Comparison of squatting stress echocardiography and dobutamine stress echocardiography for the diagnosis of coronary artery disease

Background: Dobutamine stress echocardiography (DSE) is commonly used for the diagnosis for coronary artery disease (CAD). We previously demonstrated that squatting induces wall motion abnormalities (WMA) in areas subtended by stenotic coronary arteries. Objective: This study was designed to test the hypothesis that dobutamine and squatting stress echocardiography are equally useful for the diagnosis of CAD. Methods: We studied 39 patients who were scheduled to have coronary angiography for the evaluation of chest pain. Each patient had squatting stress echocardiography followed by DSE. For squatting stress echocardiography the echocardiogram in standard views was recorded in the standing position. The procedure was repeated during squatting for 2 minutes. Dobutamine echocardiography was performed using standard protocol. The squatting and dobutamine stress echocardiograms were interpreted by an observer blinded to the results of coronary angiography. Results: During squatting, new or worsening WMA developed in 20 patients. Six patients developed WMA in the left anterior descending artery territory, three in circumflex territory, three in the right coronary artery territory, and eight in multiple coronary territories. The sensitivity, specificity, and accuracy of squatting echocardiography for diagnosis of CAD were 95%, 94%, and 94%, respectively. For DSE, the sensitivity, specificity, and accuracy for the diagnosis of CAD were 85%, 94%, and 90%, respectively. There was no significant difference between squatting and dobutamine stress echocardiography for the diagnosis of CAD (P = 0.702). Conclusion: These data indicate that squatting and dobutamine echocardiography are equally useful in the diagnosis of CAD. In selected patients, squatting echocardiography may be used in place of dobutamine echocardiography for the diagnosis of CAD. (Echocardiography 2012;29:695–699)     

Effect of loading conditions on Doppler-derived transmitral flow indices in normal subjects and patients with coronary artery disease

The influence of alterations in preload and afterload on left ventricular diastolic filling using echocardiography was examined in nine normal volunteers (NLS) and nine patients (PTS) with coronary artery disease. The sequential interventions used were handgrip to increase afterload, nitroglycerin to decrease preload, and nifedipine to decrease afterload. Transmitral flow was measured using pulsed-Doppler echocardiography. Measurements were made pre- and post interventions. With increase in afterload using handgrip, the A and E wave velocities and the A/E ratio increased in both groups: 0.62 +/- 0.14 versus 0.86 +/- 0.17 in NLS; 0.75 +/- 0.45 versus 0.84 +/- 0.50 in PTS (P less than 0.05). Following administration of nitroglycerin to reduce preload, the A wave velocities increased, the E wave velocity decreased in both groups, and the A/E ratio increased 0.57 +/- 0.11 versus 0.67 +/- 0.13 in NLS; 0.78 +/- 0.40 versus 0.91 +/- 0.44 in PTS (P less than 0.05). Following use of nifedipine, the A and E wave velocities decreased in both groups with an increase in the A/E ratio in the patient group 0.83 +/- 0.13 versus 0.89 +/- 0.11 (P = NS). Thus, both normal subjects and patients with coronary artery disease had similar changes in Doppler-derived indices of left ventricular filling following interventions that changed left ventricular preload and afterload.     

Prognostic value of dobutamine echocardiography in elderly patients with suspected coronary artery disease and an abnormal resting electrocardiogram

The prognostic value of dobutamine stress echocardiography (DE) in elderly patients over 70 years of age with suspected coronary artery disease (CAD) and an abnormal electrocardiogram (ECG) at rest has not been well documented. We investigated 158 consecutive outpatients (97 men) aged 76 +/- 4 years presenting with right bundle branch block with or without a left anterior hemiblock (41%), left bundle branch block (23%), or repolarization abnormalities (36%). The basic clinical and echocardiographic data were analyzed and correlated with the DE results. The patients were followed for a mean of 24 +/- 13 months. Twenty-three (14.5%) patients presented with a nonfatal cardiac event (CE). According to univariate analysis, the parameters associated with the onset of a CE included arterial hypertension, angina pectoris, anti-angina therapy, the presence of calcifications on the aortic valve and the ascending walls of the aorta, and the presence of segmental-contraction abnormalities of the left ventricle (LV) at rest during echocardiography. According to a Cox regression model, the only independent predictive parameter for the onset of a CE was the appearance of segmental-contraction abnormalities of the LV and their severity during peak dose administration during DE (odds ratio [OR] = 2.58, P < 0.001). This parameter remains independent when spontaneous CEs (myocardial infarction and unstable angina) were considered as endpoints (OR = 2.31, P < 0.001). Conclusions: DE is a safe and reliable method for investigating CAD in patients over 70 years of age with an abnormal resting ECG. In our study, the most predictive independent parameter for the onset of a CE was the appearance of segmental-contraction abnormalities of the LV and their severity during DE.     

Use of dobutamine echocardiography for cardiac risk stratification of patients with chronic renal failure

OBJECTIVES: This study sought to define the value of dobutamine echocardiography (DbE) for cardiac risk stratification in patients with chronic renal failure (CRF). DESIGN: Outcome study correlating results of DbE with late cardiac events in patients with CRF. SETTING: Academic medical centre. SUBJECTS: All patients with CRF (serum creatinine > 2.5 mg dL-1) undergoing DbE were studied; we analysed 193 consecutive patients (aged 63 +/- 13 years, 73 men). INTERVENTIONS: A standard dobutamine-atropine stress was administered until attainment of peak dose, or the development of severe ischaemia or side-effects. The electrocardiogram (ECG) and echocardiogram were obtained before, during and after stress. Ischaemia was identified by new or worsening wall-motion abnormalities with stress. OUTCOME MEASURES: Patients were followed up after 38 +/- 14 months for cardiac death, myocardial infarction or coronary disease progression requiring revascularization. RESULTS: DbE demonstrated ischaemia in 36 patients (19%), scar in 36 (19%) and a normal study in 121 patients. The heart-rate response to dobutamine was submaximal (< 85% age-predicted heart rate) in the absence of wall-motion abnormalities in 69 patients (36%), 54 of whom completed the protocol. Follow-up data were complete in 191 patients (99%); cardiac events occurred in 33 patients (17%), including 17 with cardiac death, 7 with infarction, and 9 requiring late revascularization. Spontaneous events occurred in 7 patients with ischaemia, 3 with scar (8%), 11 with a nondiagnostic study (16%) and 3 patients with a normal study (6%). Over the entire follow-up, the event-free survival in patients with ischaemia (66%) was markedly lower than those without ischaemia (84%, P = 0.006). However, the event rate in patients with nonischaemic responses increased from 8% to 16% between 24 and 40 months, and whilst ischaemia was an independent predictor of outcome at 24 months, it was not at 40 months. CONCLUSIONS: In patients with CRF, the identification of ischaemia at DbE is associated with a significant risk of adverse cardiac events. Patients with nonischaemic scans have a low frequency of events over short-term follow-up, but this increases at later follow-up. These later events may reflect progressive coronary disease, attributable to the atherogenic milieu of these patients, and imply that repeated testing may be required to maintain cardiac risk stratification in patients with CRF.     

Stress Doppler echocardiography using dobutamine in coronary patients with and without ischaemia induction.

To examine the effects of dobutamine on pulsed-Doppler left ventricular ejection dynamics and its utility for evaluation of coronary disease (CAD) we studied 10 patients with normal coronaries (Group 1) and 24 patients with significant CAD (greater than or equal to 70% diameter stenosis) using a graded stress infusion (5 to 20 micrograms.kg-1.min-1). Two-dimensional echocardiography was performed to detect regional asynergy and analysed using an 11-segment model. Patients with CAD were divided into those with (Group 3, n = 14) and without (Group 2, n = 10) inducible ischaemia; six patients had reversible involvement of greater than or equal to three segments (subset 3A). Groups were well matched for baseline left ventricular function and all studies were carried out while the patients were not taking cardioactive therapy. Hyperkinetic wall motion was typical and exaggerated hyperkinesis of normal segments was commonly seen in those with baseline (n = 9) or reversible asynergy (n = 14). Normals and CAD patients showed comparable changes in heart rate and blood pressure (P = NS between groups).(ABSTRACT TRUNCATED AT 250 WORDS)     

老年人慢性肾功能不全对冠心病预后的影响

目的探讨慢性肾功能不全对冠心病临床表现及预后的影响。方法收集2006年6月至2007年12月明确诊断冠心病的老年患者142例,根据是否合并慢性肾功能不全分组,对比临床特点和冠状动脉病变情况,随访心血管事件发生情况。结果 (1)慢性肾功能不全的冠心病患者与对照组比较,高血压发病率高(79.6%vs59.1%,P0.05)、左室射血分数低〔(50.6%±9.5%)vs(54.8%±6.2%),P0.01〕、室间隔厚度增加〔(12.2±0.9)mmvs(11.5±0.6)mm,P0.001〕。(2)慢性肾功能不全组与对照组比较,三支病变多(69.4%vs31.8%,P0.001),多处钙化病变多(57.1%vs29.5%,P0.01),接受介入治疗比例低(24.5%vs52.3%,P0.001),药物治疗多(70.4%vs34.1%,P0.001)。(3)肾功能不全组发生急性冠脉综合征(53.1%vs27.3%,P0.05)、急性左心衰竭(27.6%vs11.4%,P0.05)的比例明显高于对照组。(4)Logistic分析显示,收缩压水平(β=0.65,P0.001)和肾小球滤过率(β=-0.49,P0.001)是随访期内冠心病患者发生不良心血管事件重要的独立危险因素。结论肾功能不全的冠心病患者冠脉病变广泛,钙化明显,接受再血管化治疗的比例低;随访期心血管事件的发生率高但症状不典型。慢性肾功能不全是冠心病病情发生发展的重要预测指标。     

Role of contrast-enhanced dobutamine stress echocardiography in predicting outcome in patients with known or suspected coronary artery disease

Although the application of intravenous contrast agents during stress echocardiography has been shown to improve diagnostic accuracy for detecting coronary artery disease, less information exists regarding its prognostic value. The aim of this study was to determine the role of contrast-enhanced dobutamine stress echocardiography (DSE) for predicting future cardiac events in patients with coronary artery disease (CAD). We studied 893 patients (mean age: 66, 581 men) with known or suspected CAD undergoing contrast-enhanced DSE. Positivity was defined as new/worsened wall motion abnormality or fixed abnormality during stress. All patients were followed for 15 +/- 10 months to evaluate hard cardiac events (cardiac death and nonfatal myocardial infarction) and total cardiac events (hard cardiac events, congestive heart failure, unstable angina, and late revascularization). Three patients were lost to follow-up, and 128 patients developed cardiac events, including 21 hard cardiac events. The 3-year event free survival rate was significantly lower in patients with positive DSE results than in those with negative DSE results. Stepwise Cox multivariate analysis revealed that positivity of DSE (P < 0.0001, Hazard ratio (HR): 2.48) and peak wall motion score index (WMSI) >1.5 (P < 0.0001, HR: 2.41) were independent predictors for total cardiac events. Considering hard cardiac events, the independent predictors were peak WMSI > 1.5 (P < 0.0001, HR: 6.65) and age > 70 years (P < 0.005, HR: 3.27). We conclude that contrast-enhanced DSE provides important prognostic information for future cardiac events.     

Transmitral pulsed-Doppler echocardiography is a more accurate technique compared with two-dimensional echocardiography using dobutamine,in patients with one vessel coronary artery disease

To examine the effects of dobutamine on pulsed-Doppler left ventricular filling indices and its utility for evaluation of CAD we studied 14 patients with normal coronary arteries (Group 1) and 39 patients with significant CAD (>70% diameter stenosis). Patients with coronary artery disease (CAD) were divided into two groups: patients with one-vessel coronary disease (Group 2); and those with multivessel CAD (Group 3). After stopping cardioactive treatment, patients underwent incremental dobutamine stress (5, 10, 20, 30 and 40 microg/kg/min) during pulsed-Doppler interrogation of diastolic filling with simultaneous heart rate and blood pressure measurements. The following transmitral Doppler variables were measured at baseline and at peak-dose of dobutamine: peak early (E) and peak atrial (A) velocity; E/A ratio; acceleration time (AT) and deceleration time (DT) of E wave; isovolumic relaxation time (IVRT); and time-velocity integral (TVI). Two-dimensional echocardiography was performed to detect regional asinergy and analyzed using a 16 segment model. RESULTS: Normals and CAD patients showed comparable changes in heart rate and blood pressure (P=NS between groups). Intergroup analysis of the changes of transmitral flow showed the significant changes for these indices (P<0.001): E velocity (-2.78+/-10.04, 12.4+/-9.4 and 16.47+/-10.65 cm/s); AT of E wave (1.66+/-2.47, -5.2+/-1.38 and -4.66+/-2.39 m/s(2)); DT of E wave (-0.23+/-0.18, 0.2+/-0.2 and 0.2+/-0.28 m/s(2)); and TVI of transmitral flow (-1.26+/-0.7, 3.5+/-1.75 and 4.1+/-1.66 cm), respectively for Groups 1, 2 and 3. All other transmitral Doppler variables showed insignificant changes (P=NS) to dobutamine between groups. It is important that the significance of these changes were the same for patients with one-vessel and those with multivessel coronary disease. In conclusion, during dobutamine stress testing, patients with CAD, had an abnormal response of these transmitral Doppler indices: E wave; AT of E wave; DT of E wave; and the TVI of transmitral flow. The abnormal responses of these Doppler indices of left ventricular filling are more accurate markers of significant single vessel CAD than new wall motion abnormalities during conventional DSE.     

Complications of pharmacologic stress echocardiography in coronary artery disease

In the last few years, pharmacologic stress echocardiography is emerging as a promising diagnostic tool with a favorable cost/benefit ratio. Its main clinical applications include the assessment of coronary artery disease, the identification of viable myocardium, and risk stratification before major vascular surgery. However, cardiac (arrhythmic, ischemic, or hemodynamic) as well as noncardiac complications have been reported, so that a risk/benefit analysis is advisable in view of the extensive introduction of this technique in the clinical arena. The most popular pharmacologic agents employed for stress echocardiography are dipyridamole, do-butamine, and adenosine. A comparative analysis with exercise stress testing, the classical standard of reference of all ischemia-provoking tests, confirms that in terms of safety and tolerability pharmacologic stress echocardiography may be considered a good alternative in patients unable to exercise maximally. No appreciable difference among the safety profiles of the most common pharmacologic agents has been found, but a careful evaluation of the risk/benefit ratio is advisable for any stressor in the individual patient by considering the relative importance of the expected diagnostic contribution and the pharmacodynamic impact of the test. Finally, adequate training of the operator and monitoring of the patient during stress and recovery are essential for getting optimal safety conditions.     

Provocation of coronary spasm by dobutamine stress echocardiography in a patient with angiographically minimal coronary artery disease

Dobutamine stress echocardiography (DSE) has been widely used for the noninvasive diagnosis of obstructive coronary artery disease. The ST-segment elevation during DSE has been reported as an infrequent event, caused by old myocardial infarction and/or critical coronary narrowings. The patient presented here was a 35-year-old man with a recent history of nonexertional chest pain. He had hyperc-holesterolemia and a history of heavy smoking as risk factors. The patient developed ST-segment elevation with chest pain during 40 mcg/min dobutamine infusion for the stress echocardiographic examination. Subsequent coronary angiograms revealed only mild coronary atherosclerosis. It is speculated that coronary spasm occurred in this patient as a paradoxical response to increased coronary blood flow with dobutamine administration.     

Diagnosis of coronary artery disease in elderly patients: safety and efficacy of dobutamine echocardiography

Coronary artery disease may be difficult to diagnose in theelderly because its clinical symptomatology is frequently atypicaland because the performance of submaximal tests makes exercisestress testing sometimes unreliable. Dobutamine stress testingmay be a useful alternative in such patients. This study comparedthe safety and accuracy of dobutamine stress echocardiographyin 73 ‘young’ (<60 years old) and 63 ‘old’( 60 years old) patients without previous myocardial infarctionundergoing diagnostic coronary angiography. The sensitivity in young patients (79%, (67–91, 95% CI))was similar to that in old patients (80% (69–91, 95% CI)).Similar levels of specificity (88% (75–101, 95% CI) vs75% (54–96, 95% CI)) were foundin the two groups. Bothgroups showed a trend to a higher sensitivity for multi-vesseldisease than for single-vessel disease. No major side effectoccurred during the entire study and peak dose (40 µg. kg^–1 . min^–1) was attained with similar frequencyin both groups (56% vs 49%). Minor side effects occurred equallyin ‘young’ and ‘old’ patients and neverpersisted more than a few minutes after ending the first infusionof dobutamine. Dobutamine echocardiography appears to be safe and accuratefor the detection of coronary artery disease regardless of age.     

Hypotensive response during dobutamine stress echocardiography in coronary patients: A common event of well-functioning left ventricle

Background: Hypotensive response during dobutamine stress echocardiography (DSE) is a common complication, lacking the prognostic significance of hypotension during exercise treadmill test. Hypothesis: The present study aimed to assess the possible mechanisms of hypotensive response during DSE and to compare it with exercise treadmill test. Methods: In all, 91 patients with known coronary artery disease (CAD) underwent both DSE and exercise treadmill test. Dobutamine-induced hypotension was defined as a systolic blood pressure drop ≥20 mmHg from baseline or from the previous level of infusion. Results: Twenty-one (23%) patients, 10 of whom also had bradycardia, developed hypotension during dobutamine infusion. Five (5.5%) patients were severely symptomatic and the infusion was stopped prematurely, while in the remaining 16 the addition of atropine allowed the continuation of the test. Patients prone to hypotension were predominantly female (p = 0.0004). had smaller (p = 0.01) and better functioning left ventricles (p = 0.0004), were unlikely to have rest wall motion abnormalities (p = 0.0008) or multivessel CAD (p = 0.02), and had less ischemia (wall motion score difference) (p = 0.03). Hypotension during exercise treadmill test was observed in only one (1%) patient with left main disease. Conclusions: Hypotension during DSE is unrelated to the anatomical or functional extent of CAD and is frequent in the setting of a well-functioning left ventricle. We suppose that vigorous contraction of a small chamber during dobutamine infusion results in an excessive stimulation of cardiac mechanoreceptors that mediate reflex hypotension and bradycardia.     

An assessment of dobutamine echocardiography and end-diastolic wall thickness for predicting post-revascularization functional recovery in patients with chronic coronary artery disease

AIMS: This study investigated the functional outcome of wall-thinned,akinetic myocardium after revascularization and evaluated theaccuracy of dobutamine echocardiography in predicting post-revascularizationfunctional recovery with the assessment of end-diastolic wallthickness in chronic ischaemic patients. METHODS AND RESULTS: Fifty-three patients underwent dobutamine echocardiography beforecoronary revascularization. End-diastolic wall thickness wasalso evaluated before and after revascularization. The sensitivityand specificity of dobutamine echocardiography to predict post-revascularizationfunctional recovery were 69% and 100% in 58 akinetic/dyskineticsegments, and 86% and 57% in 96 hypokinetic segments. Of 19akinetic/dyskinetic segments with a preserved end-diastolicwall thickness, 17 (89%) showed functional recovery after revascularization,and dobutamine detected 14 (83%) of these 17 segments. Of 39akinetic/dyskinetic segments with a thinned end-diastolic wallthickness, 15 (38%) achieved functional recovery, whereas dobutamineechocardiography detected recovery in only eight (53%). Further,of these 15 viable, wall-thinned segments, 12 (80%) showed anincreased end-diastolic wall thickness after revascularization(mean±SD were from 5·6±0·7 mm atbaseline to 7·4±1·3 mm and 9·7±1mm after 1 week and after 3 months, respectively), and only5 (42%) of these responded to dobutamine. CONCLUSION: Dobutamine echocardiography showed a lessened sensitivity topredict post-revascularization functional recovery in akinetic/dyskineticsegments with a thinned end-diastolic wall thickness that subsequentlyincreased in size.     

Accelerated dobutamine stress testing: safety and feasibility in patients with known or suspected coronary artery disease

BACKGROUND: Dobutamine pharmodynamics require approximately 10 min to reach steady state. Despite this, standard dobutamine stress echo typically uses 3-min stages of advancing dobutamine doses because of safety concerns. HYPOTHESIS: In patients with a high pretest probability of coronary artery disease (CAD), a continuous infusion of high-dose dobutamine is a feasible and safe method for performing a dobutamine stress test. METHODS: Forty-seven consecutive patients (mean age 64 +/- 11 years) with 3.0 +/- 1.4 cardiac risk factors underwent dobutamine stress testing utilizing a single, high-dose (40 mcg/kg/min), continuous dobutamine infusion. The 40 mcg/kg/min infusion was continued for up to 10 min or until a test endpoint had been reached. If a test endpoint was not achieved, atropine (up to 1.0 mg) was added. RESULTS: Heart rate rose from 71 +/- 12 to 137 +/- 18 beats/min at peak (p<0.0001) with a concomitant change in systolic blood pressure (143 +/- 35 vs. 167 +/- 38 mmHg; p = 0.001) but no change in diastolic blood pressure (74 +/- 19 vs. 75 +/- 18 mmHg; p = NS). Target heart rate was achieved in 20 of 47 (43%) patients with accelerated dobutamine alone and in 34 of 47 (72%) with the addition of atropine. An average of 11.6 +/- 3.7 min was required to obtain target heart rate. Subjective sensations from the dobutamine occurred in 49% of patients (palpitations 21%, nausea 6%, chest pain 6%, headache 6%, dizziness 13%), mild arrhythmia in 48% of patients (ventricular premature beats 38%, supraventricular tachycardia 10%), and one patient had nonsustained ventricular tachycardia. CONCLUSION: A single, high-dose (40 mcg/kg/min) dobutamine-atropine protocol provides an efficient means of performing dobutamine stress echocardiography with a similar symptom profile as conventional dobutamine infusion protocols in patients with a high pretest probability of CAD. Randomized, controlled studies will be necessary to assess the sensitivity and specificity of this accelerated dobutamine echo protocol.     

Likelihood of obstructive coronary disease in metabolic syndrome patients with abnormal stress echocardiography

Background

Metabolic syndrome (MetSx) encompasses several risk factors for macrovascular coronary artery disease. An association between MetSx and coronary syndrome X has also been reported, suggesting that patients with MetSx are more likely to have endothelial dysfunction in the setting of angiographically normal coronary arteries. It remains unknown whether MetSx patients with abnormal stress echocardiography (SE) are more likely to have obstructive coronary disease (CAD) compared to patients without MetSx.

Methods

We identified symptomatic patients without known CAD and abnormal SE who underwent coronary angiography within 4 weeks after the SE. Patients were grouped according to their MetSx and impaired fasting glucose (IFG) status. We compared the proportion of patients with obstructive CAD in each subgroup using the x² test. Multivariate regression analysis was used to adjust for the pre-test probability of underlying coronary artery disease.

Results

Among 583 consecutive symptomatic patients who had an abnormal SE and were referred for angiography, 158 (36%) met the NCEP definition of MetSx. MetSx patients had a trend towards having more obstructive CAD than those without MetSx (OR 1.44, p = 0.07). After adjusting for pre-test probability of coronary disease, smoking and LDL-C, MetSx/IFG combination was an independent predictor of obstructive CAD (OR 2.06 [1.24-3.44], p < 0.001) but MetSx with normal fasting blood glucose was not (OR 0.91 [0.47-1.70], p 0.09).

Conclusion

Symptomatic patients with MetSx and IFG are more likely to have angiographically significant CAD after abnormal SE than patients without MetSx or those with normal fasting blood glucose.     

Simultaneous dobutamine stress echocardiography and dobutamine scintigraphy (99mTc-MIBI-SPET) for assessment of coronary artery disease

Background: Simultaneous dobutamine stress echocardiography (DSE) and^99mTc-MIBI-SPET (DMS) for the evaluation of the presence and the extent of coronary artery disease (CAD) were assessed for a head to head comparison regarding the diagnostic accuracy of the two tests. Methods and Results: Forty-five consecutive patients (33 males and 12 females: 53±6.8 yr.) underwent exercise electrocardiography and simultaneous dobutamine stress echocardiography and MIBI-SPET imaging. Coronary angiography was performed in all patients (significant coronary stenosis > 50%). On the basis of the results of exercise electrocardiogram the pre-test probability for coronary artery disease (Diamond's algorithm) was low (45.6±12.7 %). The overall specificity, sensitivity and predictive accuracy of Echo-dobutamine stress test for diagnosis of the presence or absence of CAD were: specificity 82%, sensitivity 76%, diagnostic accuracy 80%, positive predictive value 90%, negative predictive value 40%. The overall specificity, sensitivity and predictive accuracy of MIBI-SPET-dobutamine test for diagnosis of the presence or absence of CAD were: specificity 86%, sensitivity 87%, diagnostic accuracy 84%, positive predictive value 97%, negative predictive value 54%. MIBI-SPET-dobutamine test showed a significantly higher sensitivity in comparison with ECHO-dobutamine test (P<0.05). Conclusion: Both noninvasive methods for the detection of CAD showed a good diagnostic accuracy. Nevertheless the SPET model showed an higher sensitivity in comparison with DSE model, essentially in the presence of a lower extent of CAD and during submaximal test.     

Head to head comparison of transesophageal and transthoracic contrast-enhanced echocardiography during dobutamine administration for the detection of coronary artery disease

Dobutamine stress echocardiography (DSE) has been shown to be a very useful non-invasive technique for the detection of coronary artery disease. However, inadequate transthoracic images preclude the use of DSE in a significant proportion of patients. Transesophageal (TEE) or transthoracic contrast echocardiography (CE) can however overcome this limitation. The comparison between the two techniques has never been investigated during a stress test. Therefore, we designed a prospective study to compare DSE-CE and DSE-TEE for the detection of coronary artery disease in patients with poor echo image quality. We studied 42 patients scheduled for quantitative coronary angiography. Prospective DSE-CE and DSE-TEE with maximum one day interval were performed in a random order. Significant coronary artery disease was detected in 30 patients, nine with single vessel disease and 21 with multivessel disease. Sensitivity of DSE was higher with CE than with TEE (90% vs 87%, p = NS). There was no significant difference with respect to specificity in both groups (100% vs 92%, p = NS). The diagnostic accuracy was similar in both groups (93% vs 88%, NS). The κ value for identical interpretation of a stress echocardiography study was nearly identical with both modalities 0.75 to 0.78. In poorly echogenic patients, DSE-CE is a valuable alternative for the detection of myocardial ischemia in comparison with DSE-TEE. Because DSE-CE is more comfortable than TEE, it should be used in patients with suboptimal transthoracic echocardiograms for the evaluation of coronary artery disease during DSE.     

Abnormal ventricular activation and repolarisation during dobutamine stress echocardiography in coronary artery disease

Objective—To assess possible ECG changes caused by dobutamine stress and their relation to wall motion disturbances in patients with coronary artery disease.
Design—Prospective recording and analysis of 12 lead ECG at rest and during each stage of dobutamine stress echocardiography, and correlation with wall motion changes.
Setting—A tertiary referral centre for cardiac disease equipped with non-invasive facilities for pharmacological stress tests.
Subjects—27 patients, mean (SD) age 60 (8) years, with documented evidence of coronary artery disease in whom dobutamine stress echo was clinically indicated, and 17 controls of similar age.
Results—In controls, all ECG intervals shortened with increasing heart rate but in the patient group only PR and QT intervals shortened while QRS duration broadened and QTc interval prolonged progressively. In the 27 patients, 16 developed chest pain, 15 with reduced left ventricular long axis systolic excursion (p < 0.001), and all showed reduced peak lengthening rate; ST segment shift appeared in 16, 13 of whom developed chest pain, but did not correlate with reduction of either systolic long axis excursion or peak lengthening rate; QRS duration broadened in 20, 16 with reduction of long axis excursion (p < 0.02) which was more often seen at the septum (p < 0.005); QTc interval prolonged in 19, all of whom had associated reduction of peak long axis lengthening rate (p < 0.02).
Conclusions—QRS duration and QTc interval both normally shorten with dobutamine stress, while in coronary artery disease they both lengthen: changes in QRS duration correlate with systolic and QTc interval with diastolic left ventricular wall motion disturbances. ST segment shift also occurred in most patients, but without consistent correlation with wall motion abnormalities. It was thus less discriminating than the other two abnormalities in this respect.

Keywords: long axis;  QRS duration;  QTc interval;  stress echocardiography;  coronary artery disease