Altitude and the heart: is going high safe for your cardiac patient?

Our aging population combined with the ease of travel and the interest in high altitude recreation pursuits exposes more patients to the acute physiologic effects of high altitude and lower oxygen availability. Acute exposure to high altitude is associated with significant alterations to the cardiovascular system. These may be important in patients with underlying cardiovascular disease who are not able to compensate to such physiologic changes.

Stress-induced abnormalities in myocardial perfusion imaging that are not related to perfusion but are of diagnostic and prognostic importance.

Introduction: Certain stress-induced ancillary findings on myocardial perfusion scintigraphy increase the likelihood that the patient has coronary artery disease (CAD); furthermore, among CAD patients, they indicate more severe and extensive disease, placing these patients at higher risk for future cardiac events. Indeed, in studies with no obvious perfusion defect yet with serious CAD--for example, balanced ischemia--it can be these high-risk findings that necessitate invasive intervention.

Discussion: Besides reversible perfusion defects, such findings include increased pulmonary radiotracer uptake, transient cavity dilatation, increased end-diastolic or end-systolic volume, decreased post-stress ejection fraction, and increased right ventricular tracer uptake on stress images.

Left bundle-branch block artifact on single photon emission computed tomography with technetium Tc 99m (Tc-99m) agents: mechanisms and a method to decrease false-positive interpretations.

Myocardial perfusion scintigraphy is a well validated noninvasive method of evaluating for significant coronary artery disease, especially in cases where electrocardiographic changes are nondiagnostic, including left bundle-branch block. However, such testing with a technetium Tc 99m agent is often confounded by left ventricular septal-based false-positive perfusion defects. These defects can be either reversible or irreversible in the septal or anteroseptal wall, problematically then, in the territory supplied by the left anterior descending coronary artery.

Electrocardiographic exercise stress testing: an update beyond the ST segment.

Routine exercise testing is frequently ordered to evaluate a patient's cardiovascular performance. The test is more direct and less expensive than imaging technology, and derives valuable information. New variables such as dyspnea and heart rate recovery, as well as integrated scores, provide incremental value to conventional analysis of exercise-induced angina or electrocardiographic changes.

Chlamydia pneumoniae and coronary artery disease: legitimized linkages?

Chlamydia pneumoniae (Cp) infection in early life may accelerate atherosclerosis over ensuing decades, leading to cardiovascular complications. Cp promotes endothelial dysfunction and may modulate inflammation underlying atherosclerosis. It represents a biologically plausible candidate for the causation of atherosclerosis.

Elevation of cardiac troponin I indicates more than myocardial ischemia.

Elevated cardiac troponin I (cTnI) levels in patients hospitalized with chest pain often lead to a diagnosis of acute myocardial infarction (MI) or unstable angina. However, as we describe in this review, this finding may occur in other conditions, leading to an incorrect diagnosis and other, sometimes invasive, tests. We review briefly cTnI, its release and detection.

Peripheral arterial disease--Part II: Management.

While knowledge about peripheral arterial disease (PAD) appears well disseminated, the condition still goes largely undiagnosed and untreated. In PART 1 of this paper, we summarized the diagnosis, epidemiology and risk factors for PAD. Non-invasive treatment involves management of risk factors and targeted drug therapy.

Peripheral arterial disease--Part I: Diagnosis, epidemiology and risk factors.

While knowledge about peripheral arterial disease (PAD) appears well disseminated, the condition still goes largely undiagnosed and untreated. We reviewed the current literature and found that PAD is a common condition that is equally prevalent in men and women. Most cases are asymptomatic and more so in women.

Epidemiology of peripheral arterial disease in women.

Background: Peripheral arterial disease is a common disease, which increases with age and presence of vascular risk factors. The extended longevity in industrialized nations coupled with the expanding elderly female population is predicted to lead to an increase in the prevalence of this condition. Little attention has been focussed on gender differences in peripheral arterial disease, or its epidemiology in women.