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Patients with coronary artery disease (CAD) and concomitant left bundle branch block have increased mortality compared with those with CAD but without left bundle branch block. We retrospectively analyzed the extent of CAD in 200 patients with left bundle branch block referred for coronary angiography. Only 13% had left main or 3-vessel CAD. These findings were irrespective of left ventricular (LV) function. Of the 65 patients with normal LV function, only 5 (8%) had left main or 3-vessel disease, and of the 135 patients with depressed LV function, only 21 (16%) had left main or 3-vessel disease. [Copyright &y& Elsevier]

Describes the hemodynamic characteristics and response to percutaneous or surgical intervention of patients with mitral stenosis and a depressed cardiac output in the absence of diuretic therapy. Tendency for subjects to have low periprocedure mortality; Symptomatic benefit from percutaneous or surgical intervention.

Background: In humans, the use of cocaine and cigarette smoking each increases the heart's metabolic need for oxygen but may also decrease the supply of oxygen. As cocaine abuse has proliferated, cocaine-associated chest pain, myocardial infarction, and sudden death have occurred, especially among smokers. We assessed the influence of intranasal cocaine and cigarette smoking, alone and together, on myocardial oxygen demand and coronary arterial dimensions in subjects with and subjects without coronary atherosclerosis. Methods: In 42 smokers (28 men and 14 women; age, 34 to 79 years; 36 with angiographically demonstrable coronary artery disease), we measured the product of the heart rate and systolic arterial pressure (rate-pressure product) and coronary arterial diameters before and after intranasal cocaine at a dose of 2 mg per kilogram of body weight (n = 6), one cigarette (n = 12), or intranasal cocaine at a dose of 2 mg per kilogram followed by one cigarette (n = 24). Results: No patient had chest pain or ischemic electrocardiographic changes after cocaine use or smoking. The mean (±SE) rate-pressure product increased by 11 ±2 percent after cocaine use (n = 30, P<0.001), by 12 ±4 percent after one cigarette (n = 12, P = 0.021), and by 45 ±5 percent after both cocaine use and smoking (n = 24, P<0.001). As compared with base-line measurements, the diameters of nondiseased coronary arterial segments decreased on average by 7 ±1 percent after cocaine use (P<0.001), by 7 ±1 percent after smoking (P<0.001), and by 6 ±2 percent after cocaine use and smoking (P<0.001). The diameters of diseased segments decreased by 9 ±2 percent after cocaine use (n = 18, P<0.001), by 5 ±5 percent after smoking (n = 12, P = 0.322), and by 19 ±4 percent after cocaine use and smoking (n = 12, P<0.001). The increase in the rate-pressure product and the decrease in the diameters of diseased segments caused by cocaine use and smoking together were greater (P<0.001 and P = 0.037, respectively) than the changes caused by either alone. Conclusions: The deleterious effects of cocaine on myocardial oxygen supply and demand are exacerbated by concomitant cigarette smoking. This combination substantially increases the metabolic requirement of the heart for oxygen but simultaneously decreases the diameter of diseased coronary arterial segments. (N Engl J Med 1994;330:454-9.) [ABSTRACT FROM AUTHOR]

Intra-aortic balloon counterpulsation (IABP) is sometimes used in critically ill patients with cardiac disease. By increasing diastolic arterial pressure and decreasing systolic pressure, it reduces left ventricular afterload. IABP may be beneficial in subjects with cardiogenic shock, mechanical complications of myocardial infarction, intractable ventricular arrhythmias, or advanced heart failure or those who undergo "high-risk" surgical or percutaneous revascularization, but the evidence to support its use in these patient groups is largely observational. Contraindications to IABP include severe peripheral vascular disease as well as aortic regurgitation, dissection, or aneurysm. The potential benefits of IABP must be weighed against its possible complications (bleeding, systemic thromboembolism, limb ischemia, and, rarely, death).

Context: Homocysteine is emerging as a novel marker of atherothrombosis. Its role as an independent risk factor for cardiovascular disease is generally accepted. There is scanty data correlating homocysteine levels measured by immunoassay with cardiovascular disease. We previously validated a fluorescence polarization immunoassay for measuring homocysteine, which compared favorably with high performance liquid chromatography., Objective: To determine if homocysteine levels measured by immunoassay correlate with extent of atherosclerotic burden, as represented by degree of coronary artery stenosis determined by coronary angiography., Design: Fasting plasma samples were obtained from patients undergoing coronary angiography (N = 165). Homocysteine levels were measured by immunoassay and coronary artery stenosis was determined by coronary angiography., Results: Median coronary artery stenosis for the 3 homocysteine subgroups, less than 1.35, 1.35 to 6.75, and greater than 6.75 mg/L (<10, 10-15, and >15 micromol/L), was 75%, 90%, and 99%, respectively (P = .01 for trend). Also, folate and vitamin B12 levels decreased with increasing homocysteine levels (P = .01 and .04, respectively, for trend). Spearman's correlation showed a significant association between homocysteine level and coronary artery stenosis (r = 0.20; P = .009). When men and women were examined separately, the correlation was significant only for women (r = 0.30; P = .01)., Conclusion: Homocysteine levels, as measured by immunoassay, show a positive correlation with cardiovascular disease in women. Thus, this is a valid measure of atherosclerotic burden and, therefore, a reliable addition to the established laboratory repertoire for the assessment of cardiovascular disease.

Internists and cardiologists are often asked to estimate the risk for perioperative myocardial infarction or cardiac death in patients being considered for noncardiac surgery. Estimating this risk in an individual patient is difficult and complex. Although noninvasive imaging tests are often used for this purpose, a review of the literature reveals that the positive predictive value of noninvasive imaging tests is uniformly low and that they do not provide information beyond that obtained by assessing simple clinical risk variables. Moreover, no evidence exists that noninvasive imaging tests lead to a therapeutic strategy that reduces the risk for perioperative myocardial infarction or cardiac death. Since the publication of guidelines for preoperative risk stratification by the American College of Cardiology/American Heart Association in 1996 and the American College of Physicians in 1997, three clinical trials have shown that beta-blocker therapy reduces the risk for perioperative cardiac events. This paper focuses on the relationship between risk stratification and subsequent therapy to minimize or eliminate risk. In short, the paradigm is shifting from predicting which patient is at high risk for having a perioperative cardiac event to minimizing the likelihood of such an event with specific perioperative pharmacologic therapy.