.05). In contrast, LVAD support was associated with no change in cell thickness. These cellular changes were associated with reductions in left ventricular dilation and left ventricular mass measured echocardiographically in 6 of 10 LVAD-supported patients. CONCLUSIONS: These studies suggest that the regression of cellular hypertrophy is a major contributor to the "reverse remodeling" of the heart after LVAD implantation. The favorable alterations in geometry that occur in parallel fashion at both the organ and cellular levels may contribute to reduced wall stress and improved mechanical performance after LVAD support.     

Landmarks in the development of coronary artery bypass surgery

Genetic linkage maps have been produced for a wide range of organisms during the last decade, thanks to the increasing availability of molecular markers. The use of microsatellites (or Simple Sequence Repeats, SSRs) as genetic markers has led to the construction of "second-generation" genetic maps for humans, mouse and other organisms of major importance. We constructed a second-generation single-tree genetic linkage map of Norway spruce (Picea abies K.) using a panel of 72 haploid megagametophytes with a total of 447 segregating bands [366 Amplified Fragment Length Polymorphisms (AFLPs), 20 Selective Amplification of Microsatellite Polymorphic Loci (SAMPLs) and 61 SSRs, each single band being treated initially as a dominant marker]. Four hundred and thirteen markers were mapped in 29 linkage groups (including triplets and doublets) covering a genetic length of 2198.3 cM, which represents 77.4% of the estimated genome length of Picea abies (approximately 2839 cM). The map is still far from coalescing into the expected 12 chromosomal linkage groups of Norway spruce (2n = 2x = 24). A possible explanation for this comes from the observed non-random distribution of markers in the framework map. Thirty-eight SSR marker loci could be mapped onto 19 linkage groups. This set of highly informative Sequence Tagged Sites (STSs) can be used in many aspects of genetic analysis of forest trees, such as marker-assisted selection, QTL mapping, positional cloning, gene flow analysis, mating system analysis and genetic diversity studies.     

Perception of cognitive function in older adults following coronary artery bypass surgery.

This study examined the effects of coronary artery bypass grafting (CABG) on objective and subjective measures of neurocognitive functioning. Participants were 170 older patients (127 men and 43 women; mean age?=?61 years) undergoing CABG. Measures of neurocognitive function, depression, anxiety, and perceived cognitive abilities were administered immediately prior to and 6 weeks following surgery. Although objective measures of impaired cognitive performance following CABG were not related to perceived cognitive difficulties, the presence of anxiety and depression was related to the perception of cognitive functioning. Patients who reported high levels of anxiety and depression 6 weeks after surgery perceived themselves as having poorer cognitive function. Interventions designed to reduce emotional distress could improve patient's perceived cognitive abilities following CABG. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anomalous origin of left coronary artery from pulmonary artery: recovery of left ventricular function after dual coronary repair

OBJECTIVES: We reviewed our institutional experience with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) after dual coronary repair to assess preoperative variables predictive of outcome, the time course for postoperative recovery of cardiac function, the short- and long-term complications and our experience with left ventricular assist devices (LVAD) in these patients. BACKGROUND: Outcome after surgical repair of ALCAPA remains incompletely defined. METHODS: The surgical records and echocardiograms of 42 patients were reviewed. Left ventricular function was assessed by fractional shortening z-score (FSz) and stress-velocity index. RESULTS: The overall survival rate was 86%. All six patients who died were < 1 year old and died within 3 days of the operation. More severe preoperative mitral regurgitation (MR) was associated with increased mortality, but age, body surface area, preoperative FSz and end-diastolic dimension were not. We used an LVAD for 7 of 28 patients who underwent repair for ALCAPA since its introduction at our institution, with a survival of 5 of 7 patients. The degree of MR improved in 62% of patients and remained unchanged in 38%. Complications included supravalvar pulmonary stenosis (16 of 21 patients) and baffle leaks (11 of 21 patients) with the intrapulmonary baffling technique. Supravalvar pulmonary stenosis developed in 1 of 11 patients after direct coronary reimplantation. Left ventricular function became normalized in all 28 patients with follow-up past 1 year, regardless of preoperative FSz. Of 13 patients who underwent serial postoperative echocardiography, the average time to normalization of function was 2 to 7 months. CONCLUSIONS: The degree of preoperative MR was predictive of outcome, whereas the severity of preoperative cardiac dysfunction and ventricular dilation were not. Mild and moderate MR tended to improve without mitral valvuloplasty. Complete recovery from myocardial dysfunction is expected after dual coronary repair of ALCAPA.     

Early effects of coronary artery bypass surgery and cold cardioplegic ischemia on left ventricular diastolic function: evaluation by computer-assisted transesophageal echocardiography

OBJECTIVE: Although left ventricular (LV) systolic function undergoes a temporary decrease after cardiopulmonary bypass (CPB) in patients undergoing coronary artery bypass grafting (CABG), data on the effects of CABG and cardioplegic arrest on LV diastolic function are contradictory. The objective of the present study was to further evaluate the effects of CABG and CPB on LV diastolic function. DESIGN: A prospective study. SETTING: A multi-institutional investigation at a university hospital. PARTICIPANTS: 20 patients on beta-receptor antagonists, scheduled for CABG and with a preoperative ejection fraction over 0.5. INTERVENTIONS: Central hemodynamic measurements, transesophageal LV short-axis images, and mitral Doppler flow profiles were obtained before and after volume loading that in turn was performed both before surgical incision and after weaning from CPB. MEASUREMENTS AND MAIN RESULTS: Heart rate, cardiac output, and peak atrial filling velocity increased; systemic vascular resistance decreased; whereas stroke volume, LV area ejection fraction, deceleration rate and slope of early diastolic filling, time-velocity integral of early diastolic filling, and the ratio between early and atrial peak filling velocity were unchanged post-CPB compared with pre-CPB. LV end-diastolic stiffness that was calculated for each patient pre-CPB and post-CPB using the formula: P = B*eS*A), where P is the LV filling pressure and A is the end-diastolic short-axis area, was unchanged post-CPB compared with pre-CPB. CONCLUSIONS: Both the active and passive components of LV diastolic function are well maintained shortly after CABG and cardioplegic arrest in patients with a good preoperative systolic LV function.     

Diabetes mellitus and morbidity and mortality risks after coronary artery bypass surgery

Of 1025 patients (912 men, 113 women) who underwent coronary artery bypass grafting and were followed up for a mean of 7.4 years, 45 (4.4%) had diabetes mellitus. Norwegian population is 1.8-2%). Early mortality was not significantly greater among diabetics than in non-diabetics (2.2 vs. 3.1%, odds ratio--OR-0.44, confidence interval--CI- 0.05-3.56). Diabetic patients had no increased risk of perioperative myocardial infarction (OR = 0.87, CI 0.36-2.10) or of low-output syndrome necessitating intraortic balloon pumping (OR = 0.42, CI 0.55-3.05), and no excess incidence of late non-fatal myocardial infarction (relative risk = 0.69, CI 0.10-1.28) or late chronic heart failure (OR = 2.50, CI 0.5-11.0). Long-term mortality was increased in the diabetic patients (relative risk 1.87, CI 1.60-2.14). Thus diabetes did not entail heightened risk of early mortality, perioperative myocardial infarction or low-output syndrome. Nor was there excess risk of recurrent angina pectoris, late non-fatal myocardial infarction or chronic heart failure among the diabetic patients, but the late mortality risk was increased.     

Incidence of right ventricular asynergy in patients with coronary artery disease

The effects of coronary artery disease on patterns of left ventricular contractility have been thoroughly investigated. In contrast, little is known about the incidence of right ventricular dysfunction induced by this disease. To evaluate the frequency of right ventricular asynergy, biplane right ventricular cineangiograms were obtained in 26 patients. Seven segmental axes of shortening were analyzed in each end-systolic and end-diastolic frame and normalized as percent decrease (or increase) in axis from end-diastolic length. Of 26 patients, 8 (Group I) served as normal (control) subjects. The remaining 18 patients had significant coronary artery disease; 6 of these (Group II) had no significant disease of the right coronary artery, whereas 12 (Group III) had significant obstruction of this artery. Four patients in Group II had a previous anteroseptal myocardial infarction, and six in Group III had a previous inferior myocardial infarction. There was a progressive decrease in segmental axes of shortening from Group I to II and from Group II to II, but the decrease was not significant at the level P less than 0.01. Only one patient in Group II had frank dyskinetic segmental motion of the interventricular septum (this patient had had a previous anteroseptal myocardial infarction), whereas two patients in Group III had dyskinetic segmental motion of the free right ventricular wall (both had previous inferior myocardial infarction). Therefore, coronary artery disease seldom produces significant right ventricular asynergy. Abnormal septal motion is associated with previous anteroseptal myocardial infarction; however, dyskinetic motion of the free right ventricular wall occurs only in patients with a right coronary arterial lesion and previous inferior myocardial infarction.