Two dimensional echocardiographic evaluation of exercise-induced left and right ventricular asynergy: correlation with thallium scanning

Optimal use of dobutamine stress for the detection and evaluation of coronary artery disease: combination with echocardiography or scintigraphy, or both?

OBJECTIVES

This study was conducted to examine the efficacy of dobutamine stress two-dimensional echocardiography and perfusion scintigraphy for the detection of coronary artery disease in routine practice, to establish the causes of erroneous results and to derive appropriate criteria for the selection of either or both tests.

BACKGROUND

Dobutamine stress combined with echocardiography or perfusion scintigraphy may be used to detect coronary artery disease. Although both imaging approaches have demonstrated similar levels of accuracy, it is not known whether there may be particular indications for the use of one or the other technique or a rationale for their combination.

METHODS

Two hundred seventeen patients without previous infarction were studied prospectively with dobutamine stress echocardiography and technetium-99m methoxy isobutyl nitrile (sestamibi) single-photon emission computed tomography at the time of diagnostic coronary angiography. The presence of coronary stenoses of > or = 50% diameter was compared with the presence of rest or stress-induced abnormalities of perfusion and regional function. The extent of these abnormalities was correlated with an equivalent score of extent of angiographic disease.

RESULTS

Significant coronary artery disease was found in 142 patients; 102 (72%) were identified by dobutamine echocardiography and 108 (76%, p = NS) by perfusion imaging. In 75 patients without significant disease, the specificity of dobutamine echocardiography was 83% compared with 67% for scintigraphy (p = 0.05). Echocardiographic sensitivity was lower in patients unable to complete the test because of side effects (n = 64) than in the remainder (59% vs. 77%, p = 0.02); this influence was less apparent with scintigraphy (71% vs. 78%, p = NS). Selective use of scintigraphy in the 31 patients with a negative submaximal stress echocardiogram led to a sensitivity of 80% for this combination. Patients with left ventricular hypertrophy accounted for most of the difference in specificity between echocardiography and scintigraphy (94% vs. 59%, p = 0.02). Their respective accuracies were 76% and 73%.

CONCLUSIONS

Dobutamine stress echocardiography and perfusion scintigraphy have equivalent accuracy. In patients with left ventricular hypertrophy, echocardiography appears to be the test of choice. Selective use of sestamibi scintigraphy in patients with a negative submaximal echocardiogram enhances the accuracy of stress echocardiography alone.

Exercise echocardiography for the evaluation of patients after nonsurgical coronary artery revascularization

OBJECTIVES

The purpose of this study was to demonstrate the accuracy of stress echocardiography for detecting the progression of coronary artery disease after nonsurgical revascularization.

BACKGROUND

The expanding role of nonsurgical coronary revascularization procedures mandates the development of sensitive noninvasive techniques for the detection of recurrent ischemia.

METHODS

Bicycle stress echocardiography was performed in a series of 86 patients 6.5 +/- 1.3 months after a revascularization procedure. Seven patients were excluded from analysis because of poor echocardiographic image quality.

RESULTS

Digital analysis achieved a sensitivity of 83% for the entire group and a specificity of 85% for stress echocardiographic detection of significant coronary artery disease. Sensitivity was greater in patients with (88%) than in those without (75%) prior myocardial infarction, but this difference did not reach statistical significance. Additional analysis using an increase in end-systolic volume index or a decrease in ejection fraction during stress as an additional marker for ischemia tended to enhance sensitivity (90% for the entire group and 93% for the subgroup with prior myocardial infarction).

CONCLUSIONS

Stress echocardiography is a useful and sensitive method for the follow-up of patients undergoing nonsurgical revascularization procedures. The addition of volume determination to routine wall motion analysis may be helpful in patients with prior infarction who have scar tissue that may be difficult to distinguish from an adjacent exercise-induced wall motion abnormality.

Detection of coronary artery disease with upright bicycle exercise echocardiography

This study examined the advantages and limitations of upright bicycle exercise echocardiography in the evaluation of a large series of patients with known or suspected coronary artery disease. The study population consisted of 309 patients (231 men, mean age 57 +/- 11 years) who underwent exercise echocardiography within 8.5 +/- 16.1 days of coronary angiography. All stress electrocardiographic, echocardiographic, and angiographic data were reinterpreted in a blinded manner by the investigators. No patient was excluded because of poor echocardiographic image quality. Wall motion was analyzed at baseline, peak exercise, and immediately after exercise with a 16-segment model, and a regional wall motion score index was calculated at each stage. Abnormalities were ascribed to the distribution of the three coronary arteries and correlated with qualitative angiography. There were 126 patients with wall motion abnormalities at rest and 211 (75%) with coronary artery disease. The stress electrocardiogram (ECG) was negative in 61, positive in 144, and nondiagnostic in 104, yielding a sensitivity of 40% and a specificity of 89%. Echocardiography was normal in 76 of 98 patients without coronary disease (78% specificity) and abnormal in 193 of 211 patients with disease (91% sensitivity). Sensitivity was higher among patients with multivessel disease compared with those with single vessel disease (95% versus 86%, respectively, p = 0.03). Among patients with normal wall motion at rest (n = 183), sensitivity was 83% and specificity was 84%. Of the 104 patients with a nondiagnostic stress ECG, echocardiography correctly identified 95% of those with coronary disease and 75% of those without disease. Among 82 patients with a wall motion abnormality at rest, an additional exercise-induced wall motion abnormality developed in 32 of 46 patients (70%) with multivessel disease and seven of 32 (22%) with single-vessel disease. Overall, echocardiography detected 258 of 392 (66%) individual coronary lesions. Accuracy was higher for lesions in the left anterior descending and right coronary arteries (both 79%) compared with the left circumflex artery (36%, p < 0.001). In conclusion, upright bicycle exercise echocardiography is an accurate technique for the evaluation of patients with known or suspected coronary artery disease and is especially valuable in patients with a nondiagnostic stress ECG. The test provides supplemental information on the extent and location of coronary lesions and is useful in patients with and without prior myocardial infarction.

Exercise echocardiography

Exercise testing is an indispensable component of clinical cardiology. Latent disease or the full extent of a problem may not be apparent on a resting examination. Some form of stress is frequently necessary, especially in patients with coronary disease, to appreciate whether a patient has stress-induced ischaemia as manifested by exercise-induced chest discomfort, a drop in blood pressure or electrocardiographic changes of ischaemia. Unfortunately as with every test ECG and clinical monitoring have limitations. Patients may have ischaemia without pain, ECG changes may be non-specific, a resting abnormal ECG has limited value, and the location and amount of ischaemic muscle is not directly assessed. Monitoring the echocardiogram adds significant additional information to routine stress testing. By visualising the myocardium in the exercising individual, it is possible to assess a fundamental manifestation of ischaemia, regional wall motion abnormalities. This information helps identify the vessels and the amount of muscle involved. In addition resting wall motion abnormalities may detect clinically silent infarction or hibernating myocardium. Direct visualisation of the exercising heart provides an improved understanding of a patient's cardiac status. The technique is particularly useful in evaluating revascularisation procedures. Advances in instrumentation have reduced or eliminated many of the technical difficulties with obtaining and interpreting exercise echocardiograms. This examination has become an extremely useful adjunct to routine stress testing.

Exercise echocardiography after stabilization of unstable angina: correlation with exercise thallium-201 single photon emission computed tomography

The diagnostic usefulness of predischarge exercise echocardiography in 35 patients with unstable angina who responded to medical therapy was correlated with exercise thallium-201 single photon emission computed tomography (TI-SPECT) performed, on the average, three days after the exercise echocardiography. None of the patients had myocardial infarction prior to hospitalization or before TI-SPECT and none had left bundle-branch block on their rest electrocardiogram (ECG). Exercise echocardiography was positive in 21 patients and TI-SPECT in 24. The results of the two techniques were concordant in 28 of 35 patients (agreement = 80%, k = 0.57 +/- 0.14, p less than 0.001). Wall-by-wall comparison of the distribution of exercise-induced wall motion abnormalities with reversible thallium defects showed complete or partial correlation in all of 19 patients in whom both the tests were positive. A positive exercise ECG and positive exercise echocardiography identified 11 of 11 patients with angiographically verified significant coronary artery disease (CAD) and 11 of 12 patients (92%) with positive TI-SPECT. Thus, exercise echocardiography is a valuable addition to routine predischarge exercise test in the noninvasive diagnosis of myocardial ischemia and shows a good correlation with TI-SPECT in detecting and localizing ischemia in patients with unstable angina stabilized on medical therapy.

Relationship between exercise echocardiography and perfusion single-photon emission computed tomography in patients with single-vessel coronary artery disease

The aim of this study was to assess the relative value of exercise echocardiography and perfusion single-photon emission computed tomography (SPECT) in identifying the presence and severity of coronary artery stenosis. Accordingly, 44 consecutive patients with stenosis in one vessel performed simultaneous postexercise echocardiography and perfusion SPECT (with either thallium-201 [n = 19] or 99m-Tc-methoxyisobutyl isonitrile [n = 25]) in conjunction with symptom-limited bicycle exercise testing. Positive test results were based on the presence of new or worsened exercise-induced wall motion abnormalities and transient perfusion defects, respectively. Moreover, an "ischemic" score index was derived for semiquantitative assessment of both echocardiography (with a 14-segment model of left ventricular wall on a 4-point scale) and SPECT (47-segment model on a 5-point scale). All patients underwent correlative coronary arteriography, assessed by digital caliper. Significant coronary artery disease (diameter stenosis greater than or equal to 50%) was present in 30 patients. There was a good overall concordance between the two tests in terms of result (79%); compared with patients with positive results of both tests, in the seven patients with positive SPECT and negative echocardiography the time of recording echocardiographic images was longer (p = 0.05). When analyzing patients according to the percent diameter stenosis (greater than 70%, 50% to 70%, and less than 50%) for both echocardiography and SPECT, the prevalence of an ischemic response was directly related to the severity of the coronary stenosis (p less than 0.001); moreover, a negative test result was highly predictive of a diameter coronary stenosis less than 70%.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise echocardiography

Exercise echocardiography is a versatile, noninvasive diagnostic test that involves the recording and interpretation of 2-dimensional echocardiograms prior to, during, and after exercise. By analyzing and comparing wall motion at each stage, a prediction about the presence or absence of coronary artery disease can be made. The development of a wall motion abnormality is both sensitive and specific for the presence of a significant coronary stenosis. Changes in regional systolic function during exercise enable the clinician to distinguish between infarction and ischemia. Thus, the test yields information on the presence, extent, severity, and location of coronary artery disease. Echocardiography can be adapted to almost any form of stress, although treadmill or bicycle exercise are most commonly employed. An advantage of bicycle stress echocardiography is the opportunity to image during exercise, rather than relying on postexercise recording. This contributes to enhanced sensitivity, although false-positive results may increase due to the difficulties of analyzing wall motion during strenuous exercise. Exercise echocardiography increases the diagnostic accuracy of stress testing in a manner similar to radionuclide perfusion imaging. It is particularly useful in the setting of an ambiguous stress electrocardiography (ECG) or when a false-negative or false-positive result is suspected. It has been successfully applied to patients following revascularization and yields useful prognostic data in a variety of clinical situations. Exercise echocardiography is being increasingly utilized as a safe and accurate test in patients with known or suspected coronary artery disease.

Diagnosis of coronary artery disease using exercise echocardiography and positron emission tomography: comparison and analysis of discrepant results

Both exercise echocardiography and rubidium-82 positron emission tomography are used in the detection and characterization of coronary artery disease. This study compared results of both in 74 patients with known coronary anatomy, by use of exercise echocardiography before and after treadmill exercise and positron emission tomography with intravenous dipyridamole-handgrip stress. Significant (greater than 50%) coronary stenoses were present in 70 patients; exercise echocardiography and positron emission tomography each identified 63 patients (sensitivity 90%). Significant stenoses without previous myocardial infarction were present in 34 patients; 29 (85%) were identified by exercise echocardiography and 28 by positron emission tomography (82%, p = NS). Four patients had no significant coronary disease, and were all identified as normal by both methods. Segments were classified as either normal or showing stress or resting abnormalities, and the diagnoses were compared in the territories of the three major coronary arteries. Results were concordant with respect to the presence or absence of coronary disease in 185 of 222 territories (83%). The remaining 37 regions had abnormalities by exercise echocardiography or positron emission tomography but not both. Stress defects were identified by only one of the tests in 24 areas (in 12 [50%], angiographic findings correlated with positron emission tomography). Resting defects were diagnosed by only one modality in 13 regions (angiographic findings correlated with the results of positron emission tomography in 9 [69%] of these). Both exercise echocardiography and positron emission tomography are sensitive for the identification of coronary artery disease, although on a regional basis, positron emission tomography appears to be more specific for the diagnosis of resting perfusion defects.

Bicycle stress echocardiography

Bicycle stress echocardiography involves the recording and interpretation of two-dimensional echocardiographic information before, during, and after bicycle exercise. The exercise test can be performed in the supine or upright posture. While there are important physiological differences between these two positions, they appear to provide similar diagnostic information on the presence or absence of coronary artery disease. A major advantage of bicycle stress echocardiography compared to treadmill exercise is the ability to image at peak exercise, rather than relying solely on pre- and postexercise imaging. This contributes to the greater sensitivity of the test for the detection of ischemia. The recent application of digital processing techniques may also improve sensitivity by permitting side-by-side comparison of rest and stress images. In summary, bicycle stress echocardiography is a useful tool in the management of patients with known or suspected coronary artery disease. It is a versatile and accurate technique, which competes favorably with other imaging modalities and provides information on regional and global left ventricular function.

Stress echocardiography versus radionuclide stress techniques

The different modalities of stress echocardiography and stress thallium-201 imaging have comparable sensitivity, specificity, and overall predictive accuracy in the diagnosis and prognosis of coronary artery disease. They are also comparable in the assessment and follow-up of patients treated with thrombolytic therapy or who have undergone percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery. Stress radionuclide ventriculography has a lower sensitivity and specificity as compared to stress echocardiography and stress thallium. Dipyridamole thallium has a higher sensitivity as compared to dipyridamole echocardiography in the diagnosis and prognosis of coronary artery disease. New techniques such as dobutamine echocardiography, adenosine stress thallium-201, and adenosine echocardiography have individually shown high sensitivities, specificities, and accuracy. However, further studies are needed on their comparative value. The major advantages of stress echocardiography over radionuclide stress techniques are: lack of radiation exposure; less expense; less time consumption; less personnel required; and greater availability. Its major disadvantage, however, is the inability to obtain adequate studies in all patients.

Exercise echocardiography and single photon emission computed tomography in patients with left anterior descending coronary artery stenosis

To compare the diagnostic value of exercise echocardiography and perfusion single photon emission computed tomography (SPECT) in the detection of the presence and the severity of coronary artery disease, we studied 21 patients with isolated stenosis of different degree of the left anterior descending artery. Both echocardiography and SPECT were performed in conjunction with the same symptom-limited bicycle exercise test. Positivity of the test was based on the presence of exercise-induced wall motion abnormalities and transient perfusion defects, respectively. For both tests, an 'ischemic' score was derived, as index of extent and severity of myocardial ischemia. Coronary arteriography was evaluated by caliper. The agreement between exercise echocardiography and SPECT for the presence of coronary artery disease was 90%; the discordance was due to two patients with positive echocardiography and negative SPECT. A good correlation between ischemic wall motion and perfusion score indices was found (r = 0.78, p less than 0.0001. Moreover, the percent diameter stenosis was well correlated with both ischemic indices (r = 0.75, p less than 0.0001; r = 0.67, p less than 0.001, respectively). In patients with a positive test, the mean value of ischemic wall motion score index was higher in patients with a diameter stenosis greater than or equal to 70% than in patients with a diameter stenosis less than 70% (0.59 +/- 0.19 vs 0.29 +/- 0.12, p less than 0.01); a similar trend was found for ischemic perfusion score index (0.51 +/- 0.35 vs 0.27 +/- 0.12, ns).(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise echocardiography versus 201Tl single-photon emission computed tomography in evaluation of coronary artery disease. Analysis of 292 patients

BACKGROUND

Exercise echocardiography (digital cine-loop technique) and 201Tl single-photon emission computed tomography (SPECT) were performed simultaneously in 292 patients being evaluated for coronary artery disease.

METHODS AND RESULTS

Pretreadmill and posttreadmill echocardiographic images of diagnostic quality were obtained in 289 patients, and the left ventricle was divided into anterior, inferior, and lateral regions. Any wall motion or perfusion abnormality observed within each region was classified as totally reversible, fixed, or partially reversible. Exercise echocardiography and SPECT were normal in 137 patients and abnormal in 118 (88% agreement). Equal numbers of regional abnormalities were detected by one test when missed by the other. The two tests had an 82% agreement in detecting the same type of finding within the regions analyzed. SPECT detected more reversible abnormalities than echocardiography, whereas echocardiography detected more fixed abnormalities than SPECT: Regions with a fixed abnormality by echocardiography frequently showed partial reversibility of a perfusion defect by SPECT: Nearly one third of regions with fixed perfusion defects by SPECT demonstrated normal resting function or reversible abnormalities by echocardiography. Sensitivity for coronary artery disease by angiography (greater than or equal to 50% diameter stenosis) in 112 patients was similar for the two tests, ranging from 58% and 61% (echocardiography and SPECT, respectively) for one-vessel disease to 94% for three-vessel disease. The specificities for echocardiography and SPECT were 88% and 81%, respectively.

CONCLUSIONS

Exercise echocardiography had a diagnostic accuracy comparable to that of SPECT for the detection of regional abnormalities produced by significant coronary artery disease. A greater number of abnormal regions were detected with the combined use of both tests.

Usefulness and limitations of transesophageal echocardiography in the assessment of proximal coronary artery stenosis

To assess the usefulness of transesophageal echocardiography in the evaluation of proximal coronary artery stenosis, 111 consecutive patients (mean age 61 years) who had intraoperative transesophageal echocardiography and coronary angiography within 1 week of surgery were studied. Transesophageal echocardiography visualized the entire length of the left main artery (0.2 to 2.2 cm, mean 0.93), 0.2 to 2.2 cm of the proximal left anterior descending artery and 0.1 to 3.4 cm of the proximal left circumflex artery in 103 patients (93%) and 0.1 to 4.6 cm of the proximal right coronary artery in 55 patients (49%). In the coronary artery segments visualized by echocardiography and compared with the corresponding angiographic segments, transesophageal echocardiography correctly identified 23 (96%) of 24 left main stenoses, 11 (78%) of 14 stenoses involving the left anterior descending artery, 6 (75%) of 8 left circumflex stenoses and all 7 stenoses (100%) of the right coronary artery. In all seven patients with ostial stenosis (left main artery in five and right coronary artery in two), the condition was correctly diagnosed by this technique. The sensitivity and specificity of transesophageal echocardiography in the overall evaluation of proximal coronary artery stenosis as customarily defined by angiography were 96% and 99% for the left main artery, 48% and 99% for the left anterior descending artery, 67% and 100% for the left circumflex artery and 37% and 100% for the right coronary artery, respectively. The distance of the stenotic lesion from the origin of the vessel by transesophageal echocardiography also correlated well with that measured by angiography (r = 0.63 to 0.99).(ABSTRACT TRUNCATED AT 250 WORDS)

Stress echocardiographic techniques. An overview

The choice of upright or supine exercise, pharmacological agents, or atrial pacing for the induction of ischemia depends on the goals and the imaging modality. Dynamic stress echocardiography has improved diagnostic accuracy over and above the stress electrocardiogram. Indications include patients with atypical symptoms, prior nondiagnostic stress electrocardiograms, or baseline electrocardiographic abnormalities. Pharmacological agents coupled with echocardiography do well in the high-risk preoperative patient (e.g., abdominal aneurysmectomy) or in those unable to walk due to orthopedic, neurological, or peripheral vascular disease. When there is uncertainty as to the physiological significance of anatomical (angiographic) stenosis, dynamic stress echocardiography in the ambulatory patient or atrial pacing (or beta-agonist pharmacological stressors) in the catheterization laboratory are useful. The accuracy of stress echocardiography for detection of ischemia in the follow-up of interventional procedures or for postmyocardial infarction risk stratification is superior to standard stress electrocardiography alone.

Accuracy and limitations of exercise echocardiography in a routine clinical setting

Despite the high reported accuracy of exercise echocardiography in the detection of coronary artery disease, factors that compromise its sensitivity and specificity are less clear. This study examined the results of 179 post-treadmill stress echocardiograms in 150 consecutive patients who also underwent cardiac catheterization and in 29 normal persons at low risk for coronary artery disease. Of 114 patients who had significant coronary stenoses at angiography, 96 had an abnormal exercise echocardiogram (overall sensitivity 84%). False negative results correlated with the performance of submaximal exercise, single-vessel disease and moderate (50% to 70% diameter) stenoses. After the exclusion of seven patients performing submaximal exercise, the sensitivity was 90%. In 54 patients without previous infarction performing maximal exercise, the sensitivity was 87%, higher in patients with multivessel coronary disease (96%) than in those with single-vessel disease (79%). After the exclusion of patients with nondiagnostic results, due either to the performance of submaximal stress or the presence of electrocardiographic (ECG) changes at rest, exercise echocardiography had a higher sensitivity than did exercise electrocardiography (87% vs. 63%, p = 0.01). In 36 patients without significant coronary disease, exercise echocardiography had an overall specificity of 86%. After the exclusion of patients with a nondiagnostic test, exercise echocardiography had a specificity of 82% compared with 74% specificity for exercise electrocardiography (p = NS). Similarly, of the 29 normal subjects, 93% had a normal exercise echocardiogram and 97% had a normal exercise ECG (p = NS). Similarly, of the 29 normal subjects, 93% had a normal exercise echocardiogram and 97% had a normal exercise ECG (p = NS). Age, gender, body weight and image quality did not significantly influence the accuracy of exercise echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic accuracy of peak exercise echocardiography in coronary artery disease: comparison with thallium-201 myocardial scintigraphy

To evaluate the accuracy of exercise two-dimensional echocardiography for the recognition of coronary artery disease, 53 patients (46 men and 7 women, age range 35 to 69 years) without either previous myocardial infarction or resting wall motion abnormalities, were studied. According to coronary angiography 26 had normal coronary arteries, 14 had one-vessel, seven had two-vessel, and six had three-vessel disease. After withdrawal of any therapy, all patients underwent a single exercise stress test with a stress table during which cine-loop digitized echocardiography was acquired and 74 MBq of thallium-201 (TI-201) were injected. Echocardiographic images were evaluated at rest and at peak exercise. Three-view planar scintigraphic images were collected immediately after exercise and 4 hours later. For the overall recognition of coronary artery disease, exercise electrocardiography had 77.8% sensitivity and 65.4% specificity; myocardial scintigraphy had 100% sensitivity and 92.3% specificity; and exercise echocardiography had 92.6% sensitivity and 96.2% specificity (both NS versus myocardial scintigraphy). Global accuracy was 71.7% for exercise electrocardiography, 94.3% for stress echocardiography, and 96.2% for myocardial scintigraphy. For the classification of the individual involved coronary arteries, the sensitivity of myocardial scintigraphy was 84.8% and that of exercise echocardiography was 63% (p less than 0.01); the related specificities were 98% and 98.2% respectively (NS). It may be concluded that exercise echocardiography is highly accurate for the recognition of coronary artery disease, whereas it appears less sensitive in the identification of the involved vessels, particularly in patients with multivessel disease.

Role of Doppler echocardiography in coronary artery disease

Doppler echocardiography can have a major role in the evaluation of patients with coronary artery disease. This review deals with the imaging planes in relation to coronary vascular territories and the role of Doppler echocardiography in evaluating patients with acute and chronic ischemic syndromes.

Exercise echocardiography as a screening test for coronary artery disease and correlation with coronary arteriography

We evaluated exercise echocardiography as a screening test for coronary artery disease in 228 patients, all of whom underwent subsequent coronary angiography. After an echocardiogram at rest was obtained, each patient performed maximal, symptom-limited, upright treadmill exercise, immediately after which repeat imaging was performed. The exercise echocardiogram was abnormal if any segment failed to become hypercontractile with exercise, and these regional wall motion abnormalities were used to predict the extent and distribution of coronary disease. At subsequent angiography, coronary stenosis was defined as significant if luminal diameter was reduced greater than or equal to 50%. Compared with electrocardiography, exercise echocardiography was more sensitive (97 vs 51%) and specific (64 vs 62%), and had higher positive (90 vs 82%) and negative (87 vs 28%) predictive accuracies. Exercise echocardiography was also highly predictive of the extent (no, 1-, 2- or 3-vessel disease) and distribution (which vessel) of coronary stenoses. It is concluded that exercise echocardiography is an excellent screening test for the presence, extent and distribution of coronary artery disease.

Assessment of severity of coronary narrowings by quantitative exercise echocardiography and comparison with quantitative arteriography

To determine the correlation of quantitative assessment of coronary narrowings with left ventricular functional impairment induced by exercise, 57 patients with 1-vessel coronary artery disease and without evidence of collateral flow were studied. A significant relation was observed between minimal cross-sectional area, percent area stenosis, minimal lumen diameter, percent diameter stenosis and the percentage of segmental area change from rest to peak exercise in a vascular distribution territory (r = 0.76, p less than 0.001; r = -0.55, p less than 0.001; r = 0.56, p less than 0.001; r = -0.75, p less than 0.001, respectively). For minimal cross-sectional area, the best cut-off value to separate significantly patients who had a decrease in contractility at peak exercise testing from those who had a normal response was 2 mm2 (p less than 0.001); for percent cross-sectional area stenosis, it was 75% (p less than 0.001); for minimal lumen diameter, it was 0.7 mm (p less than 0.001); and, for percent diameter stenosis, it was 85% (p less than 0.001). High cut-off values for angiographic variables are necessary to separate significantly patients who have a decrease in contractility at peak exercise testing from those who have a normal response. Several patients with mild coronary stenoses may have either normal or abnormal wall motion during exercise. Thus, exercise echocardiography is a useful tool in detecting the presence of fairly severe anatomic narrowing, whereas it is of limited clinical use in the assessment of intermediate coronary atherosclerotic lesions.

Exercise echocardiography and technetium-99m MIBI single-photon emission computed tomography in the detection of coronary artery disease

To compare the relative diagnostic value of exercise echocardiography with perfusion technetium-99m metoxyisobutylisonitrile single-photon emission computed tomography (SPECT) in detecting coronary artery disease (CAD), 75 patients with suspected CAD but a normal electrocardiogram (ECG) at rest were included in a prospective correlative study. Both the exercise echocardiograms and SPECT studies were performed in conjunction with the same symptom-limited bicycle exercise test. The development of either a new wall motion abnormality or a reversible perfusion defect after exercise, or both, were regarded as a positive test for the exercise echocardiographic and SPECT studies, respectively. The results of these 2 diagnostic tests were compared with coronary arteriography. Exercise echocardiography identified 35 (71%) and SPECT 41 (84%, p = 0.13) of the 49 patients with significant CAD (defined as greater than 50% diameter stenosis). Twenty-five of the 26 patients (96%) without significant coronary stenosis had negative exercise echocardiographic results and 23 of 26 (88%) had negative SPECT results. Exercise-induced new wall motion abnormalities showed a good correlation with reversible perfusion defects, and the results of the 2 methods were concordant in 65 of 75 patients (agreement = 88%, kappa = 0.75 +/- 0.14). Both the diagnostic accuracy of exercise echocardiography and SPECT were significantly higher than the exercise ECG (81 vs 64%, p less than 0.02 and 88 vs 64%, p less than 0.005). The sensitivity and specificity for detecting individual diseased vessels were 60 and 95% for exercise echocardiography and 67 and 94% for SPECT.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous transesophageal atrial pacing and transesophageal two-dimensional echocardiography: a new method of stress echocardiography

The diagnostic use of exercise echocardiography has been widely reported. However, transthoracic exercise echocardiography is inadequate in up to 20% of patients because of poor image quality related to exercise. In an attempt to overcome these limitations, a system was developed in which transesophageal echocardiography is combined with simultaneous transesophageal atrial pacing by means of the same probe. In a prospective study, transesophageal echocardiography was performed before, during and immediately after maximal atrial pacing in 50 patients with suspected coronary artery disease. Results of transesophageal stress echocardiography were considered abnormal when new pacing-induced regional wall motion abnormalities were observed. Correlative routine bicycle exercise testing was carried out in 44 patients. Cardiac catheterization was performed in all patients. The success rate in obtaining high quality diagnostic images was 100% by transesophageal echocardiography. All nine patients without angiographic evidence of coronary artery disease had a normal result on the transesophageal stress echocardiogram (100% specificity). Thirty-eight of 41 patients with coronary artery disease (defined as greater than or equal to 50% luminal diameter narrowing of at least one major vessel) had an abnormal result on the transesophageal stress echocardiogram (93% sensitivity). The sensitivity of the technique for one, two or three vessel disease was 85%, 100% and 100%, respectively, compared with 44%, 50% and 83%, respectively, for bicycle exercise testing; the 12 lead electrocardiogram (ECG) during rapid atrial pacing showed a sensitivity of 25%, 64% and 86%, respectively. Thus, rapid atrial pacing combined with simultaneous transesophageal echocardiography is a highly specific and sensitive technique for the detection of coronary artery disease. Ischemia-induced wall motion abnormalities were detected earlier than observed ECG changes. The technique appears to be particularly suited to patients who are unable to perform an active stress test or those with poor quality transthoracic echocardiograms.

Prediction of cardiac events after uncomplicated myocardial infarction by cross-sectional echocardiography during transesophageal atrial pacing

Atrial pacing can safely be utilized shortly after myocardial infarction. To evaluate the prognostic value of wall motion abnormalities induced by such pacing 83 consecutive patients with recent uncomplicated myocardial infarction underwent transthoracic cross-sectional echocardiography during transesophageal atrial pacing and upright bicycle exercise stress test. Patients were followed-up for 14 +/- 5 months. During the atrial pacing and the echocardiography, patients were defined at high risk if abnormalities of wall motion were detected in left ventricular regions remote from the infarcted area. Then, during the exercise stress test, high risk patients were those with ST segment depression greater than or equal to 1 mm. On the other hand, patients were considered to be at low risk if they had no abnormalities of wall motion during atrial pacing in remote regions or, in the case of the stress test, if they did not develop ST depression greater than or equal to 1 mm. Of the 83 patients, 21 had major cardiac events during the period of follow-up. Cardiac events occurred in 15/23 (65%) and 5/60 (8%, P less than 0.001) patients assigned to the groups adjudged to be at high and low risk, respectively, on the basis of echocardiographic results. Exercise testing was less reliable in identifying patients at risk of future cardiac events. Major events occurred in only 6 of the 19 patients with a positive stress test (32%, P less than 0.05 vs positive stress echocardiography) and in 14 of the 64 patients with a negative exercise stress test (22%, P = NS vs positive exercise stress test, P less than 0.05 vs negative atrial pacing echocardiography).

Echocardiography in coronary artery disease

Echocardiography has a major role in the evaluation of patients with CAD. To obtain the maximal amount of information using this technique, certain basic principles relating to regional myocardial mechanics during ischemia and flow-function relations are required. In addition, a detailed knowledge of cardiac anatomy and the three-dimensional orientation of the heart within the chest cavity is required to access meaningful information from two-dimensional planes. Furthermore, skill is also required in acquiring data in proper imaging planes and in separating true (actual pathology) from the false (artifacts, etc.). Echocardiography is not a "mature" technology. It is still developing and it is sometimes difficult to keep up with the advances. However, keeping abreast of these developments is essential to fully exploit the advantages of this technique. In addition, knowledge of the ever-changing aspects of CAD is required in order to correctly interpret visual information in context of a particular patient. Finally, more clinical studies are needed to further define the role of echocardiographic techniques in patients with CAD.

Relation of quantitative coronary lesion measurements to the development of exercise-induced ischemia assessed by exercise echocardiography

To assess the relation of quantitative measures of coronary stenoses to the development of exercise-induced regional wall motion abnormalities, 34 patients with isolated, single vessel coronary artery lesions and normal wall motion at rest underwent exercise echocardiography and quantitative angiography on the same day. Although all 11 patients with a visually estimated stenosis greater than or equal to 75% had an ischemic response and 10 (91%) of 11 patients with a less than or equal to 25% visually estimated stenosis had a normal response by exercise echocardiography, among 12 patients with a visually estimated stenosis of 50%, 6 (50%) had an ischemic response and 6 (50%) had a normal exercise echocardiogram. Quantitative measurements of stenosis severity distinguished patients with ischemic (group 1) from normal (group 2) exercise echocardiographic responses as follows: minimal luminal diameter (mm), group 1 1.0 +/- 0.4 versus group 2 1.7 +/- 0.4, p less than 0.0001; minimal cross-sectional area (mm2), group 1 0.9 +/- 0.6 versus group 2 2.5 +/- 1.1, p less than 0.0001; percent diameter stenosis, group 1 68.3 +/- 14.2 versus group 2 42.2 +/- 12.1, p less than 0.0001; and percent area stenosis, group 1 87.5 +/- 7.8 versus group 2 64.8 +/- 15.9, p less than 0.0001. These data validate the utility of exercise echocardiography by demonstrating that 1) coronary stenosis severity measured by quantitative angiography is closely related to wall motion abnormalities detected by exercise echocardiography, and 2) exercise echocardiography can be used as a noninvasive means to assess the physiologic significance of coronary artery lesions.

Altered left ventricular volume and ejection fraction responses to supine dynamic exercise in athletes

Two-dimensional echocardiography was used to determine the responses of left ventricular volumes, ejection fraction and segmental left ventricular motion to supine dynamic exercise in 22 professional athletes, comparing these responses with those in 22 age- and gender-matched healthy untrained individuals. End-systolic volume was significantly greater at rest and during exercise in the athletes (50 +/- 6 versus 29 +/- 4 ml and 40 +/- 5 versus 17 +/- 4 ml, respectively, p less than 0.001 for both). It decreased during exercise in all the untrained subjects, but did not change or increased in nine athletes (41%). End-diastolic volume was greater in the athletes at rest (143 +/- 12 versus 98 +/- 9 ml) and during exercise (157 +/- 14 versus 121 +/- 13 ml, p less than 0.01 for both). It increased in all the untrained subjects, but decreased or did not change in six athletes (27%). Ejection fraction was significantly lower in the athletes at rest and during exercise (65 +/- 4% versus 70 +/- 5% and 73 +/- 5% versus 86 +/- 5%, p less than 0.01 and 0.001, respectively); the values augmented normally in all the untrained subjects, but increased only by less than 5% units, did not change or decreased in nine athletes (41%). Eight athletes (36.5%) failed to demonstrate the expected symmetric hyperkinetic wall motion changes during exercise, which were seen in all the untrained subjects. No correlation was found between atypical responses to exercise and electrocardiographic patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement in rest and exercise-induced wall motion abnormalities after coronary angioplasty: an exercise echocardiographic study

Exercise echocardiography was performed in 36 patients to evaluate functional improvement after coronary angioplasty. Thirty-one patients (86%) had provokable ischemia before angioplasty including 22 with an abnormal exercise electrocardiographic test (angina or ST depression), 25 with an abnormal exercise echocardiogram (exercise-induced wall motion abnormalities) and 16 with both tests abnormal. Nineteen patients had no induced ischemia after angioplasty. Seventeen (47%) continued to have ischemia that was limited in 12 to exercise-induced wall motion abnormalities, which were less severe compared with those of preangioplasty studies. Fifteen (65%) of 23 patients had improvement in rest wall motion abnormalities after angioplasty. The rest to immediate postexercise change in global wall motion score was significantly improved after angioplasty. The change in regional wall motion score was significantly improved after angioplasty in patients with single vessel right or left circumflex coronary artery disease and approached significant improvement (p = 0.06) in those with single vessel disease of the left anterior descending coronary artery. Exercise echocardiography improves the sensitivity of functional testing for ischemia, aids in localizing the ischemic zone and documents improvement in regional function after coronary angioplasty.

Exercise echocardiographic detection of coronary artery disease in women

The utility of exercise echocardiography for the diagnosis of coronary artery disease has been demonstrated in populations consisting largely of men with a high prevalence of disease. To determine the diagnostic value of exercise echocardiography in women, 57 women who presented with chest pain were studied with coronary cineangiography and echocardiography combined with either treadmill (n = 38) or bicycle exercise (n = 19). Significant coronary artery disease (greater than or equal to 50% reduction in luminal diameter) was present in 28 (49%) of 57 patients, including 16 (84%) of 19 who had typical angina, and 12 (32%) of 38 who had atypical chest pain. The overall sensitivity and specificity of echocardiography were both 86%. Exercise echocardiography correctly determined the presence or absence of coronary artery disease in 32 (84%) of 38 patients who had atypical chest pain and in 17 (89%) of 19 who had typical angina (p = NS). The exercise electrocardiogram (ECG) was nondiagnostic in 17 patients (30%) who had rest ST segment depression or ST depression with exercise that could also be induced by hyperventilation or changes in position. The correct diagnosis was made by echocardiography in 14 (82%) of 17 patients with a nondiagnostic exercise ECG. In conclusion, exercise echocardiography has a clinically useful level of sensitivity and specificity for the detection of coronary artery disease in women. The technique provides diagnostic information in women presenting with atypical chest pain and in those who have a nondiagnostic exercise ECG.

Reproducibility of two-dimensional exercise echocardiography

To determine the reproducibility of two-dimensional exercise echocardiography, duplicate studies were performed on the same patients a median of 14 days apart. Because measurements are operator-dependent, interobserver variability was calculated for two experienced readers who interpreted the findings independently in a blinded manner. A high degree of interobserver agreement was found in evaluation of both ejection fraction measurements and wall motion abnormalities. Readings for ejection fraction immediately after exercise taken on different days could be estimated within 4% of the values measured in the first test; similarly measured wall motion score index was within 6% of that in the first test. Ejection fractions and wall motion scores were highly correlated between tests 1 and 2. The correlation coefficients between tests 1 and 2 were 0.92 for both the pre- and postexercise ejection fractions and 0.98 for both the pre- and postexercise wall motion scores. Quantitative two-dimensional echocardiography immediately after exercise is highly reproducible, providing a valuable tool for assessing serial changes in left ventricular function.

Usefulness of immediate postexercise two-dimensional echocardiography in post-myocardial infarction patients without ischemic ECG changes in stress testing: comparison with radionuclide angiography

Of 38 post-myocardial infarction (MI) applicants for a cardiac rehabilitation program, 17 (45%) did not have ischemic ECG changes in exercise testing. Ten (59%) of these 17 patients had echocardiographic wall motion abnormalities at rest. Immediate postexercise two-dimensional echocardiography demonstrated exercise-induced changes in 8 (47%) patients (2 with normal and 6 with abnormal results from rest studies). The comparative radionuclide (RNA) examinations showed that there were 6 patients with abnormal findings from rest RNA; exercise-induced changes were detected in 7 (44%) of 16 patients (3 with normal and 4 with abnormal results from rest RNA tests). Statistical analyses, using RNA as reference point, revealed that the total correctly diagnosed cases for the echocardiographic rest studies was 13/17 (77%) and for the exercise studies, 13/16 (81%). The negative predictive values were 7/7 (100%) and 7/8 (88%), respectively. The corresponding positive predictive values were 6/10 (60%) and 6/8 (75%). The same pattern was observed when each segment (septal, apical, and posterolateral) was evaluated separately. The authors conclude that in post-MI patients with a negative stress test, the efficacy of postexercise echocardiography equals that of RNA in the identification of additional patients with ischemia.

The effects of successful PTCA on left ventricular function: assessment by exercise echocardiography

To assess the usefulness of exercise echocardiography in the follow-up of patients after percutaneous transluminal coronary angioplasty (PTCA), we studied 56 patients at rest and immediately following exercise with two-dimensional echocardiography. Sixty-nine of 73 stress/echo studies (94%) were suitable for interpretation. Seventeen patients (group I) with significant coronary artery disease (CAD) were studied before and after PTCA. Sixteen patients with coronary disease not undergoing PTCA (group II) and 23 individuals without significant coronary disease (group III) served as age-matched controls. Left ventricular ejection fraction did not change significantly in group I patients prior to PTCA (56 +/- 7 versus 54 +/- 12, p = ns) or in group II patients (52 +/- 10 versus 56 +/- 15, p = ns), rest versus immediate after exercise measurements. Following angioplasty, left ventricular ejection fraction increased in group I patients from 55 +/- 7 to 65 +/- 8, p less than 0.001 from rest to exercise, and to a similar extent in group III individuals (55 +/- 6 to 66 +/- 8, p less than 0.001). Electrocardiographic (ECG) evidence of ischemia (greater than 1 mm ST segment depression) was found in 13 of 17 group I patients prior to PTCA and in 8 of 16 group II patients (CAD). None of the 25 normal patients and four of the group I patients following PTCA had abnormal ECG changes with exercise. New exercise-induced echocardiographic wall motion abnormalities were found in 12 of 17 group I patients prior to PTCA and in none of the group I patients following PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler and two-dimensional echocardiographic assessment of left ventricular function before and after intravenous dipyridamole stress testing for detection of coronary artery disease

Thallium perfusion imaging following the intravenous infusion of dipyridamole, a potent coronary vasodilator, has been demonstrated to be useful in the evaluation of the functional significance of coronary artery disease (CAD). While recent studies have demonstrated that 2-dimensional echocardiographic monitoring of left ventricular (LV) function after intravenous dipyridamole has a sensitivity somewhat less than that of thallium perfusion imaging, none has examined the usefulness of Doppler evaluation of aortic blood flow in this setting. One hundred patients undergoing dipyridamole-thallium imaging for clinical indications were studied. Technically adequate Doppler echocardiographic studies were obtained in 97 patients. LV ejection fraction, peak aortic velocity and acceleration, as well as segmental LV wall motion, were analyzed before and at peak dipyridamole effect. Thallium perfusion images were normal in 41 and abnormal in 53 patients studied. A statistically significant difference in percent change from baseline to peak dipyridamole effect in velocity, acceleration and ejection fraction was seen between the 2 groups (26 vs -2%, 51 vs -2% and 16 vs 4%, respectively, all p less than 0.05). Comparison of 2-dimensional wall motion analysis to thallium yielded a sensitivity and specificity of 74 and 80%, respectively. In the group of patients who underwent cardiac catheterization, 2-dimensional wall motion analysis yielded a sensitivity of 64% in the detection of CAD. The combination of 2-dimensional and Doppler echocardiographic parameters increased the sensitivity in the detection of CAD to 85%.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic accuracy of 2-D echocardiography for detection of exercise-induced wall motion abnormalities in patients with coronary artery disease: comparison to biplane cineventriculography

To determine the accuracy of two-dimensional echocardiography (2-D echo) for assessment of exercise-induced wall motion abnormalities in patients with coronary artery disease, the results of stress echocardiography were compared with exercise cineventriculography. In 56 consecutive patients, biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echo was obtained using the apical two- and four-chamber-views for left ventricular imaging under identical conditions. In 6 of the 56 patients 2-D echo, in 8 patients cineventriculogram, and in 2 patients both methods were of inadequate quality at rest or during exercise. Of the remaining 40 patients, 34 had coronary artery disease. Local wall motion in 360 wall segments from these patients was analyzed. In 49 segments (14%) in 24 of these patients exercise-induced ischemic wall motion abnormalities were evident during cineventriculography. Only 24 of these 49 asynergies (49%) were also recognized by 2-D echo. Using cross-sectional echocardiography, ischemia-related wall motion abnormalities were best detected septal, whereas apical asynergies were identified in only 3 of 12 segments (25%). Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected of having coronary artery disease is limited and restricted to patients where excellent visualization of the left ventricular endocardium is possible.

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.

Comparison of echocardiography at peak exercise and after bicycle exercise in evaluation of patients with known or suspected coronary artery disease

To determine if echocardiography done immediately after bicycle exercise provides the same information as imaging at peak exercise, we evaluated 104 consecutive patients being studied for coronary artery disease. Interpretable exercise echocardiograms were obtained in 96 patients (92%), 29 of whom had a new wall motion abnormality detected with exercise echocardiography. Of these 29 patients, 10 had a wall motion abnormality detected in apical views obtained during peak exercise that resolved by the time apical imaging was performed after exercise. Three of these 10 patients, however, had wall motion abnormalities in parasternal views taken after exercise in areas adjacent to the wall motion abnormality imaged at peak exercise. The sensitivity of exercise-induced wall motion abnormality for the detection of significant coronary artery disease in those patients undergoing coronary arteriography was 70% for imaging done after exercise versus 100% for imaging done at peak exercise. Six patients' conditions would have been misclassified as normal if only imaging done after exercise had been performed. We conclude that the addition of echocardiographic imaging at peak exercise on a bicycle enhances the sensitivity for the detection of coronary artery disease with exercise echocardiography.

[Value of 2-D echocardiography in the detection of stress-induced wall-motion abnormalities in coronary heart disease--a comparison with biplane cineventriculography]

To determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography. In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions. In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise. Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected laterally and septaly, whereas apical asynergies were identified in 3 of 12 segments only. Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.

Evaluation of left ventricular systolic and diastolic dysfunction during transient myocardial ischemia produced by angioplasty

Acute myocardial ischemia is known to cause impairment of both left ventricular systolic and diastolic function. To further investigate these changes as well as their relation to common clinical variables (electrocardiographic [ECG] changes and chest pain), 32 patients were evaluated with Doppler echocardiography during coronary angioplasty. Doppler indexes of left ventricular diastolic function included the ratios of peak early to late and peak early to mean diastolic velocities as well as the ratios of early to late and first third to total velocity integral (one-third filling fraction). All diastolic indexes showed significant impairment by 15 seconds after coronary occlusion (ratio peak early to late filling velocity: 1.11 versus 0.96, p less than 0.01; ratio peak early to mean filling velocity: 1.9 versus 1.7, p less than 0.01; ratio early to late velocity integral: 1.58 versus 1.25, p less than 0.01; one-third filling fraction: 41.2 versus 37.7, p less than 0.01). Left ventricular systolic function was evaluated during coronary occlusion both qualitatively, as assessed by the appearance of a new wall motion abnormality on two-dimensional echocardiography (mean 28.8 seconds), and quantitatively by measurement of systolic percent area change on the two-dimensional short-axis view as well as the Doppler echocardiographic stroke integral index. Systolic indexes did not show significant change until 30 seconds after balloon inflation (percent area change: 42.8 versus 29.2, p less than 0.01; stroke integral index: 11.04 versus 9.36, p less than 0.01). ECGs were performed at 15 second intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of two-dimensional echocardiography during low-level exercise testing early after uncomplicated acute myocardial infarction

To determine whether 2-dimensional (2-D) echocardiographic measures of segmental and global left ventricular (LV) function immediately on recovery of low-level, symptom-limited treadmill exercise are as sensitive as the same variables measured at peak bicycle exercise, 21 patients were studied after acute myocardial infarction (AMI). The recovery treadmill ejection fraction analysis was predictive of the peak bicycle results in 18 of the 21 patients (86%) and recovery treadmill wall motion abnormalities were predictive of the peak bicycle analysis in 17 (81%) (p less than 0.01). These data indicate that 2-D echocardiography during the immediate recovery phase of low-level postinfarction treadmill testing was as sensitive as the peak exercise assessment of segmental and global LV function. Accordingly, the predictive value of rest and recovery exercise measures were prospectively assessed in 67 patients during a mean follow-up interval of 11 months (range 3 to 24). Clinical characteristics and treadmill electrocardiographic findings did not identify the 16 of 67 patients (24%) who had new cardiac events (3 cardiac deaths, 8 recurrent AMIs and 6 coronary artery bypass graft operations). However, a decrease in recovery ejection fraction units of more than 10% was seen in 7 of these 16 patients (44%) with events, compared with only 4 of the 51 (13%) without events (p less than 0.002), and new or worsening wall motion abnormalities on exercise recovery were seen in 10 of the 16 patients (63%) with events, but in only 10 of the 51 (20%) without (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Color Doppler assessment of mitral regurgitation induced by supine exercise in patients with coronary artery disease

Development of mitral regurgitation (MR) during acute myocardial ischemia is a well known occurrence. To assess the feasibility and clinical utility of detecting MR during exercise testing, color Doppler examinations were performed in 22 patients with angiographically proved coronary artery disease (CAD) and in 17 normal subjects before, during and after graded supine bicycle exercise. Not only was MR visualized using color Doppler during dynamic testing, but it was also slightly more sensitive (59% vs 54%) and specific (100% vs 88%) than the electrocardiographic response in identifying patients with CAD. When the appearance of MR or diagnostic electrocardiographic changes or both were used to identify patients with CAD, the sensitivity of exercise tolerance testing increased to 82%, although the specificity was 88%. In addition, exercise-induced MR was observed to be as sensitive and specific as exercise-induced wall motion abnormalities. Combining exercise-induced MR with wall motion abnormalities also increased the sensitivity to 82%, with the specificity remaining at 100%. With use of exercise-induced MR, wall motion abnormalities or electrocardiographic changes, the sensitivity and specificity of the exercise test in diagnosing CAD was 91% and 88%, respectively. The degree of MR as estimated by maximal area of regurgitation signals, as well as by its ratio to left atrial area, did not correlate with extent of CAD. However, the presence of exercise-induced MR suggested an increased likelihood of 3-vessel CAD because it was found in 9 of 11 patients with 3-vessel CAD, compared with 2 of 5 patients with 2-vessel and 2 of 6 patients with 1-vessel CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the high-dose dipyridamole-echocardiography test and exercise two-dimensional echocardiography for diagnosis of coronary artery disease

Fifty-five patients with effort angina pectoris and technically satisfactory baseline echocardiograms performed a supine exercise-echocardiography test (EET) and a high-dose dipyridamole-echocardiography test (DET, up to 0.84 mg/kg of intravenous dipyridamole in 10 minutes). All underwent coronary arteriography, which showed that at least 1 major artery had more than 70% stenosis in 34 patients. For each patient, the same physician performed both tests, with the same echocardiographic equipment. Detection of new onset or worsening regional asynergy was the only criterion of positivity for both tests. DET yielded interpretable studies in all 55 patients (100%); EET yielded only 40 such studies (73%) (p less than 0.01). In the 40 patients in whom both tests were interpretable, DET showed, compared with EET, a similar sensitivity (72% vs 76%) and specificity (100% vs 87%) (difference not significant for both) for detecting angiographically assessed coronary artery disease. In the 16 patients in whom both DET and EET yielded positive responses for ischemia, the same myocardial region showed reversible asynergy. Thus, independent of all factors that can affect the performance of each test (operator, patient and instrumentation), DET was significantly more feasible than EET, with comparable sensitivity and specificity. Dipyridamole provokes asynergy in the same regions that show ischemia during exercise.

High dose dipyridamole echocardiography test in effort angina pectoris

The dipyridamole echocardiography test (intravenous dipyridamole with two-dimensional echocardiographic monitoring) was performed in 93 patients with effort chest pain and in 10 control subjects. The test was considered positive when regional asynergy appeared after dipyridamole administration. When negative at the low dose (0.56 mg/kg body weight in 4 minutes), the test was repeated on a different day with a higher dose (0.84 mg/kg in 10 minutes). All 93 patients underwent coronary arteriography; 72 of them had significant (greater than 70% luminal reduction) coronary artery disease. Thirty-eight of the 93 patients had a positive low dose dipyridamole echocardiography test; 15 other patients with a negative low dose test had a positive high dose test. All 53 patients with a positive test had significant coronary artery disease; 12 of them had a negative exercise stress test. In relation to the presence of coronary artery disease, the dipyridamole echocardiography test had an overall specificity higher than that of the exercise stress test (100 versus 71%) and a similar overall sensitivity (74 versus 69%). The dipyridamole echocardiography test is feasible in all patients with a good baseline echocardiogram. It detects the site of apparent ischemia more precisely than does an exercise stress test, and can unmask electrocardiographically silent ischemia. If performed in patients with a negative low dose dipyridamole echocardiography test, the high dose test adds sensitivity (probably by achieving maximal dilation in patients in whom the low dose is only partially effective), without any loss in specificity and with no apparent increase in risk.