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Patients with chest pain and normal coronary angiograms have excellent long-term survival and are unlikely over the ensuing years to develop clinically significant atherosclerotic coronary artery disease. Specifically, of the 17 subjects with a previously normal coronary angiogram who had repeat angiography an average of almost 9 years later, 15 showed no appearance of coronary artery disease and 2 developed single-vessel coronary artery disease, 1 of whom had a myocardial infarction. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to assess whether: 1) very small increases in troponin T, measured by a new highly sensitive cardiac troponin T (hs-cTnT), may reflect ischemia without necrosis; and 2) serial changes can discriminate ischemia from other causes of cardiac troponin T (cTnT) release., Background: A new hs-cTnT assay offers greater sensitivity than current assays., Methods: Nineteen patients referred for diagnostic catheterization underwent cannulation of the coronary sinus (CS). Serial CS and peripheral plasma samples were obtained at multiple time points during and after incremental rapid atrial pacing. cTnT was quantified using both a standard and a pre-commercial highly sensitive assay. Ischemia was determined by the presence of significant coronary artery disease (CAD) and myocardial lactate release with pacing., Results: cTnT concentrations in CS blood increased from a median of 6.8 pg/ml prior to pacing to 15.6 pg/ml 60 min after termination of rapid atrial pacing (p < 0.0001), changes that were mirrored at 180 min in peripheral blood (5.1 to 11.8 pg/ml, p < 0.0001). Although peripheral cTnT concentrations tended to be higher at 180 min following pacing for patients with CAD and lactate elution (n = 7) when compared with those without either marker (n = 5) (25.0 pg/ml vs. 10.2 pg/ml, p = 0.10), relative (1.7-fold vs. 5.2-fold) and absolute (6.8 pg/ml vs. 8.8 pg/ml, p = 0.50) changes were not different between groups., Conclusions: Brief periods of ischemia, without frank infarction, cause low-level cTnT release, and small increases are common after periods of increased myocardial work, even among patients without objective evidence of myocardial ischemia or obstructive CAD. Additional research is needed before hs-cTnT assays are widely adopted in the management of subjects with chest pain syndromes., (Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: To assess the influence of acute hypoxemia on the dimensions of diseased and nondiseased coronary arterial segments in humans., Methods: In 18 subjects (age 53 +/- 8 years) with known or suspected coronary artery disease, quantitative coronary angiography was performed before and after being randomly assigned to breathing (1) an inspired oxygen concentration (fraction of inspired oxygen, FIO2) of 21% (room air, RA) for 20 min (n = 4, controls) or (2) an FIO2 of 15 and 10% for 10 min each (corresponding to altitudes of 2,500 and 5,500 m, respectively; n = 14)., Results: In the control subjects, no hemodynamic, oximetric or angiographic variable changed. In the 14 study subjects, the arterial partial pressure of oxygen averaged 85 +/- 13 mm Hg on RA, 65 +/- 15 mm Hg on 15% FIO2 and 44 +/- 13 mm Hg on 10% FIO2. Average arterial segment diameter was 2.52 +/- 0.63 mm on RA, 2.55 +/- 0.62 mm on 15% FIO2 (not significant vs. RA) and 2.66 +/- 0.66 mm on 10% FIO2 (p < 0.001 vs. RA). The increase in coronary arterial diameter with 10% FIO2 occurred only in normal segments (2.74 +/- 0.64 vs. 2.97 +/- 0.64 mm; p < 0.001), but not in diseased segments (2.34 +/- 0.57 vs. 2.38 +/- 0.55 mm; not significant)., Conclusions: In humans, severe hypoxemia induces vasodilation of angiographically normal coronary arterial segments, whereas it causes no change in diseased segments., (Copyright 2008 S. Karger AG, Basel.)

Although oximetric analysis of blood from the right heart chambers is the most commonly used method for assessing the presence of intracardiac left-to-right shunting, it sometimes provides misleading information because a patient with a left-to-right shunt in only 1 location sometimes manifests a significant oxygen step-up (1) in >1 chamber or (2) in a chamber other than that in which the shunt is actually located. This study was performed (1) to assess the frequency with which oximetric data provide such misleading results and (2) to determine which variables (if any) may contribute to the occurrence of such erroneous oximetric results. Accordingly, we analyzed oximetric data from 168 patients (61 men, 107 women, 14 to 76 years of age) with a proved left-to-right shunt at only 1 site and oximetric evidence of significant oxygen step-up. Using the criteria of Dexter et al (J Clin Invest 1947;26:554-560), Antman et al (Am J Cardiol 1980;46:265-271), or Pirwitz et al (Am Heart J 1997;133:413-417) for a significant oxygen step-up, 34%, 42%, and 35% of subjects, respectively, manifested a significant step-up in >1 chamber or a step-up only in an incorrect chamber. Compared with those with a step-up in the correct chamber only, those with a step-up in >1 chamber had larger Qp/Qs ratios (mean +/- SD, 2.7 +/- 1.2 vs 3.5 +/- 1.8, respectively, p <0.001), whereas subjects with a step-up only in an incorrect chamber had smaller Qp/Qs ratios than those with a step-up in the correct chamber (2.2 +/- 0.9 vs 2.8 +/- 1.3, respectively, p <0.001). In conclusion, in adult subjects with left-to-right intracardiac shunting in only 1 location, carefully obtained oximetric data often provide erroneous information.

Patients with left bundle branch block (LBBB) and concomitant coronary artery disease (CAD) have a worse prognosis than those with LBBB without CAD. In addition, subjects with CAD and concomitant LBBB have a higher cardiovascular mortality than those with a similar extent of CAD but without LBBB. Because the presence of LBBB makes the noninvasive identification of CAD problematic, patients with LBBB often are referred for coronary angiography to assess the presence and severity of CAD. To determine the clinical and demographic variables that might help identify those with CAD, we analyzed data from 336 consecutive patients with LBBB referred for coronary angiography. Of the 336, 54% had CAD. In conclusion, those with CAD were likely to be older, Caucasian, and men; they were more likely to have angina pectoris, myocardial infarction, and diabetes mellitus; and they were more likely to have a left ventricular ejection fraction <0.50. In contrast, patients with heart failure were less likely to have CAD.

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).

An ever-growing number of patients are being referred for coronary revascularization in an attempt to reduce morbidity or to reduce mortality. Multiple randomized trials comparing percutaneous and surgical coronary revascularization have been performed. The decision to proceed with percutaneous or surgical revascularization should be based ona thorough understanding of the short- and long-term risks and benefits of each procedure in conjunction with the individual patient's coronary arterial anatomy and clinical risk profile.

In patients who have ST-segment elevation myocardial infarction (STEMI), a patent infarct-related artery on the initial angiogram is associated with improved clinical outcomes, including decreased mortality. The present study assessed the influence of administering aspirin, beta blockers, statins, and angiotensin-converting enzyme inhibitors before STEMI on infarct-related artery patency. Our data demonstrate that patients who have STEMI and receive these medications on an outpatient basis before the event have a higher likelihood of having a patent infarct-related artery compared with patients who do not receive these medications. Further, our data demonstrate a graded association according to the number of such medications being administered: the likelihood of a patent infarct-related artery increased to >50% as the number of these medications increased.

We report the case of a 29-year-old man who developed acute congestive heart failure secondary to cardiac Chagas' disease in the setting of Trypanosoma cruzi reactivation by acquired immune deficiency syndrome.

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.