Myocardial Stunning and Unique ECG Changes Associated with Dobutamine Stress Echocardiography

The clinical, electrocardiographic, and echocardiographic changes associated with myocardial stunning during dobutamine stress echocardiography in a patient with severe left main coronary artery disease are presented.     

Long-Term Follow-Up and Dobutamine Stress Echocardiography of 19-mm Prosthetic Heart Valves

BACKGROUND: In patients with a small aortic root, the use of 19-mm valve prostheses for valve replacement is controversial because of the small orifice area of these valves. METHODS: To assess stress hemodynamics in patients with 19-mm valve prostheses, to find predictors of unfavorable hemodynamics, and to document the long-term follow-up, we examined 30 patients (age, 64 +/- 19 years; 27 women and 3 men; follow-up, 38 +/- 50 months) clinically and with the use of dobutamine stress echocardiography. A history was taken, and a physical examination was performed. At rest and during dobutamine stress, Doppler echocardiography was performed. RESULTS: At rest, transprosthetic gradients were moderately elevated with mean and peak gradients of 15 +/- 7 and 32 +/- 14 mmHg, and effective orifice areas were small (0.91 +/- 0.31 cm(2)). Gradients rose markedly during stress (mean, 37 +/- 14 mmHg; peak, 83 +/- 41 mmHg). Predictors of high transprosthetic gradients were larger body surface area, younger age, and valve type. Mean and peak gradients were lower with St. Jude Medical Hemodynamic Plus valves than with standard St. Jude Medical (P < 0.05) and other valves, and the effective orifice area was highest (1.07 +/- 0.29 cm(2); P < 0.05 versus standard St. Jude Medical) in this valve model. Sixty percent of patients developed significant dynamic subvalvular or intraventricular gradients (84 +/- 41 mmHg) during dobutamine stress. CONCLUSIONS: After aortic valve replacement with 19-mm prostheses in patients with a small aortic root, dobutamine stress leads to high transvalvular gradients, which are dependent on valve model, age, and body surface area. In addition, 60% of patients develop significant dynamic outflow obstructions. These findings and the persistence of some degree of exercise-induced symptoms in 70% of patients suggest that alternative surgical techniques should be considered if the size of the aortic annulus demands a 19-mm valve, especially if the patient seeks physical activity, is young, or is of larger body size.     

Changes in Systolic and Diastolic Function Indexes Throughout Dobutamine Stress Echocardiography in Healthy Volunteers and Patients with Ischemic Heart Disease

BACKGROUND AND HYPOTHESIS: Dobutamine stress echocardiography is a well-established diagnostic method for investigating patients with suspected ischemic coronary disease. A positive test result is based on systolic parameters, but left ventricular filling parameters also are affected by myocardial ischemia. The aim of the present study was to study changes in both systolic and diastolic left ventricular variables throughout the test, including the period following it. METHODS AND RESULTS: Seven healthy control subjects (group I), 10 patients with chest pain but without significant coronary stenosis (group II), and 17 patients with significant coronary stenosis (group III) were entered in the study. Dobutamine stress echocardiography was performed according to a preset standardized protocol. Two-dimensional echocardiography and transmitral pulsed-Doppler images were stored for later analysis at rest, low dose, peak dose, and 5 minutes after termination of the dobutamine infusion. The wall motion score index increased from rest to low dose by 6.7% +/- 6.4% (P < 0.05) and to the peak dose by 39.1% +/- 9.9% (P < 0.001) in all three groups. The increase from rest to peak dose was significantly higher in groups I and II than in group III (P < 0.01). There was a significant increase in the atrial velocity-time integral (A-VTI) at peak dose in groups I and II (64.8% +/- 52.1% and 103.8% +/- 68.7%, respectively; P < 0.05 and <0.001), but no change in group III was noted. At the peak dose, A-VTI was significantly greater in groups I and II than in group III (P < 0.05). Among the 17 patients with proved coronary stenosis, 15 (88.2%) had a positive systolic response and 14 (82.3%) had a positive diastolic response, expressed as an A-VTI increase of 相似文献   

The Risk of Adverse Events Associated With Atropine Administration During Dobutamine Stress Echocardiography in Cardiac Transplant Patients: A 28-Year Single-Center Experience

BackgroundAlthough dobutamine stress echocardiography (DSE) is performed in heart transplant patients, the safety profile of atropine administration in DSE in this setting is unclear.Methods and ResultsWe identified heart transplant patients who received atropine during DSE from January 1984 to August 2011 at our institution and compared them with a propensity-scored matched control group of heart transplant patients who underwent DSE without atropine. Adverse events were defined as significant arrhythmias (sinus arrest, Mobitz type II heart block, complete heart block, ventricular tachycardia, or ventricular fibrillation), hypotension requiring hospitalization, syncope or presyncope, myocardial infarction, and death. Forty-five heart transplant patients (median age 62 years, 82% male) received 0.2–1 mg atropine during DSE. Of these, 1 patient (2.2%) developed temporary complete heart block. No adverse events were identified in the control group of 154 patients who received dobutamine without atropine.ConclusionsOur findings suggest that complete heart block can occur infrequently with the administration of atropine in heart transplant patients undergoing DSE. Therefore, patients should be appropriately monitored for these adverse events during and after DSE.     

The Contribution of the Left Atrioventricular Plane Displacement During Low Dose Dobutamine Stress Echocardiography in Predicting Recovery of Left Ventricular Dyssynergies

The aim of this study was to assess the significance of the left systolic atrioventricular (AV) plane displacement during low dose dobutamine stress echocardiography (DSE), in predicting the recovery of left ventricular dyssynergies after revascularization. In 30 infarctiers with left ventricular dysfunction scheduled for RE (14 percutaneous transluminal coronary angioplasty and 16 coronary artery bypass graft) and in 25 age- and sex-matched healthy subjects, a DSE, using a 16 ventricular segment model and a four-grade scoring system for the assessment of regional wall motion of the left ventricle was performed. Prior and during DSE, the left systolic AV plane displacement was recorded from the apical four- and two-chamber views, by M-mode echo, at four left ventricular sites, corresponding to the septal, lateral, anterior, and inferior walls, both in patients and controls. The study was repeated in all patients 101 +/- 14 days after successful revascularization. Healthy subjects showed a significant increase of left systolic AV plane displacement at all left ventricular sites during dobutamine infusion (DI) (P < 0.001). Patients also exhibited a significant maximum increase of left systolic AV plane displacement during DSE only in the dyssynergic sites with functional improvement in the postrevascularization echocardiogram (P < 0.001). In the remaining dyssynergic sites, without functional improvement after revascularization, the left systolic AV plane displacement did not change (P > 0.05). Selecting a maximum LAVPD increase of >2 mm at any site of the left ventricule to predict recovery of the regional ventricular dyssynergies, results in a sensitivity of 91%, specificity of 83%, positive predictive value of 88%, and negative predictive value of 87%. When two-dimensional DSE was used for the detection of reversible dysfunction, sensitivity and specificity were found to be 81.5% and 87.5%, respectively, while the positive and negative predictive values were 90% and 78%, respectively. When the two methods were in agreement the sensitivity was 90%, the specificity 100%, and the positive and negative predictive values were 100% and 84.2%, respectively. The assessment of left systolic AV plane displacement during DI constitutes a new, simple, and accurate method in the prediction of left ventricular dyssynergy recovery after revascularization. The combination of this method and two-dimensional DSE are basic predictor markers of viability of dysfunctional myocardium. (ECHOCARDIOGRAPHY, Volume 13, November 1996)     

Impact of Age on the Safety and the Hemodynamic Response Pattern During High Dose Dobutamine Echocardiography

Background: The purpose of the present study was to assess the safety and hemodynamic response of high dose dobutamine echocardiography (DE) in different age groups. DE is frequently used in the diagnosis of coronary artery disease; its safety in very elderly patients is not established, and there are no standards for blood pressure and heart rate response. Methods and Results: The test was performed using up to 50 μg/kg/min in 400 patients: 164 middle-aged (age < 65 years), 187 elderly (age, 65–79 years), and 49 very elderly (age ≥ 80 years). It was stopped because of side effects in 91 (23%) patients. Serious side effects occurred in 1.5% of the patients. There was a significant (60%± 35%) increase in heart rate, and a modest (10%± 19%) increase in the blood pressure (P <.001). The change in heart rate was similar in the three age groups, but there was a blunting of the blood pressure response with age. Hypotension was related to ischemia only in the very old. Conclusions: High-dose dobutamine is safe in all age groups. Dobutamine induces mainly a chronotropic and less a hypertensive response. The chronotropic response of the very old is similar with that of younger patients, but the hypertensive response is blunted in this group .     

Regional Diastolic and Systolic Function by Strain Rate Imaging for the Detection of Intramural Viability during Dobutamine Stress Echocardiography in a Porcine Model of Myocardial Infarction

The aim of this study was to evaluate diastolic and systolic strain rate measurements for differentiation of transmural/nontransmural infarction during dobutamine stress echocardiography (DSE). An ameroid constrictor was placed around the circumflex artery in 23 pigs inducing chronic vessel occlusion. Five pigs without constrictor served as controls. During high‐dose DSE systolic strain rates (SR_sys), systolic and postsystolic strain values (?_sys, ?_ps) and early and late diastolic strain rates (SR_E and SR_A) were determined. At week 6, animals were evaluated regarding myocardial fibrosis. Histology revealed nontransmural in 14 and transmural infarction in 9 animals. In controls, dobutamine induced a linear increase of SR_sys to 12.3 ± 0.4 s^?1 at 40 μg/kg per minute (P = 0.001) and a linear decrease of SR_E to ?6.6 ± 0.3 s^?1 (P = 0.001). In the nontransmural group, SR_sys, ?_sys, ?_ps at rest, and during DSE were higher and SR_E was lower than in the transmural infarction group (P = 0.01). Best predictors for viability were SR_sys (ROC 0.96, P = 0.0003), SR_E at 10 μg/kg per minute dobutamine stimulation (ROC 0.94, P = 0.001) and positive SR values during isovolumetric relaxation at 40 μg/kg per minute dobutamine (ROC 0.86, P = 0.004). The extension of fibrosis correlated with SR_sys at rest, ?_sys at rest, and SR_E at rest (P < 0.001). For the detection of viability similar diagnostic accuracies of SR_E and SRsys were seen (sensitivity 93%/93%, specificity 96%/94%, respectively). Diastolic SR analysis seems to be equipotent for the identification of viable myocardium in comparison to systolic SR parameters and allows the differentiation of nontransmural from transmural myocardial infarction with high diagnostic accuracy. (Echocardiography 2010;27:552‐562)     

Impact of Beta Blockers on Dobutamine-Atropine Stress Echocardiography

Dobutamine increases oxygen demand in the myocardium and is used in conjunction with echocardiography to detect coronary artery disease. Beta blockers (BB) are partial antagonists of dobutamine and, therefore, offset dobutamine effects. Still, the impact of BB therapy on dobutamine stress echocardiography is not clear. One hundred forty-one dobutamine-atropine echocardiographic studies have retrospectively been analyzed: 27 patients were on BB (19%; group I); and 114 off BB (81%; group II). Coronary angiography was performed in a similar percentage of patients (97% and 85%, respectively; P = NS). No differences in clinical and angiographic profile were found between the groups. Sensitivity (83% vs 71%; P = NS) and specificity (100% vs 95%; P = NS) for coronary artery disease were similar in both groups. Atropine was infused more frequently to patients from group I (67% vs 46%; P = 0.04). Limiting side effects and prolonged ischemia presented with the same frequency in both groups. When the dobutamine test was positive, severe extent of ischemia appeared more often in patients from group I than in patients from group II (66% vs 33%; P = 0.03). The majority of patients from group I (55%) with severe extent of ischemia and only 12% from group II received atropine (P = 0.02). No differences were found in dobutamine time and extent of ischemia in patients from group I who had a positive response to dobutamine. On the contrary, patients from group II with one vessel disease had a dobutamine time longer (10.5 +/- 3.8 vs 7.8 +/- 3.7 min; P < 0.05) and extent of ischemia smaller (1.8 +/- 0.4 vs 2.6 +/- 0.5 segments; P < 0.05) than patients from group II with multivessel disease. We conclude that: 1) sensitivity of dobutamine-atropine echocardiography for diagnosis of coronary artery disease remains even if patients are on BB; 2) patients with significant coronary artery disease who are taking BB often develop severe myocardial ischemia during dobutamine-atropine stress echocardiography; and 3) BB therapy precludes stratification of a positive echocardiographic response. These conclusions should be confirmed in a prospective study to be considered as definitive. (ECHOCARDIOGRAPHY, Volume 13, July 1996)     

Usefulness and Limitation of Dobutamine Stress Echocardiography to Predict Acute Response to Cardiac Resynchronization Therapy

Background: It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT. Methods: Fifty-one consecutive patients with advanced heart failure, LV ejection fraction ≤ 35%, QRS duration > 120 ms, and intraventricular asynchronism ≥ 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a ≥15% increase in LV stroke volume. Results: The average of viable segments was 5.8 ± 1.9 in responders and 3.9 ± 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT. Conclusion: Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy. (Echocardiography 2010;27:50-57)     

Reproducibility of the Dobutamine-Atropine Echocardiography Stress Test

To assess the reproducibility of dobutamine-atropine echocardiography testing, two studies (1 to 20 days apart [mean 3.3 days]) were performed in 23 patients with stable effort angina pectoris or chest pain. During the study, 20 (87%) patients were receiving beta blockers alone or combined with nitrates or calcium antagonists. Dobutamine was infused at doses of 10 μg/kg per minute every 3 minutes up to a maximum of 40 μg/kg per minute and this maximal dose was continued for 6 minutes. In patients not achieving 85% predicted maximal heart rate or myocardial ischemia, atropine (0.25–1 mg) was added and dobutamine continued for another 3 minutes, until either an adequate heart rate was achieved or the test was considered positive. During dobutamine infusion, electrocardiographic, echocardiographic, and blood pressure monitoring were obtained in each patient. Side effects including tremor, nausea, palpitation, dizziness, headache, and nonsustained ventricular tachycardia occurred in three patients. The same symptoms, but no ventricular tachycardia, developed during the same stage of the second test. Angina pectoris (eight patients), electrocardiographic changes (six patients), and ischemic wall-motion abnormalities (six patients) were observed at the same stage of the two tests. The mean values of heart rate, blood pressure, and rate-pressure product were comparable for each stage in duplicate tests. Our data show that pharmacological stress echocardiography using dobutamine-atropine has good reproducibility and provides a useful tool for assessing disease progression and the effects of therapeutic interventions in patients with coronary artery disease.     

Normal Coronary Angiogram and Dobutamine-Induced Left Ventricular Obstruction During Stress Echocardiography: A Higher Hemodynamic Responsiveness to Dobutamine

This study assessed the clinical or echographic factors predisposing to dynamic left ventricular obstruction (LVO) during dobutamine echocardiography (DE) in patients with angina-like chest pain but without coronary artery disease (CAD). DE is an effective technique for the noninvasive diagnosis of underlying CAD. During DE, an LVO is not unusual in ischemic patients. METHODS: DE (5-40 microg/kg/min) was performed in 52 consecutive patients with angina-like chest pain and normal coronary angiogram. Mean (standard deviation) age was 61 +/- 10 years (27 men, 25 women). Dobutamine-induced LVO was defined as a new intracavitary flow acceleration of at least 3 msec in the left ventricle. RESULTS: Dynamic LVO was observed during DE in 20 (38%) of the 52 patients and was not related to clinical or baseline echocardiographic parameters. The chronotropic response and the systolic blood pressure during DE were higher in the group with LVO (P < 0.03 and P < 0.05, respectively). Appearance of chest pain during the test was also more frequent when LVO occurred (P < 0.02). CONCLUSION: Dynamic LVO is common during DE in a population of patients with angina-like chest pain without epicardial CAD and is associated with a higher hemodynamic responsiveness to dobutamine.     

Left Ventricular Apical Thrombus and Myocardial Viability: A Dobutamine Stress Echocardiographic Study

The objective of this article was to determine whether the presence of left ventricular apical thrombus is a marker of nonviable myocardium. Reduced coronary blood flow secondary to atherosclerosis may result in chronic reversible left ventricular wall-motion abnormalities. Severe regional abnormalities also predispose to formation of left ventricular thrombus. The relationship between left ventricular apical thrombus and myocardial viability has not been previously described. Eighty patients with coronary artery disease and chronic left ventricular dysfunction were studied by dobutamine stress echocardiography. Left ventricular apical thrombus was identified using echocardiographic criteria. Wall-motion analysis was performed using a standard 16-segment model and ejection fraction was calculated. As a result, 48 patients (60%) had definite or highly suspicious findings for left ventricular thrombus (group 1), and 32 patients (40%) had no thrombus (group 2). Group 1 had significantly higher composite (  54.0 ± 5.8 vs 43.3 ± 6.4  ) and apical (  6.0 ± 2.7 vs 12.4 ± 3.4  ) wall-motion scores compared to those in group 2 (  P = 0.01  ). Thirty-two patients (67%) in group 1 demonstrated no contractile reserve in the apical segments, consistent with lack of viability, versus eight patients (25%) in group 2 (  P = 0.0003  ). The number of viable apical segments per patient was significantly less in group 1 (  0.7 ± 1.2  ) versus group 2 (  1.8 ± 1.3  ) (  P = 0.01  ). Left ventricular apical thrombus is more likely to be present when there is absence of myocardial viability in the corresponding segments.     

急性心肌梗塞后应用多巴酚丁胺负荷超声心动图对心肌存活性的研究

本文目的应用多巴酚丁胺负荷超声心动图研究急性心肌梗塞后梗塞区域心肌存活性。选择36例急性心肌梗塞患者，用5μg／kg·min多巴酚丁胺静脉滴注，体表超声心动图于用药前后对比观察梗塞区域心肌室壁运动和收缩期增厚率（T％），识别心肌存活性。36例患者分为576段心肌，基础状态下94段心肌运动消失，T％为0。静注5μg/kg·min多巴酚丁胺后，94段心肌中30段心肌恢复或部分恢复运动，T％增加121～60．0％。结果提示94段运动消失的心肌中30段（31．9％）具有存活性。表明多巴酚丁胺负荷超声心动图对急性心肌梗塞后存活心肌的识别是安全、可靠的，具有十分重要的临床意义。     

The Role of Optical Coherence Tomography in Clarifying the Mechanisms for Dobutamine Stress Echocardiography‐Induced Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy is a clinical disorder characterized by a transient dilatation and akynesis or dyskinesis of the left ventricular (LV) apex, mimicking an anterior wall acute myocardial infarction in the absence of significant coronary artery disease (CAD). It typically occurs during an episode of severe emotional or physical stress. Recent reports suggested the potential of dobutamine stress echocardiography (DSE) in inducing the aforementioned syndrome. The transient dysfunction of the LV does not fit any known coronary distribution. Furthermore, there is no obstructive CAD demonstrated at angiography to account for the observed dysfunction. Consequently, the pathophysiology of this syndrome is still undetermined. Here, we report a case of DSE‐induced Takotsubo cardiomyopathy in which high‐resolution intracoronary imaging was utilized to exclude possible vessel alterations to help provide potential mechanistic explanations for the development of this condition.     

Evaluation of Longitudinal Tissue Velocity and Deformation Imaging in Akinetic Nonviable Inferobasal Segments of Left Ventricular Myocardium by Dobutamine Stress Echocardiography

Aim: To study tissue velocity imaging (TVI) and strain rate imaging (SRI) indices in akinetic nonviable and normal left ventricular (LV) inferobasal segment and effect of dobutamine infusion on these indices in nonviable segments. Methods: The study population consisted of two groups: 25 patients (mean age 60.75 ± 8.69 years) with left ventricular akinetic inferobasal nonviable segment determined by dobutamine stress echocardiography (DSE) and 14 normal coronaries (mean age 56.67 ± 11.90 years) with normal echocardiography as control group. The following TVI and SRI parameters were measured in patient and control group: ejection phase velocity (Sm [cm/sec]), peak systolic strain (ST [%]), and strain rate (SR [per second])). Results: Ejection fraction was significantly lower in patient group (29.40%± 5.46% vs. 55.00%± 3.39%; P < 0.001). Several differences were observed in patients with nonviable inferobasal segments compared to control group: Sm was reduced (3.58 ± 1.08 cm/sec vs. 5.56 ± 1.28 cm/sec; P < 0.001); SR and ST were significantly decreased (−0.39 ± 0.20/second vs. −1.44 ± 0.64/second, and −3.86%± 4.12% vs. −17.64%± 7.44%, respectively; P < 0.001 in both). The range of SR for nonviable segments (−0.04 to −0.77/second) did not overlap with that of the normal segments (−0.80 to −3.0/second). This range for Sm and ST overlapped with those of the normal segments. Conclusion: All TVI and SRI parameters are reduced in akinetic nonviable inferobasal compared with normal segments. According to findings of this study, resting strain rate has a potential to discriminate nonviable inferobasal from normal segments.