Uses and limitations of high dose dipyridamole stress echocardiography for evaluation of coronary artery disease.

OBJECTIVE--To compare the usefulness of high dose dipyridamole stress echocardiography with dipyridamole stress electrocardiography and exercise electrocardiography for the evaluation of coronary artery disease. DESIGN--Prospective investigation with coronary angiography as the criterion standard and blinded assessment of study data. SETTING--Cardiology unit of a tertiary referral centre. SUBJECTS--Fifty eight patients with suspected coronary disease; three of these were excluded because of poor echogenicity at baseline (test feasibility 95%). Angiography showed normal coronary arteries in 15 and coronary disease (greater than or equal to 70% diameter stenosis) in 40. INTERVENTIONS--Cross sectional echocardiography and 12 lead electrocardiography during dipyridamole stress (up to 1 mg/kg) and exercise electrocardiography on a separate occasion. Wall motion was analysed with an 11-segment model developed at Hammersmith Hospital. MAIN OUTCOME MEASURES--Test sensitivity, specificity, and side effect data. RESULTS--16 of 40 patients with coronary artery disease had inducible asynergy; all had multivessel disease and a tight stenosis in the vessel that supplied the abnormal segment. Exercise duration and time to 1 mm ST segment depression were significantly shorter in patients with a positive echocardiogram than in those without (both p less than 0.01). The sensitivity and specificity of dipyridamole stress echocardiography were 40% and 93% respectively; sensitivity improved to 60% when baseline (n = 18) or reversible asynergy defined an abnormal study (likelihood ratio = 9). Corresponding figures for stress electrocardiography were 38% and 80% for dipyridamole and 80% and 67% for exercise. Adverse reactions were seen in 67% of patients and included two instances of pronounced hypotension, one episode of prolonged myocardial ischaemia, and one cardiac arrest in a patient who was successfully resuscitated. CONCLUSION--A positive high dose dipyridamole echocardiogram predicts multivessel disease and impaired coronary reserve, but low overall sensitivity and occasionally troublesome side effects limit its clinical usefulness.     

Short term reproducibility of exercise testing in patients with ST segment elevation and different responses to the dipyridamole test.

The short term reproducibility of exercise testing in 25 patients who had exercise induced ST segment elevation without baseline regional asynergy or a previous myocardial infarction, who had different responses to the dipyridamole test, was assessed. The patients performed a dipyridamole echocardiography test and a second exercise stress test. All underwent coronary arteriography. Seventeen patients had transient regional asynergy after dipyridamole (group 1) and either ST segment elevation (14 patients) or depression (three patients); a second group of eight had no asynergy and no electrocardiographic changes (group 2). The repeated exercise stress test was positive in 16 of the 17 patients of group 1 (11 with ST elevation and five with ST depression) and in two patients of group 2 (both had ST depression and one had coronary artery disease). The dipyridamole echocardiography test was positive in 17 of the 19 patients with coronary artery disease and was negative in all six patients without coronary artery disease. The repeated exercise stress test was positive in 17 of the 19 patients with coronary artery disease and in one patient without. The dipyridamole echocardiography test and a repeated exercise stress test, but not a single exercise stress test, identified coronary artery disease causing exercise induced ST segment elevation.     

Comparison of usefulness of high-dose dipyridamole echocardiography and exercise electrocardiography for detection of asymptomatic restenosis after coronary angioplasty

The present study compares the relative usefulness of the maximal treadmill exercise electrocardiography test with the high-dose dipyridamole echocardiography test (echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg in 10 minutes) in detecting severe restenosis or coronary artery disease progression (>70% stenosis) in asymptomatic patients 12 months after a primary successful coronary angioplasty. Criteria of positivity were: for the exercise electrocardiography test, an ST-segment shift ≥0.1 mV from baseline, 0.08 second from the J point; for the dipyridamole echocardiography test, a transient dyssynergy of contraction, absent or of a lesser degree than that in the baseline examination. The exercise electrocardiography and dipyridamole echocardiography tests revealed a similar feasibility (91 vs 87%, difference not significant). Both tests could be performed in 75 patients. For detection of restenosis or disease progression, or both, the exercise electrocardiography test revealed a sensitivity similar to the dipyridamole echocardiography test (71 vs 71%, difference not significant), but a lower specificity (61 vs 90%). It is concluded that the high-dose dipyridamole echocardiogrphy test is equally feasible but more accurate than the exercise electrocardiography test for noninvasive detection of severe asymptomatic restenosis or disease progression at 1 year after successful coronary angioplasty.     

Short term reproducibility of exercise testing in patients with ST segment elevation and different responses to the dipyridamole test

The short term reproducibility of exercise testing in 25 patients who had exercise induced ST segment elevation without baseline regional asynergy or a previous myocardial infarction, who had different responses to the dipyridamole test, was assessed. The patients performed a dipyridamole echocardiography test and a second exercise stress test. All underwent coronary arteriography. Seventeen patients had transient regional asynergy after dipyridamole (group 1) and either ST segment elevation (14 patients) or depression (three patients); a second group of eight had no asynergy and no electrocardiographic changes (group 2). The repeated exercise stress test was positive in 16 of the 17 patients of group 1 (11 with ST elevation and five with ST depression) and in two patients of group 2 (both had ST depression and one had coronary artery disease). The dipyridamole echocardiography test was positive in 17 of the 19 patients with coronary artery disease and was negative in all six patients without coronary artery disease. The repeated exercise stress test was positive in 17 of the 19 patients with coronary artery disease and in one patient without. The dipyridamole echocardiography test and a repeated exercise stress test, but not a single exercise stress test, identified coronary artery disease causing exercise induced ST segment elevation.     

Echocardiographic test of dipyridamole in recognition of coronary artery disease]

To assess the feasibility, safety and usefulness of dipyridamole stress echocardiography for the detection of coronary artery disease we evaluated 194 patients (124 men, 70 women) with effort chest pain. All patients underwent electrocardiographic submaximal bicycle exercise testing and 2-dimensional echocardiography after dipyridamole injection. Echocardiographic test was considered positive when new wall motion abnormalities were observed after dipyridamole i.v. injection (0.56 mg/kg b.m.). Sensitivity and specificity of electrocardiographic exercise test and dipyridamole stress echocardiography were assessed in 37 persons who underwent selective coronary angiography. The sensitivity and specificity of dipyridamole stress echocardiography, were respectively 85.0% and 91.7% and were higher than those of exercise electrocardiography. 2-dimensional echocardiography after dipyridamole injection is a well tolerated, feasible and effective test in the diagnosis of coronary artery disease.     

Predicting the extent and location of coronary artery disease in acute myocardial infarction by echocardiography during dobutamine infusion

The feasibility, safety and usefulness of 2-dimensional echocardiography (2-D echo) during dobutamine infusion for identifying patients with multivessel coronary artery disease (CAD) after acute myocardial infarction (AMI) were evaluated in 30 patients 5 to 10 days after AMI. Patients underwent (1) 2-D echo under basal conditions and during dobutamine infusion at each dose from 5 to a maximum of 40 μg/kg/min, (2) limited multilead submaximal bicycle exercise testing and (3) coronary and left ventricular angiography. Echocardiograms were analyzed independently by 2 observers. The test response was considered positive if abnormal wall motion and reduced myocardial thickening were observed during dobutamine infusion in vascular distributions other than the area of infarction identified during basal conditions. Exercise testing was considered positive when more than 1 mm of ST depression occurred 80 ms after the J point. Dobutamine stress testing was well tolerated; no complications and no significant arrhythmia were observed. Echocardiographic recordings were adequate in all patients during the entire test; the concordance in interpretation between the 2 observers was perfect for the prediction and location of ischemic segments during dobutamine infusion.

In 15 of 17 patients without multivessel CAD, no asynergy was observed outside the infarct zone during dobutamine infusion (specificity 88%). In 11 of 13 patients with multivessel CAD, new wall motion abnormalities were identified in the segments corresponding to the arterial lesions diagnosed by angiography (sensitivity 85%). The overall accuracy of dobutamine stress 2-D echo (87%) was higher than that of dobutamine stress electrocardiography (70%) or exercise electrocardiography (59%). Thus, dobutamine stress 2-D echo is a well tolerated, widely available and cost effective stress test for detecting multivessel CAD early after AMI.     

Dobutamine stress echocardiography for detection and assessment of coronary artery disease.

Stress echocardiography with dobutamine infusion for detection of coronary artery disease is a potential alternative to exercise stress testing with some theoretic advantages. Fifty patients who were not receiving cardioactive medication were prospectively studied with two-dimensional echocardiography and 12-lead electrocardiography (ECG) during incremental dobutamine infusion (5, 10, 15 and 20 micrograms/kg body weight per min, each dose for 8 min). Images were analyzed by using an 11-segment left ventricular model. All patients underwent correlative exercise ECG and coronary angiography, which revealed normal coronary arteries in 14 and significant disease (greater than or equal to 70% diameter stenosis) in 36. Peak rate-pressure product during dobutamine infusion was 18,845 +/- 4,156 versus 23,740 +/- 6,158 mm Hg/min on exercise (p less than 0.01). Interobserver concordance for wall motion analysis was good (kappa coefficient = 0.77). The use of baseline (n = 14) or reversible (n = 24) regional asynergy to define an abnormal dobutamine echocardiogram resulted in a sensitivity for detecting coronary artery disease of 78% and a specificity of 93%. Corresponding data for the dobutamine ECG were 47% and 71% and for the exercise ECG were 72% and 71%, respectively. The development of new mitral regurgitation on Doppler color flow imaging (n = 4) improved sensitivity to 81% without loss of specificity. Inducible asynergy or new mitral regurgitation was observed in 6 (50%) of 12 patients with single-, 6 (60%) of 10 with double- and 12 (86%) of 14 with triple-vessel disease. The site of transient asynergy provided additional localizing information. Exercise duration and time to diagnostic ST segment shift were shorter in patients with coronary artery disease with versus those without echocardiographic evidence of ischemia (both p less than 0.05). Side effects during dobutamine infusion were mild and short-lived. Dobutamine stress echocardiography is well tolerated, is useful for detection and assessment of coronary artery disease and is applicable to patients unable to exercise.     

Two dimensional echocardiographic analysis of wall motion abnormalities during handgrip exercise in patients with coronary artery disease

Studies were made of the feasibility and value of two dimensional echocardiography in detecting left ventricular asynergy during handgrip exercise in 45 patients with suspected coronary artery disease. Resting echocardiography revealed normal wall motion in 32 patients, and in 17 of these handgrip exercise induced abnormal wall motion. All 17 patients had significant stenoses in the coronary arteries. However, only 65 percent of patients with coronary artery disease whose resting two dimensional echocardiogram revealed normal wall motion showed abnormal wall motion during handgrip exercise. The left ventricular wall visualized in the short axis plane was divided into 5 segments, and a total of 225 segments were analyzed. Of 49 segments with exercise-induced asynergy, 46 (94 percent) reflected significant stenosis in the perfusing coronary artery. In particular, 16 (89 percent) of 18 segments with exercise-induced akinesia reflected stenosis of greater than 90 percent. Resting or exercise two dimensional echocardiography (or both) was able to diagnose multivessel disease with a predictability of 92 percent. It is concluded that two dimensional echocardiography combined with handgrip exercise has high specificity in detecting coronary artery disease and would be useful for predicting severely stenotic or multivessel coronary arterial lesions.     

Dobutamine stress echocardiography: its role in the diagnosis of coronary artery disease.

We have assessed the usefulness of dobutamine infusion for the diagnosis of coronary artery disease by using two-dimensional echocardiography and 12-lead electrocardiogram. Dobutamine was infused at incremental doses (up to a maximum of 40 micrograms kg-1 min-1) in 52 patients with chest pain; all the patients underwent coronary angiography; significant coronary artery disease was quantitatively defined as greater than or equal to 50% diameter stenosis. Thirty-six patients were on betablockers. The test was considered positive when new regional wall motion abnormalities appeared during dobutamine infusion. No significant side effects occurred in any patient during the test. Transient wall motion abnormalities were detected in 20 of 37 patients with coronary artery disease (sensitivity = 54%); ischaemic ST segment changes were present on ECG in nine patients (sensitivity = 24%). Dobutamine stress echocardiography was negative in 12 of 15 patients with coronary artery diameter stenosis less than 50% (specificity = 80%). Exercise electrocardiography (ECG) was performed in 35 of these 52 patients. Maximum heart rate and systolic blood pressure were significantly higher during exercise than during dobutamine stress test (127 +/- 23 vs 99 +/- 24 beats min-1, P less than 0.0001; 179 +/- 25 vs 152 +/- 30 mmHg, P less than 0.0001). The exercise ECG test was positive in 12 of the 26 patients with significant coronary artery disease (sensitivity = 46%), and dobutamine stress echocardiography in 16 (sensitivity = 62%). Dobutamine stress echocardiography test is a safe and feasible diagnostic test for the noninvasive diagnosis of coronary artery disease and can be performed in patients unable to exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of multivessel coronary artery disease by exercise echocardiography

Objectives. This study examined the ability of exercise echocardiography to identify multivessel coronary artery disease and ascertain its incremental value when combined with clinical and exercise test variables.Background. Although exercise echocardiography has been shown to be accurate for the detection of coronary artery disease, little is known about its utility for identifying multivessel involvement, and its incremental value when combined with clinical and exercise test variables has not been studied.Methods. One hundred fifty consecutive patients were selected on the basis of having had an exercise echocardiographic and a coronary angiographic study within 6 months without any revascularization procedure. Significant coronary artery disease (≥50% diameter stenosis in any major coronary artery) was present in 117 patients, and multivessel (two- or three-vessel) disease was present in 90 patients. The exercise echocardiographic studies were reviewed by an experienced observer unaware of the results of the coronary angiogram.Results. The overall sensitivity and specificity of exercise echocardiography for the identification of multivessel disease were 73% and 70%, respectively. A stepwise logistic regression analysis identified the number of abnormal regions on the postexercise images as the strongest independent predictor of multivessel disease; also significant were a history of myocardial infarction and ST segment depression of at least 2 mm on the peak exercise electrocardiogram.Conclusions. Exercise echocardiography adds independent and incremental information to clinical and exercise test variables for identifying multivessel coronary artery disease.     

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.     

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.     

The echo-dipyridamole test early after acute myocardial infarct: echocardiographic aspects and angiographic correlations

To assess whether the different mechanical effects of intravenous dipyridamole were correlated with the location and distribution of the coronary arteries stenosis, 98 patients underwent high dose DET 8-10 days after an acute myocardial infarction. Left ventricular regional wall segments were identified in multiple views; a vascular territory was assigned to each coronary vessel. DET was positive in 68.4% of the patients (67/93), 59% (23/39) of those with single vessel disease, and 81% (44/54) of those with multivessel disease. Four different mechanical patterns of positivity of DET were observed: 1) marked worsening of wall motion in the same region showing asynergy (type I); 2) development of new wall motion abnormality adjacent to the infarct zone and located in the same vascular region (type II); 3) development of new wall motion abnormality adjacent to the infarct zone, but located in a different vascular region (type III); 4) development of transient remote asynergy (that is, a new wall motion abnormality in a region normal at rest and not directly adjacent to the infarct zone, type IV). Types I and II (asynergies in the infarct zone coronary bed) were found in patients both with single vessel disease or multivessel disease; by contrast, type III and IV were almost exclusively found in patients with multivessel disease (24/54 and 14/54 respectively) and occasionally in patients with single vessel disease (2/39 and 1/39 respectively). Thus, these two mechanical behaviours during dipyridamole infusion showed to be highly specific for predicting multivessel disease (95% and 97% respectively, sensitivity 44% and 26% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of myocardial perfusion and contractile function by inotropic stress Tc-99m sestamibi SPECT imaging and echocardiography for optimal detection of multivessel coronary artery disease

Objective—To assess whether inotropic stress myocardial perfusion imaging, echocardiography, or a combination of the two could enhance the detection of multivessel disease, over and above clinical and exercise electrocardiographic data.
Design—100 consecutive patients investigated by exercise electrocardiography and diagnostic coronary arteriography underwent simultaneous inotropic stress Tc-99m sestamibi SPECT (MIBI) imaging and echocardiography. MIBI imaging and echocardiographic data were analysed using a 12 segment left ventricular model, and each segment was ascribed to a particular coronary artery territory. The presence of perfusion defects with MIBI imaging or of wall thickening abnormality with echocardiography in at least two coronary artery territories at peak stress was taken as diagnostic of multivessel disease. Arteriographic evidence of  50% stenosis was considered significant.
Results—56 patients had multivessel disease. The sensitivity of the combination of MIBI imaging and echocardiography for detecting this was greater than either MIBI imaging or echocardiography alone (82%, 68%, and 68%, respectively; p = 0.005). Clinical and exercise electrocardiographic variables gave an R² value of 18.2% for predicting multivessel disease. The addition of either MIBI imaging (R² = 29.2%; p = 0.002) or echocardiography (R² = 28.8%; p < 0.001) enhanced the detection of multivessel disease, and the inclusion of both had further incremental value (R² = 34.8%; p = 0.003). Age (p = 0.03), MIBI imaging (p = 0.007), and echocardiography (p = 0.001) were independent predictors of multivessel disease.
Conclusions—The assessment of both myocardial perfusion and contractile function by simultaneous inotropic stress MIBI imaging and echocardiography optimises the non-invasive detection of multivessel disease.

Keywords: multivessel disease;  inotropic stress;  SPECT imaging;  echocardiography     

Early dobutamine echocardiography for the assessment of coronary stenosis after first Q-wave myocardial infarction

We assessed the accuracy of early dobutamine stress echocardiography to detect infarct-related coronary artery and multivessel disease in patients with first Q wave myocardial infarction after withdrawal of cardioactive drugs. Dobutamine-atropine echocardiography was performed in 91 consecutive patients (mean age 59+/-6 years) 7+/-4 days after myocardial infarction. Dobutamine was infused at incremental doses of 5, 10, 20, 30 to 40 microg/kg/min each one dose for 3 min. Peak heart rate was 134+/-17 bpm. All patients underwent coronary angiography before discharge. Sensitivity, specificity and accuracy of ischemic and biphasic response to detect residual stenosis of infarct-related coronary artery were 70, 92 and 73%, respectively. The sensitivity, specificity and accuracy of ischemic or biphasic response were similar in the vascular territories of left anterior descending (74, 86 and 75%, respectively), right (67, 100 and 70%, respectively) and circumflex coronary arteries (64, 100, and 69%, respectively). Sensitivity, specificity and accuracy of heterozonal wall motion abnormalities for multivessel coronary artery disease were 64, 82 and 76%, respectively. Dobutamine stress echocardiography is sensitive and specific in detecting residual coronary stenosis and multivessel disease in patients with first Q-wave myocardial infarction. The test is safe even without pharmacological protection.     

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)     

Examination of the usefulness of echocardiography with dobutamine for diagnosis of coronary disease]

To assess the feasibility, safety and usefulness of dobutamine stress echocardiography for the detection of coronary artery disease we evaluated 63 patients (45 men, 18 women) with effort chest pain. All patients underwent electrocardiographic submaximal bicycle exercise testing and 2-dimensional echocardiography during dobutamine infusion. Echocardiographic dobutamine test response was considered positive when new wall motion abnormalities were observed during dobutamine infusion. Sensitivity and specificity of electrocardiographic exercise test and dobutamine stress echocardiography were assessed in 25 patients who underwent selective coronary angiography. The sensitivity and specificity of dobutamine stress echocardiography, respectively 93.3% and 83.3%, were higher than those of exercise electrocardiography. 2-dimensional echocardiography during dobutamine infusion is a well tolerated, feasible and effective test for detecting coronary artery disease.     

Digital high frame rate stress echocardiography for detection of coronary artery stenosis by high dose dipyridamole stress testing

Diagnostic accuracy of high dose dipyridamole stress echocardiography (0.84 mg i.v./kg) for detecting coronary artery stenosis was assessed in 94 patients undergoing coronary angiography, and adverse effects were registered in the total study population of 120 patients. Echocardiographic analysis was performed with digital systolic cineloops with high frame-rate (47 frames/sec) for optimal left ventricular wall motion display. Results showed sensitivity of 73% for detection of arterial luminal stenosis 75% or retrograde collateral flow to an occluded coronary artery. Sensitivity for detection of 1-vessel stenosis was 43% (6 of 14 patients), and for 2- and 3-vessel disease 79% (19 of 24) and 88% (16 of 18), respectively. Specificity was 92% (35 of 38), diagnostic accuracy 81%. The stenosed coronary artery was correctly localized in 85% of positive tests. Dipyridamole-induced increase in wall motion score index differed significantly between patients with 1-, 2-, and 3-vessel disease (0.02 ± 0.17, 0.15 ± 0.17, and 0.27 ± 0.24, respectively), and early positive tests (dipyridamole dose of 0.56 mg/kg) were almost exclusively seen in patients with multivessel disease. Six patients (5%) developed symptomatic bradycardia and hypotension during the test. In conclusion, dipyridamole stress echocardiography is useful for detection and localization of coronary artery stenosis, particularly in patients with multivessel disease.The work was supported by a grant from the Norwegian Council on Cardiovascular Diseases, Oslo, Norway.     

Diagnostic value of exercise electrocardiography and dipyridamole stress echocardiography in hypertensive and normotensive chest pain patients with right bundle branch block

OBJECTIVES: Studies on the diagnostic value of exercise electrocardiography in right bundle branch block produced controversial results, and data on the accuracy of stress echo are still lacking. The aim of the study was to compare the diagnostic value of exercise electrocardiography and dipyridamole stress echo in chest pain patients with right bundle branch block, and to verify whether stress testing accuracy is affected by history of hypertension. METHODS: The study group was made up of 71 patients (56 men, aged 63 +/- 8 years) with chest pain of unknown origin and complete right bundle branch block. Of them, 35 were hypertensives and 36 normotensives. Patients performed, on different days and in random order, exercise electrocardiography and dipyridamole stress echo and underwent coronary angiography. RESULTS: Significant (> or = 70% diameter stenosis) coronary artery disease was found in 34 patients (17 hypertensives and 17 normotensives). Positive exercise electrocardiography (ST-segment shift > 1 mm at 80 ms after the J point in leads V5 and V6 or leads II and Vf) and dipyridamole stress echo (new wall motion abnormalities) were observed in 38 and 30 patients, respectively. The result of tests was concordant in 69% of hypertensives and 92% of normotensives. The two tests shared the same sensitivity in hypertensives (82%) and normotensives (71%). Of 37 patients without coronary artery disease, 12 had a false-positive result during exercise electrocardiography and four during stress echo. The specificity was lower for exercise electrocardiography than for stress echo in hypertensives (50 versus 89%, P = 0.0006), while no difference was evidenced in normotensives (84 versus 89%, P = 0.4). In hypertensives, the accuracy, positive, and negative predictive values were 66, 61, and 75% for exercise electrocardiography, and 86, 87, and 84% for stress echo. Corresponding figures in normotensives were 78, 80, and 76% for exercise electrocardiography, and 81, 86, and 77% for stress echo. CONCLUSIONS: In chest-pain patients with right bundle branch block, dipyridamole stress echo was effective to diagnose coronary artery disease in both normotensives and hypertensives. Moreover, it exhibited superior diagnostic information than exercise electrocardiography in hypertensives, due to significantly higher specificity. However, the two tests had similar diagnostic value in normotensives.     

Integrated evaluation of relation between coronary lesion features and stress echocardiography results: the importance of coronary lesion morphology

OBJECTIVES: The aim of this study was to analyze, in the same group of patients, the relationship between multiple variables of coronary lesion and results of exercise, dobutamine and dipyridamole stress echocardiography tests. BACKGROUND: Integrated evaluation of the relation between stress echocardiography results and angiographic variables should include not only the assessment of stenosis severity but also evaluation of other quantitative and qualitative features of coronary stenosis. METHODS: Study population consisted of 168 (138 male, 30 female, mean age 51+/-9 years) patients, on whom exercise (Bruce treadmill protocol), dobutamine (up to 40 mcg/kg/min) and dipyridamole (0.84 mg/kg over 10 min) stress echocardiography tests were performed. Stress echocardiography test was considered positive for myocardial ischemia when a new wall motion abnormality was observed. One-vessel coronary stenosis ranging from mild stenosis to complete obstruction of the vessel was present in 153 patients, and 15 patients had normal coronary arteries. The observed angiographic variables included particular coronary vessel, stenosis location, the presence of collaterals, plaque morphology according to Ambrose classification, percent diameter stenosis and obstruction diameter as assessed by quantitative coronary arteriography. RESULTS: Covariates significantly associated with the results of physical and pharmacological stress tests included for all three stress modalities presence of collateral circulation, percent diameter stenosis and obstruction diameter, as well as lesion morphology (p < 0.05 for all, except collaterals for dobutamine stress test, p = 0.06). By stepwise multiple logistic regression analysis, the strongest predictor of the outcome of exercise echocardiography test was only percent diameter stenosis (p = 0.0002). However, both dobutamine and particularly dipyridamole stress echocardiography results were associated not only with stenosis severity - percent diameter stenosis (dobutamine, p = 0.04; dipyridamole, p = 0.003) - but also, and even more strongly, with lesion morphology (dobutamine, p = 0.006; dipyridamole, p = 0.0009). As all of stress echocardiography results were significantly associated with percent diameter stenosis, the best angiographic cutoff in relation to the results of stress echocardiography test was: exercise, 54%; dobutamine, 58% and dipyridamole, 60% (p < 0.05 vs. exercise). CONCLUSIONS: Integrated evaluation of angiographic variables have shown that the results of dobutamine and dipyridamole stress echocardiography are not only influenced by stenosis severity but also, and even more importantly, by plaque morphology. The results of exercise stress echocardiography, although separately influenced by plaque morphology, are predominantly influenced by stenosis severity, due to a stronger exercise capacity in provoking myocardial ischemia in milder forms of coronary stenosis.