Faculty Bibliography

BACKGROUND: Elevated troponin I in the absence of angiographically visible coronary lesions is seen in up to 10-15% of those undergoing angiography for suspected coronary artery disease. This study aims to elucidate the etiology of elevated cardiac troponin I in patients with normal coronary arteries on angiography. METHODS: We identified 1551 (8.6%) patients with normal coronary arteries from our catheterization database of 17,950 patients from Jan 2000 to Jun 2004. Elevated troponin I levels were found in 217 (14%) of 1551 patients with normal coronary arteries. Of these 217 patients, 73 surgical patients were excluded, and the remaining 144 patients formed the study population. The study population was compared with age and gender matched patients with myocardial infarction and coronary artery disease (Group II). RESULTS: The patients with elevated cardiac troponin I (cTnI) with normal coronary arteries had significantly lower prevalence of atherosclerotic risk factors and significantly higher left ventricular ejection fractions. The cTnI in patients with normal coronary arteries was elevated due to a number of causes including tachycardia, myocarditis, pericarditis, severe aortic stenosis, gastrointestinal bleeding, sepsis, left ventricular hypertrophy, severe congestive heart failure, cerebrovascular accident, electrical trauma, myocardial contusion, hypertensive emergency, myocardial bridging, pulmonary embolism, diabetic ketoacidosis, chronic obstructive pulmonary disease exacerbation and coronary spasm. CONCLUSIONS: Cardiac troponin I could be elevated in a number of conditions, apart from acute myocardial infarction, and could reflect myonecrosis. Acute myocardial infarction is a clinical diagnosis as the laboratory is an aide to, not a replacement for, informed decision making

Left main coronary artery disease carries a poor prognosis. The etiology of isolated and significant left main coronary artery (ILMCA) disease is not well understood. Studies so far were limited by small numbers. The authors identified 46 patients with ILMCA disease from their database over 10 years (group I) and compared them with 83 consecutive patients undergoing catheterization (group II). They also compared patients with ostial vs distal ILMCA disease. Group I represented 0.1% of catheterization patients. The demographic profile and atherosclerotic risk factor profile of the 2 groups as well as ostial and distal ILMCA disease were compared. This is the largest study of ILMCA disease. Risk factors for atherosclerosis were commonly seen. Nonatherosclerotic causes of ILMCA disease were not seen. This study suggests coronary atherosclerosis as the predominant cause of ILMCA disease. ILMCA disease is more common in women. Diabetes is more commonly associated with distal ILMCA lesion. There is a trend suggesting that ostial ILMCA lesion is more common in smokers and women

BACKGROUND: Acute coronary syndrome (ACS) resulting from culprit lesion in left main coronary artery (LMCA) can cause rapid hemodynamic deterioration. It is important to identify these patients early to facilitate timely revascularization. ST segment elevation in aVR greater than or equal to V(1) (aVR-V(1)>or= 0) has been suggested as a sensitive predictor of LMCA disease. As a result of balanced forces, we hypothesized that ST deviation in V(6) greater than or equal to ST deviation in V(1) (V(6)-V(1)>or= 0) might be a good determinant of LMCA disease. METHODS: We compared admission 12-lead ECGs of ACS resulting from culprit LMCA lesion (n = 75, group I) with ACS resulting from culprit left anterior descending lesion (n = 81, group II). Group I was selected over a period of 10 years. We compared V(6)-V(1)>or= 0 to aVR-V(1)>or= 0 in both groups. We also looked at ratios of ST deviations in V(6),V(1) (V(6)/V(1)>or= 1) and aVR,V(1) (aVR/V(1)>or= 1) in patients where ST segment in V(1) was not isoelectric (group I = 54 and group II = 55). RESULTS: ST deviation in V(6) was significantly greater in group I as compared to group II (P < 0.001). The reliabilities of V(6)-V(1)>or= 0, V(6)/V(1)>or= 1, aVR-V(1)>or= 0, and aVR/V(1)>or= 1 in predicting LMCA disease were determined. CONCLUSION: This is the largest series of ECG analysis on ACS resulting from culprit LMCA lesion. V(6)-V(1)>or= 0 and V(6)/V(1)>or= 1 were more sensitive in predicting LMCA as culprit vessel in comparison to previously reported greater ST segment elevation in aVR than V(1)

OBJECTIVES: To evaluate the sensitivity and safety of contrast injection beyond total occlusions in acute cardiac patients in order to ensure balloon position within the coronary lumen and occasionally to enable the estimate of occlusion length. BACKGROUND: Percutaneous therapy of total coronary occlusions is generally more challenging than the treatment of stenotic lesions. It more frequently entails the risk of irreversibly disrupting a protruding plaque, of advancing the wire through a false route, or rarely, of causing coronary perforation. Therefore, ascertaining intraluminal position prior to inflation is important. METHODS: In a large group of consecutive acute cardiac patients undergoing percutaneous coronary intervention (PCI) we employed a technique of crossing the lesion with a soft-tipped guidewire supported by an over-the-wire (OTW) balloon catheter, and then injecting dilute contrast through the balloon under fluoroscopy to achieve distal lumen visualization. RESULTS: In 106 patients, this technique yielded a sensitivity of 94%, a specificity of 70%, a positive predictive accuracy of 97%, and a negative predictive accuracy of 54% for intraluminal position of the balloon. CONCLUSIONS: The technique of lumen demonstration by contrast injection through an OTW balloon beyond acute or subacute total obstructions was shown to be a safe and effective method to ascertain proper position of the angioplasty balloon. Occasionally, it enabled the estimation of lesion length or the identification of lesions distal to the obstruction. This technique was found to be valuable in doubtful situations where the determination of wire position was crucial for achieving procedural success

INTRODUCTION: Sudden cardiac death (SCD) survival decreases by 10% for each minute of delay in defibrillation, however, survival rates of 98% can be achieved when defibrillation is accomplished within 30s of collapse. Recently, a fully automated external cardioverter-defibrillator (AECD) was approved by the FDA for in-hospital use. The AECD can be programmed to automatically defibrillate when a life threatening ventricular arrhythmia occurs. The purpose of this study was to assess the potential impact of in-hospital AECDs on the critical time to defibrillation in monitored hospital units. METHODS: Mock emergency (n = 18) were conducted using simulated ventricular fibrillation in various monitored units. Observers were stationed to record the time staff responded to the arrhythmia, and the time to shock. These times were compared to an AECD protocol that defibrillates automatically in an average of 38.3 s from onset of arrhythmia (n = 18). RESULTS: Staff versus AECD response time to arrhythmia (s) was 76.3 +/- 113.7 (CI 19.8-132.8) versus 7.6 +/- 0.6 (CI 7.3-7.9). Staff versus AECD time to shock was 169.2 +/- 103.1 (CI 117.9-220.4) versus 38.3 +/- 0.7 (CI 37.9-38.6). P-values are <0.0001 for differences between the groups. CONCLUSION: The use of AECDs on monitored units would significantly reduce the critical time to defibrillation in patients with SCA. We anticipate this would translate to improved survival rates, and better neurologic outcomes

PURPOSES: We studied the use of perioperative IV and oral administration of amiodarone for the prevention of postoperative atrial fibrillation in patients undergoing coronary artery bypass graft surgery (CABG). BACKGROUND: In the United States, > 500,000 patients undergo CABG each year. Numerous studies to date have suggested that postoperative atrial fibrillation occurs in 30 to 50% of patients, leading to significant morbidity, including hypotension, heart failure, thromboembolic complications, prolonged hospital stay, and increased hospital costs. The objective of this study was to assess the use of IV amiodarone in combination with oral amiodarone to reduce the incidence of postoperative atrial fibrillation. METHOD: From January 1999 to October 1999, 51 patients scheduled for CABG were randomly selected for participation in the amiodarone administration trial. IV amiodarone, 0.73 mg/min, was administered on call to the operating room for 48 h, followed by oral amiodarone, 400 mg q12h, for the next 3 days. The amiodarone group was case-control matched to the incidence of postoperative atrial fibrillation in 92 patients undergoing CABG using conventional medical therapy during the same period. The primary end point of this study was the incidence of postoperative atrial fibrillation, length of hospital stay, and hospital costs, compared to the control group undergoing CABG during the same time. RESULTS: Atrial fibrillation occurred in 3 of 51 patients (5.88%) in the amiodarone group, compared to 24 of 92 patients (26.08%) in the control group. Length of hospital stay in the amiodarone group was less than in the control group (5.3 days vs 6.7 days), with a trend toward decrease in hospital costs. CONCLUSION: The administration of IV amiodarone in conjunction with oral amiodarone for a total dose of 4,500 mg over 5 days appears to be a hemodynamically well-tolerated, safe, and effective treatment in decreasing the incidence of postoperative atrial fibrillation, shortening length of stay, and a trend toward lowering hospital costs, even in patients with significantly reduced left ventricular function (< 30%). A large multicenter study using IV and oral amiodarone should be pursued prior to deciding whether its use should become standard therapy in all patients undergoing CABG in order to decrease the incidence of postoperative atrial fibrillation

Studies of patients scheduled for percutaneous coronary intervention with acute coronary syndrome have shown that the addition of intravenous glycoprotein (GP) IIb/IIIa inhibitors to aspirin and heparin is associated with a reduction in death or myocardial infarction compared to therapy with aspirin and heparin alone. The principle safety issue with GP IIb/IIIa inhibitors is the risk of bleeding, as the potent antiplatelet effect of these drugs may adversely affect hemostasis. In addition, antagonists of GP IIb/IIIa may increase the risk of thrombocytopenia. We report a case of abciximab-induced severe thrombocytopenia which led to fatal intra-cranial hemorrhage

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)

We have performed a comparative evaluation of systemic (i.v.) and intraarterial (i.a.) cisplatin by using a trace dose of the radiolabeled form of this drug [( 195mPt]cisplatin) to monitor the drug's biodistribution by dynamic scintigraphic imaging. We have analyzed the drug's metabolism using a compartmental model both following i.a. and i.v. administration in patients with gliomas. Significantly larger amounts of radioactivity (up to 10 times higher than in the uninvolved brain) were measured in tumors following i.a. administration, whereas the differential localization following i.v. drug administration was, at best, only twofold that of the uninvolved brain. On the other hand, no significant differences could be detected in the pharmacokinetics of either free cisplatin or platinated proteins in blood. The washout slope in tumors following i.a. administration may be an indicator of the higher local concentration of free cisplatin; no such washout could be observed in tumors following i.v. administration. The present noninvasive methods may help document the amount and the rate of (active) drug deposition at the desired target site. They may also assist in monitoring, prospectively and/or, on line, the probable effect of chemotherapy in an individual patient. In turn it may lead to novel methods for optimizing chemotherapeutic effectiveness at specific tumor-bearing sites and in defined treatment protocols.

Two hundred consecutive patients undergoing only coronary bypass surgery were studied. Forty-five patients (group A) developed new fascicular conduction blocks and 155 patients (group B) did not. The 45 patients in group A developed the following fascicular conduction blocks: right bundle branch block 47%, right bundle branch block and left anterior hemiblock 8%, right bundle branch block and first-degree atrioventricular block 2%, left anterior hemiblock 11%, left bundle branch block 18%, right bundle branch block-left anterior hemiblock and first-degree atrioventricular block 5%. There were no significant differences in sex, incidence of diabetes, number of grafts performed, ejection fraction (less than 55%), and perioperative infarction. Group A patients were older (p less than 0.01). Hypertension was found frequently in group A (27 vs 45 patients; p less than 0.01) and was present for a mean of 12.4 years in group A and 4.9 years in group B (p less than 0.01). Preoperative use of digitalis was found in 14 (31%) patients in group A and in 18 (12%) patients in group B (p less than 0.01). Twenty-one (47%) patients in group A had significant disease (greater than 70%) of the left main coronary artery as compared to 17 (10.9%) in group B (p less than 0.001). There was no difference in the recurrence of angina or the survival rate at 14 months. In conclusion, the incidence of new fascicular conduction block after bypass surgery is 22.5%. Long-standing hypertension, left main coronary disease, and the preoperative use of digitalis appear to be predisposing factors. New fascicular conduction block does not affect prognosis.