Decreased Left Atrial Reservoir Strain Is Associated with Adverse Outcomes in Restrictive Cardiomyopathy.

Background: Restrictive cardiomyopathy (RCM) places patients at high risk for adverse events. In this study, we aim to evaluate the association between left atrial function and time to adverse events such as all-cause mortality and cardiovascular hospitalizations related to RCM. Material and Methods: In this single-center study, ninety-eight patients with a clinical diagnosis of RCM were recruited from our registry: 30 women (31%); age (mean ± standard deviation) 61 ± 13 years. These patients underwent cardiac magnetic resonance (CMR) imaging from May 2007 to September 2015. Left atrial (LA) function (reservoir, contractile, and conduit strain), LA diameter and area, and left ventricular function (global longitudinal strain, ejection fraction), and volume were quantified, and the presence of late gadolinium enhancement was visually assessed. The cutoff value of the LA reservoir strain was selected based on tertile. An adjusted Cox proportional regression analysis was used to assess time to adverse outcomes with a median follow up of 49 months. Results: In our cohort, all-cause mortality was 36% (35/98). Composite events (all-cause mortality and cardiovascular hospitalizations) occurred in 56% of patients (55/98). All-cause mortality and composite events were significantly associated with a decreased LA reservoir strain (adjusted hazard ratio (aHR) = 0.957, p = 0.002 and aHR = 0.969, p = 0.008) using a stepwise elimination of imaging variables, demographics, and comorbidities. All-cause mortality and composite events were six and almost four times higher, respectively, in patients with the LA reservoir strain <15% (aHR = 5.971, p = 0.005, and HR = 4.252, p = 0.001) compared to patients with the LA reservoir strain >34%. Survival was significantly reduced in patients with an LA reservoir strain <15% (p = 0.008). Conclusions: The decreased LA reservoir strain is independently associated with time to adverse events in patients with RCM.

Effects of an Electronic Medical Record Intervention on Appropriateness of Transthoracic Echocardiograms: A Prospective Study.

BACKGROUND: Transthoracic echocardiograms (TTEs) account for approximately half of U.S. spending on cardiac imaging. We developed an electronic medical record (EMR)-based decision-support algorithm for TTE ordering and hypothesized that it would increase the appropriateness of TTE orders. METHODS: This prospective observational study was performed at the Veterans Affairs Ann Arbor Healthcare System. From October to December 2016 (preintervention), consecutive TTEs ordered in the inpatient, outpatient, and emergency department settings were included. In May 2017, a decision-support algorithm was incorporated into the EMR, giving immediate feedback to providers. Chart review was performed for TTEs ordered from June to August 2017 (early intervention) and from June to August 2018 (late intervention). Appropriateness was determined based on the 2011 appropriate use criteria for echocardiography. RESULTS: Appropriate TTE orders increased from 87.6% preintervention to 94.5% at early intervention (z = 0.00018) but decreased to 90.0% at late intervention (z = 0.51, compared with preintervention). Among patients with no previous TTEs in our system, 95.3% of TTEs were appropriate, compared with 87.7% of TTEs for patients with prior TTEs within 30 days prior (odds ratio = 2.85; 95% CI, 1.18-6.31; P = .005). CONCLUSIONS: The EMR algorithm initially increased the percentage of appropriate TTEs, but this effect decayed over time. Further study is needed to develop EMR-based interventions that will have lasting impacts on provider ordering patterns.

Acute Postpartum Heart Failure With Preserved Systolic Function.

Dyspnea in the postpartum period can be a symptom of a wide range of causes spanning normal pregnancy to life-threatening pathology. We describe a case of acute postpartum heart failure with preserved systolic function in the absence of pre-eclampsia or prior cardiovascular disease. (Level of Difficulty: Beginner.).

Effect of Race on Echocardiographic Measures of Cardiac Structure and Function.

The relations between race and cardiac structure and function are incompletely understood. We hypothesized that race-specific differences in echocardiography measurements exist. We compared the relation between echocardiography measurements and race among 12,429 nonobese adults without known cardiovascular disease who underwent echocardiography. We compared measurements between whites (n = 10,508), blacks (n = 792), Asians (n = 628), Hispanics (n = 315), Native Americans (n = 34), and multiracial/other (n = 152) cohorts. Multivariate analysis compared measurements indexed to body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 46.9 ± 17.4 years and 60.5% were women. After multivariable adjustment and using whites as a baseline, there were significant differences (p <0.05) in left ventricular end-diastolic diameter/BSA for blacks (-0.5 mm/m2), Asians (0.4 mm/m2), Hispanics (0.2 mm/m2), and multiracial/others (0.1 mm/m2); septal wall thickness/BSA for blacks (0.4 mm/m2) and Asians (0.1 mm/m2); posterior wall thickness/BSA for blacks (0.4 mm/m2), Asians (0.1 mm/m2), Hispanics (0.04 mm/m2), and multiracial/others (0.03 mm/m2); left atrial diameter/BSA for Asians (0.2 mm/m2), Hispanics (0.3 mm/m2), and multiracial/others (0.1 mm/m2); septal and lateral e' for blacks (-0.7 cm/s; -0.9 cm/s); and peak tricuspid regurgitation gradient for blacks (4.3 mm Hg) and Asians (-0.9 mm Hg). Race is associated with significant differences in left ventricular size, left atrial size, mitral annular velocity, and tricuspid regurgitation gradient. Normal reference ranges for echocardiography measurements should utilize racially diverse cohorts to prevent misclassification of echocardiography findings based on race.

Differences in Echocardiographic Measures of Aortic Dimensions by Race.

It is not clear whether there are differences in aortic dimensions by race. Our hypothesis was that race-specific differences in aortic size exist. We compared the relation between race and aortic dimensions among 15,295 adults without known risk factors for cardiovascular disease or aortic dilatation, who underwent clinically indicated transthoracic echocardiography. We compared inner edge-to-inner edge measurements between whites (n = 12,932), blacks (n = 958), Asians (n = 827), Hispanics (n = 366), Native Americans (n = 38), and others (n = 174). Multivariate analysis compared measurements indexed with body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 49.9 ± 17.6 years, and 58.7% were female. On gender-specific comparisons, there were significant differences in aortic size between races (p <0.001 for each). Using whites as a baseline, multivariable analysis demonstrated that blacks had smaller BSA-indexed aortic sinus (-0.34 mm/m2, p <0.001) and ascending aorta (-0.43 mm/m2, p <0.001) dimensions; Asians had larger BSA-indexed aortic sinus (0.36 mm/m2, p <0.001), ascending aorta (0.41 mm/m2, p <0.001), and aortic arch (0.20 mm/m2, p = 0.002) dimensions; Hispanics had larger BSA-indexed aortic arch dimensions (0.15 mm/m2, p = 0.01); Native Americans had increased BSA-indexed aortic arch dimensions (0.32 mm/m2, p = 0.01); and other races had increased BSA-indexed aortic arch dimensions (0.11 mm/m2, p = 0.03). In a cohort without known risk factors for aortic dilatation, race is associated with significant differences in aortic dimensions. In conclusion, these findings suggest that reference ranges for aortic size should be established using racially diverse cohorts to prevent misdiagnosis of aortic dilatation based on race.

Indexing left ventricular wall thickness to body surface area improves prognostic value.

BACKGROUND: Guidelines provide normal ranges of left ventricular (LV) wall thicknesses (WT) without indexing. We hypothesized that indexing WT to body surface area (BSA) improves prognostic value. METHODS: We examined the relationship between WT and BSA in 9737 patients undergoing echocardiography without risk factors for LV hypertrophy other than obesity. We compared WT to BSA and examined the relationship of WT and LV mass index (LVMI) to mortality. RESULTS: There is a linear relationship between BSA and septal and posterior WT (r = 0.38, P < 0.001 for each). Higher quartiles of BSA were associated with increased WT (P < 0.001). After adjusting for age and gender, greater mean WT (MWT) (Hazards Ratio [HR] 1.10 per mm, 95% Confidence Interval [CI] 1.04-1.16, P = 0.001, C-statistic 0.66), LVMI (HR 1.01, 95% CI 1.001-1.01, P = 0.01, C-statistic 0.66), and indexed MWT (HR 1.34 per mm/m2 , 95% CI 1.23-1.47, P < 0.001, C-statistic 0.67) are each associated with increased mortality, with indexed MWT having the highest prognostic value. Each decile of indexed MWT ≥8th decile was associated with increased mortality compared to the 1st decile (P < 0.01 for each). Individuals with indexed MWT ≥8th decile (≥5.0 mm/m2 ) had increased adjusted mortality (HR 1.67, 95% CI 1.43-1.94, P < 0.001, C-statistic 0.67); this had improved prognostic value over guideline definitions of increased MWT (C-statistic 0.66) or LVMI (P = NS). CONCLUSIONS: We observe a linear relationship between BSA and WT. Indexing WT improves mortality prediction over LVMI and nonindexed WT. These findings support indexing WT to BSA.

Standardization of left atrial, right ventricular, and right atrial deformation imaging using two-dimensional speckle tracking echocardiography: a consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging.

The EACVI/ASE/Industry Task Force to standardize deformation imaging prepared this consensus document to standardize definitions and techniques for using two-dimensional (2D) speckle tracking echocardiography (STE) to assess left atrial, right ventricular, and right atrial myocardial deformation. This document is intended for both the technical engineering community and the clinical community at large to provide guidance on selecting the functional parameters to measure and how to measure them using 2D STE.This document aims to represent a significant step forward in the collaboration between the scientific societies and the industry since technical specifications of the software packages designed to post-process echocardiographic datasets have been agreed and shared before their actual development. Hopefully, this will lead to more clinically oriented software packages which will be better tailored to clinical needs and will allow industry to save time and resources in their development.

Reduced Myocardial Flow Reserve Is Associated With Diastolic Dysfunction and Decreased Left Atrial Strain in Patients With Normal Ejection Fraction and Epicardial Perfusion.

INTRODUCTION: Coronary microvascular dysfunction (MVD) may contribute to the pathogenesis of heart failure with preserved ejection fraction (HFpEF). Using myocardial flow reserve (MFR) measured by positron emission tomography (PET) as an assessment of microvascular function, we hypothesized that abnormal MFR is associated with LV diastolic dysfunction (DD) and reduced LV and LA strain in patients with risk factors for HFpEF and normal epicardial perfusion on cardiac PET. METHODS AND RESULTS: Retrospective study of patients without heart failure who underwent cardiac rubidium-82 PET and echocardiography. Global MFR was calculated as the ratio of global stress to rest myocardial blood flow. Echocardiographic measures of diastolic function were recorded. Global longitudinal LA and LV strain were measured with a 2-dimensional speckle-tracking technique. Relationships among MFR and echocardiographic measures were assessed with linear regression, analysis of variance, and test for trend. Seventy-three patients (age 64 ± 11 years, 52% male) were identified with no epicardial perfusion defect on cardiac PET and an ejection fraction ≥50%. Decreased MFR was associated with LV DD (P = .02) and increased E/e', an estimation of LV filling pressure (low E/e' [<8] vs. high E/e' [>15], P < .001). MFR was associated with LA strain independent of age, gender, and common comorbidities (adjusted ß = 2.6% per unit MFR, P = 0.046); however, MFR was only marginally related to LV strain. CONCLUSIONS: In patients with risk factors for HFpEF, MVD assessed with MFR was associated with DD, increased estimated LV filling pressure, and abnormal LA strain.

Right atrial strain is predictive of clinical outcomes and invasive hemodynamic data in group 1 pulmonary arterial hypertension.

Transthoracic echocardiography (TTE) is a practical and widely used tool for risk stratification in pulmonary arterial hypertension (PAH). We hypothesized that right atrial (RA) reservoir function, represented by peak RA systolic strain, correlates with invasive hemodynamic measurements and clinical outcomes in PAH. Patients with group 1 PAH who had TTE within 6 months of index PAH clinic visit and right heart catheterization were included in this retrospective study. Peak RA strain in the 2D apical 4-chamber view was measured with speckle-tracking software. The primary endpoint was a composite of prostacyclin initiation, lung transplantation, and death. RA strain was also measured in healthy control subjects. Among the 37 patients studied, 25 (68%) met the primary endpoint. RA strain was significantly lower among patients who met the primary endpoint than among those who did not (mean 20% vs. 33%, P = 0.002). Strain was lower in PAH patients than in controls (mean 24% vs. 35%, P = 0.0001). RA strain correlated negatively with hemodynamic data including RA pressure (R = -0.31), mean pulmonary arterial pressure (R = -0.33), and pulmonary vascular resistance (R = -0.39), and positively with cardiac index (R = 0.44). In receiver operating characteristic analysis to distinguish between patients meeting the primary endpoint and event-free survivors, RA strain was not significantly different from RA volume, right ventricular (RV) fractional area change, RV basal diameter, or right ventricular systolic pressure (area under the curve 0.82, 0.81, 0.83, 0.86, and 0.97, respectively). Our results demonstrate that RA strain is predictive of clinical outcomes in PAH. Further research is needed to determine if RA strain is independently associated with outcomes in this population.

Randomized comparison of exercise haemodynamics of Freestyle, Magna Ease and Trifecta bioprostheses after aortic valve replacement for severe aortic stenosis.

OBJECTIVES: The purpose of this study was to compare haemodynamics at rest and during exercise after clinically indicated aortic valve replacement (AVR) for aortic stenosis among patients randomly assigned to one of three haemodynamically excellent bioprostheses. METHODS: In a single-centre, prospective trial, 60 patients undergoing clinically indicated AVR were randomly assigned to Freestyle, Magna Ease or Trifecta bioprostheses. Six months after surgery, patients underwent supine bicycle stress echocardiography for the assessment of aortic valve haemodynamics. RESULTS: There were 5 protocol deviations from random valve assignments, and 4 patients did not return for follow-up stress echo, yielding a study group of 56 patients {17 Freestyle, 21 Magna Ease, 18 Trifecta; median age 70 [interquartile range (IQR) 63-78 years], 37 (66%) men}. There were no statistically significant differences between groups in valve size, concomitant procedures or exercise variables. Resting haemodynamics revealed significant differences between groups in mean gradient [Freestyle 7 (IQR 5-9) mmHg, Magna Ease 9 (IQR 7-11) mmHg, Trifecta 5 (IQR 4-8) mmHg; P = 0.04], effective orifice area (EOA) [2.5 (IQR 2.2-2.7), 2.1 (IQR 1.7-2.3) and 2.6 (IQR 2.3-2.8), respectively; P = 0.02] and EOA index [1.22 (IQR 1.11-1.32), 1.02 (IQR 0.89-1.14) and 1.31 (IQR 1.00-1.42), respectively; P = 0.03]; in each case, Trifecta had better haemodynamics compared with Magna Ease. With exercise, significant differences between groups were evident in peak velocity at 50 watts and peak exercise; mean gradient at 25 watts, 50 watts and maximal exercise; and EOA at 25 watts and at peak exercise; all with haemodynamic superiority of Trifecta compared with Magna Ease. There were no statistically significant differences between Trifecta and Freestyle haemodynamics at rest or with exercise. CONCLUSIONS: In a prospective, randomized study comparing haemodynamics after Freestyle, Magna Ease and Trifecta, all three valves exhibited good haemodynamics at rest and with exercise. There were small but significant differences between groups, with favourable haemodynamics associated with Trifecta compared to Magna Ease, and no significant differences between Trifecta and Freestyle. The Trifecta valve appears to offer haemodynamics similar to a stentless valve without the technical complexity of stentless valve implantation. CLINICALTRIALSGOV IDENTIFIER: NCT01635244.

Nationwide Trends in Reported Incidence of Takotsubo Cardiomyopathy from 2006 to 2012.

Takotsubo cardiomyopathy (TC) is believed to be an increasingly diagnosed syndrome; however, data on its incidence are limited. The purpose of this study was to determine the reported incidence of TC in the United States and to examine its trend over several years. Data was obtained from the Nationwide Inpatient Sample, created by the Agency for Healthcare Research and Quality, for each of the years from 2006 to 2012. Hospital discharges with principal diagnosis of TC, identified using Internal Classification of Diseases, Ninth Revision, code 429.83, were included. We tabulated estimated total numbers of discharges, incidence per 100,000 persons, mean length of stay, inhospital death rates, and diagnoses stratified by age group and gender. The reported incidence of TC based on principal diagnosis at hospital discharge increased significantly over the study period, with 315 cases ± 43 (standard error) in 2006 and 6,230 cases ± 232 (standard error) in 2012 (p <0.001 for trend). Mean length of hospital stay was stable over the study period (3.4 days in 2006 vs 3.6 days in 2012; p = 0.74 for trend). The diagnosis was most frequent in patients aged 65 to 84 years (50% of all diagnoses in 2012), followed by those aged 45 to 64 years (39% of all diagnoses in 2012). Women accounted for >90% of diagnoses throughout the study period. In conclusion, the reported incidence of TC has increased significantly from 2006 to 2012, most likely because of increasing recognition of the syndrome.

Definitions for a common standard for 2D speckle tracking echocardiography: consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging.

Recognizing the critical need for standardization in strain imaging, in 2010, the European Association of Echocardiography (now the European Association of Cardiovascular Imaging, EACVI) and the American Society of Echocardiography (ASE) invited technical representatives from all interested vendors to participate in a concerted effort to reduce intervendor variability of strain measurement. As an initial product of the work of the EACVI/ASE/Industry initiative to standardize deformation imaging, we prepared this technical document which is intended to provide definitions, names, abbreviations, formulas, and procedures for calculation of physical quantities derived from speckle tracking echocardiography and thus create a common standard.

Definitions for a common standard for 2D speckle tracking echocardiography: consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging.

Recognizing the critical need for standardization in strain imaging, in 2010, the European Association of Echocardiography (now the European Association of Cardiovascular Imaging, EACVI) and the American Society of Echocardiography (ASE) invited technical representatives from all interested vendors to participate in a concerted effort to reduce intervendor variability of strain measurement. As an initial product of the work of the EACVI/ASE/Industry initiative to standardize deformation imaging, we prepared this technical document which is intended to provide definitions, names, abbreviations, formulas, and procedures for calculation of physical quantities derived from speckle tracking echocardiography and thus create a common standard.

New universal strain software accurately assesses cardiac systolic and diastolic function using speckle tracking echocardiography.

BACKGROUND: We have developed new universal strain software (USS) that can be used to perform speckle tracking of any Digital Imaging and Communications in Medicine (DICOM) image, regardless of the ultrasound system used to obtain it. METHODS: Fifty patients prospectively underwent echocardiography immediately prior to cardiac catheterization. Biplane peak global longitudinal strain (GLS), peak systolic longitudinal strain rate (SSR), peak early diastolic longitudinal strain rate (DSR), and peak early diastolic circumferential strain rate (DCSR) were determined using conventional strain software (CSS) that uses raw data, and using the new USS applied to DICOM images. RESULTS: Universal strain software correlated with CSS for GLS (r = 0.78, P < 0.001), SSR (r = 0.78, P < 0.001), DSR (r = 0.54, P < 0.001), and DCSR (r = 0.43, P = 0.019). GLS and SSR using USS correlated with left ventricular ejection fraction (LVEF) (r = -0.67 and -0.71, respectively) as well as using CSS (r = -0.66 and -0.71). Patients with diastolic dysfunction had significantly lower DSR (0.61 vs. 0.87/sec, P = 0.02) and DCSR (0.89 vs. 1.23/sec, P = 0.03), and less negative GLS (-10.8 vs. -16.1%, P = 0.002) using USS in all patients, as well as among those with LVEF ≥ 50%. Receiver-operating characteristic (ROC) analysis for detection of diastolic dysfunction revealed a sensitivity and specificity of 82% and 83% for DCSR < 1.09/sec (area under the curve [AUC = 0.80]) and 85% and 83% for GLS > -13.7% (AUC = 0.84) using USS. CONCLUSION: Universal strain software can be used to accurately assess LV systolic and diastolic function using speckle tracking echocardiography.

Low-sodium DASH diet improves diastolic function and ventricular-arterial coupling in hypertensive heart failure with preserved ejection fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFPEF) involves failure of cardiovascular reserve in multiple domains. In HFPEF animal models, dietary sodium restriction improves ventricular and vascular stiffness and function. We hypothesized that the sodium-restricted dietary approaches to stop hypertension diet (DASH/SRD) would improve left ventricular diastolic function, arterial elastance, and ventricular-arterial coupling in hypertensive HFPEF. METHODS AND RESULTS: Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD (target sodium, 50 mmol/2100 kcal) for 21 days. We measured baseline and post-DASH/SRD brachial and central blood pressure (via radial arterial tonometry) and cardiovascular function with echocardiographic measures (all previously invasively validated). Diastolic function was quantified via the parametrized diastolic filling formalism that yields relaxation/viscoelastic (c) and passive/stiffness (k) constants through the analysis of Doppler mitral inflow velocity (E-wave) contours. Effective arterial elastance (Ea) end-systolic elastance (Ees) and ventricular-arterial coupling (defined as the ratio Ees:Ea) were determined using previously published techniques. Wilcoxon matched-pairs signed-rank tests were used for pre-post comparisons. The DASH/SRD reduced clinic and 24-hour brachial systolic pressure (155 ± 35 to 138 ± 30 and 130 ± 16 to 123 ± 18 mm Hg; both P=0.02), and central end-systolic pressure trended lower (116 ± 18 to 111 ± 16 mm Hg; P=0.12). In conjunction, diastolic function improved (c=24.3 ± 5.3 to 22.7 ± 8.1 g/s; P=0.03; k=252 ± 115 to 170 ± 37 g/s(2); P=0.03), Ea decreased (2.0 ± 0.4 to 1.7 ± 0.4 mm Hg/mL; P=0.007), and ventricular-arterial coupling improved (Ees:Ea=1.5 ± 0.3 to 1.7 ± 0.4; P=0.04). CONCLUSIONS: In patients with hypertensive HFPEF, the sodium-restricted DASH diet was associated with favorable changes in ventricular diastolic function, arterial elastance, and ventricular-arterial coupling. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00939640.

A novel noninvasive method to assess left ventricular -dP/dt using diastolic blood pressure and isovolumic relaxation time.

BACKGROUND: Left ventricular Doppler-derived -dP/dt determined from the continuous-wave Doppler spectrum of the mitral regurgitation (MR) jet has been shown to be a valuable marker of diastolic function, but requires the presence of MR for its assessment. We sought to determine if a novel method of determining -dP/dt using the diastolic blood pressure and isovolumic relaxation time (DBP-IVRT method) correlates with Doppler-derived -dP/dt using the MR method (Doppler-MR method). METHODS: Thirty-three patients with less than severe MR were enrolled. -dP/dt was determined using the Doppler-MR method from the continuous-wave Doppler spectrum of the MR jet (32 mmHg/time from 3 to 1 m/sec). -dP/dt was also determined using the DBP-IVRT method using the following equation: -dP/dt = (DBP - LVEDP)/IVRT, where left ventricular end-diastolic pressure (LVEDP) was estimated based on tissue Doppler and mitral inflow patterns. RESULTS: Twenty-five patients had adequate Doppler waveforms for analysis. The average amount of MR was mild-to-moderate severity. The mean -dP/dt was 680 ± 201 mmHg by the Doppler-MR method and 681 ± 237 mmHg by the DBP-IVRT method. There was a significant correlation between the 2 methods of determining -dP/dt (Pearson r = 0.574, P = 0.003). The Bland-Altman plot revealed almost no bias between the 2 methods; the difference in -dP/dt between the 2 techniques was noted to be greater for patients with higher -dP/dt, however. CONCLUSION: Diastolic blood pressure and isovolumic relaxation time may be used to noninvasively assess diastolic function in patients who do not have MR, especially in those with reduced diastolic function.

Low-sodium dietary approaches to stop hypertension diet reduces blood pressure, arterial stiffness, and oxidative stress in hypertensive heart failure with preserved ejection fraction.

Recent studies suggest that oxidative stress and vascular dysfunction contribute to heart failure with preserved ejection fraction (HFPEF). In salt-sensitive HFPEF animal models, diets low in sodium and high in potassium, calcium, magnesium, and antioxidants attenuate oxidative stress and cardiovascular damage. We hypothesized that the sodium-restricted Dietary Approaches to Stop Hypertension diet (DASH/SRD) would have similar effects in human hypertensive HFPEF. Thirteen patients with treated hypertension and compensated HFPEF consumed the DASH/SRD for 21 days (all food/most beverages provided). The DASH/SRD reduced clinic systolic (155-138 mm Hg; P=0.02) and diastolic blood pressure (79-72 mm Hg; P=0.04), 24-hour ambulatory systolic (130-123 mm Hg; P=0.02) and diastolic blood pressure (67-62 mm Hg; P=0.02), and carotid-femoral pulse wave velocity (12.4-11.0 m/s; P=0.03). Urinary F2-isoprostanes decreased by 31% (209-144 pmol/mmol Cr; P=0.02) despite increased urinary aldosterone excretion. The reduction in urinary F2-isoprostanes closely correlated with the reduction in urinary sodium excretion on the DASH/SRD. In this cohort of HFPEF patients with treated hypertension, the DASH/SRD reduced systemic blood pressure, arterial stiffness, and oxidative stress. These findings are characteristic of salt-sensitive hypertension, a phenotype present in many HFPEF animal models and suggest shared pathophysiological mechanisms linking these 2 conditions. Further dietary modification studies could provide insights into the development and progression of hypertensive HFPEF.

Comparison of 2-D speckle tracking and tissue Doppler imaging in an isolated rabbit heart model.

Ultrasound strain imaging has been proposed to quantitatively assess myocardial contractility. Cross-correlation-based 2-D speckle tracking (ST) and auto-correlation-based tissue Doppler imaging (TDI) [often called Doppler tissue imaging (DTI)] are competitive ultrasound techniques for this application. Compared with 2-D ST, TDI, as a 1-D method, is sensitive to beam angle and suffers from low strain signal-to-noise ratio because a high pulse repetition frequency is required to avoid aliasing in velocity estimation. In addition, ST and TDI are fundamentally different in the way that physical parameters such as the mechanical strain are derived, resulting in different estimation accuracy and interpretation. In this study, we directly compared the accuracy of TDI and 2-D ST estimates of instantaneous axial normal strain and accumulated axial normal strain using a simulated heart. We then used an isolated rabbit heart model of acute ischemia produced by left descending anterior artery ligation to evaluate the performance of the two methods in detecting abnormal motion. Results showed that instantaneous axial normal strains derived using TDI (0.36% error) were less accurate with larger variance than those derived from 2-D ST (0.08% error) given the same spatial resolution. In addition to poorer accuracy, accumulated axial normal strain estimates derived using TDI suffered from bias, because the accumulation method for TDI cannot trace along the actual tissue displacement path. Finally, we demonstrated the advantage 2-D ST has over TDI to reduce dependency on beam angle for lesion detection by estimating strains based on the principal stretches and their corresponding principal axes.