Intraoperative three-dimensional versus two-dimensional echocardiography for left ventricular assessment.

BACKGROUND: Three-dimensional (3D) transesophageal echocardiography (TEE) technology is now widely used intraoperatively in cardiac surgery. Left ventricular (LV) measurements with 3D transthoracic echocardiography correlate better with cardiac magnetic resonance measurements compared with traditional two-dimensional (2D) transthoracic echocardiography. In this study, we compared intraoperative 3D TEE against 2D TEE regarding quantitative indices of LV function. METHODS: We performed 2D TEE and 3D TEE examinations on 156 patients scheduled for elective cardiac surgery. Two-dimensional TEE images of midesophageal 4-, 2-chamber, and long-axis views were acquired. LV volumes and ejection fraction (EF) were calculated by Simpson's method. Three-dimensional full-volume images were recorded to calculate by a semiautomated procedure LV volumes (indexed to body surface area) and EF. 3D and 2D LV dimensions and function, image quality, time for acquisition/analyses, and reproducibility were compared by the Wilcoxon matched-pairs signed-ranks test. Pairwise differences between 3D and 2D data were compared using 95% prediction intervals (PIs) and Bland-Altman methodology. 3D volumes were also plotted against 2D volumes in scatter plots using a 3-zone error grid. RESULTS: There was no significant difference between 3D and 2D in the estimation of EF (P = 0.227; median pairwise difference, -0.4% [95% PIs, -8.6% to 8.8%]). 3D LV indexed end-diastolic volumes (iEDVs) and end-systolic volumes (iESVs) were larger than 2D iEDVs (P < 0.001; median pairwise difference, 3.3 mL/m [95% PIs, -9.4 to 14.1 mL/m] and iESV: P < 0.001; median pairwise difference, 1.4 mL/m [95% PIs, -5.2 to 10.1 mL/m]). In the vast majority of cases (98.8% of cases for iEDV and 92.8% of cases for iESV), the difference between 2D and 3D TEE indexed volumes did not alter classification into normal, mildly to moderately dilated, or severely dilated volumes, as demonstrated by the 3-zone error grid analysis. Acquisition of 3D TEE image and analysis were not feasible in 4 patients (2.5%) for whom a quantitative 2D assessment of the LV was also impossible. 3D and 2D quality image was similar (P = 0.206). There was no difference in 3D versus 2D acquisition time (P = 0.805; pairwise difference = 2 seconds [95% PIs, -20 to 35 seconds]), but 3D analysis required more time (P < 0.001; pairwise difference = 117 seconds [95% PIs, 66 to 197 seconds]). Differences in repeated 3D versus 2D indexed volumes were not statistically significant, both considering interobserver reproducibility (iEDV: P = 0.125; pairwise difference, 0.26 ± 1.76 mL [95% PIs, -3.58 to 3.73 mL] and iESV: P = 0.126; pairwise difference, -0.16 ± 1.67 mL [95% PIs, -3.96 to 3.69 mL]) and intraobserver reproducibility (iEDV: P = 0.975; pairwise difference, -0.02 ± 1.20 mL [95% PIs, -2.32 to 2.08 mL] and iESV: P = 0.228; pairwise difference, -0.19 ± 1.13 mL [95% PIs, -2.47 to 2.53 mL]). CONCLUSIONS: Intraoperative 3D TEE quantification of LV global function, image acquisition time, and reproducibility was not statistically different when compared with 2D TEE. It was however associated with calculation of larger LV volumes and a longer analysis time. Nevertheless, the 3-zone error grid analysis of the LV indexed volumes showed that the difference between 3D and 2D measurements does not affect the LV classification as normal, mildly to moderately dilated, or severely dilated.

Mechanisms and predictors of mitral regurgitation after high-risk myocardial infarction.

BACKGROUND: Mitral regurgitation (MR) has been associated with adverse outcomes after myocardial infarction (MI). Without structural valve disease, functional MR has been related to left ventricular (LV) remodeling and geometric deformation of the mitral apparatus. The aims of this study were to elucidate the mechanistic components of MR after high-risk MI and to identify predictors of MR progression during follow-up. METHODS: The Valsartan in Acute Myocardial Infarction Echo substudy prospectively enrolled 610 patients with LV dysfunction, heart failure, or both after MI. MR at baseline, 1 month, and 20 months was quantified by mapping jet expansion in the left atrium in 341 patients with good-quality echocardiograms. Indices of LV remodeling, left atrial size, and diastolic function and parameters of mitral valve deformation, including tenting area, coaptation depth, anterior leaflet concavity, annular diameters, and contractility, were assessed and related to baseline MR. The progression of MR was further analyzed, and predictors of worsening among the baseline characteristics were identified. RESULTS: Tenting area, coaptation depth, annular dilatation, and left atrial size were all associated with the degree of baseline MR. Tenting area was the only significant and independent predictor of worsening MR; a tenting area of 4 cm(2) was a useful cutoff to identify worsening of MR after MI and moderate to severe MR after 20 months. CONCLUSIONS: Increased mitral tenting and larger mitral annular area are determinants of MR degree at baseline, and tenting area is an independent predictor of progression of MR after MI. Although LV remodeling itself contributes to ischemic MR, this influence is directly dependent on alterations in mitral geometry.

Timing and magnitude of regional right ventricular function: a speckle tracking-derived strain study of normal subjects and patients with right ventricular dysfunction.

BACKGROUND: The aim of this study was to evaluate the timing and magnitude of global and regional right ventricular (RV) function by means of speckle tracking-derived strain in normal subjects and patients with RV dysfunction. METHODS: Peak longitudinal systolic strain (PLSS) and time to PLSS in 6 RV segments (the basal, mid, and apical segments of the RV free wall and septum) were obtained in 100 healthy volunteers and 76 patients with RV dysfunction by tracking speckles inside the myocardium using grayscale images. Global PLSS and time to PLSS were based on the average of the 6 regional values. RESULTS: There was a significant and close correlation between RV contractility as measured by PLSS and tricuspid annular plane systolic excursion (r = -0.83, P < .001). In normal subjects, PLSS was significantly greater in the free wall than in the septum (-28.7 + or - 4.1% vs -19.8 + or - 3.4%, P < .001), whereas time to PLSS was similar in the different regions of the right ventricle. In patients with RV dysfunction, global and regional PLSS was significantly less than in normal subjects (-13.7 + or - 3.6% vs -24.2 + or - 2.9%, P < .001), and a global PLSS cutoff value of -19% was helpful in distinguishing the two groups. Furthermore, time to PLSS in all of the RV septal segments and dispersion in RV contraction timing were significantly longer. Global PLSS in the patients with RV dysfunction was also significantly less in the presence of moderate to severe pulmonary hypertension (-12.7 + or - 3.6% vs -14.4 + or - 3.4%, P = .038). CONCLUSIONS: Speckle tracking not only makes it possible to quantify global RV function but also illustrates the physiology of RV contraction and the pattern of activation at regional level. Speckle tracking-derived strain could become an important new means of assessing and following up patients with impaired RV function and increased pulmonary pressure.

Left atrial remodelling in patients with myocardial infarction complicated by heart failure, left ventricular dysfunction, or both: the VALIANT Echo study.

AIMS: To assess the relationship between left atrial (LA) size and outcome after high-risk myocardial infarction (MI) and to study dynamic changes in LA size during long-term follow-up. METHODS AND RESULTS: The VALIANT Echocardiography study prospectively enrolled 610 patients with left ventricular (LV) dysfunction, heart failure (HF), or both following MI. We assessed LA volume indexed to body surface area (LAVi) at baseline, 1 month, and 20 months after MI. Baseline LAVi was an independent predictor of all-cause death or HF hospitalization (P = 0.004). In patients who survived to 20 months, LAVi increased a mean of 3.00 +/- 7.08 mL/m(2) from baseline. Hypertension, lower estimated glomerular filtration rate, and LV mass were the only baseline independent predictors of LA remodelling. Changes in LA size were related to worsening in MR and increasing in LV volumes. LA enlargement during the first month was significantly greater in patients who subsequently died or were hospitalized for HF than in patients without events. CONCLUSION: Baseline LA size is an independent predictor of death or HF hospitalization following high-risk MI. Moreover, LA remodelling during the first month after infarction is associated with adverse outcome.

Prognostic implications of left ventricular mass and geometry following myocardial infarction: the VALIANT (VALsartan In Acute myocardial iNfarcTion) Echocardiographic Study.

OBJECTIVES: This study sought to understand prognostic implications of increased baseline left ventricular (LV) mass and geometric patterns in a high risk acute myocardial infarction. BACKGROUND: The LV hypertrophy and alterations in LV geometry are associated with an increased risk of adverse cardiovascular events. METHODS: Quantitative echocardiographic analyses were performed at baseline in 603 patients from the VALIANT (VALsartan In Acute myocardial iNfarcTion) echocardiographic study. The left ventricular mass index (LVMi) and relative wall thickness (RWT) were calculated. Patients were classified into 4 mutually exclusive groups based on RWT and LVMi as follows: normal geometry (normal LVMi and normal RWT), concentric remodeling (normal LVMi and increased RWT), eccentric hypertrophy (increased LVMi and normal RWT), and concentric hypertrophy (increased LVMi and increased RWT). Cox proportional hazards models were used to evaluate the relationships among LVMi, RWT, LV geometry, and clinical outcomes. RESULTS: Mean LVMi and RWT were 98.8 +/- 28.4 g/m(2) and 0.38 +/- 0.08. The risk of death or the composite end point of death from cardiovascular causes, reinfarction, heart failure, stroke, or resuscitation after cardiac arrest was lowest for patients with normal geometry, and increased with concentric remodeling (hazard ratio [HR]: 3.0; 95% confidence interval [CI]: 1.9 to 4.9), eccentric hypertrophy (HR: 3.1; 95% CI: 1.9 to 4.8), and concentric hypertrophy (HR: 5.4; 95% CI: 3.4 to 8.5), after adjusting for baseline covariates. Also, baseline LVMi and RWT were associated with increased mortality and nonfatal cardiovascular outcomes (HR: 1.22 per 10 g/m(2) increase in LVMi; 95% CI: 1.20 to 1.30; p < 0.001) (HR: 1.60 per 0.1-U increase in RWT; 95% CI: 1.30 to 1.90; p < 0.001). Increased risk associated with RWT was independent of LVMi. CONCLUSIONS: Increased baseline LV mass and abnormal LV geometry portend an increased risk for morbidity and mortality following high-risk myocardial infarction. Concentric LV hypertrophy carries the greatest risk of adverse cardiovascular events including death. Higher RWT was associated with an increased risk of cardiovascular complications after high-risk myocardial infarction.

Ischemic mitral regurgitation: mechanisms and echocardiographic classification.

Chronic ischemic mitral regurgitation (IMR) is a common complication of myocardial infarction and severely affects cardiovascular mortality and morbidity. Multiple pathophysiologic mechanisms, such as left ventricular (LV) remodeling and dysfunction, annular dilation/dysfunction, and mechanical dyssynchrony, are involved in generating IMR, each of them having different weight. However, the prerequisite to initially creating regurgitation is the presence of local or global LV remodeling that alters the geometrical relationship between the ventricle and valve apparatus. In the wide spectrum of patients with chronic IMR, the assessment of some echocardiographic parameters, such as tethering pattern, leaflet motion, origin and direction of the regurgitant jets, allows one to identify different specific subgroups of patients subjected to different therapeutic approaches. The aim of medical and/or surgical therapy is to ameliorate heart failure symptoms, and improve LV remodeling and function and the intermediate/long-term outcome. The targets of surgical MV repair involve annulus, leaflets, chordae and ventricles. The restricted annuloplasty is the most commonly adopted surgical procedure that improves heart failure symptoms but not survival when compared to medical therapy and is also subject to a high incidence of late failure (approximately 30%). There are some preoperative echocardiographic predictors of failure that include valve (degree of valve remodeling, jet characteristics), ventricular (degree of remodeling, diastolic dysfunction) and surgical factors.

Rest and stress echocardiographic predictors of prognosis in patients with left ventricular dysfunction and functional mitral regurgitation.

We evaluate, in 37 consecutive patients (mean age 67+/-9 years) with functional mitral regurgitation (FMR), several rest and stress echocardiographic predictors of outcome. Rest end-systolic volume, peak stress end-diastolic volume and effective regurgitant orifice were independent predictors of death at 25 months follow-up. Therefore, rest and stress echocardiographic evaluation of patients with FMR provides strong prognostic information.

The relationship between renal function and cardiac structure, function, and prognosis after myocardial infarction: the VALIANT Echo Study.

OBJECTIVES: The purpose of this study was to determine whether alterations in cardiac structure or function contribute to the increased risk associated with renal impairment after myocardial infarction (MI). BACKGROUND: Renal impairment is associated with adverse cardiovascular outcomes after MI. METHODS: Echocardiography was performed on 603 patients with left ventricular (LV) dysfunction, heart failure (HF), or both after MI. Patients were grouped according to their estimated glomerular filtration rate (eGFR), and measures of cardiac structure and function were related to baseline eGFR. The relationship between eGFR and cardiac structure and function and clinical outcomes of death or HF was assessed with multivariable Cox regression. RESULTS: Ejection fraction, infarct segment length, right ventricular function, and mitral deceleration time were not influenced by renal function. Patients with reduced eGFR had smaller LV and larger left atrial (LA) volumes and higher left ventricular mass index (LVMI) and LV mass/LV volume ratio. A greater proportion of the patients with reduced eGFR had LV hypertrophy. The relationship between eGFR and the outcome of death or HF was attenuated by including baseline differences in LVMI, and both LVMI and LA volume conferred additional prognostic information in a multivariable model. CONCLUSIONS: Renal impairment was associated with smaller LV and larger LA volumes and increased LVMI. Systolic function was similar when compared with patients with normal renal function. Thus, reduced systolic function cannot account for worse outcomes in patients with renal impairment after MI. Indirect measures of diastolic function suggest that diastolic dysfunction might be an important mediator of increased risk in this population.

Mitral regurgitation in myocardial infarction complicated by heart failure, left ventricular dysfunction, or both: prognostic significance and relation to ventricular size and function.

AIMS: Mitral regurgitation (MR) confers independent risk in patients with acute myocardial infarction. We utilized data from the VALsartan In Acute myocardial iNfarcTion echo study to relate baseline MR to left ventricular (LV) size, shape, and function, and to assess the relationship between baseline MR and progression of MR and cardiovascular (CV) outcomes. METHODS AND RESULTS: We studied 496 patients with heart failure (HF) and/or systolic dysfunction after MI who underwent echocardiography at a median of 5 days after MI. MR severity, quantified as the regurgitant jet area/left atrial area ratio, was assessed at baseline, one and 20 months post-MI and related to LV size, shape, function, and clinical outcomes. Increased MR at baseline was associated with larger LV end-diastolic and end-systolic volumes, increased sphericity index, and reduced ejection fraction (P trend < 0.001). Moderate-severe MR was an independent predictor of total mortality [adjusted hazard ratio (HR) 2.4 (1.1-5.3)], CV mortality [adjusted HR 2.7 (1.2-6.1)], hospitalization for HF [adjusted HR 2.5 (1.1-5.5)], or death or HF hospitalization [adjusted HR 2.5 (1.4-4.6)]. Patients with progression of MR during the first post-MI month were substantially more likely to die or develop HF (adjusted HR per increased MR grade 3.0, 95% CI 1.8-4.9). Progression of MR over 20 months in survivors was associated with increased hospitalizations for HF (P < 0.001). CONCLUSION: Following high-risk myocardial infarction, baseline mitral regurgitant severity is associated with larger LV volumes and worse LV function. Both baseline MR severity and progression of MR are associated with an increased likelihood of adverse outcomes.

Assessment of stress-induced pulmonary interstitial edema by chest ultrasound during exercise echocardiography and its correlation with left ventricular function.

Ultrasound lung comet images (ULC) are useful for the noninvasive assessment of extravascular lung water (EVLW). We investigated the modification of EVLW, its relation to indices of left ventricular systolic and diastolic function, and noninvasively determined pulmonary capillary wedge pressure (PCWP) (PCWP = 1.24 ratio of early diastolic mitral inflow velocity to early diastolic velocity of the mitral annulus [E/Em] + 1.9) at rest and its variation during exercise echocardiography. A total of 72 patients (mean age 66.4 +/- 8.4 years) with mean ejection fraction of 41.2 +/- 14.4% underwent symptoms-limited exercise echocardiography. The sum of the ULC yielded a score of EVLW. The ULC increased significantly from baseline to postexercise (5.9 +/- 14.9 vs 11 +/- 20.7, P = .0001). Positive linear correlations were found between baseline ULC score and baseline ejection fraction (r = -0.37, P = .002), systolic pulmonary artery pressure (r = 0.69, P = .0001), E/Em (r = 0.70, P = .0001), and estimated PCWP (r = 0.69, P = .0001). The variation between postexercise and baseline ULC score correlated significantly with the variation between peak stress and rest PCWP (r = 0.62, P = .0001), systolic pulmonary artery pressure (r = 0.44, P = .0001), wall-motion score index (r = 0.30, P = .01), and peak stress E/Em (r = 0.71, P = .0001), whereas no significant correlations were found between variations of ULC score and ejection fraction. This study shows that ULC represents a simple way to assess the presence of excess EVLW. Increased EVLW is associated with estimated PCWP and indices of left ventricular systolic and diastolic dysfunction. The additional exercise-induced increase of PCWP, the worsening of left ventricular diastolic function, and extensive wall-motion abnormalities correlate with variations of EVLW.