Beamforming algorithms for endocardial border detection.

BACKGROUND: Software-based beamforming which utilizes delay and standard beamforming is a signal processing technique that temporarily stores data from each probe element to improve specular reflections to improve the image resolution. We compared a software algorithm which uses delay and standard beamforming with delay and sum beamforming in standard, hardware to evaluate endocardial borders and need for echo contrast. METHODS: In this prospective study, eligible participants were ≥18 years of age referred clinically for transthoracic echocardiograms. A limited study consisting of three views (apical 4, apical 3, and apical 2 chamber) was performed with the software-based beamforming and standard platform. Number and quality of segments visualized were evaluated using a 17-segment model. Quality of segments was graded as 0 = not visualized, 1 = incompletely visualized, or 2 = completely visualized. Overall quality score for each study (0 = poor, 1 = adequate, 2 = good) was reported. The need for contrast was determined by ASE guidelines. RESULTS: A total of 101 patients (mean age 61 ± 16 years, males 52%) were enrolled. Mean number of segments visualized in apical 4- (6.28 vs 5.65, P < .001), apical 3- (6.27 vs 5.54, P < .001), and apical 2-chamber views (6.26 vs 5.72 P < .001) was higher with the software vs standard platform. The average overall score for image quality was significantly better for the software platform vs standard (1.4 vs 0.9, P =< .001). With the software platform, 23% were judged as requiring contrast as compared with 45% for the standard platform (P < .001). CONCLUSIONS: Delay and standard beamforming in software platform identified more segments with better image quality when compared to the standard high-end platform, decreasing the need for contrast usage.

Latent myopathy is more pronounced in patients with low flow versus normal flow aortic stenosis with normal left ventricular ejection fraction who are undergoing surgical aortic valve replacement: Multicenter study with a brief review of the literature.

BACKGROUND: Midwall fibrosis and low stroke volume are independent predictors of mortality in severe aortic stenosis (AS) with preserved LV ejection fraction (LVEF). The role of speckle tracking echocardiography (STE) to identify latent myopathy pre- and post- aortic valve replacement (AVR) in high risk AS patients with normal LVEF is limited. METHODS: Demographic, 2D echocardiographic, and STE data were analyzed in patients with severe AS and preserved LVEF who underwent tissue AVR. Velocity vector imaging (VVI) was used to assess regional and global peak systolic longitudinal strain (GLS). Low flow (LF) was defined as an indexed LV stroke volume <35 mL/m2 . RESULTS: Between December 2008 and May 2011, 37 patients (75 ± 9 years, 51% male) had both pre- and post-AVR echos within 6.6 ± 6.5 months (median = 4 months; range = 2.5-9.5) of surgery. Compared with pre-AVR, GLS (-6.9 ± 4.9% vs -11.1 ± 4.1%; P < .001) and strain rate (-0.72 ± 0.3s-1 vs -0.87 ± 0.3s-1 ; P = .01) improved post-AVR. Pre-AVR mid-segments showed a similar myopathy as the basal segments (-9.5 ± 4.3% vs -9.0 ± 4.2%;P = .3). The 16 (43%) LF patients in this study had lower pre- and post-AVR strain compared to NF patients (GLS Pre-AVR:LF vs NF: -5.1 ± 4.1% vs -8.4 ± 4.9% (P = .04) and GLS Post-AVR:LF vs NF: -9.2 ± 3.7% vs -12.5 ± 3.9% (P = .01)). However, there was no difference in absolute and %change improvement in GLS post-AVR (LF vs NF:∆ -4.2 ± 3.5% vs ∆-4.1 ± 5.3% (P = .90) and 193 ± 214% vs 143 ± 230% change (P = .5)). The lowest GLS was seen in LF/HG AS followed by LF/LG, NF/LG and NF/HG AS; P = .03. CONCLUSIONS: Latent myopathy is more pronounced in LF AS both pre- and post-AVR. Our study provides evidence of improvement in myopathy in LF AS despite a persistent worse myopathy compared to NF patients post-AVR.

Multi-modality imaging: Bird's eye view from the 2016 American Heart Association Scientific Sessions.

This review summarizes key imaging studies that were presented in the American Heart Association Scientific Sessions 2016 related to the fields of nuclear cardiology, cardiac computed tomography, cardiac magnetic resonance, and echocardiography. This bird's eye view will inform readers about multiple studies from these different modalities. We hope that this general overview will be useful for those that did not attend the conference as well as to those that did since it is often difficult to get exposure to many abstracts at large meetings. The review, therefore, aims to help readers stay updated on the newest imaging studies presented at the meeting.

Multi-modality Imaging: Bird's eye view from the 2015 American Heart Association Scientific Sessions.

Multiple novel studies were presented at the 2015 American Heart Association Scientific Sessions which was considered a successful conference at many levels. In this review, we will summarize key studies in nuclear cardiology, cardiac magnetic resonance, echocardiography, and cardiac computed tomography that were presented at the Sessions. We hope that this bird's eye view will keep readers updated on the newest imaging studies presented at the meeting whether or not they were able to attend the meeting.

Multi-modality imaging: Bird's-eye view from the 2014 American Heart Association Scientific Sessions.

A large number of studies were presented at the 2014 American Heart Association Scientific Sessions. In this review, we will summarize key studies in nuclear cardiology, computed tomography, echocardiography, and cardiac magnetic resonance imaging. This brief review will be helpful for readers of the Journal who are interested in being updated on the latest research covering these imaging modalities.

Prevalence and long-term prognosis of patients with complete bundle branch block (right or left bundle branch) with normal left ventricular ejection fraction referred for stress echocardiography.

BACKGROUND: The prognostic value of stress echocardiography (SE) in patients with complete bundle branch blocks (BBB) with normal left ventricular ejection fraction (LVEF) has not been well described. We sought to determine the prognostic value of SE in patients with BBB and normal LVEF. METHODS: We analyzed 7214 patients (58 ± 14 years; 57% female) with a mean follow-up time of 9 ± 4 years. Dobutamine SE was performed in 51% of patients and exercise SE was performed in 49%. All-cause mortality data were obtained from the Social Security Death Index. RESULTS: There were 222 (3%) patients with right bundle branch block (RBBB) and 50 (0.7%) patients with left bundle branch block (LBBB). Patients with LBBB were 3 times more likely to have an abnormal stress test after adjusting for age, gender, mode of stress test, and coronary artery disease risk factors (OR = 3.3; 95% CI: 1.86-5.92; P < 0.001). The mortality rates were 4.5%/year for patients with LBBB, 2.5%/year for patients with RBBB, and 1.9%/year for patients without BBB (P < 0.001). Among patients with a normal SE, those with LBBB had similar mortality to those without LBBB (HR = 0.9; 95% CI: 0.4-2.2; P = 0.8). Patients with LBBB and abnormal SE had more than 2 times greater risk of all-cause mortality (HR = 2.4; 95% CI: 1.4-4.2; P = 0.002). CONCLUSION: A normal stress echocardiogram in LBBB is associated with benign prognosis while those with LBBB and abnormal SE have the worst outcomes.

Prognostic Value of Stress Echocardiography in Patients Presenting with Syncope.

BACKGROUND: Evaluation for ischemia is appropriate in patients at risk for or with a history of coronary artery disease presenting with syncope. The aim of this study is to determine the prognostic value of stress echocardiography in patients presenting with syncope. METHODS: We examined our database of all patients undergoing stress echocardiography at our institution. Patients referred due to syncope were grouped as high risk based on any of the following: (1) known history of coronary artery disease, (2) left ventricular ejection fraction <50%, (3) moderate or severe mitral or aortic valve regurgitation, and (4) moderate mitral or aortic valve stenosis. The main outcomes were the presence of ischemia on stress imaging and all-cause mortality using the social security death index. RESULTS: A total of 225 patients were identified; mean age was 64.3 ± 14.5 years, the mean follow-up duration was 29.2 ± 13.8 months. There were 163 patients in the low-risk group and 62 patients in the high-risk group. On imaging, 7% of the overall cohort had ischemia. The low-risk group had 5 (3%) patients with ischemia and the high-risk group had 10 patients (16%) with ischemia (P < 0.01). The mortality rate was significantly higher in the high-risk group (3.99%/year vs. 1.02%/year; P = 0.02); this difference was not affected by the presence of ischemia. CONCLUSIONS: High-risk patients with syncope as defined by appropriateness criteria and existing evidence carry a higher risk of ischemia and all-cause mortality. The presence of ischemia may not be predictive of long-term outcome in this group.

Prognostic value of treadmill stress echocardiography at extremes of exercise performance: submaximal <85% maximum predicted heart rate versus high exercise capacity ≥ 10 metabolic equivalents.

BACKGROUND: Submaximal stress testing or achieving <85% maximum predicted heart rate (MPHR) may lead to nondiagnostic results and indeterminate outcomes. High exercise capacity (≥ 10 metabolic equivalents, METS) is a predictor of favorable prognosis. The purpose of this study was to evaluate the prognostic value of submaximal or high exercise capacity stress echocardiography. METHODS: We evaluated 1781 patients (55 ± 13 years; 59% male) undergoing treadmill stress echocardiography divided into 811 patients with submaximal (<85% MPHR) and 970 patients with high exercise capacity (≥ 10 METS). Resting left ventricular ejection fraction and regional wall motion were assessed. The left ventricle was divided into 16 segments and scored on 5-point scale of wall motion. Abnormal stress echocardiography was defined as stress-induced ischemia (wall-motion score of ≥ 1 grade). Follow-up (3.3 ± 1.5 years) for nonfatal myocardial infarction (MI) (n = 40) and cardiac death (n = 52) were obtained. RESULTS: By univariate analysis, echocardiographic variables of ejection fraction, peak wall-motion score index (WMSI) and number of new ischemic wall-motion abnormalities were significant predictors of cardiac events. Cumulative survival was significantly worse in patients with abnormal (ischemic) versus normal (nonischemic) stress echocardiography in submaximal (4.4%/year vs. 1.3%/year, P < 0.0001) and high exercise capacity (1.5%/year vs. 0.2%/year, P < 0.0001) studies. Multivariate Cox proportional hazards analysis identified number of new ischemic wall-motion abnormalities as the strongest predictor of cardiac events (P < 0.05) in both groups. CONCLUSIONS: Despite normal stress echocardiography, the inability to achieve 85% MPHR conferred a higher, intermediate cardiac event rate of 2.9%/year. The ability to achieve 9 minutes (≥ 10 metabolic equivalents, METS) conferred an overall low cardiac event rate of 0.4%/year. However, the absence or presence of ischemia by stress echocardiography was able to further risk stratify patients with either submaximal or high exercise capacity studies.

Feasibility and prognostic value of stress echocardiography in obese, morbidly obese, and super obese patients referred for bariatric surgery.

BACKGROUND: Stress echocardiography (SE) is clinically used in the risk stratification and prognosis of patients with coronary artery disease. Due to multiple comorbidities, obese patients have increased risk of adverse cardiovascular events perioperatively in noncardiac surgery. The aim of this study was to investigate the feasibility of SE in morbidly obese patients undergoing bariatric surgery. METHODS: Consecutive patients referred for SE for preoperative evaluation prior to bariatric surgery from January 2002 to July 2011 formed the study cohort. Contrast was used to define the endocardial border in patients with poor acoustic windows. All-cause mortality data were obtained from Social Security Death Index. RESULTS: Six hundred fifty-two patients (47 ± 10 years, 84% females) with the mean follow-up of 3.0 ± 2.7 years and mean body mass index (BMI) of 47 ± 9 kg/m² were included in this analysis. Dobutamine SE was performed in 65% of patients compared to exercise SE in 35%. Patients with higher BMI were more likely to undergo dobutamine SE (P < 0.0001). Similarly, incidence of poor acoustic windows and contrast use was higher in those with increased BMI (P < 0.001). Contrast use was higher in patients undergoing dobutamine SE (39%) versus exercise (25%), (P = 0.002). 19 patients (3%) had an abnormal SE and 8 patients (1.2%) died during the follow-up period. CONCLUSION: Stress echocardiography is feasible in the morbidly obese patients. Patients with higher BMI were more likely to undergo dobutamine SE and have higher incidence of poor acoustic windows and contrast use.

A novel technique to quantify the instantaneous mitral regurgitant rate.

BACKGROUND: The systolic variation of mitral regurgitation (MR) is a pitfall in its quantification. Current recommendations advocate using quantitative echocardiographic techniques that account for this systolic variation. While prior studies have qualitatively described patterns of systolic variation no study has quantified this variation. METHODS: This study includes 41 patients who underwent cardiovascular magnetic resonance (CMR) evaluation for the assessment of MR. Systole was divided into 3 equal parts: early, mid, and late. The MR jets were categorized as holosystolic, early, or late based on the portions of systole the jet was visible. The aortic flow and left ventricular stroke volume (LVSV) acquired by CMR were plotted against time. The instantaneous regurgitant rate was calculated for each third of systole as the difference between the LVSV and the aortic flow. RESULTS: The regurgitant rate varied widely with a 1.9-fold, 3.4-fold, and 1.6-fold difference between the lowest and highest rate in patients with early, late, and holosystolic jets respectively. There was overlap of peak regurgitant rates among patients with mild, moderate and severe MR. The greatest variation of regurgitant rate was seen among patients with mild MR. CONCLUSION: CMR can quantify the systolic temporal variation of MR. There is significant variation of the mitral regurgitant rate even among patients with holosystolic MR jets. These findings highlight the need to use quantitative measures of MR severity that take into consideration the temporal variation of MR.

Reversal of acute systolic dysfunction and cardiogenic shock in hypertrophic cardiomyopathy by surgical relief of obstruction.

A 70-year-old male with known hypertrophic cardiomyopathy (HCM) and latent obstruction presented with new onset of cardiogenic shock. He had a new resting left ventricular (LV) outflow gradient of 90 mmHg, and new severe LV systolic dysfunction. Because of rapid deterioration despite medical management he was urgently sent for surgical relief of obstruction, which immediately reversed both the LV dysfunction and shock. A second patient, a 58-year-old male also with hypertrophic cardiomyopathy and latent obstruction presented with collapse, cardiogenic shock, 135 mmHg resting LV outflow gradient and new severe LV systolic dysfunction. His profound shock was irreversible with pharmacologic management, but surgical relief of obstruction reversed both his LV dysfunction and shock. Echocardiography plays a pivotal role in the management of these acutely ill patients.

Right ventricular dysfunction is a strong predictor of developing atrial fibrillation in acutely decompensated heart failure patients, ACAP-HF data analysis.

BACKGROUND: Heart failure and atrial fibrillation (AFib) are the twin epidemics of modern cardiovascular disease. The incidence of new-onset AFib in acute decompensated heart failure (ADHF) patients is difficult to predict and the short- and long-term outcomes of AFib in a cohort of patients admitted with ADHF are unknown. METHODS AND RESULTS: A total of 904 patients admitted with ADHF were studied. Incidence of AFib on admission was recorded and a multivariate analysis was performed using echocardiographic parameters to specify the predictors of AFib incidence in this cohort. In 904 ADHF patients (57% male, mean age 69 ± 14 years), 81% had history of hypertension, 40% were diabetics, and 51% were smokers. A total of 63% of the patients had known heart failure (HF) with mean ejection fraction of 34% ± 21%, and 33% of the patients had ischemic cardiomyopathy as the etiology of HF. Echocardiographic parameters were: left atrial (LA) diameter 4.5 ± 0.8 cm, left ventricular end-systolic 4.1 ± 1.3 cm, left ventricular end-diastolic 5.3 ± 1.1 cm. Right ventricular dysfunction (RVD) was present in 34% of the patients. A total of 191 (21%) patients subsequently developed AFib with two thirds of the cases occurring in patients with RVD. Using a univariate analysis, older age (OR 1.02; P < .0001), history of HF (OR 2.93; P < .0001), LA dilation (OR 1.58; P < .0001), the presence of left ventricular hypertrophy (OR 3.01, P < .0001), and RVD (OR 4.93; P < .00001) were the strongest predictors for AFib. Controlling for LA size and left ventricular hypertrophy using a forward stepwise regression, RVD remained the strongest predictor (OR 4.45; P < .0001). Patients with RVD had more events (cardiac readmission and mortality) than those with normal RV (56% versus 38%; P < .00001), notably; all-cause mortality was 4.7%/year in the abnormal RV group versus 2.9%/year in the normal RV group; P < .05. RV function analyses by echocardiography further risk stratified these patients based on their rhythm categorizing those patients with abnormal RV and AFib as the ones with the worse prognosis. CONCLUSION: RV dysfunction is a strong predictor for developing AFib in acutely decompensated systolic failure patients. Patients with AFib and RVD have the worse outcome specially when is combined with LV dysfunction, therefore; evaluation of RV function may substantiate the difference in HF prognosis.

Assessment of left atrial appendage function with transthoracic tissue Doppler echocardiography.

AIMS: A transthoracic echocardiographic (TTE) parameter that would stratify atrial fibrillation (AF) risk would be useful. Tissue Doppler imaging can quantify left atrial appendage contraction velocity (LAA A(M)). METHODS AND RESULTS: We studied 141 patients referred for transoesophageal echocardiogram (TEE); 48 were in AF. We obtained TEE and TTE LAA A(M) velocities from the LAA apex on the parasternal short-axis and apical two-chamber views. Adequate traces were obtained in 118 patients (84%). In these patients, we measured 5382 LAA A(M) velocity tracings. There was a strong correlation between LAA A(M) on TEE and TTE parasternal short-axis (r = 0.741; P < 0.0001) and apical two-chamber views (r = 0.729; P < 0.0001). Patients in AF had lower LAA A(M) than those with sinus rhythm on parasternal short-axis (12 +/- 5 vs. 23 +/- 7 cm/s, P < 0.0001) and apical two-chamber (14 +/- 5 vs. 23 +/- 8 cm/s, P < 0.0001) views. On parasternal short axis, LAA A(M) velocities were lower in patients with spontaneous echo contrast, 11 +/- 4 vs. 22 +/- 8 cm/s (P < 0.0001), and in those with thrombus, 8 +/- 2 cm/s (P < 0.0001). On apical two-chamber, LAA A(M) velocities were also lower with spontaneous echo contrast, 12 +/- 4 vs. 22 +/- 7 cm/s (P < 0.0001), and with thrombus, 10 +/- 4 cm/s (P < 0.0001). In patients with AF and TTE LAA A(M) < or =11 cm/s, we found that nearly one-third had LAA thrombus. In patients with AF and a history of stroke or transient ischaemic attack (TIA), LAA A(M) velocities were lower compared with those without history of stroke or TIA in the parasternal short-axis (9 +/- 3 vs. 13 +/- 5 cm/s, P = 0.02) and apical two-chamber views (11 +/- 3 vs. 15 +/- 6 cm/s, P = 0.008). CONCLUSION: Acquiring and quantifying LAA A(M) contraction velocity is feasible on TTE in a high percentage of patients and correlates with TEE. LAA A(M) was lower in AF compared with sinus rhythm, with spontaneous echo contrast compared to without spontaneous echo contrast, and in AF patients with a history of stroke or TIA. Those with LAA thrombus had the lowest LAA A(M) velocities. LAA A(M) is a novel functional parameter that may prove useful for risk stratification of AF.

Severe symptoms in mid and apical hypertrophic cardiomyopathy.

BACKGROUND: We analyzed the clinical and quantitative echocardiographic characteristics of patients with sub-basal hypertrophic cardiomyopathy (HCM) to define the characteristics of patients (pts) with severe symptoms. METHODS: Of 444 pts in a referral-based HCM program, 22 (5%) had midventricular or apical HCM. Quality of life (QoL) questionnaire was administered as an independent confirmer of symptomatic state. RESULTS: Ten pts were NYHA III and IV, and 12 pts were NYHA I and II; QoL scores (41 +/- 26 vs. 10 +/- 13, P = 0.001) confirmed a priori division of two groups based on NYHA classification. Pts with more severe symptoms were more likely female (70% vs. 25%, P = 0.001) with atrial fibrillation (40% vs. 0%, P = 0.02). They more frequently had midventricular HCM 60% versus 8% (P = 0.01) (mid-LV thickness 17 +/- 6 vs. 12 +/- 2 mm, P = 0.03) and had much smaller LV diastolic volumes 68 +/- 12 versus 102 +/- 22 ml (39 +/- 4 vs. 53 +/- 12 ml/m(2), P = 0.001). Septal E/E' was higher in the severely symptomatic pts (15 +/- 5 vs. 7 +/- 3, P = 0.001) indicating higher estimated LV filling pressure. Midobstruction with apical akinetic chamber was noted in 4/10 pts who developed refractory symptoms. Cardiac mortality was higher in the severely symptomatic patients, 4/10 who had midventricular HCM as compared to 0/12 in the mildly symptomatic apical HCM group (P = 0.03). CONCLUSIONS: In subbasal HCM, pts with severe symptoms have midventricular hypertrophy, with encroachment of the LV cavity and consequent very small LV volumes that may be complicated by mid-LV obstruction. Pts with mid-LV hypertrophy are more symptomatic than those with apical HCM, are often refractory to therapy, and have higher mortality.

A Comparative Assessment of Echocardiographic Parameters for Determining Primary Mitral Regurgitation Severity Using Magnetic Resonance Imaging as a Reference Standard.

BACKGROUND: The American Society of Echocardiography (ASE) guidelines suggest the use of several echocardiographic methods to assess mitral regurgitation severity using an integrated approach, without guidance as to the weighting of each parameter. The purpose of this multicenter prospective study was to evaluate the recommended echocardiographic parameters against a reference modality and develop and validate a weighting for each echocardiographic measure of mitral regurgitation severity. METHODS: This study included 112 patients who underwent evaluation with echocardiography and magnetic resonance imaging (MRI). Echocardiographic parameters recommended by the ASE were included and compared with MRI-derived regurgitant volume (MRI-RV). RESULTS: Echocardiographic parameters that correlated best with MRI-RV were proximal isovelocity surface area (PISA) radius (r = 0.65, P < .0001), PISA-derived effective regurgitant orifice area (r = 0.65, P < .0001), left ventricular end-diastolic volume (r = 0.56, P < .0001), and PISA-derived regurgitant volume (r = 0.52, P < .0001). In the linear regression models PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet independently predicted MRI-RV. CONCLUSION: Echocardiographic parameters of mitral regurgitation as recommended by the ASE had moderate correlations with MRI-RV. The best predictors of MRI-RV were PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet, suggesting that these parameters should be weighted more heavily than other echocardiographic parameters in the application of the ASE-recommended integrated approach.

Usefulness of stress echocardiography for risk stratification and prognosis of patients with left ventricular hypertrophy.

The purpose of this study was to evaluate the role of stress echocardiography in the risk stratification and prognosis of patients with left ventricular (LV) hypertrophy. One thousand two patients (mean age 62 +/- 13 years, 35% men) with LV hypertrophy (defined by LV mass index >115 g/m(2) for men and >95 g/m(2) for women) were evaluated. LV mass was calculated using the linear dimension method, as recommended by the American Society of Echocardiography. The calculation of relative wall thickness was performed using the formula (2 x posterior wall thickness)/LV internal diameter. Concentric and eccentric LV hypertrophy were defined as relative wall thicknesses > or =0.42 and <0.42 cm, respectively. Follow-up (2.6 +/- 1.1 years) for confirmed myocardial infarction and cardiac death (n = 71) was obtained. Four hundred seventy-three patients (47%) had concentric hypertrophy, and 529 patients (53%) had eccentric hypertrophy. In patients with either concentric or eccentric LV hypertrophy, stress echocardiography was able to effectively risk-stratify normal versus abnormal subgroups (event rate 1.1% vs 4.9% per year, p <0.0001), whereas stress electrocardiography was unable to do so. In the cohort with normal stress echocardiographic results, patients with concentric LV hypertrophy had an event rate 5 times higher than those with eccentric LV hypertrophy (event rate 1.7% vs 0.3% per year, p = 0.007). In conclusion, stress echocardiography effectively risk-stratifies patients with LV hypertrophy compared with stress electrocardiography. Normal stress echocardiographic results in patients with concentric LV hypertrophy indicate a worse prognosis than in patients with eccentric LV hypertrophy, probably reflecting decreased sensitivity in this cohort. However, abnormal stress echocardiographic results portend a worse prognosis in patients with either concentric or eccentric LV hypertrophy.