Effect of diastolic dysfunction on intraventricular velocity behavior in early diastole by flow mapping

Cardiac stasis imaging, stroke, and silent brain infarcts in patients with nonischemic dilated cardiomyopathy

Cardioembolic stroke is one of the most devastating complications of nonischemic dilated cardiomyopathy (NIDCM). However, in clinical trials of primary prevention, the benefits of anticoagulation are hampered by the risk of bleeding. Indices of cardiac blood stasis may account for the risk of stroke and be useful to individualize primary prevention treatments. We performed a cross-sectional study in patients with NIDCM and no history of atrial fibrillation (AF) from two sources: 1) a prospective enrollment of unselected patients with left ventricular (LV) ejection fraction <45% and 2) a retrospective identification of patients with a history of previous cardioembolic neurological event. The primary end point integrated a history of ischemic stroke or the presence intraventricular thrombus, or a silent brain infarction (SBI) by imaging. From echocardiography, we calculated blood flow inside the LV, its residence time (TR) maps, and its derived stasis indices. Of the 89 recruited patients, 18 showed a positive end point, 9 had a history of stroke or transient ischemic attack (TIA) and 9 were diagnosed with SBIs in the brain imaging. Averaged TR, [Formula: see text] performed well to identify the primary end point [AUC (95% CI) = 0.75 (0.61-0.89), P = 0.001]. When accounting only for identifying a history of stroke or TIA, AUC for [Formula: see text] was 0.92 (0.85-1.00) with odds ratio = 7.2 (2.3-22.3) per cycle, P < 0.001. These results suggest that in patients with NIDCM in sinus rhythm, stasis imaging derived from echocardiography may account for the burden of stroke.NEW & NOTEWORTHY Patients with nonischemic dilated cardiomyopathy (NIDCM) are at higher risk of stroke than their age-matched population. However, the risk of bleeding neutralizes the benefit of preventive oral anticoagulation. In this work, we show that in patients in sinus rhythm, the burden of stroke is related to intraventricular stasis metrics derived from echocardiography. Therefore, stasis metrics may be useful to personalize primary prevention anticoagulation in these patients.

Enhanced echocardiographic assessment of intracardiac flow in congenital heart disease

BACKGROUND

4D flow magnetic resonance imaging (4D flow MRI) can assess and measure the complex flow patterns of the right ventricle (RV) in congenital heart diseases, but its limited availability makes the broad application of intracardiac flow assessment challenging. Color Doppler imaging velocity reconstruction from conventional echocardiography is an emerging alternative, but its validity against 4D flow MRI needs to be established.

OBJECTIVE

To compare intracardiac flow parameters measured by color Doppler velocity reconstruction (DoVeR) against parameters measured from 4D flow MRI.

METHODS

We analyzed 20 subjects, including 7 normal RVs and 13 abnormal RVs (10 with repaired Tetralogy of Fallot, and 3 with atrial-level shunts). Intracardiac flow parameters such as relative pressure difference, vortex strength, total kinetic energy, and viscous energy loss were quantified using DoVeR and 4D flow MRI. The agreement between the two methods was determined by comparing the spatial fields and quantifying the cross-correlation and normalized difference between time-series measurements.

RESULTS

The hemodynamic parameters obtained from DoVeR and 4D flow MRI showed similar flow characteristics and spatial distributions. The time evolutions of the parameters were also in good agreement between the two methods. The median correlation coefficient between the time-series of any parameter was between 0.87 and 0.92, and the median L2-norm deviation was between 10% to 14%.

CONCLUSIONS

Our study shows that DoVeR is a reliable alternative to 4D flow MRI for quantifying intracardiac hemodynamic parameters in the RV.

Left ventricular diastolic pressure gradient and outcome in advanced chronic kidney disease patients with preserved ejection fraction

Assessment of left ventricular (LV) diastolic dysfunction is important in patients with chronic kidney disease (CKD). The early diastolic peak intraventricular pressure gradient (IVPG) has a vital role in diastolic function. Relative pressure imaging (RPI) is a new echocardiographic method to quantify IVPG. The purpose of this study was to analyze RPI-derived IVPG in advanced CKD patients with preserved LV ejection fraction. The study population consisted of 51 advanced CKD patients and 39 healthy controls. Patients were stratified by the evidence of heart failure with preserved ejection fraction (HFpEF) into HFpEF group (32 patients) and non-HFpEF group (19 patients). RPI analysis was used to determine the early diastolic LV relative pressure and pressure distribution. The total IVPG and segmental IVPGs corresponding to basal, mid, and apical part of the LV were calculated. Total IVPG, along with apical and mid IVPGs were all significantly reduced in HFpEF Group compared with non-HFpEF Group and controls (all P < 0.05). But no significant difference of total or segmental IVPGs was found between non-HFpEF Group and the controls. Additionally, apical IVPG < 0.02 mmHg/cm (Hazard ratio 9.82, 95 % confidence interval 2.01-48.01, P = 0.005) was the independent risk factor for the composite outcome (mortality and cardiovascular hospitalization) during a median follow-up of 24 months. Advanced CKD patients with HFpEF exhibited decreased apical and mid IVPG of the LV, and the severity of apical IVPG reduction correlated with poor outcome.