Left atrial deformation analysis by speckle tracking echocardiography to predict exercise capacity after myocardial infarction.

INTRODUCTION: Left atrial (LA) size and function are associated with outcome after myocardial infarction (MI). In this study we aimed to assess the impact of LA function as a predictor of exercise capacity through speckle tracking echocardiography. METHODS: A total of 94 patients (mean age 54.8±11.0 years; 82% male) were enrolled one month after MI. Echocardiography was used to assess LA volumes and various indices of LA conduit, contraction and reservoir function. LA deformation was assessed by two-dimensional speckle tracking to calculate strain and strain rate at different phases of the cardiac cycle. Exercise capacity was assessed by oxygen uptake (VO2) on cardiopulmonary exercise testing. RESULTS: Increased LA volumes, especially LA volume before atrial contraction, were correlated with reduced peak VO2 and reduced VO2 at anaerobic threshold. Decreased peak VO2 was associated with reduced LA conduit function (ρ=0.24; p=0.02), but not with LA booster function (ρ=-0.07; p=0.53). Lower peak atrial longitudinal strain was associated with worse exercise capacity (ρ=0.24; p=0.02). CONCLUSIONS: After MI, increased LA volumes were markers of decreased functional capacity that was associated with decreased LA conduit function, but not with LA contractile function. In these patients, LA longitudinal strain analysis may be useful to predict reduced exercise capacity.

Cardiac computed tomography previous to atrial fibrillation ablation - effects of technological improvements and protocol optimization. / Tomografia computorizada cardíaca prévia a ablação de fibrilhação auricular ­ efeitos da evolução tecnológica e otimização de protocolos.

BACKGROUND: Cardiac computed tomography (CT) can provide a precise tridimentional anatomic map and exclude intra-cardiac thrombus. We aimed to access the impact of CT protocol optimization and technological evolution on the contrast and radiation dose as well as on image quality previous to atrial fibrillation (AF) ablation. METHODS: From a prospective registry of consecutive patients who underwent cardiac CT in a single center, we selected 270 patients in whom the CT was done for evaluation prior to AF ablation and they were distributed in 3 groups: Group1: the first 150 patients included; Group2: the last 60 patients performed with the same CT scanner; Group3: the first 60 exams performed with the new CT scanner. Quality of the protocol was access based on radiation dose, contrast volume used, the use of a second (delayed) acquisition, and on quantitative image quality analisis (signal to noise and contrast to noise ratios; density homogeneity racio between LA and LAA). RESULTS: We found a significant radiation dose as well as contrast dose reduction between the first and last subgroups (G1: 5,6mSv and 100ml; G2: 1,3mSv and 90ml; G3: 0,6mSv and 65ml). Even though group 3 had less radiation and contrast used it still had better quantitative image quality (signal/noise of 13,5; contrast/noise 14,8; density homogeneity racio of 0,92). CONCLUSION: Protocol optimization and technology both contributed to significant lower radiation dose and contrast volume used on cardiac CTs prior to AF ablation, without compromising image quality.

Left atrial volume index: Can it provide additional prognostic information in ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention?

INTRODUCTION: We sought to assess the prognostic impact of left atrial (LA) size on long-term outcomes of ST-segment elevation myocardial infarction (STEMI). METHODS: We studied 200 consecutive patients admitted to a single center between January 2010 and December 2014 with non-fatal STEMI treated with primary percutaneous coronary intervention (pPCI) who underwent a comprehensive echocardiographic examination at discharge. LA volume was estimated by the area-length method. The left atrium was classified as normal, mildly, moderately or severely enlarged by LA volume index (LAVI). The endpoints were defined as all-cause mortality, a cardiac composite endpoint (all-cause mortality, reinfarction, unplanned revascularization and hospitalization for heart failure) and a cardiovascular composite endpoint (cardiac endpoint plus atrial fibrillation and ischemic stroke) during follow-up. RESULTS: In this STEMI population, 58% had normal LA size, 22.5% had mild LA enlargement, 10% had moderate LA enlargement and 9.5% had severe LA enlargement. During a median follow-up of 28 (IQR 21-38) months, 14 (7.0%) patients died, 53 (26.5%) had the cardiac and 58 (29%) the cardiovascular composite endpoints. There was a stepwise increase in the incidence of all-cause mortality (p=0.020) and both cardiac (p<0.001) and cardiovascular (p<0.001) endpoints with each increment of LAVI class. In multivariate analysis, severe LA enlargement by LAVI was an independent predictor of all-cause mortality (HR: 11.153; 95% CI: 1.924-64.642, p=0.007) and the cardiac (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) and cardiovascular (HR: 4.351; 95% CI: 1.919-9.862, p<0.001) endpoints during follow-up. CONCLUSIONS: This contemporary study confirms the prognostic effect of LA size at discharge, applying the most recent reference values in STEMI patients treated with pPCI.

Acute myocardial infarction caused by left atrial myxoma: Role of intracoronary catheter aspiration.

Acute ST-segment elevation myocardial infarction (STEMI) caused by left atrial myxoma is very rare. Catheter-based approaches or thrombolytic therapy are mostly the first step in the management of STEMI with less time delay. We report a case of acute anterior/lateral STEMI caused by a left atrial myxoma. The patient was successfully treated by intracoronary aspiration with an Export aspiration catheter, with excellent distal coronary flow. Intracoronary catheter aspiration in acute myocardial infarction caused by a left atrial myxoma may help to salvage the infarcting myocardium with less time delay.

Left atrial dysfunction in light-chain cardiac amyloidosis and hypertrophic cardiomyopathy - A comparative three-dimensional speckle-tracking echocardiographic analysis from the MAGYAR-Path Study.

INTRODUCTION: While cardiac amyloidosis (CA) is a rare systemic disease characterized by extracellular deposition of protein-derived fibrils, hypertrophic cardiomyopathy (HCM) is histopathologically characterized by myocyte hypertrophy and disarray, interstitial fibrosis, and small intramural coronary arteriole dysplasia. The aim of the present study was to compare left atrial (LA) volumetric and functional characteristics between light-chain (AL) CA and HCM by three-dimensional (3D) speckle-tracking echocardiography (STE). METHODS: The AL-CA group initially consisted of 17 patients with AL-CA, but one patient was excluded due to inadequate image quality, and so the study population consisted of 16 patients (mean age: 64.0±9.6 years, five men). Their results were compared with data on 20 age-matched HCM patients (mean age: 59.8±5.2 years, 10 men) and on 16 age-matched healthy controls (mean age: 58.2±7.2 years, six men). Complete two-dimensional Doppler echocardiography and 3D-STE were performed in all cases. RESULTS: Significantly increased LA volumes were observed in both AL-CA and HCM compared with the control group. Only active atrial emptying fraction was found to be significantly reduced in AL-CA patients compared to controls. Peak global and mean segmental circumferential, longitudinal and area strains showed significant reductions in AL-CA patients compared with controls, but only peak mean segmental longitudinal strain differed significantly between HCM patients and controls. While no differences were demonstrated in global and mean segmental strain at atrial contraction between HCM patients and controls, AL-CA patients showed reductions in certain strain parameters compared to controls and HCM patients. CONCLUSIONS: Different patterns of LA functional characteristics were demonstrated in AL-CA and HCM patients by 3D-STE.

Characterization of left atrial dysfunction in hypereosinophilic syndrome - Insights from the Motion analysis of the heart and great vessels by three-dimensional speckle tracking echocardiography in pathological cases (MAGYAR-Path) Study.

INTRODUCTION: The present study was designed to compare three-dimensional speckle tracking echocardiography (3DSTE)-derived left atrial (LA) volumetric, volume-based functional and strain parameters between patients with hypereosinophilic syndrome (HES) and matched controls. METHODS: A total of 10 HES patients and 19 age- and gender-matched healthy controls were included in the study. Complete two-dimensional Doppler echocardiography and 3DSTE were performed in all HES cases and controls. RESULTS: Significantly increased maximum (72.9±38.8 ml vs. 45.6±15.5 ml, p=0.01) and minimum (46.3±33.3 ml vs. 26.0±15.0 ml, p=0.03) LA volumes and LA volume before atrial contraction (62.0±36.0 ml vs. 36.5±16.6 ml, p=0.01) were found in HES patients compared to controls. Both peak global (18.3±6.7% vs. 25.6±9.0%, p=0.03) and mean segmental (22.2±6.0% vs. 31.0±12.1%, p=0.04) circumferential strains were significantly reduced in HES patients, suggesting decreased LA reservoir function. CONCLUSION: Increased LA volumes can be demonstrated in HES patients, accompanied by reduced LA peak circumferential strain as assessed by 3DSTE, suggesting LA remodeling.

Left atrial ejection force correlates with left atrial strain and volume-based functional properties as assessed by three-dimensional speckle tracking echocardiography (from the MAGYAR-Healthy Study).

INTRODUCTION AND OBJECTIVE: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) is a novel method for assessment of left atrial (LA) volumes and function without geometrical assumptions. 3DSTE allows detailed assessment of LA features including volume measurements, strain assessments and calculation of LA ejection force (LAEF). LA strain and volume-based functional parameters originate from the same 3D dataset, but assessment of LAEF requires more data including measurement of mitral annular dimensions and Doppler-derived inflow velocities. The present study was designed to find correlations between LAEF and 3DSTE-derived LA volume-based functional properties and strain parameters in healthy subjects. METHODS: The study population comprised 34 randomly selected healthy subjects (age 36.1±11.2 years, 15 men) in sinus rhythm, all of whom had undergone standard two-dimensional transthoracic Doppler echocardiographic study extended with 3DSTE. RESULTS: Mitral annulus diameter-based LAEF correlated with global LA peak circumferential (r=0.39, p=0.02), longitudinal (r=0.32, p=0.05) and area (r=0.43, p=0.01) strain, total atrial stroke volume (r=0.30, p=0.05) and total atrial emptying fraction (r=0.31, p=0.05) characterizing (systolic) LA reservoir function and global LA 3D strain at atrial contraction (r=-0.44, p=0.01) and active atrial emptying fraction (r=0.36, p=0.04) characterizing (diastolic) LA contraction function (booster pump phase). CONCLUSIONS: Complex LA functional assessment can be provided by 3DSTE, including calculation of LAEF and volume-based and strain functional properties, with significant correlations between these parameters.

Prognostic value of left atrial volume in patients with dilated cardiomyopathy.

BACKGROUND: Increased left atrial (LA) size is a prognostic marker of mortality in the general population. LA size varies considerably in patients with dilated cardiomyopathy (DCM), but its clinical significance has not been widely studied. OBJECTIVE: To evaluate the long-term prognostic value of LA volume (LAV) in patients with DCM. METHODS: We prospectively studied patients admitted from January to December 2004 with a diagnosis of DCM, in sinus rhythm. Complete echocardiographic study at rest and after pharmacological stress was performed in all patients. The composite endpoint of mechanical ventricular assistance (MVA), heart transplantation or death during follow-up was assessed by univariate and multivariate analysis using a Cox regression model. RESULTS: The study population consisted of 35 patients (68.6% male, mean age 52.0) with DCM, 82.9% of non-ischemic etiology. Ejection fraction (EF) at rest was 31.1 ± 9.4%. During follow-up, eight patients died, one was placed on MVA and one underwent transplantation. Univariate Cox analysis showed various potential echocardiographic markers of prognosis in our population, including LA size in M-mode (HR 1.12, CI: 0.99-1.26, p=0.067), LAV (HR 1.03, CI: 1.00-1.07, p=0.046), LAV adjusted for body surface area (HR 1.03, CI: 0.99-1.26, p=0.049), E/A ratio (HR 0.99; CI: 0.99-1.81; p=0.060); E/A >2 (HR 7.00, CI: 1.48-32.43, p=0.014) and mitral E/E' ratio (HR 1.04, CI: 1.00-1.09, p=0.074). The only variable that remained in the multivariate model was LAV, with a cut-off value of 63 ml (HR 7.7, CI: 0.97-60.61, p=0.05). CONCLUSIONS: LAV was the only echocardiographic determinant of MVA, heart transplantation or death in our population with DCM. The echocardiographic parameters commonly used for risk stratification such as EF, left ventricular end-diastolic diameter and contractile reserve did not show prognostic significance in our study.