Dipyridamole Echocardiography Test Research Articles

Protective effect of nisoldipine on dipyridamole-induced myocardial ischemia: correlation with exercise electrocardiography.

Nisoldipine, a dihydropyridine calcium channel blocker with strong coronary dilatative action, is commonly used in the treatment of myocardial ischaemia; its beneficial effect on effort angina has been demonstrated by several previous reports. Infusion of dipyridamole in doses sufficient to provoke myocardial ischaemia in patients with significant coronary artery disease is used safely in imaging studies for diagnostic purposes. To evaluate the potential effect of nisoldipine on dipyridamole-induced ischaemia and to compare the results with the effect of nisoldipine on exercise-induced ischaemia. Twelve patients (10 men and two women, mean age 62 +/- 8 years) with significant coronary artery disease (at least 70% lumen reduction in at least one major coronary vessel) were selected for inclusion in the study. In accordance with the inclusion criteria, the patients exhibited an ischaemic diagnostic response to a multistage exercise electrocardiography stress test (> 0.15 mV ST segment depression compared with the resting electrocardiographic tracing) and to a dipyridamole-echocardiography test (transient left ventricular dyssynergy of contraction during infusion of dipyridamole up to 0.84 mg/kg over 10 min), after 3 days' cessation of antianginal treatment. After treatment with oral nisoldipine (10 mg twice daily) was introduced, the patients repeated the two tests, within 18 days of the first evaluation. The dipyridamole-echocardiography test was positive for ischaemia in 12 patients who were not receiving nisoldipine and in eight patients who were receiving the drug (100% and 67% respectively, P < 0.05). In the eight patients who gave positive dipyridamole-echocardiography tests both with and without treatment, dipyridamole time (time to onset of dyssynergy during the test) increased from 7.9 +/- 2.9 min to 10.2 +/- 3.1 min (P < 0.01). In these patients, no significant changes were observed, at ischaemia, in the severity and extent of induced dyssynergy, evaluated as wall motion score index (each of 16 left ventricular segments scored from 1 = normal to 4 = dyskinetic) after treatment (score variations from baseline to ischaemia: 0.20 +/- 0.11 without nisoldipine and 0.16 +/- 0.06 with nisoldipine; NS). Variations in dipyridamole time (arbitrarily considered to be 15 min in the negative dipyridamole-echocardiography test) were significantly correlated with variations in exercise time (duration of exercise to exhaustion or diagnostic positive response on the electrocardiogram): r = 0.75 (P < 0.01). No significant differences were recorded in rate-pressure product (beats/min x mmHg x 100) at peak ischaemia between patients who were or were not receiving nisoldipine, during either the exercise electrocardiography stress test (233 +/- 36 with nisoldipine and 244 +/- 39 without nisoldipine; NS) or the dipyridamole-echocardiography test (147 +/- 21 with nisoldipine and 133 +/- 30 without nisoldipine; NS). Nisoldipine treatment can protect from dipyridamole-induced ischaemia, being associated with a longer stress time, and completely preventing the development of ischaemia in some patients. The therapy-induced changes in ischaemic threshold during the dipyridamole-echocardiography test correlate with variations in exercise tolerance.

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

Technetium-99m sestamibi myocardial tomography based on dipyridamole echocardiography testing in hypertensive patients with chest pain

The non-invasive diagnosis of coronary artery disease in hypertensives with chest pain is an important clinical concern because all exercise-dependent tests display limited feasibility and diagnostic accuracy; by contrast, dipyridamole echocardiography testing has been shown to have a similar feasibility and accuracy in hypertensive and normotensive subjects. The aim of this study was to evaluate the diagnostic capability of technetium-99m sestamibi tomography based on dipyridamole echocardiography testing in hypertensives with chest pain, and to compare the scintigraphic results with those of coronary angiography, exercise electrocardiography and dipyridamole echocardiography. Forty subjects with mild to moderate hypertension, chest pain and no previous myocardial infarction were submitted to 99mTc-sestamibi tomography (at rest and after high-dose dipyridamole echocardiography) and to exercise electrocardiography testing. At coronary angiography 22 patients (group A) had significant epicardial coronary artery disease (>/=70% stenosis of at least one major vessel) and 18 normal main coronary vessels (group B). Dipyridamole 99mTc-sestamibi imaging was positive in 21/22 patients of group A and in 5/18 of group B. Dipyridamole echocardiography was positive in 18/22 patients of group A and in 5/18 of group B. Exercise electrocardiography was positive in 15/22 patients of group A and in 11/18 of group B. Four out of five subjects in group B with positive results in all the tests showed a slow run-off of angiographic contrast medium, probably due to small-vessel disease. Significant epicardial coronary artery disease in hypertensives with chest pain is unlikely when dipyridamole 99mTc-sestamibi tomography is negative. When scintigraphy is positive, either epicardial coronary artery disease or a small-vessel disease condition is possible. The association of scintigraphy with dipyridamole echocardiography testing allows the assessment of contractile function and myocardial perfusion by a single pharmacological stress.

Detection of significant residual stenosis of the infarct‐related artery after thrombolysis by high‐dose dipyridamole echocardiography test: Is it detected often enough?

It has been reported that high-dose dipyridamole echocardiography test (DET) can be successfully used for the detection of critical residual stenosis of the infarct-related artery (IRA). However, we have recently noticed low sensitivity of DET for the detection of residual IRA stenosis in patients with single-vessel disease. This study sought to determine the value of DET for the detection of significant residual stenosis of the IRA after thrombolysis. Dipyridamole echocardiography test was performed in 55 consecutive patients after a first acute myocardial infarction before hospital discharge. All patients underwent coronary angiography 23 +/- 6 days after infarction. Nine of 19 patients with positive DET revealed new adjacent asynergy and all of the patients had patient and significantly stenotic IRA. Sensitivity and specificity of DET in identifying significant residual stenosis of the IRA were 24 and 100%, respectively. Among 49 patients with significantly stenotic of occluded IRA, 40 patients without adjacent asynergy during DET had higher baseline wall motion score index (WMSI) compared with 9 patients who revealed adjacent asynergy during DET (1.45 +/- 0.30 vs. 1.24 +/- 0.18; p < 0.05). When all patients with positive DET (adjacent or remote asynergy) were compared with those with negative DET, no difference in baseline WMSI was found (1.37 +/- 0.24 vs. 1.44 +/- 0.24; p > 0.05). Our data indicate that sensitivity of DET in detecting significant residual stenosis of the IRA after thrombolysis is low. It seems that the extent of myocardial infarction affects the ability of DET to detect adjacent, but not remote asynergy.

Impact of culprit lesion morphology on prevalence of provoked myocardial ischaemia in patients with old myocardial infarction. A dipyridamole stress echocardiography, exercise electrocardiography and angiographic study.

We have recently shown that in patients with single vessel disease and no myocardial infarction, a complex plaque morphology makes myocardium more vulnerable to ischaemia during dipyridamole echocardiography testing. Whether coronary lesion morphology in the infarct-related artery in a chronic phase may also modulate prevalence of ischaemia in the same territory remains unknown. In order to determine the possible relationship between culprit lesion morphology in the infarct-related artery and the prevalence of homotopic ischaemia during stress tests, data from high dose dipyridamole echocardiography tests (up to 0.84 mg.kg-1 over 10 min), exercise electrocardiography and coronary angiography from 73 in-hospital patients with a previous myocardial infarction and patent infarct-related single-vessel disease (> or = 50% diameter reduction) were analysed. An angiographic culprit lesion was considered complex (Ambrose classification) when irregular borders, ulcers, thrombus and/or intraluminal lucencies were present. According to angiographic lesion morphology, two groups were identified: Group I, with simple-type culprit lesions; Group II, with complex type culprit lesions. Number of patients (I = 36; II = 37), age (I = 57 +/- II vs II = 55 +/- 9 years), ejection fraction (I = 58.8 +/- II 3 vs II = 56.5 +/- 10.2%), number of Q or non-Q wave myocardial infarctions, prevalence of rest angina (I = 9; II = II) or effort angina (I = 10; II = 10), culprit lesion stenosis severity (I = 57.9 +/- 7.2% vs II = 57.7 +/- 6.2% by computer analysis) and degree of infarct artery anterograde flow (I = 2.64 +/- 0.48 vs II = 2.56 +/- 0.50 by Thrombolysis in Myocardial Infarction definition) did not differ between the two groups (P = ns for all intergroup differences). Dipyridamole echocardiography test-induced ischaemia (considered as new or worsening abnormal wall motion) in the infarct-related artery territory was 25% in Group I and 59% in Group II (P < 0.01). Among positive dipyridamole echocardiography tests, low dose (0.56 mg.kg-1 over the 4 min) positivity occurred in two out of nine Group I patients and in 16 out of 22 Group II patients (22 vs 73%, P < 0.05). Exercise electrocardiography was positive in seven out of 32 Group I patients, and in 16 out of 35 Group II patients (22 vs 46%, P < 0.05). The peak rate pressure product tended to be higher in Group I than in Group II patients (282 +/- 65 vs 257 +/- 65 mmHg x beats.min x 10(2), P = 0.07). Thus, in patients with previous myocardial infarction and a patent infarct-related artery, complex culprit lesion morphology is associated with a higher prevalence of ischaemia and a lower ischaemic threshold during both exercise and dipyridamole stress testing. The morphology of culprit stenosis is important in modulating different stress responses in the chronic phase of myocardial infarction.

Head-to-head prognostic comparison between exercise Sestamibi tomography (MIBI) and dipyridamole-echocardiography testing (DET) in stable patients after myocardial infarction

Head-to-head prognostic comparison between exercise Sestamibi tomography (MIBI) and dipyridamole-echocardiography testing (DET) in stable patients after myocardial infarction

Dipyridamole and Dobutamine-Atropine Stress Echocardiography in the Diagnosis of Coronary Artery Disease: Comparison With Exercise Stress Test, Analysis of Agreement, and Impact of Antianginal Treatment

To compare the usefulness of dipyridamole echocardiography, dobutamine-atropine echocardiography, and exercise stress testing in the diagnosis of coronary artery disease and to analyze the agreement among the tests. Performance of these three tests in random order on a consecutive cohort of patients. A tertiary care and university center. One hundred two consecutive patients with chest pain and no history of coronary artery disease. Dipyridamole echocardiography, dobutamine-atropine echocardiography, exercise stress testing, and coronary angiography. Dobutamine-atropine test was positive in 49 (77%) of 63 patients with coronary artery disease, dipyridamole test in 49 (77%), and exercise stress test in 44 (68%; p = NS). Both echocardiographic tests showed an overall specificity (dipyridamole, 97%; dobutamine, 95%) higher than exercise stress test (79%; p < 0.05). Sensitivity of dipyridamole testing decreased from 93 to 61% (p = 0.002) if patients were receiving antianginal treatment but sensitivity of dobutamine-atropine testing was not affected (77% in patients receiving and not receiving treatment). When results were considered as positive-negative, agreement between dipyridamole and dobutamine-atropine echocardiography was 85% (kappa = 0.70). With regards to regional analysis, concordance was good (93% for segments, kappa = 0.76; and 95% for coronary arteries, kappa = 0.92). Major complications were more frequent during dobutamine-atropine (n = 7) than during dipyridamole infusion (n = 2) (p = 0.06). Dobutamine-atropine and dipyridamole echocardiography have a similar sensitivity and a higher specificity than that obtained by exercise ECG for the diagnosis of coronary artery disease. Similar information is obtained with dipyridamole and dobutamine-atropine echocardiography. It is our thought that pharmacologic stress echocardiography should be used as a first-step test to rule out coronary artery disease in patients not capable of exercising.

Assessment of Heart Rate Variability Changes During Dipyridamole Infusion and Dipyridamole-Induced Myocardial Ischemia: A Time Variant Spectral Approach

Objectives. We sought to evaluate changes in RR interval variability during dipyridamole infusion and dipyridamole-induced myocardial ischemia.Background. Myocardial ischemia and the autonomic nervous system can be mutually interdependent. Spectral analysis of RR interval variability is a useful tool in assessing autonomic tone.Methods. We used a time variant autoregressive spectral estimation algorithm that could extract spectral variables even in the presence of nonstationary signals. Two groups were considered: group A (patients with ischemia, n = 15) with effort or mixed angina, angiographically assessed coronary artery disease and positive exercise and dipyridamole echocardiographic test results, and group B (control subjects, n = 10) with normal exercise and dipyridamole echocardiographic test results. We investigated the following variables: RR interval mean and variance, low frequency (LF) and high frequency (HF) power in normalized units, LF ratio (LF/LFbasal power), HF ratio (HF/HFbasal power) and LF/HF ratio. For each test epoch, we calculated for group A and group B the mean value ± SE of all indexes considered. Differences due to an effect either of group (ischemic vs. control) or of time (including both drug and ischemia effects) were analyzed by using analysis of variance for repeated measurements.Results. Dipyridamole injection was characterized by a reduction of all spectral components in negative test. The LF ratio was the only variable able to discriminate patients with ischemia from control subjects (p < 0.05), whereas a time effect was evident for both mean RR interval and high frequency power in normalized units (p < 0.05). The LF ratio decreased in group B from 1 ± 0.00 (basal) to 0.31 ± 0.22 (peak), and increased in group A from 1 ± 0.00 to 15.41 ± 6.59, respectively. Results of an unpaired t test comparing the peak values of the two groups were also statistically significant (p < 0.01).Conclusions. Our data show that time variant analysis of heart rate variability evidences an increase in the low frequency ratio that allows differentiation of positive from negative test results, suggesting that the electrocardiogram may contain ischemia information unrelated to ST-T variations, even if their enhancement requires a more complex data processing procedure.

Comparison of the diagnostic potential of four echocardiographic stress tests shortly after acute myocardial infarction: submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine

This study assessed and compared the diagnostic potential of submaximal exercise, transesophageal atrial pacing, dipyridamole, and dobutamine-atropine stress echocardiography tests shortly after acute myocardial infarction. In 121 study patients, 325 digital echocardiographic stress tests were attempted 10 to 11 days after acute myocardial infarction: 83 submaximal exercise tests, 121 high-dose dipyridamole echocardiography tests (DET), 69 transesophageal atrial pacing tests (< 150 beats/min), and 52 dobutamine tests, starting at 10 μg/kg per minute, increasing stepwise to 40 μg/ kg/min, and coadministering atropine in 12 patients (dobutamine-atropine stress echocardiography [DASE]). Results were correlated to a coronary artery diameter stenosis ≥50% as determined by quantitative angiography. Feasibility to perform submaximal exercise echocardiography, atrial pacing echocardiography, DET, and DASE was 89%, 52%, 98%, and 88%, respectively. Atrial pacing was not tolerated by 18 patients and refused by 6 (9%). Severe but not life-threatening side effects were hypotension in DET (2%) and tachyarrhythmias in DASE (6%). Test positivity in multivessel disease with submaximal exercise, DET, and DASE was 55%, 93%, and 90%, respectively, and in 1 -vessel disease 47%, 65%, 71%, and for atrial pacing, 82%, respectively. We conclude that submaximal exercise has limited sensitivity and atrial pacing limited feasibility. The pharmacologic stressors provide a useful, safe diagnostic approach: DET with slightly lower sensitivity in 1-vessel disease and DASE with insignificantly less feasibility.

Mechanisms of regional ischaemic changes during dipyridamole echocardiography in patients with severe aortic valve stenosis and normal coronary arteries.

Vasodilator stress echocardiography can cause myocardial ischaemia in patients with severe aortic valve stenosis and angiographically normal coronary arteries. The aim of the study was to determine the mechanism of ischaemia in this clinical model. The study group comprised patients with severe aortic valve stenosis and normal coronary arteries: 25 patients (17 males, eight females; age 63 (SD 11) years) underwent a high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography test both before (2-4 d) and after (10-15 d) aortic valve replacement. Mean aortic pressure gradient was 96 (15) mm Hg, with a left ventricular mass index of 228 (49) g/m2. The dipyridamole echocardiography test was well tolerated and interpretable in all patients. Dipyridamole infusion induced chest pain in seven patients before and in no patient after surgery (28 v 0%, P < 0.01), ST segment depression in 12 patients before and two after surgery (48 v 8%, P < 0.01), and a transient regional dyssynergy in 10 patients before and two after surgery (40 v 8%, P < 0.01). In the preoperative evaluation, patients with an echocardiographically positive dipyridamole echocardiography test were comparable with patients with negative test as far as left ventricular mass index [240 (67) v 230 (64) g/m2, NS] and mean aortic pressure gradient [95 (22) v 92 (21) mm Hg, NS] were concerned. When compared to the preoperative assessment, the resting echo assessment in the postoperative evaluation showed unchanged values of left ventricular mass index [pre 228 (49) g/m2 v post 220 (36) g/m2, NS], but markedly decreased values of mean aortic gradient [pre 95 (15) mm Hg v post 22 (5) mm Hg, P < 0.01] and left ventricular wall stress index [pre 134 (30) g/cm2 v post 89 (19) g/cm2]. Dipyridamole echocardiography is a suitable clinical technique for assessing the ischaemic vulnerability of the left ventricle in severe aortic valve stenosis with angiographically normal coronary arteries. The frequent disappearance of the ischaemic response early after aortic valve replacement suggests that haemodynamic factors such as compressive diastolic wall stress or afterload reduction are important components of myocardial ischaemic vulnerability under these circumstances.

Failure of protective effect of Captopril and Enalapril on exercise and dipyridamole-induced myocardial ischemia

Fifteen patients with angiographic evidence of significant coronary artery disease, exertional myocardial ischemia, and positive dipyridamole echocardiographic test results at basal conditions and after 7 days of placebo treatment were prospectively studied to see whether captopril (containing sulfhydryl) and enalapril (nonsulfhydryl) modify myocardial ischemia induced by exercise testing and the effects of dipyridamole echocardiographic testing on regional myocardial contractility. Patients were randomized to captopril (150 mg/day in 3 separate doses) or enalapril (20 mg/day) for 1 week. At the end of this period each patient crossed over to the alternate regimen after a washout period of 7 days. Exercise stress testing and dipyridamole echocardiographic testing were repeated at the end of each treatment period. Neither captopril nor enalapril had a significantly greater anti-ischemic effect than placebo in any patient. Exercise duration, time to onset of ST-segment depression, maximal workload, degree of ST-segment depression, and rate-pressure product were not affected by either drug. Neither captopril nor enalapril improved dipyridamole-induced mechanical dysfunction or ST-segment depression.

Dipyridamole echocardiography for diagnosis of coexistent coronary artery disease in hypertrophic cardiomyopathy

The recognition of coexistent coronary artery disease (CAD) in patients with hypertrophic cardiomyopathy may be difficult by noninvasive testing based upon electrocardiographic changes or perfusion defects. Dipyridamole-stress echocardiography has proved a sensitive and highly specific test for noninvasive diagnosis of CAD in various patient subsets. To establish the feasibility, safety, and diagnostic accuracy of dipyridamolestress echocardiography in patients with hypertrophic cardiomyopathy, we performed high-dose dipyridamole testing (up to 0.84 mg/kg over 10 minutes) in 88 patients with hypertrophic cardiomyopathy (63 men; mean age ± SD, 46 ± 17 years). A subset of 60 patients was referred for coronary angiography independently of test results; CAD was defined as ≥50% diameter narrowing in at least 1 major coronary vessel. Dipyridamole echocardiography/electrocardiography testing was completed in all patients, with no limiting side effects or adverse reactions. In the subgroup of 60 patients with coronary angiography (14 with and 46 without CAD), chest pain occurred in 18 patients (8 with and 10 without CAD, p = NS); ST-segment depression ≥2 mm from baseline in 28 (7 with and 21 without CAD, p = NS); and transient dyssynergy in 10 patients (10 with and none without CAD, p < 0.0001). Assuming the transient regional dyssynergy to be the only criterion of positivity, the dipyridamole echocardiography test showed 71% sensitivity, 100% specificity, 100% positive predictive value; and 93% diagnostic accuracy for diagnosis of angiographically assessed CAD. We conclude that high-dose dipyridamole echocardiography testing may be considered a feasible and accurate tool for the noninvasive diagnosis of CAD in patients with hypertrophic cardiomyopathy.

Safety of echo-dipyridamole test in elderly patients with coronary artery disease.

The authors prospectively studied the feasibility and safety of high-dose dipyridamole echocardiography in 166 patients (77 younger and 89 elderly patients) referred for clinical evaluation of coronary artery disease. Echocardiographic examinations were adequate for analysis of parameters considered in 135 of the 166 patients (81.3%; 73 elderly, 62 younger patients). The feasibility of dipyridamole echocardiography test was 80.5% in young and 82% in elderly patients (P = ns). The incidence of side effects during dipyridamole echocardiography was similar in the two groups, except for dyspnea, which was observed in 20.5% of older and 3.2% of younger patients (p < 0.05). These data demonstrate that the dipyridamole test combined with echocardiographic monitoring of regional myocardial contractility may be considered a valid noninvasive method of evaluating coronary artery disease in the elderly.

1023-110 Stress Echo and the Risk of Reinfarction: A Fatal Attraction?

The identification of future reinfarction seems an elusive target for physiologic testing, consistently with the accepted notion that it is plaque type, rather than plaque size, that matters in provoking coronary occlusion. However, large sample populations are needed to detect phenomena with a low event rate. In addition, one should employ noninvasive stress test results that are tightly related to the extent and severity of CAD — in a stronger way than exercise-ECG. Aim of this study was to assess the capability of dipyridamole echocardiography test (DET) to predict reinfarction in patients evaluated early after acute uncomplicated myocardial infarction. In an updated analysis of the EPIC Study, we assessed the value of DET in predicting reinfarction in 1080 pts (age = 56 ± 9, 926 men and 154 women) evaluated early (10 ± 5 days) after uncomplicated acute myocardial infarction and followed up for 14 ± 10 months. A positive test occurred in 475 pts (44%). During follow-up, there were 50 reinfarctions: 45 non-fatal, and 5 fatallfollowed by cardiac death after ≤ 4 days from the reinfarction). Reinfarction (either nonfatal or fatal) occurred in 30 pts with positive and in 20 with negative DET (6.3 vs 3.3%, p &lt; 0.01). Nonfatal reinfarction occurred in 25 patients with positive and in 20 with negative DET (5 vs 3%, P = 0.05). Reinfarction was fatal in 5 out of 25 reinfarcted patients with positive and in none out of 20 reinfarcted patients with negative DET (20 vs 0%, P = 0.07). The relative risk (i.e., the relative risk of the occurrence of future cardiac events in the group with negative DET) of reinfarction was 1.9. In conclusion, DET positivity identifies patients evaluated early after uncomplicated myocardial infarction at higher risk of reinfarction and especially of fatal reinfarction.

Positive high-dose dipyridamole echocardiography test after acute myocardial infarction is an excellent predictor of cardiac events

To determine the prognostic value of the high-dose (0.84 mg/kg over a 10-minute period) dipyridamole echocardiography test (DET) after a first acute myocardial infarction (AMI) in comparison with clinical, electrocardiographic, echocardiographic, and angiographic variables, follow-up data over an average period of 16 months were obtained in 93 consecutive patients. There were 41 total cardiac events (TCE): one death, two reinfarctions, 13 postinfarction anginas, five percutaneous transluminal coronary angioplasty procedures, and 20 coronary artery bypass graft procedures. TCE without revascularization procedures were considered adverse cardiac events (ACE). The DET result was positive in 28 of 41 patients with TCE and in only 4 of 52 patients without TCE ( p < 0.001). The sensitivity, specificity, and accuracy of positive DET in predicting TCE were 68%, 92%, and 82%, respectively. According to Cox's proportional regression model the best predictor of TCE was positivity of DET ( p = 0.002, relative risk ratio 4.3), followed by multivessel coronary artery disease ( p = 0.018, relative risk ratio 2.9) and patent infarct-related artery ( p = 0.042, relative risk ratio 2.9). DET was positive in 12 of 16 patients with ACE and 20 of 77 patients without ACE ( p = 0.001). The sensitivity, specificity, and accuracy of DET in predicting ACE were 75%, 74%, and 74%, respectively. According to Cox's proportional regression model significant predictors of ACE were positivity of DET ( p = 0.002, relative risk ratio 29.4) and ejection fraction ≤40% at the time of DET ( p = 0.017, relative risk ratio 22.2). These data indicate that the positivity of DET is an excellent predictor of cardiac events after AMI and is more powerful as a predictor than the extent of coronary artery disease, suggesting its ability to identify “functionally” critical stenosis. A positive DET result can identify high-risk patients after AMI who should undergo coronary angiography and may benefit from revascularization procedures.

Hypertension and Ischemic Heart Disease Role of Dipyridamole Echocardiography Test

The aim of this study is to try to evaluate the relationship between arterial hypertension and ischemic heart disease (IHD) in the light of the physiopathologic response pattern to the dipyridamole echocardiography test (DET) in hypertensive patients, in pharmacologic washout, without any electrocardiographic ST segment depression during exercise tests or at rest. Sixty patients affected by mild to moderate asymptomatic essential arterial hypertension were studied: the subjects had a sitting diastolic blood pressure > or = 95 < or = 114 mmHg; there were 38 men and 22 women with a mean age of 49.8 +/- 7.6 years (range twenty-nine to sixty-eight). All patients had undergone high-dose DET (0.84 mg/kg in ten minutes). No patients developed side effects or asynergy in cardiac contractility during the test. In the absence of any significant coronary artery obstruction assessed angiographically, 18 patients (30%) showed ST segment depression > 1.0 mV during DET, sometimes with the presence of ventricular and/or supraventricular extrasystoles. In this group of patients the left ventricular mass index (LVMI) and duration of hypertension (in months) were higher as compared with those of the other 42 patients (respectively: 160.2 +/- 5.1 vs 129.2 +/- 9.2 g/m2, P < 0.02; and 30 +/- 4.8 vs 9 +/- 5.4 months, P < 0.007). In conclusion it is reasonable to speculate from these data that the ischemic-like" dipyridamole-induced ST segment depression, like that shown by patients affected by Syndrome X, might involve a worse prognosis in hypertensive patients. This may be because of increased coronary resistance due to structural modification or anatomic background.

Dipyridamole echocardiographic test performed 3 days after an acute myocardial infarction: feasibility, tolerability, safety and in-hospital prognostic value.

In recent years, increasing evidence has pointed to the potential of dipyridamole stress echocardiography as a fast, effective, inexpensive method of risk stratification after an acute myocardial infarction. A very early stratification by this test could improve the patient's management and reduce the duration of in-hospital stay, and, thus, the costs. Two-hundred and fifty-one consecutive patients (208 male, age 58 +/- 11) with a two-dimensional echocardiogram of good technical quality underwent a dipyridamole echocardiographic test (DET) 70 +/- 6 h after an acute myocardial infarction. Criterion for positivity was the identification of a transient regional asynergy that was absent or of a lower degree in the baseline examination. Positivity was defined as 'at low-dose' or 'at high-dose' if the asynergy was detected before or after the 8th min of a drug infusion. All tests were performed without any major side effects. DET was positive in 149 (59%) and negative in 102 (41%) patients. During the hospital stay, cardiac events (death, reinfarction, angina) occurred in 52/251 patients: in 49/149 with a positive and in 3/102 with a negative test (sensitivity 94%, negative predictive value 97%, P < 0.00001). Severe events (death and reinfarction) occurred in 14/251: in 12/149 with a positive DET and in 2/102 with a negative DET (sensitivity 86%; negative predictive value: 98%; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Dipyridamole-dobutamine echocardiography: A novel test for the detection of milder forms of coronary artery disease

Objectives. This study was designed to assess the clinical, hemodynamic and diagnostic effects of the addition of dobutamine to dipyridamole echocardiography.Background. Pharmacologic stress echocardiography with either dipyridamole or dobutamine has gained acceptance because of its safety, feasibility, diagnostic accuracy and prognostic power. The main limitation of the two tests is a less than ideal sensitivity in some patient subsets, such as those with limited coronary artery disease. We hypothesized that two pharmacologic stresses might act synergistically in the induction of ischemia by combining the mechanisms of inappropriate coronary vasodilation (with dipyridamole) and an increase in myocardial oxygen consumption (with dobutamine).Methods. One hundred fifty patients (mean [±SD] age 51 ± 11 years) referred for stress echocardiography were initially studied by dipyridamole-dobutamine echocardiography. The test was stopped during the dipyridamole step in 95 patients for achievement of a predetermined end point (obvious dyssynergy induced by lower or higher dipyridamole dose), and dipyridamoledobutamine tests were performed in 55 patients (negative dipyridamole echocardiographic test). In the same 150 patients the dobutamine echocardiographic test (up to 40 μg/kg body weight per min) was performed on a separate day.Results. Significant coronary artery disease (>50% diameter stenosis of at least one major coronary vessel by quantitative coronary arteriography) was present in 131 patients (one vessel in 115; two vessels in 10, three vessels in 6), with normal coronary arteriography in 19. The feasibility of the dipyridamoledobutamine test was 96%. Self-limiting side effects occurred in 5% of patients. The peak rate-pressure product was lowest during the dipyridamole test (132 ± 30) and was comparable during the dobutamine (186 ± 59) and dipyridamole-dobutamine tests (179 ± 45, p = NS vs. dobutamine; p < 0.01 vs. dipyridamole). Sensitivity was 71% for dipyridamole, 75% for dobutamine and 92% for dipyridamole-dobutamine echocardiography (dipyridamole vs. dipyridamole-dobutamine, p < 0.01; dobutamine vs. dipyridamole-dobutamine, p < 0.01; dipyridamole vs. dobutamine, p = NS), whereas specificity was 89% for dipyridamole, 79% for dobutamine and 89% for dipyridamole-dobutamine echocardiography (p = NS for all).Conclusions. Routine dobutamine addition to dipyridamole stress testing is clinically useful and well tolerated. It expands the spectrum of the disease detectable by pharmacologic stress echocardiography and allows documentation of milder forms of coronary artery disease that can be missed by conventional dipyridamole or dobutamine stress echocardiography.

Dipyridamole stress echocardiography in patients with severe left main coronary artery narrowing

From a population of 2,698 patients (579 evaluated early after an uncomplicated acute myocardial infarction) who underwent dipyridamole echocardiography testing (DET) and subsequent coronary angiography, left main (LM) stenosis ⩾50% was present in 73 (61 men and 12 women, mean age 62 ± 8 years). These 73 patients were compared with a control group comprising 100 consecutive coronary patients without LM disease/ Both groups were similar regarding mean age, sex, incidence of previous myocardial infarction, left ventricular function at rest, and severity of coronary artery disease by the number of diseased vessels excluding the LM. The proportion of patients receiving antianginal therapy during DET was higher in the LM than in the non-LM group (32 vs 14%; p <0.01). No major complication (severe hypotension, sustained arrhythmia, myocardial infarction or death) occurred during DET. Of 73 patients with LM disease, 68 had positive DET (sensitivity 93%), dipyridamole time was 7.1 ± 3.8 minutes, and the rest-peak stress variation in dipyridamole wall motion score index (1 = normal to 4 = dyskinesia, in an 11-segment model) was 0.37 ± 0.23; 14 patients (19%) were resistant to aminophylline and needed nitrates to resolve ischemia. In the non-LM group, DET was positive in 72% (p <0.001 vs LM), with a longer dipyridamole time (9.6 ± 5.2 minutes; p <0.001 vs LM), lower rest-peak stress wall motion score index variation (0.29 ± 0.25; p <0.05 vs LM), and less frequent antidote resistance (1%; p <0.001 vs LM). In the LM group, severity of LM stenosis, and the extent of associated disease did not influence the results of the test, whereas in the non-LM group, dipyridamole time, rest-peak stress variation of wall motion score index, and DET positivity increased with the number of narrowed arteries. DIET is feasible, safe and accurate in patients with LM disease/ Although no pathognomonic response for LM disease could be recognized, the DET positivity pat]tern in the time and space domain was characterized by a shorter dipyridamole time, larger extent and severity of the induced dyssynergy, and more frequent antidote resistance than in patients without LM disease.

Assessment of anatomic and physiological severity of single-vessel coronary artery lesions by dipyridamole echocardiography. Comparison with positron emission tomography and quantitative arteriography.

The aim of this study was to compare the results of dipyridamole-echocardiography test (DET: two-dimensional echo monitoring during dipyridamole infusion up to 0.84 mg/kg over a period of 10 minutes) with both anatomic and physiological parameters of coronary artery disease severity, assessed by computer-assisted quantitative coronary arteriography, and regional coronary flow reserve, measured by [13N]ammonia (13NH3) and dynamic positron emission tomography (PET), respectively. We studied 31 patients with a history of chest pain and neither previous myocardial infarction nor resting wall motion abnormalities. Eighteen patients had single-vessel disease (> 50% stenosis of one major coronary vessel), and 13 had normal coronary arteries. The criterion for DET positivity was the appearance of a new transient regional wall motion abnormality. In patients with a positive DET, two parameters were evaluated: the dipyridamole time (ie, the time from the beginning of drug infusion to the development of obvious dyssynergy) and the wall motion score index (WMSI, a semiquantitative integrated estimation of extent and severity of the stress-induced dyssynergy). WMSI was derived by summation of individual segment scores divided by the number of segments interpreted. Quantification of regional myocardial blood flow was obtained by PET measurements of 13NH3 arterial input function and left ventricular myocardial tissue concentration both at control and after dipyridamole (0.56 mg/kg over 4 minutes). Maximal regional blood flow after dipyridamole in the region supplied by the stenotic vessel was significantly lower in the 11 patients with coronary artery disease and positive DET than in the 7 patients with coronary artery disease and negative DET (1.08 +/- 0.33 versus 1.98 +/- 0.37 mL.min-1.g-1, P < .01). In patients with a positive DET, regional coronary flow reserve correlated well with dipyridamole time (r = .87, P < .01) but not with peak WMSI (r = .25, P = NS). Patients with dipyridamole-induced akinesia or dyskinesia (n = 6) had a greater reduction in regional coronary flow reserve than did those showing hypokinesia (n = 5): 1.38 +/- 0.51 versus 2.17 +/- 0.42, P < .05. Percent area reduction was more severe in patients with DET positivity than in those with DET negativity (93.7 +/- 8.7% versus 77 +/- 10.3%, P < .01), and it correlated with regional coronary flow reserve (r = .64, P < .01) and dipyridamole time (r = -.59, P < .01). In patients with single-vessel disease, DET shows an excellent specificity but a limited sensitivity; in these patients, DET positivity is associated with a physiologically important coronary stenosis. Severity of the anatomic stenosis and impairment in regional flow reserve are greater when the dipyridamole-induced dyssynergy appears earlier during the test. Therefore, a stratification of the anatomo-physiological severity of coronary artery disease can be obtained with DET, based mainly on the temporal allocation of the transient dyssynergy.