Enhanced recognition of ischemia by three variable analysis of the exercise stress test.

Background: ECG ST-segment deviations have been the standard measure of coronary artery disease (CAD) during the exercise stress test (EST). Our past research has shown other ECG variables to be significant in EST. This study evaluates the benefit of routinely combining these variables in the detection of CAD.

Usefulness of p-wave duration to identify myocardial ischemia during exercise testing.

It is well recognized that ST-segment depression is due to subendocardial ischemia secondary to an increase in left ventricular end-diastolic pressure. The increase in left ventricular end-diastolic pressure is associated with increased left atrial pressure, resulting in left atrial wall distension that contributes to increasing P-wave duration (PWD). The objective of this study was to determine if PWD measured in leads II and V(5) during maximum exercise stress testing could be a reliable predictor of myocardial ischemia.

Exercise hypertension: an adverse prognosis?

We sought to clarify the prognostic importance of an "exaggerated" or "hypertensive" systolic blood pressure response to exercise during an exercise test. Studies evaluating the prognosis for cardiovascular events and cardiovascular mortality in those with hypertension during exercise testing were systematically reviewed. Fourteen studies were identified.

Hyperbaric oxygen: its application in cardiology: a historical perspective and personal journey.

Hyperbaric oxygen (HBO) was first used by placing a patient with the "bends" in a pressure chamber and increasing the pressure to 3 atm with 100% oxygen. It was soon recognized that HBO could also facilitate wound healing in infected ischemic extremities. Before the pump oxygenator was developed, it was also shown to facilitate corrective surgery, especially in congenital heart disease.

New York Heart Association functional class predicts exercise parameters in the current era.

Background: The New York Heart Association (NYHA) functional class is a subjective estimate of a patient's functional ability based on symptoms that do not always correlate with the objective estimate of functional capacity, peak oxygen consumption (peak V(O2)). In addition, relationships between these 2 measurements have not been examined in the current medical era when patients are using beta-blockers, aldosterone antagonists, and cardiac resynchronization therapy (CRT). Using baseline data from the HF-ACTION (Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing) study, we examined this relationship.

Point: a prescription to decrease left ventricular function.

The Courage Trial, published in 2007, has significantly reduced the incidence of treating stable angina with angioplasty. The investigators randomized 2297 patients with documented cardiac ischemia to conservative or invasive therapy and concluded that there was no difference in major events during a follow-up of 2.5 to 7 years and that the urge to open the narrowed artery was unjustified.

Unconventional electrocardiographic signs of ischemia during exercise testing.

Because of the failure to consider some of the unconventional electrocardiographic signs of ischemia during exercise testing, its sensitivity and specificity are lower than optimum. Two cases are presented to illustrate how precordial peaking of the T waves and lead-strength calculations in patients with low-voltage R waves can be used to improve the diagnostic power of exercise testing. Other rarely used electrocardiographic changes during exercise testing include ST elevation in lead aVR, an increase in P-wave duration, and ST depression in premature ventricular complexes.

Xanthine oxidase inhibitors the unappreciated treatment for heart failure.

The recognition that uric acid plays a significant role in cardiac function has been slow to be appreciated. About 50 years ago it was recognized that gout and high uric acid levels were often a marker for coronary heart disease, Since then the literature has contained several hundred studies which have demonstrated a great deal of the physiology of xanthine oxidase inhibition. A reduction in xanthine oxidase improves cardiac output, improves endothelial function, reduces myocardial infarct size, reduces inflammation, reduces myocardial oxidative stress and platelet adhesiveness.

Significance of lead strength during exercise testing.

Background: The aim of the study was to evaluate the contribution of relative lead strengths to exercise-induced ECG changes (ST depression) to predict the degree of myocardial ischemia as compared to the angiograms. This was accomplished by comparing the magnitude of ST depression to the ST/R ratio. Studies have shown that the diagnostic strength of a lead is directly related to the R wave amplitude and that sensitivity is significantly improved.

The value of upsloping ST depression in diagnosing myocardial ischemia.

We evaluated the value of upsloping ST-segment depression in predicting the severity of myocardial ischemia. Comparison of the exercise electrocardiographic changes was made to myocardial perfusion images and coronary angiograms as the criteria for ischemia. We retrospectively reviewed 621 patients who underwent exercise technetium-99m tetrofosmin single photon emission computed tomography (SPECT) for the assessment of suspected or known coronary artery disease followed by coronary angiography within a 3-month period.

The severity of myocardial ischemia can be predicted by the exercise electrocardiogram.

The aim of the study was to evaluate the utility of exercise-induced ECG changes in predicting the degree of myocardial ischemia as compared to angiographic and nuclear scintigraphic images. Four hundred and seventy one patients in whom exercise nuclear scintigraphy and coronary angiography revealed significant coronary narrowing (> or =70% luminal diameter narrowing) were studied. Down-sloping ST depression was found to be the best predictor of a large area of reversible ischemia (RI).