Kinase MB Fraction Research Articles

Prognostic Significance of the Number of Leads with ST Depression during an Anginal Attack in High Risk Patients with Unstable Angina.

We examined the prognostic significance of electrocardiographic predictors (number of leads with ST depression, maximal ST depression, QT dispersion), C-reactive protein, fibrinogen, myosin light chain 1 and creatine kinase MB fraction in 62 patients with unstable angina showing ST depression during an anginal attack. During the 90-day follow-up period, 15 patients (24%) exhibited new cardiac events (death, myocardial infarction or urgent revascularization). Using multivariate analysis, the number of leads with ST depression [relative risk 6.305 (95% confidence intervals 1.831-21.71), p<0.01] during an anginal attack was found to be an independent risk factor to predict cardiac events. Other predictors did not have prognostic significance. The number of leads with ST depression during an anginal attack is an independent risk predictor for new cardiac events in high risk patients with unstable angina.

Clinical Manifestation of Novel Stress-induced Cardiomyopathy Mimicking Acute Myocardial Infarction: Single Center Prospective Registry

Background and Objectives:The so-called 'stress-induced cardiomyopathy' or takotsubo cardiomyopathy, mimicking acute myocardial infarction (AMI, has recently been reported, particularly in Japan. We pro- spectively studied the clinical characteristics of, for the first time with a Korean series, this novel syndrome. Subjects and Methods:Eighteen patients, fore filling the inclusion criteria, were entered onto the study. The criteria for inclusion were:1 no previous history of cardiac disease, 2 acute onset, 3 a regional wall motion abnormality in the left ventriculogram, typically in the apical segment, and 4 no significant stenosis in the coronary angiogram. Results:The events preceding the condition included:emotional stress (N=7, acute illness (N=5, non-cardiac surgery or medical procedure (N=4 and accident (N=2. Chest pain, dyspnea, or nausea/vomiting were initially noted in 12 cases (66%. Pulmonary edema was demonstrated in 10 (56%, and cardiogenic shock in 4 (23% of the patients. The peak creatinine kinase MB fraction was 69±136 IU/L. A T wave inversion was noted in all patients, whereas, a Q wave was noted transiently in only 1. The average left ventricular ejection fraction (LVEF was 38±8% on the initial echocardiograms. On the left ventriculograms, 15 patients showed akinetic wall motion, or aneurysmal dilatation in the apical wall, however, notably in 3 patients in the mid-ventricular wall. The coronary vasospasm provocation tests were negative in all 10 patients tested. An intravascular ultrasonography showed no infarct-related plaques in the 4 patients examined. On a follow-up echocardiogram, the average LVEF was improved to 51±8%, and regional wall motion was normalized after 30±29 days following onset. Conclusion:We report, for the first time in a series of Korean patients, on a novel stress-induced cardiomyopathy with transient regional wall motion abnormality, mimicking AMI. The precise etiology remains to be elucidated in further studies. (Korean Circulation J 2002;32(12 :1054-1063

Prognostic value of cardiac troponin I re-elevation following percutaneous coronary intervention in high-risk patients with acute coronary syndromes

Troponin I is a predictive marker of short- and intermediate-term adverse cardiac events in patients with acute coronary syndromes (ACS). These high-risk patients may benefit from early percutaneous coronary intervention. However, whether additional myocardial injury, defined as postprocedural troponin I elevation, may be associated with adverse short- and intermediate-term outcomes has not been fully explored. Accordingly, we studied 132 consecutive patients with non–ST-elevation ACS (62% with non–Q-wave myocardial infarction) and elevated troponin I levels at admission (>0.15 ng/ml) who underwent percutaneous coronary intervention ≥48 hours after admission. Troponin I levels were routinely measured at 6 and 18 to 24 hours after intervention and patients were stratified according to the presence or absence of troponin I re-elevation, defined as postprocedural troponin I levels >1 times the admission levels. In-hospital and cumulative 6-month clinical outcomes were compared between groups. Patients with troponin I re-elevation (n = 51) were older (68 ± 13 vs 64 ± 12 years, p = 0.05) and had experienced prior myocardial infarction more frequently (92.5 vs 82.1, p = 0.09), but otherwise had similar baseline clinical characteristics. Patients with troponin I re-elevation had significantly higher in-hospital mortality (9.8% vs 0%, p = 0.016) and a higher 6-month cumulative death rate (24% vs 3.7%, p = 0.001). There was a trend for an increased 6-month myocardial infarction rate in patients with troponin I re-elevation (13.7% vs 3.7%, p = 0.11) and target vessel revascularization was similar between groups (16.7% vs 17.4%, p = 0.92). By multivariate analysis, troponin I re-elevation (odds ratio [OR] 6.2, p = 0.011) and diabetes mellitus (OR 5.7, p = 0.014) were the strongest independent predictors for increased 6-month cumulative mortality, whereas creatine kinase MB-fraction re-elevation had no prognostic value. We conclude that troponin I re-elevation after percutaneous coronary intervention in high-risk patients with ACS is associated with a substantial increase in mortality and reduced event-free survival at 6-month follow-up.

Prophylactic nitroglycerin did not reduce myocardial ischemia during accelerated recovery management of coronary artery bypass graft surgery patients

Objective: To evaluate the use of a high dose of nitroglycerin (NTG) for prophylaxis against myocardial ischemia and infarction in patients undergoing coronary artery bypass graft (CABG) surgery with accelerated recovery. Design: Prospective, double-blind, placebo-controlled randomized study. Setting: A university-based medical center. Participants: Forty adult patients presenting for elective CABG surgery. Interventions: Forty patients were divided into 2 blinded study groups. Twenty patients received 2 μg/kg/min of NTG starting before induction of anesthesia and continuing for 6 hours after extubation in the intensive care unit. The placebo group (n = 20) received normal saline during this same interval. Measurements and Main Results: Hemodynamics, incidence and severity of myocardial ischemia, and myocardial infarction rates were determined. There were no differences in hemodynamic parameters between groups. The incidence of ischemia was approximately 35 in each group. Myocardial infarction (as determined by elevated creatine kinase—MB fraction, troponin I, and electrocardiogram criteria) was 10% in the placebo group and 5 in the NTG group (p = 0.234). Conclusions: This study shows a high incidence of myocardial ischemia and infarction in patients presenting for CABG surgery with an accelerated recovery management scheme. NTG was well tolerated clinically; however, it was not found to be protective against myocardial ischemia or infarction in this setting. Copyright © 2000 by W.B. Saunders Company

Non-invasive assessment of rejection in pediatric transplant patients: serologic and echocardiographic prediction of biopsy-proven myocardial rejection

Background: Cardiac allograft rejection is a multifocal immune process that is currently assessed using biopsy-guided histologic classification systems (International Society for Heart and Lung Transplantation). Cardiac troponin T and I are established serologic markers of global myocyte damage. The use of load-independent measures of contractility have also been shown to accurately assess the presence of ventricular dysfunction. Little is known about their utility in accurately predicting rejection in the pediatric age group. We undertook the present study to compare rejection grade with echocardiographic and serologic estimates of transplant rejection–related myocardial damage. Methods We compared histologic rejection grades (0 to 4) with patient characteristics, echocardiographic measurements, catheterization measurements, and biochemical markers for 86 evaluations in 37 transplant recipients at Children’s Hospital. Results In univariate analyses, biopsy scores correlated ( p < 0.05) inversely with left ventricular systolic function (shortening fraction) and contractility (stress velocity index, SVI), and directly with mitral E-wave amplitude. In multivariate analyses, lower contractility and higher mitral E-wave amplitude remained significantly ( p ≤ 0.01) associated with rejection (SVI, p = 0.002, odds ratio = 0.393; E wave, p = 0.0002, odds ratio = 228). Most rejection episodes were associated with elevation of biochemical markers of myocardial injury. Although troponin I was weakly associated with differences between rejection grades ( p = 0.034), troponin T, creatine kinase–MB fraction, and C-reactive protein did not differ with biopsy-rejection scores. Serum markers had a poor predictive capacity for biopsy-detected rejection. Troponin T and I did correlate with increased left ventricular wall thickness and mass. Conclusion Progressively depressed left ventricular contractility and diastolic function are found with worsening pediatric heart transplant rejection–biopsy score; however, sensitive and specific serum markers do not correspond to the degree of active myocardial injury. The use of echocardiographic measures of contractility is associated with a specificity of 91.8% but low sensitivity of 66.7%. Overall we found poor concordance between serum markers and grade of rejection. It is unclear whether myocardial injury as assessed by serum markers, echocardiography, or histologic scoring is more important for assessment of acute rejection or long-term outcome, but it does not appear that serum and tissue markers of rejection can be used interchangeably.

Atherosclerotic plaque burden and CK-MB enzyme elevation after coronary interventions : intravascular ultrasound study of 2256 patients.

Elevation of serum creatine kinase MB fraction (CK-MB) after percutaneous coronary interventions has been associated with early and late mortality; however, the pathogenesis of CK-MB elevation is still unknown. We hypothesized that CK-MB elevation was related to atherosclerotic plaque burden as assessed by preintervention intravascular ultrasound (IVUS). We studied 2256 consecutive patients who underwent intervention of 2780 native coronary lesions and had complete high-quality preintervention IVUS imaging in the era before routine use of platelet glycoprotein IIb/IIIa inhibitors. Patients were divided into 3 groups: CK-MB within normal range (1675 patients; 2061 lesions); CK-MB elevation 1 to 5 times upper limit of normal (292 patients; 355 lesions); and CK-MB elevation > or = 5 times upper limit of normal (289 patients; 364 lesions). Qualitative angiographic lesion morphology and quantitative analysis were similar among the 3 groups. On preintervention IVUS, progressively more reference segment and lesion site plaque burden and lesion site calcium occurred in the groups with CK-MB elevation. Positive remodeling was more common in lesions with CK-MB elevation. As levels of CK-MB increased, cross-sectional narrowing (percentage plaque burden) increased, both at the reference site (mean cross-sectional narrowing values were 45.1%, <49.3%, and <52.2% for normal CK-MB, 1 to 5 times upper limit of normal, and > or =5 times upper limit of normal groups, respectively; P=0.03) and at the lesion site (81.9%, <85.4%, and <87.1%, respectively; P=0.04). Multivariate analysis indicated that de novo lesions, atheroablative technique, plaque burden at the lesion and reference segments, and final minimal lumen diameter were independent predictors of CK-MB elevation. CK-MB elevation correlates with a greater atherosclerotic plaque burden. CK-MB elevation after intervention may be a marker of diffuse atherosclerotic disease or a consequence of catheter-based intervention in more diseased arteries or both.

The effect of gestational age, birth weight, and disease on troponin I and creatine kinase MB in the first year of life

Objectives: To determine the effect of gestational age and birth weight (BW) on troponin I (TnI) and creatine kinase MB fraction (CKMB) levels during the first year of life. Methods: Troponin I and CKMB levels were determined in infants less than 1 year of age using the Immuno I (Bayer Corp.). Results: Troponin I fractions were greatest in the preterm infant; the levels decreased significantly with increasing gestational age and BW, (p = 0.008 and p = 0.005, respectively). The CKMB levels did not exhibit a significant difference between the preterm and term infant groups when assessed for the effects of gestational age or BW ( p = 0.12 vs. p = 0.35). Neither TnI nor CKMB levels were significantly different between preterm survivors and nonsurvivors ( p = 0.31; p = 0.34, respectively). TnI levels were elevated in critically ill patients without documented myocardial infarction, and without a comparable rise in CKMB. Conclusion: The higher TnI levels during the first 3 months of life may indicate programmed cell death, or apoptosis. This may be especially true in the preterm infant in which the greatest values were documented.

Effect of the hemoglobin-based oxygen carrier HBOC-201 on laboratory instrumentation: cobas integra, chiron blood gas analyzer 840, Sysmex SE-9000 and BCT.

As part of a clinical trial, we evaluated the effects of the hemoglobin-based oxygen-carrier (HBOC) HBOC-201 (an ultrapurified, stroma-free bovine hemoglobin product, Biopure, Cambridge, MA, USA) on our routine clinical chemistry analyzer (Cobas Integra, F. Hoffmann-La Roche Ltd, Basel, Switzerland ), blood gas analyzer (Chiron 840, Chiron Diagnostics Corporation, East Walpole, MA, USA), routine hemocytometry analyzer (Sysmex SE-9000, TOA Medical Electronics Co Ltd., Kobe, Japan), hemostasis analyzer (BCT, Dade-Behring, Marburg, Germany) and bloodbanking system (Dia-Med-ID Micro Typing System, DiaMed AG, Cressier, Switzerland). The maximum tested concentration of HBOC-201 was 65 g/l. Of the 27 routine clinical chemistry tests challenged with HBOC-201, bilirubin-direct, creatine kinase MB-fraction (CK-MB), creatine kinase (CK), gamma-glutamyltransferase (GGT), magnesium and uric acid were influenced by even low concentrations of HBOC-201. These tests were excluded from use on the plasma of patients treated with HBOC-201. Since the non-availability of the cardiac marker CK-MB may lead to problems in acute situations, we introduced the qualitative Trop T-test (Boehringer Mannheim), which was not influenced. The applicability of another nine tests was limited by the concentration of the HBOC-201 in the patients' plasma. No interference of HBOC-201 in routine hemocytometry, hemostasis-analysis and red-blood cell agglutination detection (blood-bank tests) was observed. Although immediate patient-care was not compromised, routine use of hemoglobin-based oxygen carriers will have a strong impact on logistical management. The development of robust laboratory tests free from the interference of the pigmented oxygen carriers should therefore precede its introduction into routine transfusion medicine.

Serum Concentrations of Cardiac Troponin I in Sudden Death

Sudden cardiac death due to lethal arrhythmia may be the initial presenting symptom of ischemic heart disease. In many cases, in the absence of trauma, a majority of these deaths will be visually inspected by a medical examiner and released with death being ascribed to atherosclerotic cardiovascular disease, coronary artery disease, arrhythmia, myocardial infarction, or a similar diagnosis. When an autopsy is performed, there may be significant cardiovascular disease but no gross or histologic evidence of an acute myocardial infarct unless the patient survived for several hours following the event. Biochemical assays of creatine kinase MB fraction (CKMB) performed on serum have been used to document myocardial injury in the absence of morphologic changes. Newly developed assays for cardiac troponin I (cTnI) may detect myocardial injury with a greater sensitivity than CKMB. A prospective study was performed on 28 autopsied patients at the Office of the Chief Medical Examiner of the state of Maryland. Subclavian blood was sampled for subsequent analysis of serum CKMB and cTnI. In 3 cases of cardiac-related death, there was insufficient plasma for analysis of both CKMB and cTnI, and only CKMB was quantitated. In 12 cases, hemolysis rendered interpretation questionable. Of the remaining 16 cases, the mean serum CKMB level was 857.9 ng/ml (n = 7) and the cTnI level was 93.4 ng/ml (n = 4) for cardiac-related deaths, compared with mean CKMB levels of 116.4 ng/ml (n = 9) and mean cTnI levels of 16.6 ng/ml (n = 9) for non-cardiac-related deaths. The differences in serum elevation of both CKMB and cTnI noted between the cardiac- and non-cardiac-related deaths were statistically significant. Serum cTnI concentrations >40 ng/ml were only noted in cardiac-related deaths. These data suggest that an elevated postmortem serum concentration of cTnI reflects ischemic heart disease and supports its use in determining cause of death. Quantitation of this analyte may prove useful when death may be due to an arrhythmia following a morphologically undetectable microinfarct.

Fulminant neurogenic pulmonary oedema with hand, foot, and mouth disease

An 8-year-old girl was admitted with fever, oral ulcers, constipation, headache, and vomiting for 2 days. She had a rash on the soles of both feet, and had not urinated for a day. She was alert and not cyanosed, with a heart rate of 114/min, body temperature 37·2°C, and blood pressure 114/64 mm Hg. Her neck was stiff; breath sounds were clear; her heart beat was regular without gallop; her bladder was distended; and several small pink vesicles were found on both soles. There were no focal neurological signs. White blood cell count was 14·3×109/L, blood sugar was 7·4 mmol/L, and creatine kinase MB fraction was 2 U/L. In cerebrospinal fluid, white cell count was 153×106/L with 70% neutrophils; glucose 4·2 mmol/L, and protein 43 mg/dL. The first chest radiograph was normal (Figure 1 A). Abdominal radiograph showed dilated loops of bowel and a distended bladder. Brain computed tomography was normal. Intravenous penicillin was given. 2 h after lumbar puncture, she complained of itching followed by pain in her right arm and then in her right forearm. Her muscle power was unimpaired. 1 h later, she had a severe headache and vomited bile. She became sweaty, with cold hands and feet, tachypnoeic (48/min), and had a heart rate up to 170/min. A second chest radiograph showed bilateral alveolar congestion. She coughed up pink frothy sputum and became cyanosed. She was intubated. Pink frothy fluid, followed by fresh blood, came from the endotracheal tube. She had increased leucocytosis (31·8×109/L, and hyperglycaemia (14·2 mmol/L). She was also hypoxic and had a severe metabolic acidosis. A third chest radiograph (Figure 1 B) showed both lungs to be congested. She died 4 h after intubation. DEPARTMENT OF ERROREffect of starch-free bread on metabolic control in type 2 diabetes—In this research letter by B Stilling and colleagues (Aug 1, p 369), the penultimate sentence of the fourth paragraph should read: Similar changes were not seen on the ordinary diet. Full-Text PDF

Normothermic cardiopulmonary bypass and cardioplegia reduce inotropic requirements and creatine kinase-MB after coronary artery bypass graft surgery

To determine whether normothermic cardiopulmonary bypass (CPB) and cardioplegia preserve myocardial function, reduce inotropic requirements, and reduce markers of myocardial ischemia following coronary artery bypass graft surgery (CABG). We retrospectively reviewed the charts of 171 consecutive patients undergoing elective CABG by a single surgeon from April 1994 to December 1995. Hypothermic CPB with intermittent cold cardioplegia was used in 83 patients and normothermic CPB with intermittent warm cardioplegia in 88 patients. Demographic, surgical, hemodynamic, and inotropic requirements and laboratory data were reviewed. The duration of CPB was significantly shorter in the normothermic group (113±27vs 90±21 min;P<0.0001). After CPB the cardiac index was similar between groups, but significantly larger doses of both dopamine and dobutamine were required (8vs 5μg·kg-1·min-1,P<0.0001), and significantly more patients required norepinephrine administration in the hypothermic group (18%vs 6%;P=0.01). Postoperative peak values of creatine kinase MB fraction (CK-MB) were significantly lower in the normothermic group (80±60vs 55±54 IU·I-1;P<0.0001). Normothermic CPB and cardioplegia reduce inotropic requirements and CK-MB following CABG.

Collagen scar formation after acute myocardial infarction: relationships to infarct size, left ventricular function, and coronary artery patency.

Left ventricular function after acute myocardial infarction (AMI) is determined by the expansion of the infarct zone and remodeling of the noninfarcted myocardium. An occluded infarct-related artery (IRA) is an independent risk factor for remodeling. Changes in myocardial collagen metabolism were evaluated in 36 patients with suspected AMI. The plasma creatine kinase MB fraction and myoglobin release curves were analyzed for assessment of early reperfusion and infarct size. Collagen scar formation was evaluated by measurement of serum concentrations of the aminoterminal propeptide of type III procollagen (PIIINP), the aminoterminal propeptide of type I procollagen (intact PINP), and the carboxyterminal propeptide of type I procollagen (PICP). Plasma renin activity and urine excretion of cortisol and aldosterone were also measured. Coronary angiography and left ventricular cineangiography were performed during early hospitalization. The serum concentration of PIIINP increased from 3.50+/-0.20 to a maximum of 5.08+/-0.36 microg/L (n=32) in the patients with AMI, whereas the concentrations of intact PINP and PICP tended to decrease. The area under the curve (AUC) of PIIINP during the first 10 postinfarction days was larger in patients with severe heart failure or ejection fractions < or = 40% than in those with no heart failure or with an ejection fraction > 40% (P<.05 and P<.01, respectively), and it was also larger in the patients with TIMI grade 0 to 2 flows than in those with TIMI 3 flows (P<.05), despite similar enzymatically determined infarct sizes. No significant correlations between PIIINP and neurohumoral parameters were observed. The AUC of PIIINP and the change in PIIINP during the first 4 days were significantly correlated with indices of cardiac function. Collagen scar formation after AMI can be quantified by measurement of serum PIIINP concentrations. Scar formation is more prominent in large infarctions causing left ventricular dysfunction and in patients with occluded IRAs.

Adverse event with first-dose perindopril in congestive heart failure

The first-dose effect of perindopril, a long-acting angiotensin-converting-enzyme inhibitor (ACEI), has been reported to influence blood pressure (BP) to the same extent as placebo. Therefore, perindopril has been suggested as the drug of choice when initiating ACEI therapy in heart failure. I report a patient with a serious complication after the first dose of perindopril. A 61-year-old man with episodes of mild chest pain for 3 weeks was admitted with increasing dyspnoea. He had lung rales, raised jugular venous pressure, no heart or carotid murmurs, and no liver enlargement or peripheral oedema. On admission he was treated with intravenous diuretics and a low-dose dopamine infusion. The BP was never lower than 130/90 mm Hg and dopamine was stopped the following morning. Creatine kinase MB fraction rose to 70 IU (normal <12 IU) and electrocardiograms indicated an inferior myocardial infarction. Echocardiography revealed inferolateral left ventricular dyskinesia. Previously, he had been treated with antihypertensive drugs for 5 years. 4 months before admission he took captopril (unknown dosage), which was stopped after 1 month due to a skin rash. During hospital admission his BP remained stable at 130–150/80–90 mm Hg measured three times daily and he was in constant sinus rhythm. ACEI therapy was initiated with a single dose of 2 mg perindopril 5 days after admission. The evening BP was 130/80 mm Hg 5–6 h after perindopril. The next morning he had visual disturbances. The BP that had been 90/60 mm Hg before the patient expressed any complaints normalised spontaneously. Neurological examination revealed left-sided hemianopia and no other neurological disturbances. Computed tomography showed an ischaemic infarct of the region supplied by the right posterior cerebral artery. Laboratory values before start of perindopril were: sodium 137 mmol/L, potassium 3·8 mmol/L, and creatinine 138 mol/L. The patient was on oral furosemide 40 mg four times daily, spironolactone 25 mg daily, potassium supplement, aspirin 150 mg daily, and phenoxymethylpenicillin 800 mg three times daily (pneumonia was initially suspected but not verified and the patient was afebrile when perindopril was given). The visual defect remained the same at his discharge 9 days later. Severe and moderate hypotension after initiation of 2·5 mg enalapril occurred in 0·5% and 4·7%, respectively, of 1210 heart failure patients. In the studies of left ventricular dysfunction (7487 eligible patients), 0·04% developed a stroke and 2·2% became hypotensive when enalapril 2·5 mg twice daily was initiated with most patients on diuretics. Although withdrawal of diuretics has been recommended before initiation of ACEI, such action does not always prevent severe hypotension. Perindopril has a long half-life Sunscreen alone with SPF after 15 min

Effects of short-term supplementation with coenzyme Q10 on myocardial protection during cardiac operations

Coenzyme Q10 (CoQ10) is a naturally occurring vitamin-like substance that may have a beneficial role in ischemia-reperfusion injury. Coenzyme Q10 administered either as an additive to cardioplegia or as long-term preoperative oral supplementation has been reported to ameliorate myocardial injury after cardiac operations. To determine whether short-term supplementation with large doses of CoQ10 (600 mg in divided doses 12 hours before operation) was effective in myocardial protection, 20 patients with well-preserved left ventricular function (ejection fraction greater than 0.50) undergoing elective coronary revascularization were enrolled in a prospective, double-blind, placebo-controlled randomized trial. Serial concentrations of CoQ10, myoglobin, creatine kinase MD fraction, and cardiac troponin T were measured preoperatively and 1, 6, 24, 72, and 120 hours postoperatively. Efficacy of myocardial protection was also assessed by clinical outcome and serial changes in electrocardiographic indices. The patient groups were similar with respect to preoperative and intraoperative characteristics. There was no significant difference in the preoperative plasma levels of CoQ10. These levels fell significantly in both groups after operation, although the magnitude of the decrease was less in the CoQ10-supplemented group (43% versus 60%). In both groups, there were significant postoperative increases in myoglobin, creatine kinase MB fraction, and cardiac troponin T. The magnitude of increases in cardiac troponin T was greater in the CoQ10-supplemented group, reaching marginal overall statistical significance (p = 0.06). Short-term supplementation with large doses of CoQ10 does not lead to improved myocardial protection in patients undergoing coronary revascularization with well-preserved ventricular function and relatively short ischemic times.

64-Year-Old Woman With Chest Pain and Presyncope

64-Year-Old Woman With Chest Pain and Presyncope

Predictors of conduction disturbances after coronary bypass grafting

One hundred sixty-nine patients undergoing coronary artery bypass grafting were included in a prospective study to test the effect of coronary pathology on conduction disturbances (CD). At the same time, several other proposed preoperative and intraoperative predictors of CD were collected. From the angiograms, the vascularization of the interventricular septum was classified according to Mosseri and colleagues. Ninety-four patients (56%) had type II coronary pathology, which does not allow full revascularization of the interventricular septum. The tested classification did correlate with the state of coronary disease, resulting in more left main coronary stenoses and more numerous peripheral anastomoses in type II patients. However, there was no correlation between the classification and CD. Patients with permanent CD (34%) had more left main coronary artery stenoses (29% versus 14%; p = 0.03). Their measured maximal myocardial temperatures were lower in all three myocardial regions measured ( p = 0.01 to 0.07), and their creatine kinase MB fraction values on the day of operation were also higher (92 versus 70 IU; p = 0.002). in maltivariate logistic regression analysis, the maximal temperature of the left circumflex artery region and the presence of left main coronary artery stenoses were the only inderendent predictors of permanent CD. We conclude that excessively low myocardial temperatures during caidioplegia may cause CD.

Randomised trial of normothermic versus hypothermic coronary bypass surgery

Warm heart surgery—37°C cardioplegia with systemic normothermia—has been introduced as an alternative to conventional hypothermic cardiac surgery. A randomised trial comparing warm (W) and cold (C) methods was done in 1732 patients undergoing isolated coronary bypass surgery in three adult cardiac surgery centres at the University of Toronto, Canada. Allocation to W (860 patients) or C (872) was stratified by urgent versus elective operations and by surgeon. There were no striking baseline differences in patients' demographics, angiographic findings, or operative procedures. All but 4·2% of patients initially received antegrade cardioplegia; a further 2·1% switched to retrograde delivery intra-operatively. Crossovers to C occurred in 7·7% of cases either due to difficulty in sustaining cardiac arrest or due to coronary flooding. Analysis, however, was on an intention-to-treat basis. The 30-day all-cause mortality was 2·5% in C patients and 1·4% in the W group (p 0·12). There was no difference in non-fatal Q-wave infarction rates (W 10·1%, C 11·1%), but enzymatic infarction by serial creatine kinase MB fraction (CK-MB) measurements was reduced (W 12·3% vs C 17·3%, p<0·001) as was the mean area under the CK-MB curve. Postoperative low-output syndrome was less frequent in W patients (6·1% vs 9·3%, p 0·01). There were no differences in the rates of stroke, reoperation for bleeding or tamponade, or sternal rewiring/ debridement for dehiscence or infection. Warm heart surgery is a safe and effective alternative to conventional hypothermic techniques for patients undergoing coronary bypass surgery.

A prospective randomized comparison of direct current and radiofrequency ablation of the atrioventricular junction

Objectives. The purpose of this study was to compare direct current and radiofrequency ablation of the atrioventricular (AV) junction in a prospective randomized fashion,Background. Catheter ablation of the AV junction can be performed using either direct current shocks or radiofrequency energy. To date, these two techniques have never been compared prospectively or in a randomized study.Methods. Forty patients with drug-refractory uncontrolled atrial fibrillation-flutter (38 patients) or inappropriate sinus tachycardia (2 patients) were randomly assigned to undergo direct current ablation (20 patients) using up to four shocks of 200 to 300 J or radiofrequency ablation (20 patients) using up to 15 applications of 16 to 25 W for 30 s. If complete AV block was not successfully induced, the ablation procedure was repeated using the alternate type of energy. A rate-responsive ventricular pacemaker was implanted in each patient. The intrinsic escape rhythm was evaluated 15 min, 2 days and 3, 6 and 12 months after ablation.Results. Persistent complete AV block was successfully induced during the first ablation session in 13 (65%) of 20 patients randomly assigned to undergo direct current ablation, compared with 19 (95%) of 20 patients randomly assigned to undergo radiofrequency ablation (p < 0.05). Each patient whose first ablation attempt failed had a successful outcome with the alternate type of energy. The overall efficacy of radiofrequency ablation (26 [96%] of 27 patients) was significantly greater than that of direct current ablation (14 [67%] of 21 patients, p < 0.01). The duration of the direct current and radiofrequency ablation sessions did not differ significantly. The mean peak plasma creatine kinase MB fraction concentration was significantly higher after direct current ablation (58 ± 29 IU/liter) than after radiofrequency ablation (2 ± 2 IU/liter) (p < 0.001). An escape rhythm was present 15 min after ablation in an equal proportion of patients undergoing direct current and radiofrequency ablation (78% and 85%, respectively, p = 0.6). An escape rhythm was present in all patients 3,6 and 12 months after ablation. The mean escape rhythm cycle length 15 min after direct current ablation (2,074 ± 677 ms) was significantly longer than that 15 min after radiofrequency ablation (1,460 ± 294 ms) (p < 0.05); however, the mean escape rhythm cycle lengths did not differ significantly at 2 days or 3, 6 or 12 months after ablation. Immediate arrhythmic complications did not occur after either procedure. One patient died suddenly 6.5 months after direct current ablation.Conclusion. Radiofrequency ablation of the AV junction is more efficacious and safer than direct current ablation and should be the preferred method for inducing complete AV block in patients who are appropriate candidates for ablation of AV conduction.

Selection of patients for coronary angiography and coronary revascularization early after myocardial infarction: is there evidence for a gender bias?

To determine whether a gender bias exists in the selection of patients for diagnostic and therapeutic cardiovascular procedures early after myocardial infarction. A retrospective cohort study. A community-based tertiary care teaching hospital. A total of 2473 consecutive patients with a principal discharge diagnosis of acute myocardial infarction and a peak creatine kinase MB fraction of at least 4%. Comparison of men and women regarding the frequency with which they underwent various cardiac procedures. Women had coronary angiography during hospitalization for myocardial infarction much less frequently than men (odds ratio, 0.55; 95% Cl, 0.46 to 0.65), but the age-adjusted rates were similar in women and men (odds ratio, 0.91; Cl, 0.75 to 1.12). An abnormal ejection fraction (less than 50%) was equally frequent in women and men who underwent left ventriculography (odds ratio, 0.85; Cl, 0.56 to 1.30). Among patients who had coronary angiography, women had a significantly lower rate of severe coronary artery disease, defined as either a left main stenosis of more than 50%, three-vessel disease, or two-vessel disease with a proximal left anterior descending stenosis of more than 70% (odds ratio, 0.67; Cl, 0.48 to 0.93). When adjustments were made for age, women had percutaneous transluminal coronary angioplasty as often as men (odds ratio, 1.16; Cl, 0.83 to 1.62) but had coronary artery bypass graft surgery significantly less frequently (odds ratio, 0.58; Cl, 0.37 to 0.91). When adjustments were made for age and the severity of coronary artery disease, the difference in rates was of borderline significance (odds ratio, 0.65; Cl, 0.41 to 1.01). No evidence of a difference in the rate of coronary angiography early after myocardial infarction between women and men was found after age adjustment. Among patients who have cardiac catheterization early after myocardial infarction, women and men are equally likely to have angioplasty, but women are less likely than men to have coronary artery bypass surgery.

Determinants of Elevated Creatine Kinase Activity and Creatine Kinase MB-Fraction following Cardiopulmonary Resuscitation

We undertook this study to determine the occurrence and the determinants of elevation of serum creatine kinase (CK) levels and CK MB-fraction following cardiopulmonary resuscitation (CPR). Four hundred twenty consecutive adult admissions to the Long Island Jewish Medical Center from January 1989 through December 1990 with a diagnosis of cardiac arrest were reviewed. The Long Island Jewish Medical Center, New Hyde Park, NY, the Long Island Campus for the Albert Einstein College of Medicine, Bronx, NY. Sixty-three patients survived for at least 12 h following cardiac arrest for evaluation of post-CPR CK levels and were included into the study. Clinical features, biochemical profiles, and administered drug profiles were studied in these patients. The clinical and biochemical features of the patients with (CK greater than 224 IU/L [3.7 mu kat/L]) and without rhabdomyolysis were also compared. Two major determinants responsible for elevated CK levels emerged, including physical injury (number of chest compressions during CPR) and electrical injury (cumulative number of joules administered during defibrillation). Post-CPR CK levels showed positive correlations with both the number of chest compressions given (p less than 0.001) and the number of joules administered during defibrillation (p less than 0.001). Post-CPR CK-MB levels also showed a positive correlation with the number of joules administered (p less than 0.005) and the number of chest compressions (p less than 0.02). Forty-three (68.3 percent) of the 63 patients developed rhabdomyolysis. Serum CK levels were higher (p less than 0.005) in the patients who received electrical countershock therapy as well as chest compressions when compared with patients who received chest compressions alone. There were no significant differences in electrolyte levels between patients with and without rhabdomyolysis. Thirty patients had a history of coronary artery disease (CAD) and 18 (60.0 percent) of these had a positive MB-fraction post-CPR while only ten of the 33 patients without known CAD had a positive MB-fraction post-CPR (30.3 percent, p less than 0.05). Patients with no known CAD but positive CK-MB fraction had significantly higher total CK levels, physical injury, and electrical injury compared with patients with negative CK-MB fraction. Twenty patients survived CPR and were discharged from the hospital without significant neurologic sequelae. The remaining 43 either died or suffered severe neurologic injury. The patients who survived CPR had a significantly shorter duration of CPR (p less than 0.01) compared with those who did not. Patients who did not have long-term survival following CPR were more likely to have elevated serum potassium, phosphate, and creatinine values. CK elevation is a common finding following successful CPR after cardiac arrest and this elevation of post-CPR CK levels is related to both physical as well as electrical injury sustained during CPR. Elevation of post-CPR CK-MB fraction seems to be only a crude indicator of preexisting CAD; however, a positive CK-MB fraction in patients without CAD is related to severity of physical injury and electrical injury during CPR. Patients who survive CPR without neurologic impairment appear to be those with a shorter duration of CPR. Elevated serum potassium, phosphate, and creatinine values may be related to an adverse effect on long-term survival.