Charles F. Presti

Exercise echocardiography: detection of coronary artery disease in patients with normal left ventricular wall motion at rest.

Most studies investigating the ability of exercise two-dimensional echocardiography to identify patients with coronary artery disease have included patients with left ventricular wall motion abnormalities at rest. This has the effect of increasing sensitivity because patients with only abnormalities at rest are detected. To determine the diagnostic utility of exercise echocardiography in patients with normal wall motion at rest, 64 patients were studied with exercise echocardiography in conjunction with routine treadmill exercise testing before coronary cineangiography. All 24 patients who had no angiographic evidence of coronary artery disease had a negative exercise echocardiogram (100% specificity). Nine of 40 patients with coronary artery disease (defined as greater than or equal to 50% narrowing of at least one major vessel) also had a negative exercise echocardiogram (78% sensitivity). Of the nine patients with a false negative exercise echocardiographic study, six had single vessel disease. Among 25 patients with single vessel disease, exercise echocardiography was significantly more sensitive (p = 0.01) than treadmill exercise testing alone (76 versus 36%, respectively). Among 15 patients with multivessel disease, the two tests demonstrated similar sensitivity (80%). In conclusion, exercise echocardiography is highly specific and moderately sensitive for the detection of coronary artery disease in patients with normal wall motion at rest. Although exercise echocardiography is significantly more sensitive than treadmill exercise electrocardiographic testing alone in patients with single vessel disease, the two tests are similar in their ability to detect coronary artery disease in patients with multivessel disease and normal wall motion at rest.

Thyrotoxicosis, atrial fibrillation, and embolism, revisited

Thyrotoxicosis may be complicated by atria1 fibrillation in 10% to 30% of patients, and the management of such patients often includes consideration of anticoagulants for the prevention of systemic embolism. Recently, Petersen and Hansen’ in a retrospective study of patients with thyrotoxicosis concluded that the risk of cerebrovascular events in patients with atria1 fibrillation was not significantly increased compared with that in age-matched control subjects with thyrotoxicosis who were in sinus rhythm. This conclusion differs from that of other available studies2-5 and, hence, management considerations remain controversial. This brief report critically analyzes the available literature on the incidence of systemic embolism in patients with thyrotoxic atrial fibrillation and emphasizes the difficulties in assessing the embolic risk in this condition. The majority of studies investigating the incidence of systemic embolism in patients with thyrotoxic atria1 fibril-

Influence of exercise-induced myocardial ischemia on the pattern of left ventricular diastolic filling: A Doppler echocardiographic study

Previous studies using Doppler echocardiography to evaluate left ventricular diastolic filling have shown that myocardial ischemia induced by coronary balloon angioplasty or atrial pacing results in a decrease in the left ventricular inflow peak early (E) to peak atrial (A) velocity ratio. To investigate the effects of exercise-induced ischemia on Doppler-derived filling variables, 20 patients with coronary artery disease and exercise-induced electrocardiographic changes and regional wall motion abnormalities determined by two-dimensional echocardiography were evaluated and compared with 20 patients without evidence of exercise-induced ischemia. Doppler echocardiography was performed at rest and immediately after exercise before the resolution of exercise-induced wall motion abnormalities. Peak E and A velocities increased from rest to postexercise in both the ischemic and nonischemic groups, although the ischemic group demonstrated a greater increase in peak E velocity (from 68 +/- 15 cm/s at rest to 88 +/- 22 cm/s after exercise) than the nonischemic group (70 +/- 13 to 77 +/- 18 cm/s) (p less than 0.05 for the difference in response between groups). Accompanying these changes was a slight increase in the peak E/A velocity ratio in the ischemic group (1.04 +/- 0.28 at rest to 1.13 +/- 0.42 after exercise) versus a decrease in the nonischemic group (1.07 +/- 0.30 to 0.90 +/- 0.28) (p less than 0.05 intergroup difference).(ABSTRACT TRUNCATED AT 250 WORDS)

Digital two-dimensional echocardiographic imaging of the proximal left anterior descending coronary artery

The use of 2-dimensional echocardiography to evaluate coronary artery anatomy noninvasively and directly has been primarily limited to the evaluation of the left main coronary artery. To determine the feasibility of visualization of the proximal left anterior descending coronary artery (LAD) and assessment for atherosclerotic disease in this location, 128 consecutive patients undergoing coronary arteriography were evaluated with digital 2-dimensional echocardiography. Visualization of the proximal LAD was possible in 90 (70%) of the 128 patients. Of 45 patients with proximal LAD narrowing by angiography, digital echocardiography correctly identified 44 (98% sensitivity). In 27 patients with angiographically normal coronary arteries, digital echocardiography was normal in 18 (67% specificity). In the 18 patients with an angiographically normal proximal LAD but narrowing elsewhere in the coronary system, digital echocardiographic evaluation of the proximal LAD was abnormal in 15. This initial study suggests that 2-dimensional echocardiography is a feasible technique to image the proximal LAD noninvasively in patients undergoing coronary arteriography.

Improvement in regional wall motion after percutaneous transluminal coronary angioplasty during acute myocardial infarction: Utility of two-dimensional echocardiography

In the setting of acute myocardial infarction, 16 patients undergoing successful coronary angioplasty (PTCA) within 6 hours of presentation (group I) and eight patients receiving conventional medical therapy (group II) were studied by serial two-dimensional (2D) echocardiography to assess the functional recovery of myocardium. All patients underwent 2D echocardiograms within 24 hours of presentation and at a minimum of 6 days after admission. Wall motion analysis was quantified with a wall motion score index based on 16 left ventricular wall segments. Wall motion score index improved significantly from early to late echocardiographic study in the patients undergoing PTCA (1.65 +/- 0.29 to 1.40 +/- 0.30; p less than 0.001), whereas the index did not improve in the conventionally treated group (1.54 +/- 0.26 to 1.58 +/- 0.25; p = NS). One patient in group II had a greater than or equal to 10% improvement in wall motion score index compared to 11 of 16 in group I (p less than 0.01). In all cases improvement in wall motion score index was due to improvement in regional wall motion in the area of infarction. In group I, 40 of 77 (52%) infarct zone segments showed improvement of at least one grade, versus 4 of 28 (14%) segments in group II (p less than 0.001). These data indicate that regional myocardial function improves in the majority of patients undergoing successful PTCA as emergency therapy for acute myocardial infarction and that serial 2D echocardiography is an excellent means to quantify this improvement.