Stroke in mitral valve prolapse: risk factors and left atrial function in cryptogenic versus non-cryptogenic ischemic subtypes.

Background and purpose: Mitral valve prolapse (MVP) has been associated with an increased risk of ischemic stroke. Older age, thicker mitral leaflets, and significant mitral regurgitation (MR) leading to atrial fibrillation have been traditionally considered risk factors for ischemic stroke in MVP. However, specific risk factors for MVP-stroke subtypes are not well defined. The aim of this study is to evaluate clinical and echocardiographic parameters, including left atrial (LA) function, in MVP with cryptogenic (C) vs. non-cryptogenic (NC) stroke. Methods: In this case-control matched study, MVPs were identified in consecutive echocardiograms obtained after a stroke from January 2013 to December2016 at the University of California, San Francisco. MVP was defined as leaflet displacement ≥2 mm in the parasternal long-axis view at end-systole. Age/gender matched MVPs without stroke and healthy controls without MVP were also identified. We analyzed LA end-systolic/diastolic volume index, emptying fraction (LAEF), function index (LAFI), and global longitudinal strain in all MVPs and controls. We also measured left ventricular (LV) volume indexes, mass index, ejection fraction (EF), degree of MR and leaflet thickness. Results: We identified a total of 30 MVPs (age 70 ± 12, 50% females) with stroke (11 with C- and 19 with NC-stroke), 20 age/gender matched MVPs without a stroke and 16 controls. MVPs without stroke had lower BMI, less hypertension but more MR (≥moderate in 45% vs. 17%), more abnormal LA function (lower LAEF, LAFI) and larger LV volumes/mass (all p < 0.05) when compared to MVPs with stroke. Leaflet thickness was overall mild (<3 mm) and similar in the 2 groups. Within the MVP stroke group, NC-stroke had higher BMI, more hypertension and more atrial fibrillation compared to C-stroke. In the variables tested, patients with C-stroke did not differ from controls. Conclusions: MVP-related MR may be protective against stroke despite abnormal LA function. Risk of NC-stroke in MVP is related to common stroke risk factors rather than mitral valve leaflet thickness. The etiology of C-stroke in MVP warrants further studies.

Echocardiographic estimation of pulmonary vascular resistance in advanced lung disease.

Noninvasive assessment of pulmonary hemodynamics is often performed by echocardiographic estimation of the pulmonary artery systolic pressure (ePASP), despite limitations in the advanced lung disease population. Other noninvasive hemodynamic variables, such as echocardiographic pulmonary vascular resistance (ePVR), have not been studied in this population. We performed a retrospective analysis of 147 advanced lung disease patients who received both echocardiography and right heart catheterization for lung transplant evaluation. The ePVR was estimated by four previously described equations. Noninvasive and invasive hemodynamic parameters were compared in terms of correlation, agreement, and accuracy. The ePVR models strongly correlated with invasively determined PVR and had good accuracy with biases of <1 Wood units (WU), although with moderate precision and wide 95% limits of agreement varying from 5.9 to 7.8 Wood units. The ePVR models were accurate to within 1.9 WU in over 75% of patients. In comparison to the ePASP, ePVR models performed similarly in terms of correlation, accuracy, and precision when estimating invasive hemodynamics. In screening for pulmonary hypertension, ePVR models had equivalent testing characteristics to the ePASP. Mid-systolic notching of the right ventricular outflow tract Doppler signal identified a subgroup of 11 patients (7%) with significantly elevated PVR and mean pulmonary artery pressures without relying on the acquisition of a tricuspid regurgitation signal. Analysis of ePVR and determination of the notching pattern of the right ventricular outflow tract Doppler flow velocity envelope provide reliable insights into hemodynamics in advanced lung disease patients, although limitations in precision exist.

Association of Systemic Vascular Resistance Analog and Cardiovascular Outcomes: The Heart and Soul Study.

Background Systemic vascular resistance (SVR) is an integral component of the hemodynamic profile. Previous studies have demonstrated a close correlation between an estimated SVR analog (eSVR) based on echocardiographic methods and SVR by direct hemodynamic measurement. However, the prognostic impact of eSVR remains unestablished. Methods and Results Study participants with established coronary artery disease from the Heart and Soul Study formed this study cohort. We defined Doppler-derived eSVR as the ratio of systolic blood pressure to left ventricular outflow tract velocity time integral. Study participants were separated based on baseline eSVR tertile: <5.6, 5.6 to <6.9, and ≧6.9. An elevated eSVR was defined as an eSVR in the third tertile (≧6.9). Follow-up eSVR was calculated at the fifth year of checkup. Cardiovascular outcomes included heart failure, major cardiovascular events, and all-cause death. Among the 984 participants (67±11 years old, 82% men), subjects with the highest baseline eSVR tertile were the oldest, with the highest systolic blood pressure and lowest left ventricular outflow tract velocity time integral. A higher eSVR was associated with increased risk of heart failure, major cardiovascular events, and death. The hazard ratio for major cardiovascular events was 1.38 (95% CI, 1.02-1.86, P=0.03) for subjects with the highest eSVR tertile compared with the lowest. In addition, those with a persistently elevated eSVR during follow-up had the most adverse outcomes. Conclusions An elevated eSVR, derived by the ratio of systolic blood pressure and left ventricular outflow tract velocity time integral, was more closely correlated with cardiovascular events than systolic blood pressure alone. Repeatedly elevated eSVR was associated with more adverse outcomes.

Premature Ventricular Contractions Are Presaged by a Mechanically Abnormal Sinus Beat.

BACKGROUND: Frequent premature ventricular contractions (PVCs) can lead to cardiomyopathy; it is unclear if there are abnormal myocardial mechanics operative in the PVC and non-PVC beats. OBJECTIVES: The aim of this study was to investigate regional and global myocardial mechanics, including dyssynchrony, in patients with frequent PVCs. METHODS: Fifty-six consecutive patients referred for PVC ablation were prospectively studied. During sinus rhythm (SR) and PVC beats, left ventricular (LV) global longitudinal strain (GLS), LV dyssynchrony (measured as the SD of time to peak GLS), and dyssynergy (measured as maximum regional strain minus minimum regional strain at aortic valve closure) were quantified using 2-dimensional strain echocardiography. GLS, dyssynchrony, and dyssynergy were compared in remote SR, pre-PVC SR, PVC, and post-PVC SR beats. RESULTS: In SR beats remote from the PVC, GLS was -17.3% ± 4%, dyssynchrony was 49 ± 14 ms, and dyssynergy was 22% ± 9%. Myocardial mechanics were significantly abnormal during PVCs compared with remote SR beats (GLS -7.7% ± 3% [P < 0.001], dyssynchrony 115 ± 37 milliseconds [P < 0.001], and dyssynergy 26% ± 10% [P < 0.001]). There were significant mechanical abnormalities in the SR beat preceding the PVC, which demonstrated significantly lower LV strain (pre-PVC SR, -13% ± 4%; P < 0.001) and more dyssynchrony (pre-PVC SR, 63 ± 19 milliseconds; P < 0.001) compared with remote SR beats. Dyssynergy was significantly higher for pre-PVC SR and PVC beats compared with remote SR (pre-PVC SR, 25% ± 8% [P < 0.001]; PVC, 26% ± 10% [P < 0.001]). CONCLUSIONS: In patients with frequent PVCs, the SR beat preceding the PVC demonstrates significant mechanical abnormalities. This finding suggests that perturbations in cellular physiological processes such as excitation-contraction coupling may underlie the generation of frequent PVCs.

Interrater reproducibility of the 2016 American society of echocardiography left ventricular diastolic function guidelines.

BACKGROUND: Little data exist regarding interreader variability of diastolic measurements and their application by the 2016 American Society of Echocardiography left ventricular (LV) diastolic function guidelines. METHODS: Volunteers (n = 49) were recruited from an outpatient cardiology practice. The presence and grade of diastology dysfunction (DD) was determined by the 2016 LV diastology guideline algorithm. We determined the mean, standard deviation, coefficient of variation, and intraclass correlation coefficient (ICC) for each measurement and Fleiss K-statistic to define differences in grading DD. We determined predictors associated with disagreement of DD grade using odds ratios. RESULTS: The mean LVEF was 56%, LAVI 32 ml/m2 , and peak TR velocity was 2.3 m/s. The ICC for mitral inflow and tissue Doppler velocities were >.90, for LV volumes were .80-.86, and for LA volume was .56. The Fleiss K-value for the agreement of the presence of DD was .68 and for DD grade was .59. Variables with increased odds of disagreement were (1) at least one reader considering a TR signal uninterpretable (OR 12.0; 95% CI 1.3-109.6), (2) at least one reader assessing both LVEF 50%-55% and LAVI 29-39 ml/m2 (OR 9.3; 95% CI 1.0-87), and (3) at least one reader assessing LVEF 50-55% (OR 3.8; 95% CI 1.1-13.4). CONCLUSIONS: Using the 2016 ASE/EACVI diastology guidelines, we found excellent interrater reliability of Doppler measurements, moderate-good interrater reliability of volumetric measurements, and moderate-good but not excellent agreement for diastology grade.

Left ventricular end-systolic volume response post-stress echocardiography: Dilation as a marker of multi-vessel coronary artery disease.

BACKGROUND: Transient ischemic dilation of the left ventricle (LV) during stress echocardiography indicates extensive myocardial ischemia. It remains unclear whether the change of LV end-systolic volume (ESV) or end-diastolic volume (EDV) better correlated with significant coronary artery disease (CAD). Meanwhile, the clinical significance of the extent of the volumetric change post-stress has not been investigated. METHODS: One hundred and five individuals (62 ± 12 years and 75% men) who underwent coronary angiography following exercise treadmill echocardiography were enrolled retrospectively. An additional 30 age- and sex-matched healthy subjects were included for comparison. LV dilation was defined as any increase in LV volume from rest to peak exercise. Patients who had at least two coronary arteries with significant stenosis were considered as having multi-vessel CAD. RESULTS: Thirty-four patients had ESV dilation during exercise echocardiography. On the contrary, ESV decreased at peak exercise in all healthy subjects. Forty-one patients had multi-vessel CAD, and its prevalence was higher in patients with ESV dilation (65% vs 27%, p = 0.001). The extent of ESV increase correlated with CAD severity. ESV dilation is associated with multi-vessel CAD (Odds ratio [OR] 5.02, 95% confidence interval [CI] 2.09 - 12.07, p < 0.001). After adjustment for EDV increase, clinical, electrocardiographic, and echocardiographic variables, the association remained significant (adjusted OR 5.57, 95% CI 1.37-22.64; p = 0.02). CONCLUSIONS: ESV dilation independently correlated with multi-vessel CAD, whereas EDV dilation did not. The amount of ESV increase correlated with the severity of CAD. Our findings provide a rationale for incorporating volume measurements into stress echocardiography practice.

Exercise physiology of the left atrium: quantity and timing of contribution to cardiac output.

Although the phases of left atrial (LA) function at rest have been studied, the physiological response of the LA to exercise is undefined. This study defines the exercise behavior of the normal left atrium by quantitating its volumetric response to graded effort. Healthy subjects (n = 131) were enrolled from the Health eHeart cohort. Echocardiograms were obtained at baseline and during ramped supine bicycle exercise. Left ventricular volume index, stroke volume index (LVSVI), left atrial end-systolic volume index (LAESVI), left atrial end-diastolic volume index (LAEDVI), and left atrial emptying fraction (LAEF), reservoir fraction, and conduit fraction were analyzed. The LVSVI increased with low exercise but did not increase further with peak exercise; cardiac output increased through the agency of heart rate. The LAESVI and LAEDVI decreased and the LAEF increased with exercise. As a result, the LA reservoir volume index was static throughout exercise. The reservoir fraction decreased from 46% at rest to 40% with low exercise (P < 0.001) in association with increased LVSVI and remained similar at peak exercise. The conduit volume index increased from 20 mL/m2 at rest to 24 mL/m2 at low exercise and stayed the same at peak exercise. Similarly, the conduit fraction increased from 54% at rest to 60% at low exercise (P < 0.001) and did not change further with peak exercise. Although atrial function increased with exercise, the major contribution to the augmentation of LV stroke volume is LA conduit fraction, a marker of active ventricular relaxation. Furthermore, the major determinant of raising cardiac output during high-level exercise is heart rate.NEW & NOTEWORTHY Diseases of the left atrium (LA) are major sources of disability (e.g., strokes and fatigue), but its exercise physiology has been unstudied. Such knowledge may allow early recognition of disease and suggest therapies. We show that in normal subjects, low-level exercise decreases LA volume and increases its ejection fraction. However, these changes offset each other volumetrically, and the contribution to LV filling from a full to an empty LA (reservoir function) is static. Higher levels of exercise do not change LA reservoir contribution. Blood flowing directly from the pulmonary vein to LV (conduit flow) impelled by augmented LV active relaxation (suction) is the major source of a modest increase in LV stroke volume. The major source of increased cardiac output with exercise is heart rate. During all stages of exercise, the LA works hard but only to keep up. We believe that our findings provide an additional set of benchmarks through which to quantitate LA pathology and gauge its progression.

Left atrial mass: relationship between gross anatomy and quantitative echocardiography.

BACKGROUND: Left atrial (LA) enlargement is associated with increased risk of adverse cardiovascular outcomes. Unlike the left ventricular mass, LA mass has not been described. We sought to define the anatomic mass of the LA using anatomic specimens from autopsy. We hypothesized that LA mass could be estimated by echocardiography. METHODS AND RESULTS: Using anatomic specimens of 22 subjects who died and underwent post mortem examination as well as echocardiogram, we defined normal LA mass by weighing anatomic specimens of those with normal LA volume on echocardiogram. Using 17 subjects with normal LA volume on echocardiogram, we found their LA mass on anatomic specimens to be 25.5 ± 6.3 grams (14.4 ± 3.2 g/m2). We developed an echocardiographic measure of LA mass and validated this measurement with paired LA anatomic specimens. We found the normal LA mass on echocardiogram to be 25.4 ± 6.3 g (14.4 ± 2.8 g/m2) which correlated well with anatomic specimens (ß = 0.99; Confidence interval CI 0.6-1.4, P < .0001; Pearson correlation coefficient r = 0.83). Furthermore, we defined the normal LA volume to mass ratio as 1.38 ± 0.45. CONCLUSIONS: LA mass is an additional parameter with which may contribute to the study of LA morphology.

Endurance exercise in seniors: Tonic, toxin or neither?

INTRODUCTION: Cardiac adaptation to sustained exercise in the athletes is established. However, exercise-associated effect on the cardiac function of the elderly has to be elucidated. The aim of this study was to analyse left (LV) and right ventricular (RV) characteristics at different levels of chronic exercise in the senior heart. MATERIALS AND METHODS: We studied 178 participants in the World Senior Games (mean age 68 ± 8 years, 86 were men; 48%). Three groups were defined based on the type and intensity of sports: low-, moderate- and high-intensity level. Exclusion criteria were coronary artery disease, atrial fibrillation, valvular heart disease or uncontrolled hypertension. LV and RV size and function were evaluated with an echocardiogram. RESULTS: LV trans-mitral inflow deceleration time decreased in parallel to the intensity of chronic exercise: 242 ± 54 ms in low-, 221 ± 52 ms in moderate- and 215 ± 58 ms in high-intensity level, p = .03. Left atrial volume index (LAVI) was larger in high-intensity group, p = .001. The LAVI remained significantly larger when adjusting for age, gender, heart rate, hypertension and diabetes (p = .002). LV and RV sizes were larger in the high-intensity group. LV ejection fraction and RV systolic function evaluated by tissue Doppler velocity, atrioventricular plane displacement and strain did not differ between groups. CONCLUSION: Left ventricular diastolic filling is not only preserved, but may also be enhanced in long-term, top-level senior athletes. Moreover, LV and RV systolic function remain unchanged at different levels of exercise. This supports the beneficial effects of endurance exercise participation in senior hearts.

Left Atrial End-Diastolic Volume Index as a Predictor of Cardiovascular Outcomes: The Heart and Soul Study.

BACKGROUND: The left atrial end-systolic volume index (LAESVI) is a predictor of cardiovascular outcomes and is the recommended measurement of left atrial size. The left atrial end-diastolic volume index (LAEDVI), representing the minimum or residual left atrial volume, has not been fully evaluated as a predictor of cardiovascular events. This study evaluated the predictive power of LAEDVI compared with LAESVI for heart failure (HF) hospitalizations, a composite of HF hospitalizations, myocardial infarction, stroke, and heart disease death, and all-cause mortality. METHODS: We measured LAESVI and LAEDVI in subjects without atrial fibrillation or flutter or significant mitral valve disease. Using Cox proportional-hazard models, the association of LAESVI and LAEDVI with the stated outcomes was examined. RESULTS: After a mean of 7.3±2.6 years of follow-up, there were 147 HF hospitalizations, 118 myocardial infarctions, 45 strokes, 96 heart disease deaths, and 351 deaths from all causes in 938 subjects. When comparing the highest and the lowest quartiles of LAEDVI, there was a near 6-fold increase in the hazard ratio (HR) for HF hospitalization (HR, 5.96; P<0.001). This was higher than what was seen with LAESVI (HR, 4.85; P<0.001). Similar associations were noted for the composite cardiovascular outcome (HR for LAEDVI, 2.97; P<0.001) and for all-cause mortality (HR for LAEDVI, 2.08; P<0.001). In adjusted models, LAEDVI demonstrated equal or better predictive power than LAESVI for HF hospitalization and the composite cardiovascular outcome. CONCLUSIONS: LAEDVI is a strong predictor of cardiovascular events in ambulatory patients with stable coronary heart disease and may merit routine use.

Association of Longitudinal Change in High-Sensitivity Troponin with All-Cause Mortality in Coronary Artery Disease: The Heart and Soul Study.

BACKGROUND: Serial increases in high-sensitivity cardiac troponin (hs-cTnT) have been associated with death in community-dwelling adults, but the association remains uninvestigated in those with coronary artery disease (CAD). METHODS: We measured hs-cTnT at baseline and after 5 years in 635 ambulatory Heart and Soul Study patients with CAD. We also performed echocardiography at rest and after treadmill exercise at baseline and after 5 years. Participants were subsequently followed for the outcome of death. We used a multivariable-adjusted Cox proportional hazards model to evaluate the association between 5-year change in hs-cTnT and subsequent all-cause mortality. RESULTS: Of the 635 subjects, there were 386 participants (61%) who had an increase in hs-cTnT levels between baseline and year 5 measurements (median increase 5.6 pg/mL, IQR 3.2-9.9 pg/mL). There were 182 deaths after a mean 4.2-year follow-up after the year 5 visit. After adjusting for clinical variables, a >50% increase in hs-cTnT between baseline and year 5 was associated with a nearly 2-fold increased risk of death from any cause (hazard ratio 1.7, 95% confidence interval 1.1-2.7). When addition of year 5 hs-cTnT was compared to a model including clinical variables and baseline hs-cTnT, there was a modest but statistically significant increase in C-statistic from 0.82 to 0.83 (p = 0.04). CONCLUSION: In ambulatory patients with CAD, serial increases in hs-cTnT over time are associated with an increased risk of death.

Association of Machine Learning-Derived Phenogroupings of Echocardiographic Variables with Heart Failure in Stable Coronary Artery Disease: The Heart and Soul Study.

BACKGROUND: Many individual echocardiographic variables have been associated with heart failure (HF) in patients with stable coronary artery disease (CAD), but their combined utility for prediction has not been well studied. METHODS: Unsupervised model-based cluster analysis was performed by researchers blinded to the study outcome in 1,000 patients with stable CAD on 15 transthoracic echocardiographic variables. We evaluated associations of cluster membership with HF hospitalization using Cox proportional hazards regression analysis. RESULTS: The echo-derived clusters partitioned subjects into four phenogroupings: phenogroup 1 (n = 85) had the highest levels, phenogroups 2 (n = 314) and 3 (n = 205) displayed intermediate levels, and phenogroup 4 (n = 396) had the lowest levels of cardiopulmonary structural and functional abnormalities. Over 7.1 ± 3.2 years of follow-up, there were 198 HF hospitalizations. After multivariable adjustment for traditional cardiovascular risk factors, phenogroup 1 was associated with a nearly fivefold increased risk (hazard ratio [HR] = 4.8; 95% CI, 2.4-9.5), phenogroup 2 was associated with a nearly threefold increased risk (HR = 2.7; 95% CI, 1.4-5.0), and phenogroup 3 was associated with a nearly twofold increased risk (HR = 1.9; 95% CI, 1.0-3.8) of HF hospitalization, relative to phenogroup 4. CONCLUSIONS: Transthoracic echocardiographic variables can be used to classify stable CAD patients into separate phenogroupings that differentiate cardiopulmonary structural and functional abnormalities and can predict HF hospitalization, independent of traditional cardiovascular risk factors.

Who is young at heart and when? Diastolic Doppler data from the mind your heart study.

To further define the age-related distribution of diastolic function as defined by E/A ratio, in healthy male adults. The age-sensitive ratio of mitral inflow E-wave to A-wave (E/A) velocity is often considered in the evaluation of diastolic function. To appropriately direct a comprehensive evaluation of diastolic function, we sought to improve the characterization of the influence of age on E/A ratio. We analyzed echocardiographic data from the Mind Your heart Study, a cohort of outpatients recruited from two San Francisco Veterans centers to examine the effect of mental health on cardiovascular outcomes. Individuals with a history of heart disease or hypertension were excluded, leaving 313 veterans for analysis. We examined E/A by 5-year increments and performed linear and logistic regression analysis to predict trends in E/A and E dominance. Within the age ranges of population (54.9 ± 11.5), there is a steady gradual decline in absolute E/A ratio (beta coefficient/year- 0.018, P < .001) and the odds of E dominance similarly declines with age (odds ratio/year = 0.89, P < .001). Despite this decline, 90% of individuals below the age of 50 years maintain E dominance. Beyond age 50, 55% maintain E dominance, and beyond age 70, only 28% have E dominance. In this adequately healthy population, age-related progression of delayed relaxation appears to be a state of normality rather than diastolic dysfunction. Careful attention to specific cutoff points in age and E/A ratio could avoid misinterpretation or inappropriate management.

Pulmonary Dead Space Monitoring: Identifying Subjects With ARDS at Risk of Developing Right Ventricular Dysfunction.

BACKGROUND: ARDS is a highly morbid condition characterized by diffuse pulmonary inflammation, which results in hypoxemic respiratory failure. Approximately 25% of patients with ARDS develop right ventricular dysfunction, with cor pulmonale being a common final pathway in a significant number of non-survivors. ARDS-related right ventricular dysfunction occurs due to acute elevation in ventricular afterload caused by mechanisms that are associated with increased pulmonary dead space fraction. Thus, we hypothesized that changes in pulmonary dead space fraction may reflect changes in pulmonary hemodynamics. METHODS: This was a prospective single-center study of 21 subjects with ARDS who underwent serial determination of pulmonary dead space fraction and pulmonary hemodynamics via transthoracic echocardiography. Linear mixed-effects modeling was performed to test for an association between a change in pulmonary dead space and a change in pulmonary hemodynamics. RESULTS: The tricuspid regurgitation velocity to right ventricular outflow track velocity time integral ratio, an echocardiographic surrogate for pulmonary vascular resistance, increased by 0.16 Wood units (Coefficient 0.16, 95% CI 0.09-0.23; P < .001), and the tricuspid regurgitation pressure gradient increased by 3.7 mm Hg (Coefficient 3.7, 95% CI 1.74-5.63, P < .001) for every 10% increase in pulmonary dead space fraction. CONCLUSIONS: Increases in the pulmonary dead space fraction were associated with relative increases in both the tricuspid regurgitation velocity to right ventricular outflow track velocity time integral ratio and the tricuspid regurgitation pressure gradient, which likely contributed to the high incidence of ARDS-related right ventricular dysfunction encountered in clinical practice. Pulmonary dead space monitoring may serve as a clinical indicator to identify patients with ARDS at risk of developing right ventricular dysfunction and acute cor pulmonale.

Doppler Recognition of Low or Normal Central Venous Pressure from Continuous Flow from Inferior Vena Cava Into Right Atrium.

Estimation of right atrial (RA) or central venous pressure (CVP) is a critical component of a comprehensive transthoracic echocardiographic (TTE) examination. We hypothesize that continuous inflow from the inferior vena cava (IVC) into the RA is a surrogate for low/normal CVP and can be reliably imaged in standard echocardiographic parasternal short and right ventricular inflow views. We retrospectively studied 200 patients who underwent right heart catheterization (RHC) within 8 hours of TTE between 2012 and 2016, and selected 60 patients in whom the continuous wave Doppler beam incidentally interrogated IVC inflow into RA during evaluation of the tricuspid valve. From these studies, we sought an uninterrupted Doppler wave (DW) inflow signal. CVP on RHC were then compared in patients with continuous and interrupted DW. Other TTE and RHC parameters were also noted and compared in these 2 groups. The average time interval between TTE and RHC was 266 ± 151 minutes. Of 60 patients (males = 39 (65%); age 63 ± 14 years), 12 patients (20%) had continuous DW and 48 (80%) had interrupted DW inflow signal from IVC into the RA. Of the 12 patients with continuous flow, 11 had RA pressure of ≤7 mm Hg. Similarly, of 48 patients with interrupted flow, RA pressure was >7 mm Hg in 45, and less than ≤7 mm Hg in 3 patients (two-sided p value 0.0001). The continuous DW signal predicted RA of ≤7 mm Hg with a sensitivity and specificity of 98% and 78%, respectively. Additionally, when combined with IVC size and collapsibility (normal-sized collapsible IVC), the sensitivity and specificity of DW signal to predict RA of ≤ 7 mmHg were enhanced to 94% and 92%, respectively. In conclusion, IVC flow pattern can be reliably studied to estimate CVP in standard echocardiographic views. Continuous and interrupted IVC flow predicts normal and elevated RA pressure, respectively.

Echocardiographic determination of pulmonary arterial capacitance.

A growing body of evidence has demonstrated that pulmonary arterial capacitance (PAC) is the strongest hemodynamic predictor of clinical outcomes across a wide spectrum of cardiovascular disease, including pulmonary hypertension and heart failure. We hypothesized that a ratio of right ventricular stroke volume (RVOT VTI) to the associated peak arterial systolic pressure (PASP) could function as a reliable non-invasive surrogate for PAC. We performed a prospective study of patients undergoing simultaneous transthoracic echocardiography and right heart catheterization (RHC) for various clinical indications. Measurements of the RVOT VTI/PASP ratio from echocardiographic measurements were compared against PAC calculated from RHC measurements. Correlation coefficients and Bland-Altman analysis compared the RVOT VTI/PASP ratio with PAC. Forty-five subjects were enrolled, 38% were female and mean age was 54 years (SD 13 years). The reason for referral to RHC was most commonly post-heart transplant surveillance (40%), followed by heart failure (22%), and pulmonary hypertension (18%). Pre-capillary pulmonary hypertension was present in 18%, isolated post-capillary pulmonary hypertension was present in 13%, and combined pre-and post-capillary pulmonary hypertension was present in 29%. The RVOT VTI/PASP ratio was obtainable in the majority of patients (78%), and Pearson's correlation demonstrated moderately-strong association between PAC and the RVOT VTI/PASP ratio, r = 0.75 (P < 0.001). Bland-Altman analysis demonstrated good agreement between measurements without suggestion of systematic bias and a mean difference in standardized units of - 0.133. In a diverse population of patients and hemodynamic profiles, we validated that the ratio of RVOT VTI/PASP to be a reliably-obtained non-invasive marker associated with PAC.

Embolic Stroke of Undetermined Source: A Population with Left Atrial Dysfunction.

BACKGROUND: Cryptogenic stroke, now defined as embolic stroke of undetermined source (ESUS), represents about a quarter of all ischemic strokes and the reoccurrence is high. Understanding this stroke subtype better would likely guide treatment recommendations. In this study, we tested the hypothesis that left atrial (LA) shape and function at rest, as well as with exercise, are abnormal compared to matched normal controls. METHODS: The study design was prospective enrollment of ESUS subjects who underwent measurement of LA function at rest and exercise by 2D and 3D echocardiograms. The exercise portion of the study was conducted using a ramped supine bicycle protocol during which LA function was measured. Stroke subjects were matched with normal subjects by age, gender, and body surface area. RESULTS: Over a 1-year enrollment period, 18 ESUS patients met inclusionary criteria and were studied. Their average age was 58 years old and 44% were female. ESUS subjects have larger LA end-diastolic volume at rest (14 versus 11 mL/m2, P = .04) and with exercise (11 versus 6 mL/m2, P = .001) compared to normal controls. In ESUS, there was a lack of response to maximal exercise of LA function as measured by the LA ejection fraction (61% versus 73% P = .001) and the LA function index (.68 versus .82, P = .02). The 3D analysis showed spherical remodeling of the LA in ESUS. This remodeling was documented by the sphericity index, which was increased in both diastole (.40 versus .32, P = .02) and systole (.63 versus .71 P = .03). CONCLUSIONS: In support of our hypothesis, we found that ESUS subjects have LA dysfunction and remodeling at rest and exercise in comparison to healthy, matched controls. Evaluation of the left atrium in this high-risk stroke subtype has potential to inform stroke prevention strategies and to suggest pathways for research.

Left ventricular mechanical dispersion predicts arrhythmic risk in mitral valve prolapse.

OBJECTIVE: Bileaflet mitral valve prolapse (MVP) with either focal or diffuse myocardial fibrosis has been linked to ventricular arrhythmia and/or sudden cardiac arrest. Left ventricular (LV) mechanical dispersion by speckle-tracking echocardiography (STE) is a measure of heterogeneity of ventricular contraction previously associated with myocardial fibrosis. The aim of this study is to determine whether mechanical dispersion can identify MVP at higher arrhythmic risk. METHODS: We identified 32 consecutive arrhythmic MVPs (A-MVP) with a history of complex ventricular ectopy on Holter/event monitor (n=23) or defibrillator placement (n=9) along with 27 MVPs without arrhythmic complications (NA-MVP) and 39 controls. STE was performed to calculate global longitudinal strain (GLS) as the average peak longitudinal strain from an 18-segment LV model and mechanical dispersion as the SD of the time to peak strain of each segment. RESULTS: MVPs had significantly higher mechanical dispersion compared with controls (52 vs 42 ms, p=0.005) despite similar LV ejection fraction (62% vs 63%, p=0.42) and GLS (-19.7 vs -21, p=0.045). A-MVP and NA-MVP had similar demographics, LV ejection fraction and GLS (all p>0.05). A-MVP had more bileaflet prolapse (69% vs 44%, p=0.031) with a similar degree of mitral regurgitation (mostly trace or mild in both groups) (p>0.05). A-MVP exhibited greater mechanical dispersion when compared with NA-MVP (59 vs 43 ms, p=0.0002). Mechanical dispersion was the only significant predictor of arrhythmic risk on multivariate analysis (OR 1.1, 95% CI 1.02 to 1.11, p=0.006). CONCLUSIONS: STE-derived mechanical dispersion may help identify MVP patients at higher arrhythmic risk.