Tissue tracking of segmental strain as a predictor of provoked dynamic left ventricular outflow tract obstruction

Background: Left ventricular outflow tract obstruction (LVOTO) is commonly observed in patients with hypertrophic cardiomyopathy (HCM) or left ventricular hypertrophy (LVH). Some patients develop LVOTO provoked by physical exertion, and hence termed dynamic LVOTO (DLVOTO). However, its precise prevalence and mechanism are still unclear. Aim: Two-dimensional speckle tracking echocardiography (2D STE) seems to be helpful for the detection of early LV structural abnormalities. This study aimed to examine the possible role of segmental as well as global longitudinal strain in identifying DLVOTO non-HCM patients as detected by dobutamine stress echocardiography (DSE). Methods and results: Two hundred and fifty patients without structural heart disease had undergone conventional transthoracic echocardiography, 2D STE, and DSE. All patients with non-ischemic evidence were divided into two groups according to the DSE results; DLVOTO (þ) and DLVOTO (). Among 250 patients, 50 patients (36%) had shown DLVOTO after DSE (15 males, 35 females; mean age 55±7years). They were compared with 90 non -LVOTO obstruction patients (43 males, 47 females; mean age 57±6years). Based on multivariate logistic regression analysis, the independent predictors of provoked DLVOTO during DSE were resting basal septal longitudinal strain BS-LS average (p < 0.001), resting LA reservoir strain (p < 0.001), and systolic LVOT diameter (p ¼ 0.03). Resting BS-LS average with cut-off - 17.5% was recognized as a critical indicator of DLVOTO, with sensitivity 78%, and specificity 95% (better than systolic LVOT diameter of sensitivity 76%, and specificity 15% and resting LA reservoir strain which showed poor AUC at ROC curve 0.007). Conclusion: We demonstrate that provoked LVOTO during DSE in non HCM symptomatic patients is directly correlated to resting regional LS, where the increased BS-LS of 17.5% was a key determinant of LVOT gradient provocation. Assessment of baseline BS-LS average might be a bedside simple tool for detection of patients with DLVOTO not able to do DSE.

Prevalence of Cardiotoxicity Induced by Chemotherapy Measured by Dobutamine Stress Echocardiogram (DSE) in BSMMU

Background: Cardiotoxicity related to cancer treatment is an alarming source of significant morbidity and mortality, and may differ from subclinical myocardial dysfunction to irreversible heart failure or even death. DSE is a safe, feasible, and accurate modality for finding of myocardial ischemia and prognostication in patients with known or suspected coronary artery disease, particularly when they have limited exercise capacity.Materials& Methods:This study is a cross-sectional observational study which was conducted at the department of Cardiology, in BSMMU, Dhaka from June 2019- December 2019. The sample size for this study was 50.Results:The mean age was 56� where 17(34%) of the respondents were <65 years and 33(66%) were >65 years. The male respondent was 35(70%) where female was 15(30%). Diabetes was found in 3(6%) cases and followed by Acute ischemia, Hypertension 6(12%), Coronary Artery Disease (CAD) 4(8%), ACE-inhibitors 5(10%), Beta-blockers 3(6%), Nitrates 3(6%). Acute leukemia was found in 13(26%). in M12-18 was 45�and followed by mean of LVESD (mm) was 27� 29� 29� 30� 30� 31� Mean of IVSd (mm) was 9� 9� 9� 9� 8� 8� Mean of Peak E (cm/s) was 80�, 76�, 74�, 73�, 66� 63� and the p-value was seen <0.001 which denotes a significant improvement in treatment (p<0.005).Conclusions:The early discovery of cardiotoxicity may ensure the improved chemotherapeutic process and timely management of the treatment of cardiomyopathy, such as beta-blockers and ACE inhibitors.

Objective Evidence of Inducible Ischemia in Patients with Ischaemic Heart Disease by Global Longitudinal Strain During Dobutamine Stress Echocardiography

Background: Operator dependent two-dimensional (2D) echocardiography is a noninvasive test to assess myocardial hypokinesia. Inter observer variability is more as it is subjective. Objective evidence of 2D global longitudinal strain (2D GLS) and strain rate imaging are getting popularity. Methods: This cross sectional study was done on 20 patients who came for dobutamine stress echo (DSE) in the department of cardiology of BSMMU, Dhaka from 1st February 2019 to 31st July 2019. 2D GLS was done before and just after DSE. Results: DSE findings revealed 6 patients had viable LAD, 9 had viable LCX and 6 had viable RCA, 9 had nonviable LAD, 2 had nonviable LCX and 3 had nonviable RCA territories. Difference in Post-systolic strain rate (SRps) in myocardial segments supplied by LAD at baseline peak stress in patients who had normal and nonviable LAD (-21% to. -23%, p=0.98) and (-6%to – 7%, p= 2.87) which were not significant. At peak exercise there was a trend towards greater SRps in viable territory of LAD in compared with baseline and peak stress (-1% to -16%, P = 0.05) which was significant. SRps in myocardial segments supplied by LCX at baseline and peak stress in patients who have normal and nonviable LCX (-20% to. -21%, p=0.82) and (-5%to – 5%, p=1.18) which had similar result as LAD territory. At peak exercise there was a trend towards greater SRps in viable territory of LCX compared with baseline and peak stress (-12% to -15%, P = 0.06). There was no significant difference in SRps in myocardial segments supplied by RCA at baseline and peak stress in patients who had normal and nonviable RCA (-23% to. -24%, p=1.72) and (-4%to – 5%, p=2.10). At peak exercise there was a trend towards greater SRps in viable territory of RCA compared with baseline and peak stress (-10% to -15%, P = 0.04). Conclusion: Results of subjective interpretation of DES has compared with objective evidence 2D GLS on peak stress which has similarity. It was a small study. Future large study is needed to establish these findings.

Assessment of myocardial viability and contractile function in rabbits with different ischemic periods by stress echocardiography and multilayer strain / 中华超声影像学杂志

To evaluate the changes of myocardial viability and systolic function in rabbits with different ischemic periods by layer‐specific strain of ultrasound speckled tracking imaging ( ST I) and low dose dobutamine stress echocardiography ( LDDSE ) . Methods T hirty‐six rabbits were randomly divided into 3 groups( n ＝12) : ①myocardial infarction group Ⅰ :coronary artery occlusion for 45 min ; ②myocardial infarction group Ⅱ :coronary artery occlusion for 60 min ; ③ myocardial infarction group Ⅲ :coronary artery occlusion for 90 min . Echocardiography examinations were performed at baseline ,after ligation and low dose dobutamine stress . After the experiment ,rabbits were killed and the hearts were taken to assess viable or nonviable mycardium , triphenyl tetrazolium chloride and Evans blue staining were applied . Results ①After coronary artery ligation ,left ventricular ejection fraction( LVEF) decreased in 3 groups ( all P ＜ 0 .05 ) , the ventricular global endocardial longitudinal strain ( GSLsys‐endo ) , global myocardial longitudinal strain( GSLsys‐mid) ,and global epicardial longitudinal strain( GSLsys‐epi) decreased in 3 groups ( all P ＜ 0 .05 ) ,the longitudinal strain of endocardium ( SLsys‐endo ) ,longitudinal strain of myocardium ( SLsys‐mid) ,longitudinal strain of epicardium ( SLsys‐epi) decreased in viable myocardial ( all P＜0 .05) ; ②While low dose dobutamine stressing ,the GSLsys and SLsys increased in each groups ,and the GSLsys‐endo ,GSLsys‐mid ,GSLsys‐epi and SLsys‐endo of viable segments in each group were increased ( P＜0 .05) ; ③After ligation and low dose dobutamine stress ,the GSLsys in endocardium in three groups were different( P ＜0 .05) ,and the SLsys in endocardium of viable segments in three groups were different ( P＜0 .05) . Conclusions Layer‐specific strain of STI combined with LDDSE can accurately evaluate the changes of myocardial viability and systolic function in different ischemic periods ,and the longitudinal strain of endocardium is more sensitive ;moreover ,with the increase of coronary artery occlusion time ,the infarcted myocardium increases ,myocardial viability and systolic function decrease .

Real World Utility of Dobutamine Stress Echocardiography in Predicting Perioperative Cardiovascular Morbidity and Mortality after Orthotopic Liver Transplantation

BACKGROUND AND OBJECTIVES: Stress echocardiography is the current standard for cardiac risk stratification of patients undergoing orthotopic liver transplantation (OLT). We aim to evaluate the role of dobutamine stress echocardiography (DSE) in predicting perioperative major adverse cardiac event (MACE) in patients undergoing OLT. METHODS: This was a single-center retrospective study including 144 OLT patients. Of 144 patients, 118 had DSE. MACE included myocardial infarction (MI), heart failure (HF), cardiovascular and all-cause death 1 year after OLT. RESULTS: Our study cohort included 118 patients. The mean age was 57.3±8.2 years (range, 25–72 years). There were 85 men and 33 women, male to female ratio being 2.6:1. Of 118, 15 (13%) had positive DSE and 103 (87%) had negative DSE. Perioperative MACE incidence was 5.9% (95% confidence interval [CI], 2.6–12.3%). In predicting MACE, DSE had sensitivity of 5.6% (95% CI, 0.2–29.4%), specificity 86% (95% CI, 77.3–91.9%), positive predictive value 6.7% (95% CI, 0.3–33.4%), and negative predictive value (NPV) 83.5% (95% CI, 74.6–89.8%). Eighteen patients had MACE in first year post OLT (15%, 95% CI, 9.5–23.3%). Adverse events included cardiogenic shock (2/18), systolic HF (2/18), non-ST-elevated MI (7/18), cardiac mortality (3/18), and all-cause mortality (7/18). The overall complication rate of DSE was 17% (20/118). CONCLUSIONS: In our cohort, DSE had a low sensitivity but high NPV in predicting perioperative MACE post OLT. A similar trend was noted for DSE in predicting 1-year MACE post OLT. We reiterate the need of a better screening and risk stratification tool for OLT.

Eff ect of interventional therapy on chronic total occlusion by doubutamine stress echocardiography evaluation / 中国介入心脏病学杂志

Objective To evaluate the effect of percutaneous coronary intervention (PCI) on chronic total occlusion (OCT) by doubutamine stress echocardiography. Methods Forth-six CTO patients were categorized into the reopening group and failed-reopening group based on the results of PCI. All patients had undergoing low dose doubutamine stress echocardiography before PCI and at 6-month follow-up, measuring rest and stress wall motion score index (WMSI) with semi-quantitative method. Cardiac volumes and ejection fraction were measured with 3D full volume echocardiographic. Results The two groups showed no differences in general clinical data and all baseline echocardiography data before PCI. During follow-up, the reopening group was observed to have improvement in ejection fraction[(60.00±3.22)% vs.(62.65±3.58)%,P=0.017)],and WMSI in stress status[(1.42±0.37)vs.(1.32±0.36),P<0.001], compared with pre-PCI results. The reopening group showed improvement in ejection fraction[(62.65±3.58)% vs.(57.7±5.61)%,P=0.001)]and WMSI in stress status[(1.32±0.36)vs.(1.62±0.47),P<0.001)],when compared with the failed-reopening group. Conclusions Low dose doubutamine stress echocardiography can be nsed for evaluation of the eff ect of revascularization of CTO. The cardiac volumes and contractile function representing by wall motion in stress status were improved after recanalization of CTO.

Head to Head Comparison of Stress Echocardiography with Exercise Electrocardiography for the Detection of Coronary Artery Stenosis in Women

BACKGROUND: Exercise-stress electrocardiography (ECG) is initially recommended for the diagnosis of coronary artery disease. But its value has been questioned in women because of suboptimal diagnostic accuracy. Stress echocardiography had been reported to have comparable test accuracy in women. But the data comparing the diagnostic accuracy of exercise-stress ECG and stress echocardiography directly are few. The aim of the study was to compare the diagnostic accuracy of exercise-stress ECG and dobutamine stress echocardiography (DSE) in Korean women. METHODS: 202 consecutive female patients who presented with chest pain in outpatient clinic, and who underwent treadmill exercise test (TET), DSE and coronary angiography were included for the study. The diagnostic accuracy TET and DSE were calculated by the definition of > 50% or > 75% coronary artery stenosis (CAS). RESULTS: The sensitivity and specificity were higher with DSE (70.4, 94.6%) than TET (53.7, 73.6%) for detection of > 50% CAS. The higher accuracy of DSE was maintained after exclusion of the patients who could not achieve over 85% age predicted heart rate before ischemia induction. DSE also showed greater diagnostic accuracy than TET by > 75% CAS criteria, and in subsets of patient with intermediate pretest probability. CONCLUSION: In the diagnosis of CAS, DSE showed higher accuracy than TET in female patients who presented with chest pain. As well as the test accuracy, adequate stress was more feasible with DSE than TET. These finding suggests DSE may be used as the first-line diagnostic tool in the detection of CAS in women with chest pain.

Assesment of Myocardial Ischemia by Combination of Tissue Synchronisation Imaging and Dobutamine Stress Echocardiography

BACKGROUND AND OBJECTIVES: Dobutamine stress echocardiography (DSE) is an important non-invasive imaging method for evaluating ischemia. However, wall motion interpretation can be impaired by the experience level of the interpreter and the subjectivity of the visual assessment. In our study we aimed to combine DSE and tissue syncronisation imaging to increase sensitivity for detecting ischemia. SUBJECTS AND METHODS: 50 patients with indications for DSE were included in the study. In 25 patients we found DSE positive for ischemia and in the other 25 patients we found it to be negative. The negative group was accepted as the control group. There was no significant difference in terms of risk factors and echocardiographic parameters between the two groups, except for wall motion scores. In both groups, left ventricular dyssychrony was accepted as the difference between time to peak systolic velocity (Ts) in the reciprocal four couple of non-apical segments at rest and during peak stress. Timings were corrected for heart rate. We compared the differences of the dyssynchronisation value at rest and during peak stress to determine the distinctions within the groups and between the groups of DSE positive and negative patients. RESULTS: We found that stress and ischemia did not create any significant difference over the left intraventricular dyssynchrony with DSE, although at the segmenter level it prolonged the time to peak systolic velocity (p<0.05). These alterations did not show any significant difference between positive and negative DSE groups. CONCLUSION: As a result, this segmenter dyssynchrony and the time to peak systolic velocity, which is corrected for heart rate, did not enhance any new value over DSE for detecting ischemia.

Preditores de viabilidade em pacientes com resposta negativa à ecocardiografia de estresse com dobutamina de baixa dose / Predictors of viability in patients with negative low-dose dobutamine stress echocardiograph / Predictores de viabilidad en pacientes con respuesta negativa a la ecocardiografía de estrés con dobutamina de baja dosis

FUNDAMENTO: A ecocardiografia de estresse com dobutamina de baixa dose é um teste específico para predizer disfunção de contratilidade reversível, mas mesmo assim, sua sensibilidade é menor do que ideal. OBJETIVO: Avaliar os preditores de recuperação miocárdica contrátil após a revascularização, em pacientes sem viabilidade na ecocardiografia de estresse com dobutamina de baixa dose. MÉTODOS: Trinta pacientes consecutivos foram selecionados consecutivamente, que apresentavam estenose coronária/oclusão significantes, tratáveis através de revascularização, anormalidade de motilidade de parede regional na distribuição da artéria afetada e ausência de viabilidade na ecocardiografia de estresse com dobutamina de baixa dose. Os pacientes foram submetidos a estudo de imagem com 99mTc-sestamibi em repouso e então submetidos à revascularização coronária bem sucedida. A ecocardiografia de seguimento foi realizada três meses depois. Os pacientes foram classificados em 2 grupos: grupo 1: com evidência de recuperação miocárdica contrátil após a revascularização na ecocardiografia de seguimento e grupo 2: sem evidência de recuperação miocárdica. Os dois grupos foram comparados em relação aos dados clínicos, ecocardiográficos e cintilográficos. RESULTADOS: A média da idade era 52,3 ± 5,9 anos e 97 por cento eram do sexo masculino. A porcentagem de captação total de 99mTc-sestamibi foi significantemente mais alta no grupo 1 quando comparado ao grupo 2 (p < 0,01) e foi o preditor independente mais forte de recuperação miocárdica contrátil no seguimento de 3 meses na análise de regressão multivariada. A curva ROC (Receiver Operating Characteristic) mostrou que um valor de corte da porcentagem de captação total do 99mTc-sestamibi uptake de 72 por cento, foi o melhor preditor da recuperação miocárdica contrátil, com uma sensibilidade de 100 por cento e especificidade de 95.7 por cento. CONCLUSÃO: Em pacientes sem evidência de viabilidade na ecocardiografia de estresse com dobutamina de baixa dose, a porcentagem de captação total do 99mTc-sestamibi prediz, de forma independente, a recuperação miocárdica contrátil após a revascularização coronária.

BACKGROUND: Low-dose dobutamine stress echocardiography is specific for predicting reversible contractility dysfunction, but its sensitivity is lower than ideal. OBJECTIVE: We sought to explore the predictors of myocardial contractile recovery following revascularization, in patients with no viability by low-dose dobutamine stress echocardiography. METHODS: We prospectively enrolled 30 consecutive patients with significant coronary stenosis/occlusion amenable for revascularization, regional wall motion abnormality in the distribution of the affected artery and absence of viability by low-dose dobutamine stress echocardiography. They underwent resting 99mTc-sestamibi imaging study, and then underwent successful coronary revascularization. Follow-up echocardiography was performed 3 months later. Patients were classified into 2 groups: group 1: with evidence of myocardial contractile recovery after revascularization at follow-up echocardiography and group 2: with no such evidence of recovery. The two groups were compared with respect to patients’ clinical, echocardiographic and scintigraphic data. RESULTS: The mean age was 52.3 ± 5.9 years, with 97 percent being males. The percentage of total 99mTc-sestamibi uptake was significantly higher in group 1 as compared to group 2 (p < 0.01), and it was the strongest independent predictor of myocardial contractile recovery at 3-month follow-up by multivariate regression analysis. Receiver operating characteristics curve revealed that a cutoff value of the percentage of total 99mTc-sestamibi uptake of 72 percent best predicted myocardial contractile recovery, with a sensitivity of 100 percent and specificity of 95.7 percent. CONCLUSION: In patients with no viability by low-dose dobutamine stress echocardiography, the percentage of total 99mTc-sestamibi uptake independently predicted myocardial contractile recovery following coronary revascularization.

FUNDAMENTO: La ecocardiografía de estrés con dobutamina de baja dosis es un test específico para predecir disfunción de contractilidad reversible, pero aun así, su sensibilidad es menor que lo ideal. OBJETIVO: Evaluar los predictores de recuperación miocárdica contráctil después de la revascularización, en pacientes sin viabilidad en la ecocardiografía de estrés con dobutamina de baja dosis. MÉTODOS: Treinta pacientes consecutivos fueron seleccionados consecutivamente, que presentaban estenosis coronaria/oclusión significantes, tratables a través de revascularización, anormalidad de motilidad de pared regional en la distribución de la arteria afectada y ausencia de viabilidad en la ecocardiografía de estrés con dobutamina de baja dosis. Los pacientes fueron sometidos a estudio de imagen con 99mTc-sestamibi en reposo y entonces sometidos a revascularización coronaria exitosa. La ecocardiografía de seguimiento fue realizada tres meses después. Los pacientes fueron clasificados en 2 grupos: grupo 1: con evidencia de recuperación miocárdica contráctil después de la revascularización en la ecocardiografía de seguimiento y grupo 2: sin evidencia de recuperación miocárdica. Los dos grupos fueron comparados en relación a los datos clínicos, ecocardiográficos y de cámara gamma. RESULTADOS: La media de edad era 52,3 ± 5,9 años y 97 por ciento eran del sexo masculino. El porcentaje de captación total de 99mTc-sestamibi fue significativamente más alto en el grupo 1 cuando fue comparado al grupo 2 (p <0,01) y fue el predictor independiente más fuerte de recuperación miocárdica contráctil en el seguimiento de 3 meses en el análisis de regresión multivariada. La curva ROC (Receiver Operating Characteristic) mostró que un valor de corte del porcentaje de captación total del 99mTc-sestamibi uptake de 72 por ciento, fue el mejor predictor de la recuperación miocárdica contráctil, con una sensibilidad de 100 por ciento y especificidad de 95.7 por ciento. CONCLUSIÓN: En pacientes sin evidencia de viabilidad en la ecocardiografía de estrés con dobutamina de baja dosis, el porcentaje de captación total del 99mTc-sestamibi predice, de forma independiente, la recuperación miocárdica contráctil después de la revascularización coronaria.

Dobutamine stress echocardiography for evaluating cirrhotic cardiomyopathy in liver cirrhosis / 대한간학회지

BACKGROUND/AIMS: The blunted ventricular systolic and diastolic contractile responses to physical and pharmacological stress in cirrhosis are termed cirrhotic cardiomyopathy (CCM). CCM has been known to involve multiple defects in the beta-adrenergic signaling pathway. The aim of this study was to determine whether cirrhotic patients have blunted cardiac responses to catecholamine stimulation through dobutamine stress echocardiography (DSE). METHODS: Seventy-one cirrhotic patients with normal left ventricular (LV) chamber size and ejection fraction were enrolled. The LV systolic and diastolic functions were evaluated by two-dimensional and Doppler echocardiography at rest and during peak dobutamine infusion (40 microg/kg/min). An abnormal response was defined as a decrease of less than 10% in LV end-diastolic volume, a decrease of less than 20% in end-systolic volume, and an increase of less than 10% in LV ejection fraction (EF) at peak dobutamine infusion, based on previously used criteria. The early/late diastolic flow (E/A) ratio and diastolic parameters were also measured. RESULTS: A blunted LV response to dobutamine was observed in 18 of 71 cirrhotic patients (25.4%). The baseline EF was significantly higher in 18 patients with a blunted DSE response than that of those with a normal DSE response (P<0.05). The baseline and peak E/A ratios, which are common diastolic dysfunction markers, were higher in the cirrhosis group than in the control group (P<0.001). No adverse events associated with DSE were observed. CONCLUSIONS: Blunted cardiac responses to dobutamine stimulation, which are implicated in defects in the beta-adrenergic signaling pathway, might contribute to the pathogenesis of CCM in patients with cirrhosis.

Two-dimensional speckle tracking imaging quantitative assessment of left ventricular global and regional myocardial function in normal rats / 中国医学影像技术

Objective To investigate the value of two-dimensional speckle tracking imaging (2D-STI) in assessing left ventricular global and regional myocardial function in normal rats. Methods Echocardiography was performed during low-dose dobutamine stress in 20 normal adult male Wistar rats. High frame rate of 2D images were recorded from the left ventricular short-axis views at the papillary muscle level. Peak systolic radial strain (PRS) and circumferential strain (PCS) of each segment, left ventricular global peak systolic radial strain (G_(PRS)) and circumferential strain (G_(PCS)) were measured at EchoPAC work station. Left ventricular internal diameter at diastole (LVIDd), systole (LVIDs), fractional shortening (FS) and ejection fraction (EF) were measured with anatomical M-model echocardiography. Dynamic changes of each index during stress experiment were observed. The correlations between EF and left ventricular global two-dimensional strain (G_(PRS), G_(PCS)) were analyzed respectively. Results PRS was similar in all segments of mid-ventricular in short-axis view (P>0.05) at baseline, while PCS of each segment showed heterogeneity, with the anteroseptal and anterior wall showing the largest value and the inferior wall showing the lowest value (P0.05). Conclusion With good reproducibility, 2D-STI can noninvasively and easily assess global and regional left ventricular myocardial deformation of normal rats at rest and during low-dose dobutamine stress.

Comparison Study between Dobutamine Stress Echocardiography Using Real-Time Three Dimensional and Two Dimensional Echocardiography for Diagnosis of Coronary Artery Disease : Dobutamine Stress Echocardiography Using Real-Time Three Dimensional Echocardiogr

BACKGROUND AND OBJECTIVES: Dobutamine stress echocardiography (DSE) with 2D echocardiography (2DE) is one of the time-consuming procedures in the diagnosis of coronary artery disease (CAD). Moreover, the accuracy of DSE with 2DE depends on the operator's skill or bias during the image acquisition. This study was conducted to determine the feasibility and accuracy of DSE with real-time 3D echocardiography (RT3DE) for the diagnosis of CAD. SUBJECT AND METHODS: 62 patients (RT3DE: 36, 2DE: 26), suspected of angina pectoris and post-revascularization ischemia, underwent DSE and coronary angiography (CAG). Image acquisition was performed at the baseline, and at 4 times during the dobutamine infusion and recovery stages. The procedure time (from the baseline to the end of the peak dose stage) was recorded. Off-line analyses of the volumetric images acquired with RT3DE were performed using 3D computer software (TomTec, Co.). Digitized quad-screen images acquired with 2DE were analyzed using the 2DE review system (ProSolv 4.0). >50% luminal diameter stenosis of any coronary artery on CAG was defined as significant coronary artery stenosis. RESULTS: The procedure time of DSE with RT3DE was significantly shorter than that of DSE with 2DE (25+/-4 vs. 37+/-4 mins, p0.05) or specificity (p>0.05) between the two procedures. CONCLUSION: DSE with RT3DE seems to be a feasible and less time consuming diagnostic procedure, probably providing comparable sensitivity and specificity for the detection of coronary artery stenosis, than DSE with 2DE.

Hemodynamic Responses during Dobutamine Stress Echocardiography according to Stage Duration in Normals

BACKGROUND: The 3 minutes increment of dobutamine dose protocol is most commonly used method in dobutamine stress echocardiography (DSE). But the precise hemodynamic response to dobutamine dosage and its difference by extending stage duration have not been well elucidated. MATERIALS AND METHOD: Nineteen healthy voluntary subjects with a mean age of 23.9+/-4.7 years were included. All subjects underwent 3-minutes incremental and 5-minnutes incremental protocol of DSE at random order in a same day. Heart rate, blood pressure, stroke volume, fractional shortening, rate-pressure product and cardiac output were measured every 3 minutes in 3-min protocol of DSE. In 5-min protocol, same variables were measured at 3 minutes of each stage as well as at 5 minutes. RESULTS: 1) Heart rate did not increase until 10 microgram/kg/min dose and increased thereafter by increment of dobutamine dose. 2) Fractional shortening and stroke volume increased markedly from the 5 microgram/kg/min until 20 microgram/kg/min dose and showed slow increase or plateau at a higher dobutamine dose. 3) Systolic blood pressure, cardiac output and rate-pressure product increased continuously from initial dose to maximal dose. 4) Although by extending stage duration to 5 minute in 5-min protocol produced greater hemodynamic effects than those measured at 3 minutes of each stage, there were no significant difference in the results of 3-min and 5-min protocol of DSE. CONCLUSION: The increase of cardiac contractility most contributed to increase of cardiac output until 20microgram/kg/min dose and the increase of herat rate contributed dominantly thereafter, thus the hemodynamic variables showed different responses to increment of dobutamine dose. There were no significant difference in hemodynamic effects between the two protocols. So it is considered that 3-min protocol of DSE gives similar hemodynamic information as 5-min protocol and is more time-saving method.

Comparison of Dobutamine Echocardiography and Thallium Scan in Assessment of Viable Myocardium After Acute Myocardial Infarction

BACKGROUND: It is clinically important to evaluate myocardial viability after acute myocardial infarction. There are several methods like dobutamine stress echocardiography (DSE) and thallium scan to identify viable myocardium. Thallium SPECT assesses cellular integrity and dobutamine stress echocardiography assesses contractile reserve of myocardium. METHODS: Between March and August 1995, 30 consecutive patients (27 men and 3 women; mean age 52+/-12years) within 3 weeks after acute myocardial infarction were admitted to Asan Medical Center. Each underwent two-dimensional echocardiography before and during dobutamine infusion 8.6+/-6.5 days after acute myocardial infarction and thallium scan with rest-redistribution or stress-redistribution-reinjection protocol 8.1+/-6.4 days after acute myocardial infarction. Viability myocardium was considered if there were improvement in regional wall motion during dobutamine infusion (5, 10mg/kg/min for 5min and 20, 30mg/kg/min for 3min), With thallium SPECT, myocardial viability was considered if regional wall motion was normal, if perfusion defect, were either completely or partial mildly reversible, or if myocardial perfusion decreasedly or moderately and if irreversible perfusion was defect. Follow-up echocardiography was performed 3+/-1 months after acute myocardial infarction. Recovery of regional function was identified when follow-up echocardiography showed improvement of wall motion. We evaluated the accuracy of dobutamine stress echocardiography and thallium scan by concordant interpretation in acute and follow-up studies. RESULTS: Among the enrolled 30 patients, 27 patients had Q-wave MI. Thrombolysis was performed in 17 patients (57%) and PTCA was done in 18 patients (60%). The location of myocardial infarction wall in 20 patients and the inferior and lateral wall in 10 patients. Dobutamine stress echocardiography was performed safely in 30 patients 8.6+/-6.5 days after acute myocardial infarction. Improved wall motion was apparent in 15 patients (50%) after follow-up echocardiography 3+/-1 months after acute myocardial infarction. The positive and negative predictive values of dobutamine stress echocardiography were 14/17 (82%) and 12/13 (92%), respectively. Thallium SPECT was done in 26 patients 8.1+/-6.4 days after acute myocardial infarction. Among these 26 patients, follow-up echocardiography showed improved wall motion in 12 patients. The positive and negative predictive values of thallium SPECT were 9/10 (90%) and 13/16 (80%), respectively. Positive dobutamine stress echocardiography (r=0.46, p=0.001), positive thallium SPECT (r=0.44, p=0.003), hypokinetic segments (p=0.01) and non-anterior MI (p=0.02) were associated with reversible postischemic dysfunction. CONCLUSION: Dobutamine stress echocardiography (DSE) can be safely performed early after acute myocardial infarction. Both dobutamine stress echocardiography and thallium SPECT are reliable and complementary methods to diagnose viable myocardium.

Usefulness of Dobutamine Stress Echocardiography for Detecting Restenosis after Coronary Artery Stenting

BACKGROUND AND OBJECTIVES: A noninvasive test with a high predictive value for detecting restenosis is needed to reduce the need for unnecessary coronary angiography. Recently, dobutamine stress echocardiography(DSE) has been shown to be highly sensitive, specific and accurate for the detection of coronary artery disease. No prior study, however, has evaluated its ability to detect restenosis after intracoronary stenting. The aim of this study was to determine the feasibility of DSE for detecting restenosis after intracoronary stenting. METHODS: To determine the feasibility of DSE for detecting restenosis after intracoronary stenting, the results of follow-up coronary angiography and DSE and treadmill exercise test(TMET) were examined in 36 patients(age, 61+/-6 yeas; 22 men) at least 4 months after angiographically successful intracoronary stenting. The DSE and TMET were performed at day 1. Dobutamine was infused with starting at a dose of 10 microgram/kg/min for 3 minutes, and increasing by 10microgram/kg/min every 3 minutes to a maximum of 40microgram/kg/min. In patients not achieving 85% of their age-predicted maximal heart rate, atropine (0.25mg intravenously, repeated up to maximum of 1mg if necessary) was added while the dobutamine infusion was continued. Positive findings for restenosis were defined as new or worsened wall motion abnormality at a previously dilated vascular territories. The coronary angiography was performed at day 2. Restenosis was defined as > or =50% lumen narrowing, determined by quantitative coronary angiography. RESULTS: Restenosis was angiographically demonstrated in 14 lesions(34.1%) of 41 lesions. The sensitivity and specificity of DSE for detecting restenosis was 50%(7/14) and 96.2%(26/27), and positive predictive value was 87.5%(7/8), negative predictive value was 78.8%(26/33), respectively. When restenosis was defined as > or =60% lumen narrowing, the sensitivity and specificity of DSE for detecting restenosis was 66.7%(6/9) and 96.9%(31/32), respectively. The target lesion revascularization rate(TLR) was 17%(7/41). The sensitivity of DSE for determining TLR was 85.7% (6/7) and specificity was 97.0%(33/34). CONCLUSION: It is concluded that DSE has a moderate sensitivity and high specificity for detecting restenosis after intracoronary stenting. DSE may be a useful diagnostic modality for determining target lesion revascularization of restenotic lesion but further studies are needed.

Significance of Left Ventricle Chamber Obliteration in Dobutamine Stress Echocardiography

BACKGROUND: LV chamber obliteration(COB) during dobutamine stress echocardiography indicates a vigorous inotropic response to dobutamine stress. This may suggest the absence of coronary artery disease, but a small LV cavity may also preclude recognition of wall motion abnormalities. METHODS: Chamber obliteration was defined by contact of the opposite walls in the apical 4 chamber views during dobutamine stress echocardiography. To detect of chamber obliteration and coronary artery disease, dobutamine stress echocardiography was performed in 132 patients with chest pain. To confirm of coronary artery disease, coronary angiography was performed in 64 patients among 132 patients. RESULTS: 1) Chamber obliteration during dobutamine stress echocardiography occurred in 37 patients(28%) among 132 patients. 2) Chamber obliteration during dobutamine stress echocardiography was more common in patients with hypertension(p<0.05) and left ventricular hypertrophy during baseline echocardiography(p<0.005). 3) Coronary angiography was performed in 64 patients(48 patients without chamber obliteration, 16 patients with chamber obliteration). The sensitivity of dobutamine stress echocardiography in the diagnosis of coronary artery disease was 88% in patients without chamber obliteration, 71% in patients with chamber obliteration. But, the difference of sensitivity of both groups was not significant. CONCLUSION: These results suggest that chamber obliteration during dobutamine stress echocardiography will not affect results of the sensitivity of dobutamine stress echocardiography in the diagnosis of coronary artery disease.

Usefulness of Dobutamine Stress Echocardiography for Identification of Viable Myocardium in Acute Myocardial Infarction

BACKGROUND: In patients with acute myocardial infarction(MI), dysfunctional myocardium at rest after successful reperfusion may represent either necrotic or viable myocardium. And the latter can be recovered contractility after revascularization or medication. OBJECTIVE: To evaluate the efFectiveness of the dobutamine stress echocardiography(DSE) for identifying viable but dysfunctional myocardium in acute MI before revascularization. METHOD: Twelve patients with acute MI after thrombolytic therapy underwent Tc-99m-tetrofosmin dipyridamole myocardial SPECT(Single Photon Emission Computed Tomography) and DSE before coronary angiography in 7~12 hospital days, and they were followed up for recovery of contractile reserve by two-dimensional echocardiography after revascularization procedure or medication. Regional wall motion abnorrnality was scored from l(normal) to 4(dyskinesia). Dobutamine responsiveness was defined as irnprovement or aggravation of regional wall motion in dyssynergic segment during any stage of dobutamine infusion. Reversible ischemia by SPECT was defined as increased perfusion defect after dipyridamole and interpreted by radiologist. Dobutamine responsiveness on DSE and reversible ischemia on myocardial SPECT were matched and compared each other. RESULTS: Of 69 dyssynergic segments, 38(55%) recovered contractility during follow up echocardiography after revascularization or medication. In 30(79%, sensitivity) of these latter segments, regional wall motion had changed during dobutamine. However, 31(45%) did not recovered contractility and 25(81%, specificity) of thern had not changed during dobutamine. Of 36 dobutamine responsive dyssynergic segments, 30(83%, positive predictive accuracy) had recorved contractility. In 25(76%, negative predictive accuracy) of 33 dobutamine non-responsive segments had not recovered contractility. Reversible ischemia on myocardial SPECT showed less sensitive(67%) and specific(56%) for detection of potentially recoverable myocardium than DSE. And positive(68%) and negative predictive accuracy(56%) also showed significantly lower than DSE. CONCLUSION: DSE can identify dyssynergic but recoverable myocardial segement for risk stratification before intervention in acute MI. Dobutamine responsiveness of dyssynergic segment is superior to reversible ischemia on myocardial SPECT for prediction of wall motion improvement after MI irrespective of intervention or medical therapy.

Hemodynamic Variables during Dobutamine Stress Echocardiography and Peak Oxygen Uptake during Exercise in Patients with Mitral Stenosis

BACKGROUND: This study was performed to evaluate the feasibility of dobutamine stress as an alternative to exercise and to determine the hemodynamic variables affecting exercise capacity in patients with mitral stenosis. METHODS: Hemodynamic variables were measured using Doppler echocardiography at rest and during dobutamine stress. Measured hemodynamic variables were compared with peak oxygen uptake(peak VO2) and percent predicted peak oxygen uptake(peak %VO2) obtained by the maximal symptom-limited cardiopulmonary exercise test. Thirteen patients with isolated pure mitral stenosis in sinus rhythm. RESULTS: Mean transmitral gradient(9.6+/-5.0mmHg to 17.3+/-7.6mmHg, p<0.01) and mean pulmonary artery systolic pressure(40.1+/-14.2mmHg to 66.4+/-23.1mmHg, p<0.01) increased significantly during dobutamine stress. Mean mitral valve area(0.82+/-0.38cm to 0.89+/-0.36cm, p <0.01) also increased significantly during dobutamine stress, however, changes in the area was not significantly different from the differences in intraobserver variation(0.06+/-0.06cm). In multivariate analysis, only pulrnonary artery systolic pressure during dobutamine stress correlated with peak VO2(r= -0.58, p<0.05) and peak %VO2(r= -0.60, p<0.05). CONCLUSIONS: Dobutamine stress can be an alternative to exercise in patients with mitral stenosis and pulmonary artery systolic pressure during dobutamine stress could provide information relating to exercise capacity.

Usefulness of Dobutamine Stress Echocardiography for Assessment of cardiac Risk before Noncardiac Surgery

BACKGROUND: Two-dimensional echocardiography performed during incremental infusion of dobutamine has been shown to be a safe and accurate method for detection of coronary artery disease in patients who are unable to undergo conventional exercise testing. A significant proportion of these patients are referred for evaluation before undergoing noncardiac surgery. METHOD: To assess the value of dobutamine stress echocardiography(DSE), for assessment of preoperative cardiac risk, 88 patients (male : 32, female : 56, mean age : 60 years) were evaluated. patients records were reviewed to determine the short-term outcome of surgery. significant cardiac events were defined as unstable angina, myocardial infarction and sudden cardiac death occurred before discharge. Intravenous dobutamine was infused in a graded fashion (10 to 45µg/kg/min in 3 minutes stages), with two-dimensional echocardiographic monitoring of segmental wall motion of left ventricle. RESULTS: 1) The major reasons underwent dobutamine stress echocardiography were abnormalities of ECG such as ST-T changes, abnormal Q wave(65% : 64 of 98 patients) and history of coronary artery disease(29% : 28 of 98 patients). 2) Of the 88 patients who underwent noncardiac surgery, 85(97%) patients were negative response in dobutamine stress echocardiography, and no patients had cardiac events, also 3(3%) patients who had positve response did not occur cardiac events. 3) No major adverse effects occurred with stress test in any patient. CONCLUSION: These results suggest that DSE is useful preoperative diagnostic method for predicting short-term surgical outcome in patients with suspicous coronary artery disease undergoing noncardiac surgery.

Diagnosis of Latent Hypertrophic Obstructive Cardiomyopathy with Dobutamine Stress Echocardiography

BACKGROUND: In latent type of hypertrophic obstructive cardiomyopathy, there is no pressure gradient at rest in left ventricular outflow tract(LVOT), but it develops with provocation. Dobutamine increase myocardial contractility and may inducce outflow tract obstruction. To evaluate the usefulness of dobutamine induced outflow tract obstruction as a provocation test, nine patients with latent obstructive cardiomyopathy were studied. METHOD: 680 cases of dobutamine stress echocardiography were reviewed. Nine patients developed late peaking outflow velocity pattern in response to dobutamine infusion(inducible group). Ten patients developed early peaking velocity pattern were included as control group. Left ventricular dimension, outflow tract diameter were measured, and pattern of septal hypertrophy was classified. Changes of peak velocity and acceleration time/ejection time ratio (AT/ET) were measured at rest and peak dose dobutamine. RESULTS: The peak outflow velocity at rest was not different in both groups(1.49±0.45, 1.18±0.11m/sec). Peak velocity and AT/ET ratio were significantly increased in inducible group(4.2±0.9m/sec, 0.66±0.17), but no significant changes were noted in control group. Patients with inducible group had greater septal thickness, smaller outflow tract diameter and greater prevalence of septal bulge morphology. CONCLUSION: These results suggest that dobutamine stress Doppler echocardiography could be a useful provocation test to diagnosis of latent obstructive cardiogyopathy.