Early diastolic flow propagation velocity detects induced diastolic dysfunction during dobutamine stress echocardiography

Objective: Diastolic dysfunction precedes systolic dysfunction during the development of myocardial ischemia. Detecting diastolic dysfunction during stress test for coronary artery disease (CAD) could improve diagnostic sensitivity of the test. Flow propagation velocity (FPV) derived from color M‐mode Doppler has been proposed as a sensitive marker to detect diastolic dysfunction. Methods: The FPVs at baseline and at peak dobutamine infusion were measured using color M‐mode Doppler during dobutamine stress echocardiography in 90 patients. The results are compared among the groups divided on the results of coronary angiography. Results: The FPV was similar at baseline among the groups. At peak dobutamine infusion, the FPV increased significantly in the non‐CAD group (from 56 ± 19 cm/s to 66 ± 25 cm/s), whereas it failed to increase in the groups with CAD. As a result, the peak FPV was significantly lower in the groups with CAD than in the non‐CAD group. Receiver operating characteristic analysis showed that the peak FPV and ΔFPV had good diagnostic property to detect CAD (the areas under the curves were 0.77 and 0.73, respectively). Adopting these FPV criteria, sensitivity of DSE was improved. Conclusion: FPV measurement during DSE detects ischemic left ventricular diastolic dysfunction. Adding the assessment of peak FPV to conventional DSE increases the sensitivity and the ability to reliably exclude CAD. (Echocardiography 2011;28:335‐341)     

Atypical takotsubo cardiomyopathy: dobutamine-precipitated apical ballooning with left ventricular outflow tract obstruction

Takotsubo cardiomyopathy, or transient apical ballooning syndrome, is a recently recognized form of transient left ventricular dysfunction that is presumably caused by stress. Takotsubo cardiomyopathy can clinically resemble an acute coronary syndrome. Reported cases have been preceded by emotional stress or medical illness. Herein, we report a fatal case of takotsubo cardiomyopathy that followed a dobutamine stress test. We believe that the dobutamine infusion led to stress-induced cardiomyopathy with a dynamic left ventricular outflow tract obstruction. To our knowledge, there is only 1 other report of an association between dobutamine infusion and the development of takotsubo cardiomyopathy.     

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)     

Inverted‐Takotsubo Pattern Cardiomyopathy Secondary to Pheochromocytoma: A Clinical Case and Literature Review

Takotsubo cardiomyopathy is an increasingly recognized clinical syndrome of transient left ventricular dysfunction, commonly with apical ballooning, in the context of physical or emotional stress. Recently, an inverted‐Takotsubo contractile pattern has been described with hypokinesis of the basal and mid‐ventricular segments and sparing of the apex. We report a case of a 30‐year‐old man presenting with transient left ventricular dysfunction in an inverted‐Takotsubo contractile pattern, associated with a newly discovered pheochromocytoma, and present a literature review of the inverted‐Takotsubo contractile pattern cardiomyopathy. Copyright © 2010 Wiley Periodicals, Inc.     

The Utility of Dobutamine Stress Echocardiography for the Diagnosis of Coronary Artery Disease in the HIV Population

Background: The introduction of highly active antiretroviral therapy (HAART) has increased human immunodeficiency virus (HIV) patient longevity by 10–15 years. This increased longevity has habituated new cardiovascular complications, in particular, accelerated coronary artery disease (CAD). Although dobutamine stress echocardiography (DSE) is a highly sensitive and specific test for the noninvasive detection of underlying CAD in the general population, its utility in the HIV population remains unknown. Objective: The objective of the current study was to assess the validity of DSE for the noninvasive detection of underlying symptomatic CAD in the HIV population using cardiac catheterization as the gold standard. Methods and results: A total of 40 HIV positive patients (mean 49 ± 8 years; 31 males) between 2006 and 2009 inclusively underwent routine DSE and coronary angiography. A positive stress echo with new wall motion abnormalities was detected in 9 (23%) individuals. Coronary angiography, following DSE, detected obstructive CAD in 12 (30%) individuals. For the diagnosis of obstructive CAD, DSE has a sensitivity of 67%, specificity of 97%, positive predictive value (PPV) of 89%, and negative predictive value (NPV) of 87%. Conclusion: In this select HIV population, DSE was highly specific for the noninvasive detection of obstructive CAD. (Echocardiography 2010;27:1228‐1232)     

Myocardial viability–State of the art: Is it still relevant and how to best assess it with imaging?

Despite major advances, ischemic cardiomyopathy (ICM) remains a significant cause of death and disability worldwide, with coronary artery disease (CAD) the leading cause of left ventricular (LV) systolic dysfunction. Coronary revascularization may improve LV function, heart failure symptoms and cardiovascular outcomes in high-risk patients with myocardial viability. Multiple imaging modalities have been utilized to detect viable myocardium and predict functional recovery following revascularization. Dobutamine stress echocardiography (DSE), nuclear imaging and cardiac MRI (CMR) are frequently used to assess viability. This review will summarize the extant literature on this topic, describe the role and methods for viability imaging in modern clinical practice, provide a patient-centered perspective regarding the controversies surrounding the current utility of viability imaging, as well as discuss future directions.     

Comparison of real-time tri-plane and conventional 2D dobutamine stress echocardiography for the assessment of coronary artery disease.

AIMS: Although dobutamine stress echocardiography (DSE) is an accepted tool for the diagnosis of coronary artery disease (CAD), it requires subsequent image acquisitions of the left ventricle (LV) in order to visualize all segments. This makes the procedure relatively time-consuming and might limit its accuracy. With the introduction of matrix array transducers, the real-time simultaneous acquisition of all LV segments has become possible using multi-plane imaging. The purpose of this study was: (i) to test the feasibility and efficiency of real-time tri-plane (RT3P) imaging during DSE, (ii) to compare the accuracy of RT3P DSE in detecting CAD using coronary angiography as the reference method. METHODS AND RESULTS: Thirty-six patients suspected of CAD were prospectively enrolled. Both conventional two-dimensional (2D) and RT3P imaging were performed during a DSE protocol. Coronary angiography was performed within 24 h. Ultrasound data were acquired at each stage of the DSE. The total effective acquisition time for RT3P imaging was significantly shorter (55+/-29 vs. 137+/-63 s, P<0.001). Data yield was similar for both methods (2D: 98% vs. 3D: 97%). Overall sensitivity (93%), specificity (75%), and accuracy (89%) were identical between both methods. On a segmental level, the sensitivity, specificity, and accuracy of the RT3P and the 2D DSE were similar. CONCLUSION: RT3P imaging fastens the DSE protocol without compromising the accuracy for the diagnosis of CAD. This could facilitate a more wide-spread use of DSE and therefore contributes positively to its routine clinical acceptance.     

Tako-Tsubo cardiomyopathy: new insights into the possible underlying pathophysiology.

Tako-Tsubo cardiomyopathy is characterised by an atypical distribution of left ventricular (LV) dysynergy with apical ballooning and compensatory basal hyperkinesis. Coronary angiography is normal. Several substrates have been put forward to explain the underlying pathophysiology such as raised catecholamine levels (due to physical or emotional stress), multivessel epicardial coronary spasm or diffuse microvascular spasm. However, the pathophysiology has not yet been fully clarified. We present a series of cases whose findings could explain the mechanism underlying this syndrome. Four consecutives patients, all female, were admitted with the clinical features typical of Tako-Tsubo syndrome. In all, severe widespread transient LV mid-apical a/dyskinesia was associated with a mid-cavity dynamic obstruction which resolved prior to the resolution of the LV wall motion abnormalities. In all cases the dynamic LV obstruction was related to localised mid-ventricular septal thickening. After improvement in wall motion, a low-dose strain/strain rate dobutamine stress-echocardiography (DSE) was performed to determine the underlying ischaemic substrate. This provoked an LV mid-cavity gradient at peak dose in all. Regional deformation changes during DSE showed the affected myocardium to have the typical response diagnostic of regional stunning. CONCLUSION: We postulate that an important unrecognised factor in the development of Tako-Tsubo cardiomyopathy is the presence of abnormal myocardial functional architecture (such as localised mid-ventricular septal thickening), which in the presence of dehydration and/or raised catecholamine levels due to physical or emotional stress, leads the development of a severe transient LV mid-cavity obstruction. This effectively sub-divides the LV into two functionally different chambers with a marked increase in wall stress in the high pressure distal apical chamber. This, in combination with the abnormal high circulating catecholamine levels, induces widespread sub-endocardial ischaemia which is unrelated to a specific coronary artery territory. With rehydration/fall in catecholamine levels the interventricular gradient resolves and distal function recovers. Low dose SR/S DSE confirms that the distal ischaemic substrate is myocardial stunning.     

多巴酚丁胺负荷超声与平板运动心电图诊断冠心病的临床研究

目的评价多巴酚丁胺超声心动图负荷试验(DSE)和平板运动心电图(TET)负荷试验诊断冠心病的价值。方法 46例可疑冠心病患者,行冠状动脉造影(CAG)、DSE及TET检查,以CAG作为诊断冠心病的金标准,比较多巴酚丁胺超声心动图负荷试验及平板运动心电图负荷试验诊断冠心病的准确性。结果多巴酚丁胺超声心动图负荷试验和平板运动心电图负荷试验对冠心病诊断的敏感性是86.2%vs 62.1%(P<0.05),特异性是88.2%vs 76.5%(P>0.05),准确性是87.0%vs 67.4%(P<0.05)。结论多巴酚丁胺超声心动图负荷试验对诊断冠心病有较高的敏感性、特异性和准确性。     

Biventricular Takotsubo syndrome in a patient with coronary abnormality and end-stage renal disease

The Takotsubo syndrome is a clinical entity consisting of transient, regional left ventricular (LV) contraction abnormalities in the absence of significant epicardial coronary artery disease. Patients usually present with acute hemodynamic deterioration following an emotional or physical stress. The Takotsubo syndrome is uncommon among patients with end-stage renal disease (ESRD) and patients with congenital coronary abnormalities, such as right coronary artery (RCA) originating from left sinus of Valsalva. Here we describe a patient presenting with acute respiratory distress and anterolateral ST-T segment changes, with negative troponin-I and elevated levels of brain natriuretic peptide. Coronary angiography showed a right coronary artery arising from the left sinus of Valsalva without obstructive coronary artery disease, while ventriculography and echocardiogram showed findings compatible with apical ballooning. Magnetic resonance imaging confirmed the diagnosis of a biventricular Takotsubo cardiomyopathy.     

Inverted Takotsubo Cardiomyopathy and the Fundamental Diagnostic Role of Echocardiography

Takotsubo cardiomyopathy is characterized by the development of transient focal wall-motion abnormalities that involve the apical and midventricular segments, in the absence of obstructive coronary artery disease. A variant, inverted takotsubo cardiomyopathy, was described in 2010. We report 3 cases in which each patient''s transthoracic echocardiogram revealed the characteristic basal and midventricular segmental akinesis of this variant. This pattern is not associated with coronary artery distribution, and it therefore can be differentiated from coronary artery disease with the use of echocardiography, by evaluating the distribution and temporal changes of akinetic areas.Key words: Cardiomyopathies/diagnosis/physiopathology, echocardiography, takotsubo cardiomyopathy/diagnosis, ventricular dysfunction, left/diagnosisTakotsubo cardiomyopathy is a syndrome characterized by transient apical and midventricular akinesis that is typically precipitated by acute stress. A variant, with akinesis of the mid and basal left ventricular (LV) segments and sparing of the apex, has been called inverted (or atypical) takotsubo cardiomyopathy. We describe 3 cases of this variant in which the transthoracic echocardiograms (TTEs) and temporal evolution of the condition were diagnostic. Each patient was emergently admitted to Barnes-Jewish Hospital in St. Louis and examined there; the TTEs were reviewed by a visiting cardiologist (AM).     

Transient biventricular apical ballooning: a unique presentation of the "broken heart"

Transient left ventricular (LV) apical ballooning and normal epicardial coronary arteries are the hallmarks of Takotsubo cardiomyopathy. The syndrome is often triggered by emotional or physiologic stress, and its pathogenesis is poorly understood. Current proposals focus on elevated cathecolamines in association with abnormal coronary artery endothelium, coronary microcirculation or LV geometry. Right ventricular (RV) involvement, as described in our patient, is not reported as a typical feature. Presence of RV dysfunction may affect the initial management of these patients and raises questions regarding the universal applicability of the currently proposed pathophysiologic mechanisms of this syndrome.     

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.     

An Unusual Cardiomyopathy after Physical Stress in a Child

Takotsubo cardiomyopathy, or broken heart syndrome, is characterized by transient left ventricular dysfunction associated to chest pain, elevation of cardiac enzymes, and electrocardiographic changes, mimicking an acute coronary syndrome, especially in older women after a physical or emotional stress. It is extremely infrequent in children as well as after infective stress. We described a celiac 4‐year‐old girl, following a gluten‐free diet, who developed features of cardiac failure few days after episodes of acute diarrhea with fever. The patient was treated with oral anticongestive therapy and intravenous immunoglobulins, and she had a dramatic and rapid improvement; echocardiographic features normalized in 48 hours.     

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.     

Dobutamine stress echocardiography Doppler estimation of cardiac diastolic function: a simultaneous catheterization correlation study

Background: Doppler echocardiography using the ratio of early diastolic transmitral velocity to early diastolic mitral annular tissue velocity (E/E′) is routinely used to evaluate left ventricular (LV) filling pressures at rest. We tested the hypothesis that measurement of E/E′ in patients undergoing dobutamine stress echocardiography (DSE) will detect changes in LV filling pressures. Methods: In this prospective study, 16 patients with normal LV ejection fraction and normal coronary arteries by angiography underwent a standard DSE protocol with simultaneous LV filling pressure monitoring with a fluid filled pigtail catheter. Doppler echocardiographic assessment of LV diastolic function was performed using E/E′ at rest and during DSE. Results: The average age of the study participants was 57 ± 8 years. Average heart rate was 61 ± 11 bpm at baseline and 141 ± 12 bpm at peak stress. LV mean diastolic pressure decreased from 12.3 ± 2.6 mmHg at baseline to 9.0 ± 2.3 mmHg at peak stress (P = 0.0001). Baseline E/E′ at the septum and lateral annulus were 8.7 ± 2.2 and 7.5 ± 1.9 and during peak stress were 8.3 ± 3.1 and 7.9 ± 3.5, respectively. There was no significant change in E/E′ at either the septum or the lateral annulus (P = 0.55, P = 0.66). There was no significant correlation between LV mean diastolic pressure and E/E′ with dobutamine stress. Conclusions: In patients with normal LV ejection fraction and no significant coronary artery disease undergoing DSE, the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/E′) at peak stress with dobutamine does not predict changes in LV filling pressures. (Echocardiography 2011;28:442‐447)     

Methodological analysis of diagnostic dobutamine stress echocardiography studies

BACKGROUND: Dobutamine stress echocardiography (DSE) is an accepted test for the diagnosis of coronary artery disease (CAD), despite its wide diagnostic accuracy. AIM: Which factors cause test variability of DSE for the diagnosis of CAD. METHODS: In a retrospective analysis of 46 studies in 5,353 patients, the potential causes of diagnostic variability were systematically analyzed, including patient selection, definition of CAD, chest pain characteristics, confounding factors for DSE (left ventricular hypertrophy, left bundle branch block, female gender), work-up bias (present when patient's chance to undergo coronary angiography is influenced by the result of DSE), review bias (present when DSE is interpreted in relation to CAG), DSE protocol and definition of a positive DSE. RESULTS: Diagnostic variability was related to definition of a positive test, but not related to the definition of CAD or DSE protocol. However, only three of eight methodological standards for research design found general compliance. Differences in the selection of the study population (quality of echocardiographic window, angina pectoris), handling of confounding factors and analysis of disease in individual coronary arteries were observed. Lack of data on analysis of relevant chest pain syndromes and handling of nondiagnostic test results hampered further evaluation of these standards. CONCLUSION: Methodological problems may explain the wide range in diagnostic variability of DSE. An improvement of clinical relevance of DSE testing is possible by stronger adherence to common and new methodological standards.     

QT dispersion correlates to myocardial viability assessed by dobutamine stress echocardiography in patients with severely depressed left ventricular function due to coronary artery disease

BACKGROUND: QT dispersion is prolonged in numerous cardiac diseases, representing a general repolarization abnormality. AIM: To evaluate the influence of viable myocardium on QT dispersion in patients with severely depressed left ventricular (LV) function due to coronary artery disease. METHODS AND RESULTS: 103 patients with ischemic cardiomyopathy (LV ejection fraction [EF]: 25+/-6%) were studied. Patients underwent 12-lead electrocardiography to assess QT dispersion, and two-dimensional echocardiography to identify segmental dysfunction. Dobutamine stress echocardiography (DSE) was then performed to detect residual viability. Resting echo demonstrated 1260 dysfunctional segments; of these, 476 (38%) were viable. Substantial viability (> or =4 viable segments on DSE) was found in 62 (60%) patients. QT dispersion was lower in these patients, than in patients without viability (55+/-17 ms vs. 65+/-22 ms, P=0.012). Viable segments negatively correlated to QT dispersion (r=-0.333, P=0.001). In contrast, there was no correlation between LVEF and QT dispersion (r=-0.001, P=NS). CONCLUSIONS: There is a negative correlation between QT dispersion and the number of viable segments assessed by DSE. Patients with severely depressed LV function and a low QT dispersion probably have a substantial amount of viable tissue. Conversely, when QT dispersion is high, the likelihood of substantial viability is reduced.     

Clinical features and usefulness of cardiac magnetic resonance imaging in assessing myocardial viability and prognosis in Takotsubo cardiomyopathy (transient left ventricular apical ballooning syndrome)

In Takotsubo cardiomyopathy, or transient left ventricular (LV) apical ballooning syndrome, normalization of wall motion can occur after as long as 3 months. We report 1 of the largest series to date outside Japan and emphasize the utility of cardiac magnetic resonance imaging (CMR) to show a lack of irreversible damage in the acute setting, thereby reliably predicting recovery. During the previous 6 years, we saw 22 patients who met the following criteria: (1) a suspected myocardial infarction based on symptoms, an abnormal electrocardiogram, and/or elevated serum cardiac markers; (2) an anteroapical wall motion abnormality; and (3) no significant occlusive epicardial coronary artery disease or observed vasospasm. Ten patients underwent delayed enhancement CMR to assess myocardial viability during the index presentation. All 10 patients had an absence of irreversible damage, as evidenced by lack of gadolinium "hyperenhancement"; later, their LV function returned to normal. Eight other patients, available for outpatient follow-up evaluation, also had normalization of LV function. Takotsubo cardiomyopathy is increasingly being recognized outside Japan and must be distinguished from acute myocardial infarction. In conclusion, CMR is useful to document segmental LV dysfunction and lack of irreversible damage and to predict functional recovery.