Dobutamine Stress Echo Research Articles

Incremental Benefit of Strain Rate Imaging to the Accuracy of Novice and Expert Interpreters of Dobutamine Stress Echocardiography

Background: Dobutamine stress echo (DbE) is accurate for the detection of coronary artery disease (CAD), but interpretation is subjective and accuracy is dependent on observer experience. Strain rate imaging (SRI) offers a quantitative technique for identification of CAD, but it is unclear whether this could improve the results of less expert readers. Methods: We studied 121 pts (42 female, 64 ± 10 years) who underwent DbE, SRI, and coronary angiography. Segmental peak systolic SR (SR) was measured independently and previously derived cut-offs were applied to categorize segments as normal or abnormal. The accuracy of WMS by novice, experienced and expert readers, and SRI were compared with quantitative coronary angiography (significant CAD = QCA diameter stenosis >50%). Results: The accuracy of WMS by novice (57%, AUC 0.59) and experienced echocardiographers (67%, AUC 0.63) was less than experts in DbE (89%, AUC 0.67, p < 0.0001). By applying a cut-off of <−0.9 s−1, the accuracy of SR in the diagnosis of CAD was 89% (AUC 0.69), which added incremental value to the sensitivity of WMS by experienced readers, and significantly improved the sensitivity and specificity of WMS by novice readers (Table). SRI added specificity to the diagnosis of LAD territory disease by experienced and novice readers (88% versus 80%, p = 0.03, and 62%, p < 0.0001). SRI also improved the sensitivity in the diagnosis of postero-lateral territory disease in experienced and novice readers (86% versus 47%, p < 0.0001, and 41%, p < 0.0001). SRI did not add to the accuracy of expert readers. Conclusion: SRI offers an improvement in accuracy of WMS to less expert echocardiographers.

211 Dobutamine stress echo: concordance between wall motion assessment and non-invasively evaluated coronary flow reserve

Aim: To assess consistency between left ventricular (LV) wall motion modification and coronary flow reserve in the left anterior descending coronary artery (LAD) territory during dobutamine stress-echo (DSE). Methods: 173 patients underwent DSE, according to the standard protocol, for evaluation of known or suspected coronary artery disease and, during the test, LAD flow velocity was measured at baseline and at peak stress. Segmental kinesis was evaluated both for all LV segments then limited to LAD territory (aWMSI). Coronary flow reserve (CFR) was calculated as the ratio between peak stress and baseline maximal diastolic velocity in the distal LAD. In a subgroup of 48 patients, without anterior myocardial infarction (MI), accuracy of non-invasively evaluated RFC was verified with coronary angiography data. Results: Patients were predominantly males (122.71%), mean age was 68±11 years; 69% were hypertensive, 37% diabetics, 46% presented dyslipidemia and 53% were smokers. Fifty-two patients had a recent or previous anterior MI, in 30 treated with primary PCI. Baseline echocardiography showed normal LV internal dimensions (end-diastolic volume index 63±20 ml/m 2 ; endsystolic volume index 34±18 ml/mq), with slightly reduced LV global systolic function (ejection fraction 47±27%). During ESD, both global WMSI then aWMSI resulted significantly and negatively correlated with RFC at baseline, after low dose and high dose dobutamine infusion; a similar correlation was also present between RFC and WMSI changes during high dose infusion, indicating extension of inducible ischemia. After exclusion of patients with anterior MI, these correlations remained significant; in the group with anterior MI, CFR was significantly and negatively correlated only with aWMSI after high dose infusion. Considering the final results of DSE and dividing patients in no or mild ischemia and extensive inducible ischemia (more than three LV segments), there was a significant difference in CFR value between the two groups (1.82 vs 2.26, p<0.001); otherwise presence or absence of viability didn’t influence CFR value. In absence of anterior MI, there was a good agreement between coronary angiography and noninvasively evaluated CFR (1.6 in patients with critical LAD stenosis vs 2.2 in patients with non critical lesions, p<0.05). Conclusion: LAD CFR evaluated during DSE demonstrates a good agreement with both LV segmental kinesis and coronary angiographic data, thus offering an adjunctive tool to improve DSE diagnostic accuracy.

1008 Comparison of diagnostic value of stress real-time myocardial contrast echocardiography and gated single-photon emission computed tomography in patients with suspected coronary artery disease

Background: Real time 3D echocardiography provides fast recording of a complete cardiac volume data set and allows new insights into the heart. However, reduced spatial resolution of the 3D matrix transducers led to impaired assessment of left ventricular wall motion (WM). We compaired 3D stress echocardiography combined with contrast application (CA) for improved endocardial border detection to conventional 2D echo in order to detect significant coronary artery disease. Methods: 17 patients with suspected coronary disease underwent dobutamine stress echo. 3D echo was performed in apical view using a 4S transducer (Sonos 7500, Philips) at low mechanical index (0.5-0.6) with bolus injection of 1.0 ml CA (SonoVue©) at rest and during stress. For 2D echo we used also CA and the conventional mode of 4S transducer. WM of 3D echo was evaluated in off-line mode and c-scan analysis (1 mm slices) and compared to conventional WM analysis in 2D echo. Following echo exam, all patients underwent coronary angiography and stenosis (< or ≥70%) as well as perfusion territory were determined by an experienced examiner. Results: Dobutamine stress increased heart rate (69±12 vs 131±21/min, p<0.001) but not blood pressure (RRsys 126±15 vs 149±37 mm Hg, ns). All 272 segments could be sufficiently evaluated by CA 3D stress echo. Specificity of CA 3D echo was comparable to 2D (97.4% vs 98.7%). However, positive (77.8% vs 70.0%, p<0.001) and negative predictive values were higher in CA 3D stress echo (90.6% vs 85.9%, ns). In particular, detection of ≥70% stenoses in the right and circumflex coronary supplying the inferior and posterior wall could be improved (36.4% abs.). Conclusion: Contrast agent supported real time 3D stress echo improves detection of coronary heart disease especially of the right and circumflex coronary artery supplying the inferior and posterior segments. However, less sensitivity of 2D echo supposes reduced echogenicity of the 4S transducer used in conventional mode and limits the technique.

Clinical, serum cardiac troponin T and echocardiographic evaluation for prediction of late doxorubicin cardiotoxicity

9536 Background: To evaluate whether clinical signs or symptoms of congestive heart failure, serial assessment of systolic and diastolic cardiac function by low dose dobutamine stress echo (LDSE) and serum cardiac troponin T (cTnT) can predict doxorubicin (DOXO) cardiotoxicity. Methods: Twenty five patients with osteosarcoma enrolled in the Brazilian osteosarcoma treatment group study 2000, from january 2000 to may 2004, were studied with LDSE (&gt;5μg/kg/min) before chemotherapy, 160 mg/m2 DOXO and after 160 mg/m2 DOXO. cTnT were measured before and during DOXO infusion. Cardiotoxicity was defined as shortening fraction (SF) less than 30% assessed by rest echo 1 to 6 months off chemotherapy. Group A comprised those without cardiotoxicity (16 patients, 10 male, 14.3 ± 4.7 years) whereas group B included those with a SF &lt; 30% (9 patients, 6 male, 15.4 ± 3 years). Elevated serum cTnT was defined as seric levels above 0.01ng/ml. Results: Patients were submitted to a mean 3.4 LDSE and a mean of 32.5 serum cTnT. One patient (group B) presented clinical manifestation of cardiotoxicity. There was no statistical difference of elevated serum cTnT between the group B and group A (87.5% vs 46.2%; p=0,06). Left ventricular dimensions by M- MODE and transmitral Doppler inflow diastolic parameters were not significantly different between the two groups. Resting SF showed comparable values in both groups until cumulative doses of DOXO reached 160mg/m2, then the resting SF in group B was significant lower than group A (27% ± 2 and 34.1% ± 2, p&lt;0.01). During dobutamine infusion, SF and ΔSF (dobutamine-rest) were significantly lower in group B as compared to group A at a DOXO dose 160mg/m2 (SF 36.1%±3,4 and ΔSF 2.1±2.3 vs. SF 45.2%±4.9 and ΔSF 9.4±3; p&lt; 0.01 and p &lt; 0.01) as well as at a DOXO dose &gt; 160mg/m2 (30.3%±3 and 3.1±1.9 vs. 40.8%±5.9 and 7.2±4.2;p&lt;0.01 and p&lt;0.01). Conclusions: This study suggests that LDSE is more reliable than cTnT and clinical evaluation for predicting future subclinical cardiotoxicity,even at lower doxorubicin dose. No significant financial relationships to disclose.

1157 Dobutamine stress echo in patients treated with beta blockers. New dobutamine atropine protocol

1157 Dobutamine stress echo in patients treated with beta blockers. New dobutamine atropine protocol

1075 Force frequency relationship during dobutamine stress echo predicts response to medical therapy in heart failure patients

1075 Force frequency relationship during dobutamine stress echo predicts response to medical therapy in heart failure patients

Early reduction in left ventricular contractile reserve detected by dobutamine stress echo predicts high-dose chemotherapy-induced cardiac toxicity

Background High-dose chemotherapy (HDC) is utilized in high-risk cancer patients. This type of treatment may induce cardiac toxicity which becomes clinically evident weeks or months after HDC. Hence, the possibility of early identification of patients who will develop cardiac impairment is strategic for its clinical implications. The aim of this study was to identify possible early changes of left ventricular contractile reserve (LVCR) in cancer patients undergoing HDC, as well as to evaluate the relevance of such changes as predictors of chemotherapy-induced cardiotoxicity. Methods In forty-nine female patients scheduled for HDC, due to poor-prognosis breast cancer, dobutamine stress echocardiography (DSE) was performed, before each of the three HDC cycles (C1, C2, C3), and 1, 4, and 7 months after the end of chemotherapy. According to rest left ventricular ejection fraction (LVEF) evaluated within 18 months after HDC (f-LVEF), patients were allocated to Group A (LVEF < 50% and > 10 absolute units reduction) and to Group B (LVEF ≥ 50%). Results Rest LVEF didn't show any significant difference between the two groups except at f-LVEF. Peak LVEF and LVCR significantly decreased in Group A only, starting from C3. At C3, a ≥ 5 units fall in LVCR was found to be predictive for f-LVEF drop below 50%. Conclusions In patients undergoing HDC, low-dose DSE allows the early identification of patients at a high risk of developing cardiac dysfunction.

Complications during pharmacological stress echocardiography: a video-case series

BackgroundStress echocardiography is a cost-effective tool for the modern noninvasive diagnosis of coronary artery disease. Several physical and pharmacological stresses are used in combination with echocardiographic imaging, usually exercise, dobutamine and dipyridamole. The safety of a stress is (or should be) a major determinant in the choice of testing. Although large scale single center experiences and multicenter trial information are available for both dobutamine and dipyridamole stress echo testing, complications or side effects still can occur even in the most experienced laboratories with the most skilled operators.Case presentationWe decided to present a case collection of severe complications during pharmacological stress echo testing, including a ventricular tachycardia, cardiogenic shock, transient ischemic attack, torsade de pointe, fatal ventricular fibrillation, and free wall rupture.ConclusionWe believe that, in this field, every past complication described is a future complication avoided; what happens in your lab is more true of what you read in journals; and Good Clinical Practice is not "not having complications", but to describe the complications you had.

Sustained ventricular tachycardia induced by dobutamine stress echocardiography: A prospective study

To investigate the prognostic significance and electrophysiological characteristics of dobutamine stress echo (DSE)-induced sustained monomorphic ventricular tachycardia (VT). In our department, 3022 DSE studies were carried out on 2688 patients, aged 54.7 +/- 11.8 years, over a 3.5 year period. Patients with DSE-induced VT were studied by means of coronary angiography and electrophysiological testing, and were followed-up for 17.8 +/- 9.3 months. During DSE, nine patients (0.3%) developed sustained monomorphic VT. Four patients had coronary artery disease, one developed spontaneous right coronary artery (RCA) dissection during DSE, one patient had peripartum cardiomyopathy and the remainder had normal coronary arteries. Logistic regression analysis did not identify clinical parameters such as left ventricular ejection fraction, documentation of an ischaemic response or the presence of non-viable myocardial segments during DSE, that could predict the occurrence of DSE-induced VT. Monomorphic VT was inducible by electrophysiological testing in two patients with CAD and reduced LVEF. During follow-up, only these two patients developed VT. Sustained monomorphic VT is a rare complication of DSE, with no predictive value for the identification of patients with coronary artery disease and no prognostic significance in patients with normal coronary arteries. No predictors of its occurrence were identified.

Dobutamine Stress Echo Is Superior to Exercise Stress Testing in Achieving Target Heart Rate among Patients on Beta Blockers

Published guidelines recommend continuing β-adrenergic receptor blockade in patients undergoing stress testing. We evaluated the role of pharmacological versus exercise stress testing in achieving target heart rate (THR) among patients on β-adrenergic blockade. We compared data from 140 patients who underwent dobutamine stress echo (DSE) and 143 patients who underwent exercise treadmill testing (ETT). In both groups, β-adrenergic blocker was continued at the time of stress testing. Overall, patients undergoing DSE achieved THR more frequently than ETT. With β-adrenergic blockade, DSE patients met THR more frequently than ETT patients (p < 0.001). Without β-adrenergic blockade, there was no difference between either modality in achieving THR. In both DSE and ETT patients, absence of β-adrenergic blockade increased the odds of achieving THR [odds ratio (OR): 2.46, p = 0.042 and OR: 7.44, p < 0.001, respectively]. Atropine use with DSE increased the odds of achieving THR (OR: 3.76, p = 0.006). In conclusion, pharmacological stress testing appears to be superior to exercise stress testing in achieving THR among patients on β-adrenergic blockade.

End-systolic pressure/volume relationship during dobutamine stress echo: a prognostically useful non-invasive index of left ventricular contractility

Left ventricular end-systolic pressure-volume relationship (PVR) provides a robust, relatively load-insensitive evaluation of contractility and can be assessed non-invasively during exercise echo. Dobutamine might provide an exercise-independent alternative approach to assess inotropic reserve. The feasibility of a non-invasive estimation of PVR during dobutamine stress in the echo lab and its relationship with subsequent clinical events was assessed. We enrolled 137 consecutive patients referred for dobutamine stress echo. To build the PVR, the force was determined at different heart rate increments during stepwise dobutamine infusion as the ratio of the systolic pressure/end-systolic volume index. The PVR at increasing heart rate was flat-biphasic in 65 and up-sloping in 72 patients: 42 patients underwent surgery and 95 patients were treated medically (median follow-up, 18 months; interquartile range, 12-24). Events occurred in 18 patients (death in eight, acute heart failure in 10); a flat-biphasic PVR was independent predictor of events (RR=10.16, P<0.01). PVR is feasible during dobutamine stress. This index of global contractility is reasonably simple, does not affect the imaging time, and only minimally prolongs the off-line analysis time. It allows unmasking quite different, and heterogeneous, contractility reserve patterns underlying a given ejection fraction at rest. The best survival is observed in patients with up-sloping PVR, whereas flat-biphasic pattern is a strong predictor of cardiac events.

Adjunctive handgrip during dobutamine stress echocardiography: Invasive assessment of myocardial oxygen consumption in humans

Adjunctive isometric exercise in the form of sustained submaximal handgrip (HG) is considered to increase the sensitivity of dobutamine stress echo (DSE) for detection of functionally significant coronary artery disease. The study was undertaken to quantify invasively the impact of HG in humans on hemodynamics and myocardial oxygen consumption (MVO2) during DSE. An invasive hemodynamic evaluation was performed during DSE and with addition of adjunctive HG in 11 subjects. Coronary sinus (CS) blood flow, right-sided and systemic pressures, oxygen saturations, and transthoracic two-dimensional echocardiography were obtained at each 3-min stage and after adding HG at peak DSE. Myocardial oxygen consumption was calculated by the Fick method and circumferential end-systolic wall stress (ESWS) by Mirsky's formula. At peak DSE, heart rate, left ventricular ejection fraction, CS flow, and MVO2 increased, whereas pulmonary capillary wedge pressure (PCWP) and circumferential end-systolic wall stress (ESWS) decreased from baseline. Compared with peak DSE, the addition of isometric HG at peak DSE caused an increase in PCWP (7 +/- 3 vs. 8.4 +/- 3 mmHg, p < 0.05), ESWS (112 +/- 25 x 103 vs. 125 +/- 32 x 103 dyne x s x cm2, p = 0.02), and CS flow (260 +/- 92 vs. 301 +/- 105 ml/min, p < 0.05). There was a minimal increase in left ventricular volumes, heart rate, and systolic blood pressure. The MVO2 increased from 29 +/- 8 ml/min at peak DSE to 31 +/- 9 ml/min with adjunctive HG (p = 0.03). Handgrip adjunctive to peak DSE results in a modest increase in MVO2, primarily by an increase in end-systolic wall stress.

Institutional based assessment of myocardial viability by nitrate augmented Tc99m Sestamibi gated SPECT and low dose Dobutamine stress echo - a comparative study

Institutional based assessment of myocardial viability by nitrate augmented Tc99m Sestamibi gated SPECT and low dose Dobutamine stress echo - a comparative study

Dobutamine Stress Echo and Clinical Symptoms is Superior than Nuclear Stress Testing in Predicting Coronary Artery Disease in Women

Dobutamine Stress Echo and Clinical Symptoms is Superior than Nuclear Stress Testing in Predicting Coronary Artery Disease in Women

Coenzyme Q10 improves contractility of dysfunctional myocardium in chronic heart failure

There is evidence that plasma CoQ(10) levels decrease in patients with advanced chronic heart failure (CHF). To investigate whether oral CoQ(10) supplementation could improve cardiocirculatory efficiency in patients with CHF. We studied 21 patients in NYHA class II and III (18M, 3W, mean age 59 +/- 9 years) with stable CHF secondary to ischemic heart disease (ejection fraction 37 +/- 7%), using a double-blind, placebo-controlled cross-over design. Patients were assigned to oral CoQ(10) (100 mg tid) and to placebo for 4 weeks, respectively. CoQ(10) supplementation resulted in a threefold increase in plasma CoQ(10) level (P < 0.0001 vs placebo). Systolic wall thickening score index (SWTI) was improved both at rest and peak dobutamine stress echo after CoQ(10) supplementation (+12.1 and 15.6%, respectively, P < 0.05 vs placebo). Left ventricular ejection fraction improved significantly also at peak dobutamine (15% from study entry P < 0.0001) in relation to a decrease in LV end-systolic volume index (from 57 +/- 7 mL/m(2) to 45 mL/m(2), P < 0.001). Improvement in the contractile response was more evident among initially akinetic (+33%) and hypokinetic (+25%) segments than dyskinetic ones (+6%). Improvement in SWTI was correlated with changes in plasma CoQ(10) levels (r = -0.52, P < 0.005). Peak VO(2) was also improved after CoQ(10) as compared with placebo (+13%, <0.005). No side effects were reported with CoQ(10). Oral CoQ(10) improves LV contractility in CHF without any side effects. This improvement is associated with an enhanced functional capacity.

First 100 Dobutamine Stress Echocardiography in Medicare National Hospital, Nepal

In patients with known or suspected CAD, diagnosis and risk stratification can be aided by non-invasive tests for myocardial ischemia. The scientific use of stress echo, started twenty years ago and for at least a decade, it has been considered a method of established usefulness. Medicare National Hospital, Kathmandu introduced stress echo, in June 2003 and has performed over 140 stress echo. so far, out of which 130 are dobutamine stress echo. The data of first 100-dobutamine-stress echo. were analyzed and presented.

Noninvasive assessment of coronary flow velocity reserve in left anterior descending artery adds diagnostic value to both clinical variables and dobutamine echocardiography: a study based on clinical practice

Our objective was to evaluate, in clinical practice, whether noninvasive assessment of coronary flow velocity reserve in left anterior coronary artery adds diagnostic information to both clinical variables and wall motion abnormalities derived from dobutamine stress echocardiography. We studied 130 patients who were scheduled for coronary angiography after undergoing dobutamine stress echocardiography. The same day, flow in left anterior descending artery was detected by transthoracic Doppler echocardiography. A Doppler signal of left anterior descending artery was detected in 110 patients (85%). We identified significant left anterior descending artery stenosis (>50% diameter stenosis) in 42 patients. Sensitivity and specificity of abnormal coronary flow velocity reserve (<2) to detect left anterior descending artery stenosis were 86% and 57%, respectively. Wall motion abnormalities had a sensitivity and specificity of 52% and 82%. After forcing the clinical and dobutamine stress echo variables into a regression model with three modeling steps, an abnormal coronary flow velocity reserve provided incremental information in predicting significant left anterior descending artery stenosis. An abnormal coronary flow velocity reserve by transthoracic Doppler echocardiography adds diagnostic value to both clinical data and variables derived from dobutamine stress echo to detect significant left anterior descending artery stenosis.

Stress echo in chest pain unit: the SPEED trial

Background Emergency room (ER) evaluation of patients with acute chest pain and non-diagnostic electrocardiography (ECG) remains a frequent and difficult problem. Aim To assess safety and prognostic implications of pharmacological stress echocardiography in the ER chest pain unit (CPU). Methods A total of 552 patients (321 males, age 58±12.6 years) with acute chest pain, negative serial enzymes and/or troponin, and ECG recordings, and normal/unchanged resting left ventricular function were prospectively enrolled and underwent pharmacological (dipyridamole or dobutamine) stress echo. Six echo labs that had passed the preliminary quality control for stress echo reading entered the study. Follow-up was obtained in all patients after a median period of 13 months. Results No significant adverse events were observed during the test. Stress echocardiography was negative in 502 patients (91%) and positive in 50 (9%). The 502 patients with negative stress echocardiography were discharged with no or unchanged anti-ischemic medications. While the 50 patients with positive stress echo were admitted to the coronary care unit, 44 of these underwent coronary angiography with the result that 42 out of 44 showed significant coronary artery disease. There were 45 events in the follow-up: six in the 502 patients with negative and 39 in the 50 patients with positive stress echo (1.2% vs. 78%, p<0.001). The negative predictive value of stress echocardiography was 98.8% for all events and 99.6% for hard events. Conclusions Stress echocardiography is a feasible, safe, and effective tool for early stratification of patients admitted to the ER with acute chest pain and non-ischemic ECG and resting echo.

1151-145 Accuracy of strain rate techniques for identification of viability at dobutamine stress echo: A follow-up study after revascularization

Background. Myocardial viability (VM) assessment based on wall motion scoring (WMS) with dobutamine echo (DbE) is difficult and subjective. New quantitative techniques such as strain rate imaging (SRI) correspond with isotopic techniques but their ability to predict functional recovery (FR) after revascularization is unclear. Methods. Stable post-MI pts (n=43, age 63±9, EF 36±6%) underwent SRI during DbE. WMS evidence of VM was based on lowdose augmentation at DbE. SR, end-systolic strain (ESS), post-systolic strain (PSS) and timing were analyzed at rest and low dose in abnormal segts. Pts were followed for 9±12 months; FR was defined as segt improvement on post-revascularization images. Results: Of 180 segts with abnormal resting function, 83 showed FR and 97 did not. Resting parameters were not predictive of recovery; resting post-systolic shortening had a sensitivity and specificity 0.6), SR increment (0.5±0.5 vs 0.1±0.6/s, p 0.23), ESS (11.6±9.2 vs 4.7±9.3, p 8.5), ESS increment (4.9±9.9 vs 0.7±6.2, p 3.4) and time to ES (0.31±0.9 vs 0.38±0.09, p<0.001, cutoff <0.32). Sensitivity and specificity of quantitative parameters were comparable to WM analysis (Table). Conclusions. SR and strain responses to DbE are a feasible marker of viability, comparable to WM assessment.

728 Force-frequency relationship during dobutamine stress echo: noninvasive exercise-independent assessment of left ventricular contractility

728 Force-frequency relationship during dobutamine stress echo: noninvasive exercise-independent assessment of left ventricular contractility