Echocardiography with dobutamine in hypertensive patients with chest pain

INTRODUCTION: The exercise stress test shows limited diagnostic accuracy for the detection of coronary artery disease in hypertensive patients. Echocardiography with dobutamine is a useful tool in the assessment of coronary artery disease. PURPOSE: Our purpose has been to compare dobutamine stress echocardiography and exercise stress test for diagnosing coronary disease in hypertensive patients. MATERIAL AND METHODS: Dobutamine stress echocardiography (administered up to 40 micrograms/kg/min, and atropine when necessary), exercise stress test and coronary arteriography were performed on 74 hypertensive patients with chest pain and no previous history of coronary artery disease. RESULTS: Forty-eight (65%) patients underwent a diagnostic exercise stress test and 66 (89%) a diagnostic dobutamine stress echocardiography. Coronary artery disease (> or = 70% stenosis in, at least, one major vessel) was demonstrated in 28 (58%) patients who underwent a diagnostic exercise stress test, and in 39 (59%) patients who completed a dobutamine stress echocardiography. Sensitivity for exercise stress test was 82%, and 79% for dobutamine stress echocardiography (p = NS). Specificity was higher for dobutamine stress echocardiography (100% vs 60%; p < 0.005). CONCLUSIONS: Dobutamine stress echocardiography has high sensitivity and specificity for the detection of coronary artery disease in hypertensive patients. Dobutamine stress echocardiography has higher feasibility and specificity than exercise stress test in this group of patients.     

Primary rhabdomyosarcoma of the brain: observations on a case with clinical and radiological evidence of cure

BACKGROUND: After heart transplantation, accelerated coronary vasculopathy is a major factor that limits long-term survival and is usually detected by serial coronary angiography. The aim of this study was to determine whether dobutamine stress echocardiography could accurately identify the progression of cardiac allograft vasculopathy. METHODS: Two sequential controls by dobutamine stress echocardiography were performed at an 18-month interval in 37 heart transplant recipients at the time of their routine coronary angiography. The first control (control 1) occurred 37+/-20 months after transplantation, and the second control (control 2) occurred after 56+/-21 months. Standard echocardiographic views were acquired at baseline and at incremental dobutamine infusion levels. Regional wall motion score was calculated in a 16-segment model, and each segment was graded from 1 (normal) to 4 (dyskinesia). Visual and quantitative coronary angiographic analysis were used to assess the severity of the coronary vasculopathy. RESULTS: The incidence of coronary vasculopathy increased from 46% (17/37 patients, four of whom had stenoses > 50%) at control 1 fo 70% (26/37 patients, six of whom had stenoses > 50%) at control 2. Progression of coronary vasculopathy was diagnosed by coronary angiography in 25 patients (new abnormalities in 19 and worsening of previous abnormalities in 6). Dobutamine stress echocardiography correctly identified the progression of vasculopathy in 21 of these 25 patients (84%) with new abnormalities in 17 and worsening in four. In the four remaining patients with evidence of progression of vasculopathy on coronary angiography, the result of dobutamine stress echocardiography was abnormal in three patients and normal in only one. Therefore dobutamine stress echocardiography results were abnormal in 12 patients at control 1 (sensitivity: 65%, specificity: 95%) and in 27 at control 2 (92% sensitivity, 73% specificity). CONCLUSION: Dobutamine stress echocardiography is a sensitive, noninvasive method to diagnose the progression of allograft vasculopathy, and a negative test result is a strong predictor of absence of allograft coronary vasculopathy. Therefore serial routine coronary angiography may be deferred when dobutamine stress echocardiography results are normal.     

Purification, crystallisation and preliminary X-ray diffraction study of ribosome inactivating protein: saporin

OBJECTIVES: To compare transesophageal atrial pacing stress echocardiography with dobutamine stress echocardiography for feasibility, safety, duration, patient acceptance and concordance in inducing wall motion abnormalities. BACKGROUND: Transesophageal atrial pacing is an effective method of increasing heart rate and has been used in the assessment of coronary artery disease. METHODS: Both tests were performed in sequence on the same patients in random order. Transesophageal atrial pacing stress echocardiography began at a heart rate of 10 beats/min above the baseline value and was increased by 20 beats/min every two min until 85% of the age-predicted maximum heart rate or another end point was reached. Dobutamine echocardiography was performed using three-min stages and a maximum dose of 40 microg/kg per min. Atropine (total dose < or =2 mg) was administered at the start of the 40 microg/kg per min stage if needed to augment heart rate or during pacing if Wenckebach heart block occurred. RESULTS: Transesophageal atrial pacing stress echocardiography was feasible in 100 of 104 patients (96%); the duration (8.6+/-3.6 min) was significantly shorter than that of dobutamine stress echocardiography (15.1+/-3.9 min) (p = 0.0001). With transesophageal atrial pacing stress echocardiography, the recovery period was shorter, symptoms and dysrhythmias were fewer, hypertension and hypotension were less common and target heart rate was more frequently achieved. No complications occurred with either test. Patient acceptance was satisfactory. Agreement between results of both tests was good for segmental wall motion scoring with a 16-segment model, scores 1 to 5 (kappa: rest, 0.79; peak, 0.57) and test interpretation (normal, ischemia, infarction or resting wall motion abnormality with ischemia) (kappa: 0.77). CONCLUSIONS: Transesophageal atrial pacing stress echocardiography is a feasible, well-tolerated alternative to dobutamine stress echocardiography. It can be performed rapidly and shows good agreement with dobutamine stress echocardiography in the induction of myocardial ischemia.     

Early assessment of viable myocardium after acute myocardial infarction by low-dose echo-dobutamine

BACKGROUND: The aim of the study was to evaluate the usefulness of low-dose dobutamine echocardiographic testing performed within 48 hours from anterior AMI in order to identify the extent of viable myocardium and predict its functional outcome. The early echo-dobutamine test was also compared with a predischarge test in order to evaluate the effects of different timing on the accuracy of the test. METHODS: Nineteen consecutive patients, aged 54 +/- 11 years, with a first anterior AMI entered the study. All patients underwent a low-dose dobutamine echocardiographic test within 48 hours from hospital admission and at predischarge. In all the patients, a rest follow-up echocardiogram was performed three months after hospital discharge. Eleven patients underwent a revascularization procedure (7 underwent PTCA and 4 CABG). RESULTS: Of the 159 dyssynergic segments, 26% improved spontaneously at predischarge and 51% improved at the three-month follow-up. Of the 145 predischarge dyssynergic segments, 38% improved at three months. Considering the results on a segmental basis, early low-dose dobutamine echocardiography showed a sensitivity of 52%, a specificity of 87%, a positive predictive value of 81%, a negative predictive value of 64% and a diagnostic accuracy of 69% for wall-motion improvement at three months. The predischarge test showed very similar values. A slight enhancement of the sensitivity of both tests was observed considering the akinetic segments only. Finally, considering the amount of segmental reversible dysfunction inside the infarct area in the single patients, early low-dose dobutamine echocardiography showed a sensitivity of 86% and a specificity of 80%. CONCLUSIONS: Our results indicate that: 1) recovery of regional wall motion after AMI is slow and progressive, with substantial improvement ensuing within the first days after infarction; 2) considering results on a segmental basis, low-dose dobutamine echocardiography performed within 48 hours of AMI shows a high specificity but a low sensitivity for late recovery of regional function, although it gave information similar to what was obtained performing the test at predischarge; 3) the efficiency of test can be improved by considering the amount of reversible segmental dysfunction inside the infarct area in the single patients.     

Dobutamine stress echocardiography: clinical utility and predictive value at various infusion rates

Dobutamine stress echocardiography has increasingly been used to assess patients for coronary artery disease. Despite the popularity of this test, the optimal dose of dobutamine has not been established. The objective of this study was to assess the accuracy of dobutamine stress echocardiography at various infusion doses and its utility as a predictor of perioperative risk in patients undergoing a noncardiac surgical procedure. One hundred thirteen consecutive patients underwent dobutamine stress echocardiography, subsequent cardiac catheterization and/or a noncardiac surgical procedure. Three patient groups were analyzed on the basis of peak dobutamine infusion rates (17 +/- 4, 29 +/- 2, and 40 +/- 0 micrograms/kg/min, respectively). The three groups were comparable with regard to age, sex, ejection fraction, and severity of coronary artery disease. In group I, the sensitivity and specificity of dobutamine stress echocardiography were 74% and 33%, respectively, with a positive predictive value of 78%. In group II, the sensitivity and specificity improved to 84% and 78%, with a positive predictive value of 89%. In group III, the sensitivity and specificity were 86% and 80%, respectively, with a positive predictive value of 86%. In the noncardiac surgical group there was only one nonfatal cardiac complication among the 50 patients with a dobutamine echocardiogram, which was negative for evidence of inducible ischemia. In conclusion, this study demonstrates that dobutamine stress echocardiography should use an infusion rate of > or = 30 micrograms/kg/min to optimize diagnostic accuracy relative to angiographic coronary artery disease. A test that shows no evidence of new, inducible ischemia predicts a low risk of perioperative cardiac events in patients undergoing noncardiac surgery, even at an infusion rate as low as 20 microns/kg/min.     

Feasibility and safety of dobutamine/atropine echocardiography following acute myocardial infarct

BACKGROUND: Due to the increased utilization of this test for the evaluation of chest pain and for prognostic stratification in patients with a recent myocardial infarction, the results of 235 consecutive tests have been analyzed to evaluate the incidence and clinical significance of side effects induced by dobutamine. A potential limitation to the clinical utilization of dobutamine stress echocardiography is the higher incidence of side effects comparison with to other non invasive tests for the diagnosis of coronary artery disease reported by some authors. METHODS: Dobutamine/atropine stress echocardiography was performed in 256 patients affected by acute myocardial infarction. Dobutamine was infused starting with the dose of 5 micrograms/kg/min over 3 minutes with incremental steps of 10-20-30-40 micrograms/kg/min over 3 minutes and atropine, in cases of poor chronotropic response, under 2D-echocardiographic and 12-lead electrocardiographic monitoring. RESULTS: The test was interrupted only in 4 cases for atrial fibrillation (2 patients) and symptomatic hypotension. Patients were divided according to the absence (G1) or presence (G2) of cardiac arrhythmias during the test. Patients of G2 differred from patients of G1 only in respect of the maximal dose of dobutamine infused and the incidence of a wall motion abnormality in the basal echocardiogram. CONCLUSIONS: Dobutamine/atropine echo stress test may be considered a safe test for the evaluation of the presence and severity of coronary artery disease in patients with a previous or recent myocardial infarction.     

Treatment of pathological fractures of the humeral shaft due to bone metastases: a comparison of intramedullary locking nail and plate osteosynthesis with adjunctive bone cement

The assessment of myocardial viability is of increasing clinical relevance in the era of thrombolytic therapy and coronary revascularization. Dobutamine stress echocardiography has been proposed as a method of detecting residual viability. The echocardiographic hallmark for viability of a dyssynergic segment is improvement of wall thickening after inotropic challenge. Several clinical studies published over the past year have shown the value of dobutamine stress echocardiography in predicting improvement in regional and global ventricular function after revascularization.     

Cardiac rupture with dobutamine stress echocardiography

Dobutamine stress echocardiography is a safe method for the evaluation of coronary artery disease, myocardial function, and viability. The potential for cardiac rupture exists. Although clinical and electrocardiographic criteria may be helpful in identifying those patients at risk for cardiac rupture, the criteria are neither sensitive nor specific enough to exclude patients or make recommendations regarding which patients should undergo dobutamine stress echocardiography in the post-infarction period. Physicians must be aware of the possibility and be prepared to treat cardiac rupture when performing dobutamine stress echocardiography.     

Comparison of coronary endothelial dynamics with electrocardiographic and left ventricular contractile responses to stress in the absence of coronary artery disease

Coronary artery endothelial dysfunction has been proposed as a cause of myocardial ischemia and symptoms in patients with angina-like chest pain despite normal coronary angiograms, especially those with ischemic-appearing ST-segment depression during exercise (syndrome X). We measured coronary vasomotor responses to acetylcholine (3 to 300 microg/min) in 42 patients (27 women and 15 men) with effort chest pain and normal coronary angiograms who also had normal electrocardiograms and echocardiograms at rest. All patients underwent treadmill exercise testing and measurement of systolic wall thickening responses to dobutamine (40 microg/kg/min) during transesophageal echocardiography. There were no differences in the acetylcholine-stimulated epicardial coronary diameter (+5+/-13% vs +1+/-13%, p=0.386) and flow (+179+/-90% vs +169+/-96%, p=0.756), or in the systolic wall thickening responses (+134+/-65% vs +118+/-57%, p=0.445) from baseline values in the 12 syndrome X patients compared with the 30 patients with negative exercise test results. In patients in the lowest quartile of coronary flow responses to acetylcholine, dobutamine increased systolic wall thickening by 121+/-73%; 3 had ischemic-appearing ST-segment depression during this stress. This contractile response to dobutamine was no different than the increase in systolic wall thickening (129+/-48%, p=0.777) in patients in the highest quartile of coronary flow responses, 3 of whom also had ischemic-appearing ST-segment depression during this stress. Thus, coronary endothelial dysfunction in the absence of coronary artery disease does not account for ischemic-appearing ST-segment depression in patients with chest pain despite normal coronary angiograms. Further, coronary endothelial dysfunction is not associated with myocardial contractile responses to stress consistent with myocardial ischemia.     

Prediction of functional outcome after myocardial infarction using BMIPP and sestamibi scintigraphy

We determined the predictive value of combined beta-methyl iodophenyl pentadecanoic acid (BMIPP) and sestamibi scintigraphy for the functional outcome after myocardial infarction and compared the value of this approach with dobutamine echocardiography. METHODS: Rest BMIPP, rest sestamibi and low-dose dobutamine echocardiographic studies were obtained in 18 patients 4 to 10 days after infarction (mean 6.7 +/- 2.0 days). Six months later, a rest echocardiographic study was performed to assess functional outcome. RESULTS: Wall motion improved in 27/33 segments (82%) which showed mismatching but not in 19/21 segments (90%) with matched defects (p < 0.001). The accuracy of combined BMIPP and sestamibi SPECT in predicting segmental functional outcome was higher (85%) than that of sestamibi uptake alone (77%). Wall motion improved in 16/20 segments (80%) showing contractile reserve and not in 21/34 segments (63%) with the negative dobutamine test, giving an accuracy of 69% for dobutamine echocardiography. Combination of the two techniques resulted in higher positive (94%) and negative predictive values (94%). CONCLUSION: Mismatching of BMIPP and sestamibi uptake is predictive for long-term functional recovery after acute myocardial infarction. In contrast, segments with matched defects contain only scar tissue. Combined BMIPP and sestamibi scintigraphy offers increased accuracy compared to dobutamine echocardiography.     

Usefulness of isometric hand grip exercise in detecting coronary artery disease during dobutamine atropine stress echocardiography in patients with either stable angina pectoris or another type of positive stress test

Dobutamine atropine stress echocardiography (DASE) detects coronary artery disease (CAD) by increasing myocardial oxygen demand causing ischemia. The sensitivity of the test for detection of CAD is reduced in patients with submaximal stress. We hypothesized that increasing cardiac work load by adding isometric exercise would improve the detection of ischemia during DASE. We studied 31 patients, mean age 57+/-11 years, with angiographically documented CAD. Patients underwent DASE using incremental dobutamine doses from 5 to 40 microg/kg/min, followed by atropine if peak heart rate was <85% of predicted maximal. Hand grip was then performed for 2 minutes at 33% of maximal voluntary contraction, while dobutamine infusion was maintained at the peak dose. The addition of hand grip during dobutamine stress was associated with a significant increase in systolic blood pressure (143+/-21 vs 164+/-24 mm Hg, p = 0.001) and left ventricular end-systolic circumferential wall stress (72+/-30 x 10(3) dynes/cm2 vs 132+/-34 x 10(3) dynes/cm2, p = 0.004). Wall motion score index increased from 1.0 at rest to 1.15+/-0.18 with dobutamine (p = 0.0004 vs rest), and increased further to 1.29+/-0.22 with the addition of hand grip (p = 0.004 vs dobutamine). Ischemia was detected in 19 patients (62%) with dobutamine-atropine stress alone and in 25 (83%) after the addition of hand grip (p <0.05). The addition of hand grip during DASE is feasible, and improves the detection of myocardial ischemia.     

Nursing informatics

OBJECTIVES: This study investigated the ability of on-line vectorcardiography (VCG) to detect myocardial ischaemia as assessed by dobutamine stress echocardiography after an episode of unstable coronary artery disease. DESIGN: Dobutamine stress test (incrementally infused doses of 5, 10, 20, 30 and 40 microg kg(-1) per minute) was performed during simultaneous VCG monitoring. QRS vector difference (QRS-VD), ST vector magnitude (ST-VM), ST change vector magnitude (STC-VM) and T change vector magnitude (TC-VM) were monitored. A new wall motion abnormality or worsening of abnormal wall motion was regarded as indicating a positive dobutamine stress test. SUBJECTS: Fifty-five patients with unstable angina pectoris and 16 patients with an acute non-Q-wave myocardial infarction were studied 5-8 days after admission. RESULTS: A positive dobutamine stress test was observed in 37 patients (52%). The sensitivity, specificity and total accuracy of identifying patients with a positive dobutamine stress test by VCG were: 38%, 91% and 63% for QRS-VD; 59%, 88% and 73% for ST-VM; 84%, 79% and 82% for STC-VM; and 86%, 23% and 56% for TC-VM. Patients with a positive dobutamine stress test showed higher maximum VCG values than patients with a negative dobutamine stress test (QRS-VD, P < 0.01; ST-VM, P < 0.001; STC-VM, P < 0.001). The maximum VCG values were related to the number of segments showing new or worsening wall motion abnormality (QRS-VD: r=0.41, P < 0.001; ST-VM: r=0.44, P < 0.001; STC-VM: r=0.57, P < 0.001). CONCLUSION: STC-VM and ST-VM seem to be the best VCG variables for detection of myocardial ischaemia as assessed by dobutamine stress echocardiography.     

Results of dobutamine stress echocardiography in patients with syndrome X

This study describes the results of Dobutamine stress echocardiography in 10 patients with Syndrome X. The diagnosis of Syndrome X was made on the basis of the presence of exertional angina, positive exercise stress test, negative ergonovine stress test and normal coronary arteries at angiography. All patients underwent Dobutamine stress echocardiography after interruption of any antianginal therapy. Dobutamine was infused starting with a dose of 5 mcg/kg/min over 3 minutes with incremental steps of 5 mcg/kg/min every 3 minutes up to a maximal dose of 40 mcg/kg/min. Two-dimensional echocardiography and 12-lead electrocardiography was monitored during the infusion of the drug. Nine patients received the maximal dose while one patient prematurely stopped the test for the occurrence of side effects. None of the ten patients developed segmental left ventricular wall motion abnormalities indicative of myocardial ischemia; ST-segment depression diagnostic for ischemia developed in 30% of patients; angina was elicited in one of these patients and in two additional patients. A hyperkinetic response to Dobutamine infusion involving all the segments of the left ventricle was observed both in patients with and without chest pain or electrocardiographic changes. In patients with Syndrome X Dobutamine induces a hyperkinetic left ventricular response indicative of normal contractile reserve despite the presence in some cases of angina and electrocardiographic signs of ischemia.     

Preclinical cardiac dysfunction in transfusion-dependent children and young adults detected with low-dose dobutamine stress echocardiography

Transfusion-dependent (TD) patients develop cardiac iron overload that will eventually lead to cardiac pump failure. Low-dose dobutamine stress echocardiography may complement resting echocardiography and identify preclinical myocardial dysfunction caused by early cardiac hemosiderosis. Twenty-six iron-overloaded TD patients had stress echocardiography with 5 microg/kg per minute of dobutamine. Indexed left ventricular (LV) mass, LV dimensions, meridional wall stress, and cardiac index were significantly increased. TD patients had similar LV shortening fraction by M-mode (40.5% +/- 5.6% vs 39.4% +/- 4.5%) but had a lower mean LV ejection fraction (53.3% +/- 3.9% vs 46.8% +/- 6.9%, P < .002) and a subnormal increase in cardiac index during dobutamine stress (35% +/- 20% vs 11% +/- 16%, P < .0001). Impairment in LV relaxation was demonstrated by a prolonged isovolumetric relaxation time (0.060 +/- 0.005 vs 0.088 +/- 0.019 seconds, P < .0001), increased peak mitral E wave, and abnormal E/A ratio. Asymptomatic TD patients demonstrate decreased systolic functional reserve and abnormal left ventricular relaxation that may be caused by cardiac hemosiderosis. Low-dose dobutamine stress echocardiography may be useful for detecting and following cardiac dysfunction in patients at risk for cardiac hemosiderosis.     

Transport and storage of Helicobacter pylori from gastric mucosal biopsies and clinical isolates

Presence of multivessel coronary artery disease (MVD) identifies a high risk subgroup after acute myocardial infarction (AMI). Dobutamine stress echocardiography (DSE) has recently emerged as a promising non invasive test to detect the presence and extent of coronary artery disease. Forty six consecutive patients (38 males, 8 females; mean age 48.6 +/- 10.4 years) of Q-wave acute myocardial infarction were subjected to submaximal treadmill test (TMT) and dobutamine stress echocardiography to see their ability to predict multivessel coronary artery disease as detected by coronary angiography before hospital discharge. Dobutamine infusion was started at 5 micrograms/kg/min to a maximum of 40 micrograms/kg/min, to achieve 70 percent of the age predicted heart rate. Appearance of new regional wall motion abnormality was interpreted as positive DSE for MVD. Mean peak infusion dose of dobutamine used in the study was 28.56 +/- 5.67 micrograms/kg/min. In none of the patients, the test had to be terminated due to side effects. The sensitivity and specificity of DSE to predict MVD was 80 percent and 93.7 percent, respectively as compared to 45 percent and 86 percent for submaximal TMT. Thus, DSE in patients of AMI before hospital discharge is a safe procedure with fairly accurate prediction of multivessel coronary artery disease.     

Nitroglycerin enhances the ability of dobutamine stress echocardiography to detect hibernating myocardium

BACKGROUND: A biphasic response of wall thickening with initial improvement and subsequent deterioration during dobutamine stress echocardiography (DSE) has been increasingly used for detection of hibernating myocardium. However, the improvement of wall thickening at low-dose DSE may be limited in hibernating myocardium by severe hypoperfusion. Nitroglycerin (NTG) improves myocardial perfusion, reduces oxygen demand, and may enhance low-dose dobutamine to improve wall thickening. METHODS AND RESULTS: A pig model of myocardial hibernation of 24 hours to 7 days was created through severe left anterior descending coronary artery stenosis with coronary flow reductions of approximately 40%, producing severe regional left ventricular dysfunction but no infarction in seven pigs. Myocardial infarction was produced in five pigs with occlusion of the artery. DSE was performed with incremental doses with and without an NTG infusion of 50 to 100 microg/min. In the hibernating group, NTG alone improved wall thickening in the hibernating region modestly from 11.4+/-7.2% at baseline to 19.1+/-7.0%. The improvement was associated with increased regional coronary flow from 0.46+/-0.12 to 0.55+/-0.13 mL x beat(-1) x 100 g myocardium(-1) (P<.05). There was an additive effect of NTG to low-dose (2.5 to 5 microg x kg(-1) x min(-1)) dobutamine on wall thickening in the hibernating region. The improvement of wall thickening of hibernating myocardium with NTG and dobutamine, from 23.7+/-11.1% to 31.1+/-8.9% (P<.001), was associated with an increase in regional coronary flow (P<.01). NTG did not prevent high doses of dobutamine from inducing deterioration of wall thickening in hibernating myocardium. In the infarcted group, no improvement in wall thickening was observed in infarcted regions during NTG infusion, dobutamine infusion, or the combination. CONCLUSIONS: NTG enhances the improvement of wall thickening at low-dose dobutamine and does not prevent high-dose dobutamine from inducing ischemia in hibernating myocardium. Thus, NTG augments the biphasic response of wall thickening and improves the accuracy of DSE for detecting viable myocardium.     

Ischemic heart disease and postoperative mortality in major vascular surgery. An up-to-date diagnostic approach

BACKGROUND: The aim of this study is to evaluate the efficacy the dobutamine stress echocardiography in predicting the perioperative cardiac risk of patients undergoing major vascular surgery. METHODS: Seventy-seven consecutive and not selected patients, undergoing a surgical treatment requiring aortic cross clamping, were assessed also with a transthoracic dobutamine stress echocardiography. With electrocardiographic and echocardiographic monitoring ventricular ischemia or wall motion abnormalities, 5 micrograms/kg per min of chlorhydrate dobutamine for 5 minutes were infused, followed by other 10 micrograms/kg per min increased up to 40 micrograms/kg per min. During the last 4 minutes 0.25 mg of atropin were infused increasingly up to 1 mg. RESULTS: Of all these patients, 26 had a stress ischemia but only 4 cases underwent a coronary angiography and only 2 of these underwent a preventive myocardial revascularization. Due to poor cardiac conditions pointed out with the dobutamine stress, 3 patients were not treated surgically. With an aggressive intra- and perioperative monitoring 73 patients underwent a surgical treatment: they were 28 aorto-bifemoral, 3 aorto-aortic grafts, 1 aorto-bisiliac thoraco-abdominal interposition graft, and 20 aorto-bifemoral, 4 aorto-femoral, 1 aorto-aortic thoraco-abdominal, 1 aorto-renal by-pass and 7 aorto-iliac-femoral thromboendoarterectomies. In the postoperative period 4 cardiac ischemic complications and 2 deaths (2.5%) were observed. CONCLUSIONS: According to our personal opinion, stress echocardiography can be considered a test with a excellent feasibility and safety rate, not expensive and with a good reproducibility and reliability. It allowed to predict the cardiac risk in our patients suggesting not only the surgical but also the anesthesiologic and the perioperative therapeutic management.     

Postextrasystolic potentiation and dobutamine echocardiography in predicting recovery of myocardial function after coronary bypass revascularization

BACKGROUND: Identification of viable but hibernating myocardium remains a relevant issue in the current era of myocardial revascularization. Echocardiography can be helpful in detecting reversible contractile dysfunction and optimizing the selection of patients for coronary bypass surgery. METHODS AND RESULTS: Eighty-four consecutive candidates for bypass surgery with chronic multivessel coronary artery disease were screened, and 60 were included in this prospective study. Preoperative evaluation of a reversible contractile dysfunction in asynergic myocardial regions was performed by dobutamine infusion at 5 (low dose) and 10 (intermediate dose) microg x kg(-1) x min(-1) with each stage lasting at least 5 minutes; postextrasystolic potentiation (PESP), with a coupling interval ranging from 500 to 300 ms with a progressive 10-ms decrease; or a combination of both dobutamine infusion and PESP. Sensitivity (92% versus 86%) and predictive accuracy (89% versus 84%) were higher with PESP than dobutamine (P=.009 and P=.001, respectively), but the combination did not improve sensitivity or accuracy. Dobutamine induced ischemic dysfunction in 15% of patients at the intermediate dose; however, the low dose resulted in loss of sensitivity. CONCLUSIONS: PESP echocardiography is a useful and cost-effective method to identify viable myocardium in patients with multivessel coronary disease undergoing revascularization and is more sensitive and accurate than dobutamine infusion.     

Selection of the optimal nonexercise stress for the evaluation of ischemic regional myocardial dysfunction and malperfusion. Comparison of dobutamine and adenosine using echocardiography and 99mTc-MIBI single photon emission computed tomography

BACKGROUND: The mechanisms of action of exercise-simulating and vasodilator stressors support their combination with imaging techniques that evaluate left ventricular function and perfusion, respectively. However, reported accuracies of either pharmacological stress together with two-dimensional echocardiography (2DE) or single photon emission computed tomography (SPECT) of myocardial perfusion are similar. The purpose of this study was to establish the optimal stress for each imaging technique by comparing the results of digitized 2DE and 99mTc-methoxyisobutyl isonitrile (MIBI) SPECT using both dobutamine and adenosine stresses in the same patients and conditions. METHODS AND RESULTS: Ninety-seven consecutive patients without evidence of previous infarction undergoing coronary angiography for clinical indications were studied prospectively. Dobutamine was infused during clinical, ECG, and echocardiographic monitoring in dose increments from 5 to 40 micrograms.kg-1.min-1. Adenosine was infused under the same conditions in doses of 0.10, 0.14, and 0.18 mg.kg-1.min-1. For each protocol, the end points were achievement of peak dose, development of severe ischemia, or intolerable side effects. At peak stress, 20 mCi of MIBI was injected, and SPECT imaging was performed 2 hours later; abnormal poststress images were compared with resting SPECT: Digitized 2DE images were compared qualitatively before, during, and after stress in a cine-loop display. Significant coronary disease (n = 59 patients) was defined by the quantification of > 50% stenosis in a major epicardial vessel. The sensitivity of adenosine 2DE was 58%, less than those of adenosine MIBI (86%, p = 0.001), dobutamine 2DE (85%, p = 0.001), and dobutamine MIBI (80%, p = 0.01). Their respective specificities were 87%, 71%, 82%, and 74% (p = NS). The accuracy of adenosine 2DE was 69%, compared with 80% for adenosine MIBI (p < 0.001), 84% for dobutamine 2DE (p = 0.001), and 77% for dobutamine MIBI (p = 0.005); the latter three did not differ significantly in either sensitivity or accuracy. CONCLUSIONS: This prospective, direct comparison of alternative pharmacological stresses in patients without myocardial infarction shows vasodilator stress scintigraphy and dobutamine stress echocardiography and scintigraphy to share equivalent levels of sensitivity. All three are significantly more sensitive than adenosine stress echocardiography. Dobutamine stress may be used for wall motion or perfusion imaging, but adenosine stress is best combined with perfusion scintigraphy.     

Resection of the metatarsal head for diabetic foot ulcers

Dobutamine-induced hypotension has been disregarded as a marker of more severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 microg/kg per minute) echocardiography was performed in 326 patients with prior myocardial infarction referred for evaluation of myocardial ischemia. A 16-segment, four-grade score model was used to assess left ventricular function. Wall motion score index was derived by summation of wall motion score divided by 16. SBP and heart rate increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/- 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An increase of SBP > or = 30 mm Hg occurred in 50 patients (15%). By multivariate analysis, independent predictors of failure of SBP increase were higher peak wall motion score index (p < 0.001), higher resting SBP (p < 0.01), and medication with calcium channel blockers (p < 0.05). SBP drop > or = 20 mm Hg occurred in 54 patients (17%). Independent predictors of SBP drop were higher resting wall motion score index (p < 0.001), higher resting SBP (p < 0.0001), and older age (p < 0.05). In patients with myocardial infarction, left ventricular function and baseline systolic blood pressure are powerful predictors of SBP response to dobutamine stress testing.