Validation of Echocardiographic Measurements in Patients with Pulmonary Embolism in the RIETE Registry.

Background In acute pulmonary embolism (PE), echocardiographic identification of right ventricular (RV) dysfunction will inform prognostication and clinical decision-making. Registro Informatizado Enfermedad TromboEmbolica (RIETE) is the world's largest registry of patients with objectively confirmed PE. The reliability of site-reported RV echocardiographic measurements is unknown. We aimed to validate site-reported key RV echocardiographic measurements in the RIETE registry. Methods Fifty-one randomly chosen patients in RIETE who had transthoracic echocardiogram (TTE) performed for acute PE were included. TTEs were de-identified and analyzed by a core laboratory of two independent observers blinded to site-reported data. To investigate reliability, intraclass correlation coefficients (ICCs) and Bland-Altman plots between the two observers, and between an average of the two observers and the RIETE site-reported data were obtained. Results Core laboratory interobserver variations were very limited with correlation coefficients >0.8 for all TTE parameters. Agreement was substantial between core laboratory observers and site-reported data for key parameters including tricuspid annular plane systolic excursion (ICC 0.728; 95% confidence interval [CI], 0.594-0.862) and pulmonary arterial systolic pressure (ICC 0.726; 95% CI, 0.601-0.852). Agreement on right-to-left ventricular diameter ratio (ICC 0.739; 95% CI, 0.443-1.000) was validated, although missing data limited the precision of the estimates. Bland-Altman plots showed differences close to zero. Conclusion We showed substantial reliability of key RV site-reported measurements in the RIETE registry. Ascertaining the validity of such data adds confidence and reliability for subsequent investigations.

Determinants of Tricuspid Regurgitation Progression and Its Implications for Adequate Management.

BACKGROUND: Tricuspid regurgitation (TR) is associated with an increased mortality. Previous studies have analyzed predictors of TR progression and the clinical impact of baseline TR. However, there is a lack of evidence regarding the natural history of TR: the pattern of change and clinical impact of progression. OBJECTIVES: The authors sought to evaluate predictors of TR progression and assess the prognostic impact of TR progression. METHODS: A total of 1,843 patients with at least moderate TR were prospectively followed up with consecutive echocardiographic studies and/or clinical evaluation. All patients with less than a 2-year follow-up were excluded. Clinical and echocardiographic features, hospitalizations for heart failure, and cardiovascular death and interventions were recorded to assess their impact in TR progression. RESULTS: At a median 2.3-year follow-up, 19% of patients experienced progression. Patients with baseline moderate TR presented a rate progression of 4.9%, 10.1%, and 24.8% 1 year, 2 years, and 3 years, respectively. Older age (HR: 1.03), lower body mass index (HR: 0.95), chronic kidney disease (HR: 1.55), worse NYHA functional class (HR: 1.52), and right ventricle dilation (HR: 1.33) were independently associated with TR progression. TR progression was associated with an increase in chamber dilation as well as a decrease in ventriculoarterial coupling and in left ventricle ejection fraction (P < 0.001). TR progression was associated with an increased cardiovascular mortality and hospitalizations for heart failure (P < 0.001). CONCLUSIONS: Marked individual variability in TR progression hindered accurate follow-up. In addition, TR progression was a determinant for survival regardless of initial TR severity.

Cardiac involvement in a Spanish unicentric prospective cohort of patients with systemic lupus erythematosus.

BACKGROUND: Cardiac involvement is one of the most frequent manifestations of Systemic Lupus Erythematosus (SLE). Transthoracic echocardiogram (TTE) may be valuable for the early detection of cardiac abnormalities in SLE. Few studies analyze both TTE findings in SLE and the risk factors that predispose to different cardiac manifestations in a long follow-up cohort. We aimed to investigate cardiac involvement's prevalence, risk factors, and outcomes in a Spanish Lupus Clinic. METHODS: Spanish single-center prospective study of cardiac involvement in SLE. Two hundred and one patients met the 2019 EULAR/ACR classification criteria, performed TTE, and were eligible for the study. RESULTS: Cardiac involvement was present in 43.8%. Patients with older age, hypertension, hyperlipidemia, higher body mass index, peripheral arterial disease, thrombosis, and major cardiovascular events had significantly more cardiac involvement. Neurological, hematological, and serosal involvement (pleuritis and/or pericarditis) were clinical risk factors for abnormal TTE. The combination of the four clinical variables (dyspnea, chest pain, cough, and/or syncope) was present in 40.9% of the patients with abnormal TTE in the follow-up and was superior to each of the manifestations separately. Troponin I (TnI) ≥ 0.2 ng/mL and NTproBNP ≥ 300 pg/mL were excellent biomarkers with a good correlation with cardiac abnormalities. Anti-B2GP1 was the only autoantibody associated with cardiac involvement in our cohort. Presenting cardiac involvement was correlated with higher SLICC Damage Index and increased mortality risk in the 2-year follow-up period. CONCLUSIONS: Cardiac involvement in SLE is diverse, heterogeneous, and highly prevalent. Presenting a pathological TTE was associated with greater damage accrual and greater mortality. Based on our results, we consider that echocardiographic screening of patients with SLE is essential, especially those symptomatic and/or with risk factors, to diagnose and treat cardiac involvement earlier.

Magnetic resonance in patients with cardiovascular devices. SEC-GT CRMTC/SEC-Heart Rhythm Association/SERAM/SEICAT consensus document.

Magnetic resonance has become a first-line imaging modality in various clinical scenarios. The number of patients with different cardiovascular devices, including cardiac implantable electronic devices, has increased exponentially. Although there have been reports of risks associated with exposure to magnetic resonance in these patients, the clinical evidence now supports the safety of performing these studies under specific conditions and following recommendations to minimize possible risks. This document was written by the Working Group on Cardiac Magnetic Resonance Imaging and Cardiac Computed Tomography of the Spanish Society of Cardiology (SEC-GT CRMTC), the Heart Rhythm Association of the Spanish Society of Cardiology (SEC-Heart Rhythm Association), the Spanish Society of Medical Radiology (SERAM), and the Spanish Society of Cardiothoracic Imaging (SEICAT). The document reviews the clinical evidence available in this field and establishes a series of recommendations so that patients with cardiovascular devices can safely access this diagnostic tool.

Effects of Cardiac Stem Cell on Postinfarction Arrhythmogenic Substrate.

Clinical data suggest that cardiosphere-derived cells (CDCs) could modify post-infarction scar and ventricular remodeling and reduce the incidence of ventricular tachycardia (VT). This paper assesses the effect of CDCs on VT substrate in a pig model of postinfarction monomorphic VT. We studied the effect of CDCs on the electrophysiological properties and histological structure of dense scar and heterogeneous tissue (HT). Optical mapping and histological evaluation were performed 16 weeks after the induction of a myocardial infarction by transient occlusion of the left anterior descending (LAD) artery in 21 pigs. Four weeks after LAD occlusion, pigs were randomized to receive intracoronary plus trans-myocardial CDCs (IC+TM group, n: 10) or to a control group. Optical mapping (OM) showed an action potential duration (APD) gradient between HT and normal tissue in both groups. CDCs increased conduction velocity (53 ± 5 vs. 45 ± 6 cm/s, p < 0.01), prolonged APD (280 ± 30 ms vs. 220 ± 40 ms, p < 0.01) and decreased APD dispersion in the HT. During OM, a VT was induced in one and seven of the IC+TM and control hearts (p = 0.03), respectively; five of these VTs had their critical isthmus located in intra-scar HT found adjacent to the coronary arteries. Histological evaluation of HT revealed less fibrosis (p < 0.01), lower density of myofibroblasts (p = 0.001), and higher density of connexin-43 in the IC+TM group. Scar and left ventricular volumes did not show differences between groups. Allogeneic CDCs early after myocardial infarction can modify the structure and electrophysiology of post-infarction scar. These findings pave the way for novel therapeutic properties of CDCs.

A comparison of the clinical efficacy of echocardiography and magnetic resonance for chronic aortic regurgitation.

AIMS: Timing surgery in chronic aortic regurgitation (AR) relies mostly on echocardiography. However, cardiac magnetic resonance (CMR) may be more accurate for quantifying regurgitation and left ventricular (LV) remodelling. We aimed to compare the technical and clinical efficacies of echocardiography and CMR to account for the severity of the disease, the degree of LV remodelling, and predict AR-related outcomes. METHODS AND RESULTS: We studied 263 consecutive patients with isolated AR undergoing echocardiography and CMR. After a median follow-up of 33 months, 76 out of 197 initially asymptomatic patients reached the primary endpoint of AR-related events: 6 patients (3%) were admitted for heart failure, and 70 (36%) underwent surgery. Adjusted survival models based on CMR improved the predictions of the primary endpoint based on echocardiography: R2 = 0.37 vs. 0.22, χ2 = 97 vs. 49 (P < 0.0001), and C-index = 0.80 vs. 0.70 (P < 0.001). This resulted in a net classification index of 0.23 (0.00-0.46, P = 0.046) and an integrated discrimination improvement of 0.12 (95% confidence interval 0.08-0.58, P = 0.02). CMR-derived regurgitant fraction (<28, 28-37, or >37%) and LV end-diastolic volume (<83, 183-236, or >236 mL) adequately stratified patients with normal EF. The agreement between techniques for grading AR severity and assessing LV dilatation was poor, and CMR showed better reproducibility. CONCLUSIONS: CMR improves the clinical efficacy of ultrasound for predicting outcomes of patients with AR. This is due to its better reproducibility and accuracy for grading the severity of the disease and its impact on the LV. Regurgitant fraction, LV ejection fraction, and end-diastolic volume obtained by CMR most adequately predict AR-related events.

Rationale and design of the rigorous atrial analysis in advanced interatrial block (ARABIA) prospective study.

BACKGROUND: Advanced interatrial block (IAB) is present in 10% of subjects ≥75 years and is associated with the risk of clinical events. METHODS AND RESULTS: Prospective multicenter study that will include subjects ≥75 years without exclusion criteria (indication for anticoagulation, cardiac devices, severe valve disease, systolic dysfunction, moderate or severe cognitive impairment, poor echocardiographic window, non-sinus rhythm or partial IAB, stroke, and life expectancy <2 years). A total of 356 subjects, 178 patients with advanced IAB (exposed) and 178 matched individuals with normal P-wave (non-exposed) will be included. Electrocardiogram and advanced transthoracic echocardiography will be performed. Two substudies will include magnetic resonance imaging: cardiac (86 subjects, 43 exposed, and 43 non-exposed) and brain (86 subjects, 43 exposed, and 43 non-exposed). The follow-up will be 2 years. Our main objective is to determine the association of advanced IAB, P-wave duration, and atrial imaging parameters (I] atrial global longitudinal strain, II] maximal left atrial volume index, III] left atrial ejection fraction, IV] left atrial fibrosis - % total left atrial area V] inter- and intra-atrial asynchrony/dyssynchrony) with clinical events (atrial fibrillation, stroke, cognitive impairment, and mortality). The secondary objective is to assess the association of the P-wave duration with atrial imaging parameters and of both with cerebral microemboli in magnetic resonance imaging. CONCLUSION: Our study will provide data regarding the association of advanced IAB, P-wave duration, and atrial imaging parameters with clinical events. We will also assess the association P-wave duration-atrial imaging parameters-cerebral microemboli.

Prognostic Value of Late Gadolinium Enhancement for the Prediction of Cardiovascular Outcomes in Dilated Cardiomyopathy: An International, Multi-Institutional Study of the MINICOR Group.

BACKGROUND: Dilated cardiomyopathy is associated with increased risk of major cardiovascular events. Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging is a unique tissue-based marker that, in single-center studies, suggests strong prognostic value. We retrospectively studied associations between LGE presence and adverse cardiovascular events in patients with dilated cardiomyopathy in a multicenter setting as part of an emerging global consortium (MINICOR [Multi-Modal International Cardiovascular Outcomes Registry]). METHODS: Consecutive patients with dilated cardiomyopathy referred for cardiac magnetic resonance (2000-2017) at 12 institutions in 4 countries were studied. Using multivariable Cox proportional hazard and semiparametric Fine and Gray models, we evaluated the association between LGE and the composite primary end point of all-cause mortality, heart transplantation, or left ventricular assist device implant and a secondary arrhythmic end point of sudden cardiac death or appropriate implantable cardioverter-defibrillator shock. RESULTS: We studied 1672 patients, mean age 56±14 years (29% female), left ventricular ejection fraction 33±11%, and 25% having New York Heart Association class III to IV; 650 patients (39%) had LGE. During 2.3 years (interquartile range, 1.0-4.3) follow-up, 160 patients experienced the primary end point, and 88 experienced the arrhythmic end point. In multivariable analyses, LGE was associated with 1.5-fold (hazard ratio, 1.45 [95% CI, 1.03-2.04]) risk of the primary end point and 1.8-fold (hazard ratio, 1.82 [95% CI, 1.20-3.06]) risk of the arrhythmic end point. Primary end point risk was increased in patients with multiple LGE patterns, although arrhythmic risk was higher among patients receiving primary prevention implantable cardioverter-defibrillator and widening QRS. CONCLUSIONS: In this large multinational study of patients with dilated cardiomyopathy, the presence of LGE showed strong prognostic value for identification of high-risk patients. Randomized controlled trials evaluating LGE-based care management strategies are warranted.

Valve area and the risk of overestimating aortic stenosis.

OBJECTIVE: To obtain reference values of aortic valve area (AVA) in a large population and to infer the risk of overestimating aortic stenosis (AS) when focusing on flow-corrected indices of severity. METHODS: We prospectively measured indices of AS in all consecutive echocardiograms performed in a large referral cardiac imaging laboratory for 1 year. We specifically analysed the distribution of AVA, indexed AVA and velocity ratio (Vratio) in patients with and without AS, the latter defined as the coexistence of valvular outflow obstruction (Vmax ≥2.5 m/s) and morphological findings of valve degeneration. RESULTS: 16 156 echocardiograms were analysed, 14 669 of which did not show valvular obstruction (peak jet velocity <2.5 m/s). In the latter group, AVA was 2.6±0.7 cm2 in 8190 studies with normal valves and 2.3±0.7 cm2 in 6479 studies with aortic sclerosis (AScl). There was a relatively wide overlap between values of AVA, indexed AVA and velocity ratio between studies of patients with AScl and AS. Values of AVA ≤1.0 cm2 were found in 0.5% of studies with normal valves and 1.8% of studies with AScl. These proportions were 3.1% and 9.3% for AVA ≤1.5 cm2, respectively. Vratio ≤0.25 were found in 0.1% of patients without obstruction. Risk factors for a small AVA in patients without obstruction were AScl, female sex, small body surface area, low ejection fraction and mitral regurgitation. CONCLUSIONS: Normal values of continuity-equation derived AVA are smaller than previously considered. AVA values below cutoffs of moderate or severe AS can be found in patients without the disease. Flow-corrected indices may overestimate AS in patients with low gradients, particularly in the presence of well-identified risk factors.

The Functional Significance of Paradoxical Low-Gradient Aortic Valve Stenosis: Hemodynamic Findings During Cardiopulmonary Exercise Testing.

OBJECTIVES: The goal of this study was to determine the functional impact of paradoxical low-gradient aortic stenosis (PLGAS) and clarify whether the relevance of the valvular obstruction is related to baseline flow. BACKGROUND: Establishing the significance of PLGAS is particularly challenging. METHODS: Twenty symptomatic patients (77 ± 6 years of age; 17 female subjects) with PLGAS (mean gradient 28 ± 6 mm Hg; aortic valve area 0.8 ± 0.1 cm2; ejection fraction 66 ± 7%) underwent cardiopulmonary exercise testing combined with right-heart catheterization and Doppler echocardiographic measurements. RESULTS: Aortic valve area increased by 84 ± 23% (p < 0.001) and, in 70% of subjects, it reached values >1.0 cm2 at peak exercise. Stroke volume index and blood pressure increased by 83 ± 56% and 26 ± 16%, respectively (both p < 0.0001). Peak oxygen consumption inversely correlated with the rate of increase in pulmonary capillary wedge pressure (PCWP) (PCWP slope: R = -0.61; p = 0.004). In turn, the PCWP slope was determined by changes in the valvular and vascular load but not by the rest of the indices of aortic stenosis. The functional impact of PLGAS was also not related to baseline flow. Agreement between Doppler echocardiography and the Fick technique was good up to intermediate workload. CONCLUSIONS: In symptomatic patients with PLGAS, the capacity to dynamically reduce vascular and valvular loads determines the effect of exercise on PCWP, which, in turn, conditions the functional status. A critically fixed valvular obstruction may not be the main mechanism of functional impairment in a large proportion of patients with PLGAS. Exercise echocardiography is suitable to study the dynamics of PLGAS.

Noninvasive Estimation of Epicardial Dominant High-Frequency Regions During Atrial Fibrillation.

INTRODUCTION: Ablation of high dominant frequency (DF) sources in patients with atrial fibrillation (AF) is an effective treatment option for paroxysmal AF. The aim of this study was to evaluate the accuracy of noninvasive estimation of DF and electrical patterns determination by solving the inverse problem of the electrocardiography. METHODS: Four representative AF patients with left-to-right and right-to-left atrial DF patterns were included in the study. For each patient, intracardiac electrograms from both atria were recorded simultaneously together with 67-lead body surface recordings. In addition to clinical recordings, realistic mathematical models of atria and torso anatomy with different DF patterns of AF were used. For both mathematical models and clinical recordings, inverse-computed electrograms were compared to intracardiac electrograms in terms of voltage, phase, and frequency spectrum relative errors. RESULTS: Comparison between intracardiac and inverse computed electrograms for AF patients showed 8.8 ± 4.4% errors for DF, 32 ± 4% for voltage, and 65 ± 4% for phase determination. These results were corroborated by mathematical simulations showing that the inverse problem solution was able to reconstruct the frequency spectrum and the DF maps with relative errors of 5.5 ± 4.1%, whereas the reconstruction of the electrograms or the instantaneous phase presented larger relative errors (i.e., 38 ± 15% and 48 ± 14 % respectively, P < 0.01). CONCLUSIONS: Noninvasive reconstruction of atrial frequency maps can be achieved by solving the inverse problem of electrocardiography with a higher accuracy than temporal distribution patterns.

Scar Extension Measured by Magnetic Resonance-Based Signal Intensity Mapping Predicts Ventricular Tachycardia Recurrence After Substrate Ablation in Patients With Previous Myocardial Infarction.

OBJECTIVES: The aim of this study was to determine if noninvasive measurement of scar by contrast-enhanced magnetic resonance imaging (MRI)-based signal intensity (SI) mapping predicts ventricular tachycardia (VT) recurrence after endocardial ablation. BACKGROUND: Scar extension on voltage mapping predicts VT recurrence after ablation procedures. METHODS: A total of 46 consecutive patients with previous myocardial infarction (87% men, mean age 68 ± 9 years, mean left ventricular ejection fraction 36 ± 10%) who underwent VT substrate ablation before the implantation of a cardioverter-defibrillator were included. Before ablation, contrast-enhanced MRI was performed, and areas of endocardial and epicardial scarring and heterogeneous tissue were measured; averaged subendocardial and subepicardial signal intensities were projected onto 3-dimensional endocardial and epicardial shells in which dense scar, heterogeneous tissue, and normal tissue were differentiated. RESULTS: During a mean follow-up period of 32 ± 24 months 17 patients (37%) had VT recurrence. Patients with recurrence had larger scar and heterogeneous tissue areas on SI maps in both endocardium (81 ± 27 cm2 vs. 48 ± 21 cm2 [p = 0.001] and 53 ± 21 cm2 vs. 30 ± 15 cm2 [p = 0.001], respectively) and epicardium (76 ± 28 cm2 vs. 51 ± 29 cm2 [p = 0.032] and 59 ± 25 cm2 vs. 37 ± 19 cm2 [p = 0.008]). In the multivariate analysis, MRI endocardial scar extension was the only independent predictor of VT recurrence (hazard ratio: 1.310 [per 10 cm2]; 95% confidence interval: 1.051 to 1.632; p = 0.034). Freedom from VT recurrence was higher in patients with small endocardial scars by MRI (<65 cm2) than in those with larger scars (≥65 cm2) (85% vs. 20%, log-rank p = 0.018). CONCLUSIONS: Pre-procedure endocardial scar extension assessment by contrast-enhanced MRI predicts VT recurrence after endocardial substrate ablation. This information may be useful to select patients for ablation procedures.

Adipose-derived regenerative cells in patients with ischemic cardiomyopathy: The PRECISE Trial.

AIMS: Adipose-derived regenerative cells (ADRCs) can be isolated from liposuction aspirates and prepared as fresh cells for immediate administration in cell therapy. We performed the first randomized, placebo-controlled, double-blind trial to examine the safety and feasibility of the transendocardial injections of ADRCs in no-option patients with ischemic cardiomyopathy. METHODS AND RESULTS: Procedural, postoperative, and follow-up safety end points were monitored up to 36 months. After baseline measurements, efficacy was assessed by echocardiography and single-photon emission computed tomography (6, 12, and 18 months), metabolic equivalents and maximal oxygen consumption (MVO2) (6 and 18 months), and cardiac magnetic resonance imaging (6 months). We enrolled 21 ADRC-treated and 6 control patients. Liposuction was well tolerated, ADRCs were successfully prepared, and transendocardial injections were feasible in all patients. No malignant arrhythmias were seen. Adverse events were similar between groups. Metabolic equivalents and MVO2 values were preserved over time in ADRC-treated patients but declined significantly in the control group. The difference in the change in MVO2 from baseline to 6 and 18 months was significantly better in ADRC-treated patients compared with controls. The ADRC-treated patients showed significant improvements in total left ventricular mass by magnetic resonance imaging and wall motion score index. Single-photon emission computed tomography results suggested a reduction in inducible ischemia in ADRC-treated patients up to 18 months. CONCLUSION: Isolation and transendocardial injection of autologous ADRCs in no-option patients were safe and feasible. Our results suggest that ADRCs may preserve ventricular function, myocardial perfusion, and exercise capacity in these patients.

Noninvasive identification of epicardial ventricular tachycardia substrate by magnetic resonance-based signal intensity mapping.

BACKGROUND: Endo-epicardial substrate ablation reduces ventricular tachycardia (VT) recurrences; however, not all patients in whom the epicardium is explored have a VT substrate. Contrast-enhanced magnetic resonance imaging (ceMRI) is used to characterize VT substrate after myocardial infarction. OBJECTIVE: The purpose of this study was to determine if epicardial VT substrate can be identified noninvasively by ceMRI-based endo-epicardial signal intensity (SI) mapping. METHODS: Myocardial infarction was induced in 31 pigs. Four or 16 weeks later, ceMRI was obtained, and the averaged subendocardial and subepicardial SIs were projected onto 3-dimensional endocardial and epicardial shells in which dense scar, heterogeneous tissue (HT), and normal tissue were differentiated. An HT channel was defined as a corridor of HT surrounded by dense scar and connected to normal tissue. A "patchy" scar pattern was defined as the presence of at least 3 dense scar islets surrounded by HT forming ≥2 HT channels. Electrophysiologic study was performed after ceMRI. RESULTS: Thirty-three different sustained monomorphic VTs (291 ± 49 ms) were induced in 25 pigs. Mid-diastolic electrograms were recorded in the endocardium (endocardial VT) in 17 and in the epicardium (epicardial VT) in 13. Epicardial SI mapping showed that scar area was similar in animals with and without epicardial VT (24 ± 6 cm2 vs. 25 ± 12 cm2), but HT covered a higher surface of the epicardial scar in animals with VT (76 ± 6% vs. 61 ± 10%, P = .03). A patchy scar pattern was observed in all animals with epicardial VT but only in 3 animals without VT (P < .001). CONCLUSION: CeMRI-based SI mapping allows identification of the epicardial VT substrate.

Intraventricular vortex properties in nonischemic dilated cardiomyopathy.

Vortices may have a role in optimizing the mechanical efficiency and blood mixing of the left ventricle (LV). We aimed to characterize the size, position, circulation, and kinetic energy (KE) of LV main vortex cores in patients with nonischemic dilated cardiomyopathy (NIDCM) and analyze their physiological correlates. We used digital processing of color-Doppler images to study flow evolution in 61 patients with NIDCM and 61 age-matched control subjects. Vortex features showed a characteristic biphasic temporal course during diastole. Because late filling contributed significantly to flow entrainment, vortex KE reached its maximum at the time of the peak A wave, storing 26 ± 20% of total KE delivered by inflow (range: 1-74%). Patients with NIDCM showed larger and stronger vortices than control subjects (circulation: 0.008 ± 0.007 vs. 0.006 ± 0.005 m(2)/s, respectively, P = 0.02; KE: 7 ± 8 vs. 5 ± 5 mJ/m, P = 0.04), even when corrected for LV size. This helped confining the filling jet in the dilated ventricle. The vortex Reynolds number was also higher in the NIDCM group. By multivariate analysis, vortex KE was related to the KE generated by inflow and to chamber short-axis diameter. In 21 patients studied head to head, Doppler measurements of circulation and KE closely correlated with phase-contract magnetic resonance values (intraclass correlation coefficient = 0.82 and 0.76, respectively). Thus, the biphasic nature of filling determines normal vortex physiology. Vortex formation is exaggerated in patients with NIDCM due to chamber remodeling, and enlarged vortices are helpful for ameliorating convective pressure losses and facilitating transport. These findings can be accurately studied using ultrasound.