Resting Wall Motion Abnormalities Research Articles

Resting Thallium-201 Scintigraphy for Identifying Viable Myocardium in a Patient With Severe Left Ventricular Dysfunction

Recognizing patients with coronary artery disease in whom severe left ventricular dysfunction is attributed to a chronic decrease in myocardial blood flow without infarction is often difficult but important because such patients may benefit from surgical revascularization. Herein we describe a patient with severe left ventricular dysfunction who had appreciable resting wall motion abnormalities; tomographic thallium-201 myocardial scintigraphy performed while the patient was resting identified viable myocardium. Subsequent revascularization improved regional and global left ventricular function considerably.

Accuracy of dobutamine stress echocardiography in detecting coronary artery disease

The diagnostic accuracy of dobutamine stress echocardiography (DSE) (incremental infused doses of 5, 10, 20 and 30 μg/kg/min) was evaluated in 141 patients who underwent coronary arteriography within 2 weeks of DSE. All patients were being evaluated for known or suspected coronary artery disease (CAD). DSE was interpreted blindly as normal or showing evidence of CAD, depending on the presence of resting or inducible wall motion abnormalities. Coronary arteriograms were reviewed in a blinded, quantitative fashion. DSE had a sensitivity of 96% for detecting patients with CAD, and a specificity of 66%. For the 53 patients with normal resting wall motion, sensitivity was 87% and specificity 91%. The protocol was well-tolerated by all patients. In comparison with wall motion analysis, 12-lead electrocardiograms during dobutamine infusion revealed ischemic changes in only 17% of patients with CAD. It is concluded that DSE is a clinically useful and accurate means for detecting CAD, its specificity is hindered in patients with resting wall motion abnormalities, and it can safely be used in patients with known cardiac disease.

Dobutamine stress echocardiography as a predictor of cardiac events associated with aortic surgery.

Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia produced by dobutamine infusion. In 60 patients undergoing elective aortic surgery (27 with aneurysms, 33 with occlusive disease), we evaluated the ability of dobutamine stress echocardiography to predict perioperative cardiac events. Echo images were obtained at rest and during incremental dobutamine infusion to a peak dose of 50 micrograms/kg/min, unless another test end point was reached (angina, heart rate greater than or equal to 85% of age-predicted maximum, significant ST segment depression, or new stress-induced wall motion abnormalities). Dobutamine stress echocardiography results were stratified as follows: group I, no wall motion abnormalities; group II, resting wall motion abnormalities unchanged with stress; group III, stress-induced worsening of resting wall motion abnormalities; group IV, new-onset wall motion abnormalities with stress. Twelve cardiac events occurred within the first 30 postoperative days: three cardiac deaths (5%), six nonfatal myocardial infarctions (10%), two patients with unstable angina (3.3%), and one patient with asymptomatic elevation of creatine phosphokinase MB isoenzymes without electrocardiographic changes (1.7%). Eleven events occurred in the 38 patients with an abnormal dobutamine stress echocardiograph (groups II to IV); in contrast, only one of 22 patients with a normal dobutamine stress echocardiograph (group I) had a cardiac event. These event rates (29% vs 4.6%) differed significantly (p less than 0.025). Dobutamine stress echocardiography is a new, safe, rapid, relatively low cost, noninvasive, nonexercise cardiac stress test for risk stratification before major vascular surgery.

Dobutamine stress echocardiography as a predictor of cardiac events associated with aortic surgery

Two-dimensional echocardiography can detect regional wall motion abnormalities resulting from myocardial ischemia produced by dobutamine infusion. In 60 patients undergoing elective aortic surgery (27 with aneurysms, 33 with occlusive disease), we evaluated the ability of dobutamine stress echocardiography to predict perioperative cardiac events. Echo images were obtained at rest and during incremental dobutamine infusion to a peak dose of 50 μg/kg/min, unless another test end point was reached (angina, heart rate ≥85% of age-predicted maximum, significant ST segment depression, or new stress-induced wall motion abnormalities). Dobutamine stress echocardiography results were stratified as follows: group I, no wall motion abnormalities; group II, resting wall motion abnormalities unchanged with stress; group III, stress-induced worsening of resting wall motion abnormalites; group IV, new-onset wall motion abnormalities with stress. Twelve cardiac events occurred within the first 30 postoperative days: three cardiac deaths (5%), six nonfatal myocardial infarctions (10%), two patients with unstable angina (3.3%), and one patient with asymptomatic elevation of creatine phosphokinase MB isoenzymes without electrocardiographic changes (1.7%). Eleven events occurred in the 38 patients with an abnormal dobutamine stress echocardiograph (groups II to IV); in contrast, only one of 22 patients with a normal dobutamine stress echocardiograph (group I) had a cardiac event. These event rates (29% vs 4.6%) differed significantly (p < 0.025). Dobutamine stress echocardiography is a new, safe, rapid, relatively low cost, noninvasive, nonexercise cardiac stress test for risk stratification before major vascular surgery.

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, we e 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 < 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.

Echocardiographic detection of coronary artery disease during dobutamine infusion.

Two-dimensional echocardiography performed during dobutamine infusion has been proposed as a potentially useful method for detecting coronary artery disease. However, the safety and diagnostic value of dobutamine stress echocardiography has not been established. In this study, echocardiograms were recorded during step-wise infusion of dobutamine to a maximum dose of 30 micrograms/kg/min in 103 patients who also underwent quantitative coronary angiography. The echocardiograms were digitally stored and displayed in a format that allowed simultaneous analysis of rest and stress images. Development of a new abnormality in regional function was used as an early end point for the dobutamine infusion. No patient had a symptomatic arrhythmia or complications from stress-induced ischemia. Significant coronary artery disease (greater than or equal to 50% diameter stenosis) was present in 35 of 55 patients who had normal echocardiograms at rest. The sensitivity and specificity of dobutamine-induced wall motion abnormalities for coronary artery disease was 89% (31 of 35) and 85% (17 of 20), respectively. The sensitivity was 81% (17 of 21) in those with one-vessel disease and 100% (14 of 14) in those with multivessel or left main disease. Forty-one of 48 patients with abnormal echocardiograms at baseline had localized rest wall motion abnormalities. Fifteen had coronary artery disease confined to regions that had abnormal rest wall motion, and 26 had disease remote from these regions. Thirteen of 15 patients (87%) without remote disease did not develop remote stress-induced abnormalities, and 21 of 26 (81%) who had remote disease developed corresponding abnormalities. Echocardiography combined with dobutamine infusion is a safe and accurate method for detecting coronary artery disease and for predicting the extent of disease in those who have localized rest wall motion abnormalities.

Evidence of Hibernating Myocardium by a New Transesophageal Echocardiographic Technique

Reversal of resting wall motion abnormalities after successful coronary angioplasty were documented in a patient with the use of a novel approach to stress testing. Transesophageal stress echocardiography utilizes transesophageal atrial pacing to provoke myocardial ischemia while the left ventricular contractility is being monitored by means of transesophageal echocardiography. The potential use of this technique is illustrated in this report.

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.

Value and limitation of biplane rest and exercise radionuclide angiography for assessing individual bypass grafts: A prospective study

This prospective study evaluated the ability of serial biplane rest and exercise radionuclide angiography to predict the status of individual coronary bypass grafts in 20 patients 2 to 6 months after surgery. The preoperative coronary angiogram was used to assign vessels to 10 regions of distribution on the radionuclide angiogram. Predictions of graft adequacy for individual vessels were based on a detailed assessment of rest and exercise wall motion in their regions of supply. Of 59 grafts, 38 were judged adequate (patent with less than 75% stenosis) and 21 inadequate by postoperative catheterization. Radionuclide prediction of graft status was possible for 32 of the 59 grafts, including 19 of 24 left anterior descending, 7 of 19 circumflex and 6 of 16 right coronary artery grafts. The status of the remaining 27 grafts could not be assessed because of normal wall motion in their region of supply both pre- and postoperatively (22 vessels) or because a region of supply was not represented on the biplane radionuclide angiogram (5 vessels). Of the 32 predictions made, 25 (78%) were correct, including 13 (93%) of 14 predictions of graft adequacy and 12 (67%) of 18 predictions of graft inadequacy. The single incorrect prediction of graft adequacy resulted from improved exercise wall motion in a region supplied by a graft judged as having a 75% anastomotic stenosis. Most incorrect predictions of graft inadequacy were due to new septal or other rest wall motion abnormalities postoperatively. The comparison of pre- and postoperative studies was essential to maintain the predictive ability of the test. Thus, a detailed analysis of regional wall motion by rest and exercise radionuclide angiography can be used to predict the status of individual coronary artery bypass grafts. Reliable predictions can be made for most successful anterior descending grafts, and may permit cardiac catheterization to be deferred in certain cases. However, the method is limited by the need to perform preoperative exercise studies, by the low number of right and circumflex coronary artery grafts that can be evaluated and by the poor specificity of predictions of graft failure.

The interval ejection fraction: a cineangiographic and radionuclide study.

To evaluate the clinical usefulness of the first-third ejection fraction (1/3 EF) for detecting patients with coronary artery disease (CAD), resting contrast ventriculography and first-pass radionuclide angiography with a high-count-rate, multicrystal camera system were performed in 47 subjects: 22 normal controls (group 1) and 25 patients with clinically stable angina pectoris and severe CAD (mean 2.3 vessels) without (group 2, n = 12) and with (group 3, n = 13) resting wall motion abnormalities. By contrast angiography, only group 3 had depressed global EF or 1/3 EF compared with control (global EF: group 1,0.71 +/- 0.09; group 2, 0.67 +/- 0.09 [NS]; group 3,049 +/- 0.05 [p less than 0.01 vs groups 1 and 2]; 1/3 EF: group 1,0.29% +/- 0.06;' group 2, 0.28 +/- 0.05 [NS]; group 3,0.22 +/- 0.05 [p less than 0.02 vs groups 1 and 2]). Whereas 11 of 25 CAD patients had global EF outside the normal range, only two of 25 had depressed 1/3 EF. Both had left ventricular asynergy and a depressed global EF. Studies performed using first-pass radionuclide angiography revealed similar results i.e., only four of 25 CAD patients, all with left ventricular asynergy and depressed global EF, had depressed 1/3 EF values. A wide range of 1/3 EF values was found in normal subjects by both techniques. Thus, the ejection fraction during the first third of systole at rest is of limited value for detecting patients with CAD.

Exercise-induced ST elevation in patients without myocardial infarction.

A review of 6040 consecutive exercise tests yielded 106 patients without previous myocardial infarction (MI) who had exercise-induced ST elevation (greater than or equal to 0.5 mm in a 15-lead ECG system). In 46, ST elevation was correlated with left ventriculography and coronary angiography. Coronary artery disease (CAD) (greater than or equal to 70% narrowing) was detected in 40 of 46 patients: 12 patients had one-vessel disease, 13 had two-vessel disease, and 15 had three-vessel disease. Resting ventriculograms were normal in 36 of 40 patients. Of 21 patients with anterior (V1-V3) ST elevation, 86% had a left anterior descending (LAD) obstruction and 78% had obstruction proximal to the first diagonal branch. LAD disease occurred significantly more frequently than right and circumflex CAD. There was no anatomic correlation of three persons with lateral (leads V4--6, I or aVL) or 27 patients with inferior-posterior (leads II, III, aVF, Y or Z) exercise-induced ST elevation. Therefore, exercise-induced ST elevation is strongly correlated with CAD but not resting wall motion abnormalities. Further, anterior exercise-induced ST elevation in patients without a previous MI often predicts a significant proximal LAD obstruction.