Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction?

Background: Estimative of left ventricular ejection fraction (LVEF) is a major indication for echocardiography. Speckle tracking echocardiography (STE) allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS) and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before. Objective: This study aims to check which one has the highest correlation with LVEF. Methods: Patients with normal LVEF (> 0,55) and systolic dysfunction (LVEF <0,55) were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested. Results: A total of 131 patients were included (mean age, 46 ± 14y; 43%, men). LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001), more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001). Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001); torsion (r = 0.75; r2 = 0.56; p < 0.001). Conclusion: GLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS.

Fundamento: A estimativa da fração de ejeção do ventrículo esquerdo (FEVE) é uma das pincipais indicações para a ecocardiografia. Speckle tracking (ST) permite a análise da mecânica de contração do VE que inclui a deformação (strain) longitudinal global (SLG) e o twist / torção, sendo ambos os mais utilizados. A comparação direta de correlações entre esses novos parâmetros e a FEVE nunca foi feita antes. Objetivo: Verificar qual delas tem a maior correlação com a FEVE. Métodos: Pacientes com FEVE normal (> 0,55) e disfunção sistólica (FEVE < 0,55) foram prospectivamente inscritos e submetidos a ecocardiograma com análise do ST. A correlação das variáveis foi realizada por análise de regressão linear. Além disso, também foi testada a correlação entre os níveis de comprometimento sistólico do VE. Resultados: Foram incluídos 131 pacientes (média de idade de 46 ± 14 anos e 43% de homens). A FEVE e SLG apresentaram forte correlação (r = 0,95; r2 = 0,89; p < 0,001), mais evidente em grupos com disfunção sistólica do VE do que naqueles com FEVE preservada. Também foi encontrada boa correlação com a taxa de deformação (strain rate) longitudinal (SRL) global (r = 0,85; r2 = 0,73; p < 0,001). Comparando-a à SLG, a correlação entre FEVE e mecânica de torção foi mais fraca: twist (r = 0,78; r2 = 0,60; p < 0,001); Torção (r = 0,75, r2 = 0,56, p < 0,001). Conclusão: A SLG do ventrículo esquerdo apresenta alta correlação positiva com o parâmetro clássico de fração de ejeção, principalmente nos casos de comprometimento sistólico do VE. O SRL também demonstrou uma boa correlação. A SLG incrementa a análise da função sistólica do VE. Por outro lado, apesar de ser a pedra angular da mecânica do VE, o twist e a torção têm uma correlação mais fraca com a ejeção do VE, quando comparados ao SLG.

Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction? / Strain Longitudinal Global ou Twist do Ventrículo Esquerdo e Torção? Qual se Correlaciona Melhor com a Fração de Ejeção?

Abstract Background: Estimative of left ventricular ejection fraction (LVEF) is a major indication for echocardiography. Speckle tracking echocardiography (STE) allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS) and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before. Objective: This study aims to check which one has the highest correlation with LVEF. Methods: Patients with normal LVEF (> 0,55) and systolic dysfunction (LVEF <0,55) were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested. Results: A total of 131 patients were included (mean age, 46 ± 14y; 43%, men). LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001), more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001). Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001); torsion (r = 0.75; r2 = 0.56; p < 0.001). Conclusion: GLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS.

Resumo Fundamento: A estimativa da fração de ejeção do ventrículo esquerdo (FEVE) é uma das pincipais indicações para a ecocardiografia. Speckle tracking (ST) permite a análise da mecânica de contração do VE que inclui a deformação (strain) longitudinal global (SLG) e o twist / torção, sendo ambos os mais utilizados. A comparação direta de correlações entre esses novos parâmetros e a FEVE nunca foi feita antes. Objetivo: Verificar qual delas tem a maior correlação com a FEVE. Métodos: Pacientes com FEVE normal (> 0,55) e disfunção sistólica (FEVE < 0,55) foram prospectivamente inscritos e submetidos a ecocardiograma com análise do ST. A correlação das variáveis foi realizada por análise de regressão linear. Além disso, também foi testada a correlação entre os níveis de comprometimento sistólico do VE. Resultados: Foram incluídos 131 pacientes (média de idade de 46 ± 14 anos e 43% de homens). A FEVE e SLG apresentaram forte correlação (r = 0,95; r2 = 0,89; p < 0,001), mais evidente em grupos com disfunção sistólica do VE do que naqueles com FEVE preservada. Também foi encontrada boa correlação com a taxa de deformação (strain rate) longitudinal (SRL) global (r = 0,85; r2 = 0,73; p < 0,001). Comparando-a à SLG, a correlação entre FEVE e mecânica de torção foi mais fraca: twist (r = 0,78; r2 = 0,60; p < 0,001); Torção (r = 0,75, r2 = 0,56, p < 0,001). Conclusão: A SLG do ventrículo esquerdo apresenta alta correlação positiva com o parâmetro clássico de fração de ejeção, principalmente nos casos de comprometimento sistólico do VE. O SRL também demonstrou uma boa correlação. A SLG incrementa a análise da função sistólica do VE. Por outro lado, apesar de ser a pedra angular da mecânica do VE, o twist e a torção têm uma correlação mais fraca com a ejeção do VE, quando comparados ao SLG.

Comprehensive left ventricular mechanics analysis by speckle tracking echocardiography in Chagas disease.

BACKGROUND: Chagas disease (CD) is a frequent cause of dilated cardiomyopathy (CMP) in developing countries, leading to clinical heart failure and worse prognosis. Therefore, the development and evolution of this CMP has always been a major topic in numbers of previous studies. A comprehensive echocardiographic study of left ventricular (LV) mechanics, fully assessing myocardial contraction, has never been done before. This could help characterize and improve the understanding of the evolution of this prevalent CMP. METHODS: A total of 47 chagasic and 84 control patients were included in this study and allocated in groups according to LV ejection fraction. 2D-Echocardiogram was acquired for LV mechanics analysis by speckle tracking echocardiography. RESULTS: Mean age of chagasic individuals was 55y and 16 (34 %) were men. Significant difference was found in global longitudinal velocity analysis, with lower values in indeterminate form. In the group with severe systolic dysfunction, a paradoxical increase in longitudinal and apical radial displacements were demonstrated. In parallel, segmental analyzes highlighted lower values of radial displacement, strain and strain rate into inferior and inferolateral walls, with increase of these values in septal and anterior walls. CONCLUSION: Chagasic CMP has a vicarious pattern of contraction in the course of its evolution, defined by reduced displacement and strain into inferior and posterior walls with paradoxical increase in septal and anterior segments. Also, lower longitudinal velocities were demonstrated in CD indeterminate form, which may indicate an incipient myocardial injury.

Incremental value of perfusion over wall-motion abnormalities with the use of dobutamine-atropine stress myocardial contrast echocardiography and magnetic resonance imaging for detecting coronary artery disease.

BACKGROUND: Recently, multimodality imaging has been demonstrated to improve the sensitivity of dobutamine stress for the diagnosis of coronary artery disease (CAD). OBJECTIVE: We sought to determine the additional value of myocardial perfusion (MP) over wall-motion (WM) analysis for detecting CAD, using real time myocardial contrast echocardiography (RTMCE) and cardiovascular magnetic resonance (CMR), in the same group of patients. METHODS: We studied 42 patients who underwent RTMCE and CMR during high-dose dobutamine stress with early injection of atropine. RESULTS: No difference was observed in the diagnostic accuracy of RTMCE and CMR for detecting angiographically significant CAD when considering WM analysis alone (73% [95% CI, 65-81] and 78% [95% CI, 70-84], respectively; P = NS) or combined analysis of WM and MP (80% [95% CI, 73-97] and 83% [95% CI, 77-90], respectively; P = NS). Combined analysis of WM and MP had higher sensitivity than the analysis of WM alone by RTMCE (88% [95% CI, 75-100] vs. 72% [95% CI, 54-90]) and by CMR (92% [95% CI, 81-100] vs. 80% [95% CI, 64-96]) with no differences in specificity. The association of abnormal WM and MP abnormalities during high-dose dobutamine-atropine stress had additional value for detecting CAD over the analysis of WM alone, both by RTMCE (χ(2) = 16.16-24.13; P = 0.005) and CMR (χ(2) = 12.73-27.41; P = 0.001). CONCLUSION: RTMCE and CMR using the same dobutamine-atropine stress protocol had comparable diagnostic accuracies for the detection of angiographically significant CAD. MP imaging had additional value over WM analysis for the diagnosis of CAD, both at RTMCE and CMR.

Dynamic changes in microcirculatory blood flow during dobutamine stress assessed by quantitative myocardial contrast echocardiography.

BACKGROUND: Although dobutamine-atropine stress echocardiography (DASE) has been widely used for evaluating patients with coronary artery disease (CAD), dynamic changes that occur at microcirculatory level during each stage of stress have not been demonstrated in humans. AIM: We sought to determine variations in myocardial blood flow (MBF) during DASE using quantitative real time myocardial contrast echocardiography (RTMCE). METHODS: We studied 45 patients who underwent coronary angiography and RTMCE. Replenishment velocity of microbubbles in the myocardium (ß) and MBF reserves were obtained at baseline, intermediate stage (70% of maximal predicted heart rate), peak stress, and recovery phase. RESULTS: ß and MBF reserves were lower in patients with than without CAD at intermediate (1.65 vs. 2.10; P=0.001 and 2.44 vs. 3.23; P=0.004) and peak (1.63 vs. 3.00; P<0.001 and 2.14 vs. 3.98; P<0.001, respectively). In patients without CAD, ß, and MBF reserves increased from intermediate to peak and decreased at recovery, while in those without CAD reserves did not change significantly. Optimal cutoff values of ß reserve at intermediate, peak, and recovery were 1.78, 2.09, and 1.70, with areas under the curves of 0.80 (95%CI=0.67-0.94), 0.89 (95%CI=0.79-0.99), and 0.69 (95%CI=0.53-0.85). Sensitivity, specificity and accuracy for detecting CAD at intermediate stage were 68% (95%CI=48-89), 85% (95%CI=71-98), and 78% (95%CI=66-90), at peak stress were 79% (95%CI=61-97), 96% (95%CI=89-100), and 89% (95%CI=80-98), and at recovery were 74% (95%CI=54-93), 65% (95%CI=47-84), and 69% (95%CI=55-82), respectively. CONCLUSION: RTMCE allows for quantification of dynamic changes in microcirculatory blood flow at each stage of DASE. The best parameter for detecting CAD in all stages was ß reserve.

Ecocardiografia com contraste miocárdico e cintilografia de perfusão miocárdica sincronizada ao eletrocardiograma na avaliação de pacientes com torácica / Contrast echocardiography and gated perfusion imaging in the evaluation of patients with chest pain

Introdução: A avaliação de pacientes com dor torácica é muitas vezes problemática. O desafio em diagnosticar corretamente a etiologia da dor torácica é dificultado pela baixa sensibilidade dos métodos diagnósticos disponíveis. Neste estudo, avaliou-se a utilidade diagnóstica da ecocardiografia com contraste miocárdico (MCE) e da cintilografia de perfusão miocárdica sincronizada ao eletrocardiograma (G-SPECT) para detecção de isquemia miocárdica. Métodos e Resultados: Dezoito pacientes atendidos no pronto socorro, para avaliação da dor torácica sugestiva de angina, foram submetidos à MCE e G-SPECT. Para ambos os métodos, a perfusão miocárdica e a mobilidade foram avaliados nos mesmos sete segmentos do ventrículo esquerdo. As imagens foram classificadas como positivas ou negativas para isquemia. Um segmento era considerado positivo na presença de um defeito da perfusão ou uma anomalia do movimento da parede. A cinecoronariografia foi realizada se MCE ou G-SPECT foram classificados como positivos para isquemia. Se ambos os exames foram negativos, o paciente foi submetido ao SPECT de estresse no dia seguinte. Sensibilidade e especificidade para detecção de isquemia miocárdica foram, respectivamente: A) G-SPECT: 1. avaliação de perfusão: 100 por cento e 75 por cento; 2. avaliação de contração: 66 por cento e 91,6 por cento; 3. associação perfusão+contração: 66 por cento e 91,6 por cento. B) MCE: 1. avaliação de perfusão: 20 por cento e 76 por cento; 2. avaliação de contração: 33,3 por cento e 83,3 por cento; 3. associação perfusão...

Qualitative and quantitative real time myocardial contrast echocardiography for detecting hibernating myocardium.

BACKGROUND: Real time myocardial contrast echocardiography (RTMCE) is an emerging imaging modality for assessing myocardial perfusion that allows for noninvasive quantification of regional myocardial blood flow (MBF). AIM: We sought to assess the value of qualitative analysis of myocardial perfusion and quantitative assessment of myocardial blood flow (MBF) by RTMCE for predicting regional function recovery in patients with ischemic heart disease who underwent coronary artery bypass grafting (CABG). METHODS: Twenty-four patients with coronary disease and left ventricular systolic dysfunction (ejection fraction <45%) underwent RTMCE before and 3 months after CABG. RTMCE was performed using continuous intravenous infusion of commercially available contrast agent with low mechanical index power modulation imaging. Viability was defined by qualitative assessment of myocardial perfusion as homogenous opacification at rest in ≥2 segments of anterior or ≥1 segment of posterior territory. Viability by quantitative assessment of MBF was determined by receiver-operating characteristics curve analysis. RESULTS: Regional function recovery was observed in 74% of territories considered viable by qualitative analysis of myocardial perfusion and 40% of nonviable (P = 0.03). Sensitivity, specificity, positive and negative predictive values of qualitative RTMCE for detecting regional function recovery were 74%, 60%, 77%, and 56%, respectively. Cutoff value of MBF for predicting regional function recovery was 1.76 (AUC = 0.77; 95% CI = 0.62-0.92). MBF obtained by RTMCE had sensitivity of 91%, specificity of 50%, positive predictive value of 75%, and negative predictive value of 78%. CONCLUSION: Qualitative and quantitative RTMCE provide good accuracy for predicting regional function recovery after CABG. Determination of MBF increases the sensitivity for detecting hibernating myocardium.

Value of adenosine infusion for infarct size determination using real-time myocardial contrast echocardiography.

BACKGROUND: Myocardial contrast echocardiography has been used for determination of infarct size (IS) in experimental models. However, with intermittent harmonic imaging, IS seems to be underestimated immediately after reperfusion due to areas with preserved, yet dysfunctional, microvasculature. The use of exogenous vasodilators showed to be useful to unmask these infarcted areas with depressed coronary flow reserve. This study was undertaken to assess the value of adenosine for IS determination in an open-chest canine model of coronary occlusion and reperfusion, using real-time myocardial contrast echocardiography (RTMCE). METHODS: Nine dogs underwent 180 minutes of coronary occlusion followed by reperfusion. PESDA (Perfluorocarbon-Exposed Sonicated Dextrose Albumin) was used as contrast agent. IS was determined by RTMCE before and during adenosine infusion at a rate of 140 mcg.Kg(-1).min(-1). Post-mortem necrotic area was determined by triphenyl-tetrazolium chloride (TTC) staining. RESULTS: IS determined by RTMCE was 1.98 +/- 1.30 cm2 and increased to 2.58 +/- 1.53 cm2 during adenosine infusion (p = 0.004), with good correlation between measurements (r = 0.91; p < 0.01). The necrotic area determined by TTC was 2.29 +/- 1.36 cm2 and showed no significant difference with IS determined by RTMCE before or during hyperemia. A slight better correlation between RTMCE and TTC measurements was observed during adenosine (r = 0.99; p < 0.001) then before it (r = 0.92; p = 0.0013). CONCLUSION: RTMCE can accurately determine IS in immediate period after acute myocardial infarction. Adenosine infusion results in a slight better detection of actual size of myocardial damage.

Detection of functional recovery using low-dose dobutamine and myocardial contrast echocardiography after acute myocardial infarction treated with successful thrombolytic therapy.

OBJECTIVE: We studied the value of low-dose dobutamine stress echocardiography (LDDE) and myocardial contrast echocardiography (MCE) in early prediction of left ventricular functional recovery (LVFR) after acute myocardial infarction (AMI) treated with successful thrombolysis. DESIGN: LDDE and MCE using second-harmonic intermittent imaging were performed in first week after AMI. LVFR was defined as an absolute > or =5% increase in ejection fraction, from early to 6 months of follow-up by Technetium-99m-Sestamibi single-photon emission computed tomography. PATIENTS: Out of 50 patients studied, 19 evolved with LVFR (group 1) and 31 without LVFR (group 2). Regional dysfunction was detected in 103 (37%) infarcted-related segments in group 1 and in 173 (63%) segments in group 2. RESULTS: Sensitivity, specificity, positive, and negative predictive values and accuracy for detecting LVFR by LDDE were 94.7% (18/19), 87.1% (27/31), 81.8% (18/22), 96.4% (27/28), and 90% (45/50), respectively, and by MCE were 94.7% (18/19), 51.6% (16/31), 54.5% (18/33), 94.1% (16/17), and 68% (34/50). In group 1, functional improvement was observed in 86.9% (53/61) of segments with contractile reserve by LDDE and in 65.8% (52/79) of segments with microvascular perfusion by MCE. In group 2, functional improvement was observed in 78.3% (18/23) of segments with contractile reserve by LDDE and in 25.5% (25/98) of segments with microvascular perfusion by MCE. All segments without perfusion by MCE evolved without functional recovery. CONCLUSION: LDDE was an accurate predictor of late left ventricular function recovery after AMI, while MCE was sensitive and has a high negative predictive value demonstrating that microvascular perfusion is essential for LVFR.

Papel da ecodopplercardiografia na avaliação da hipertensão arterial pulmonar / Evaluation of pulmonary hypertension with dopper echodopplercardiography

A adequada avaliação dos níveis de pressão na artéria pulmonar é fundamental para o diagnóstico e manuseio de pacientes com hipertensão arterial pulmonar (HAP) de qualquer etiologia. A ecocardiografia é um método nãoinvasivo, de baixo custo e amplamente disponível, que permite a avaliação anatômica e funcional das cavidades cardíacas direitas e a estimativa das pressões em artéria pulmonar, apresentando boa correlação com dados hemodinâmicos obtidos pelo cateterismo cardíaco. O mais preciso e confiável método utilizado pela ecocardiografia para a estimativa das pressões em artéria pulmonar é baseado na medida da velocidade do fluxo regurgitante da valva tricúspide, embora elas possam também ser estimadas pelo fluxo regurgitante pulmonar ou pela análise do fluxo sistólico pulmonar. Quando a qualidade da imagem obtida pela abordagem transtorácica não permite a avaliação adequada da anatomia cardíaca, a ecocardiografia transesofágica torna-se procedimento extremamente útil para complementar essa avaliação, permitindo, por vezes, a detecção de seus possíveis mecanismos causais. A ecocardiografia pode ser utilizada não só para o diagnóstico da HAP, mas também para orientar a conduta terapêutica e para a avaliação prognóstica desses pacientes. Em casos de tromboembolismo pulmonar agudo, já foi demonstrado que a detecção de disfunção ventricular direita pela ecocardiografia é um dado importante na indicação de terapia trombolítica. Da mesma forma, o método tem seu valor estabelecido para monitorização da resposta terapêutica em pacientes com HAP primária, na avaliação prognóstica de pacientes com doença pulmonar obstrutiva crônica e no acompanhamento de pacientes submetidos a transplante pulmonar.