title: Intraventricular vortex properties in nonischemic dilated cardiomyopathy.
abstract: 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.
authors.affiliation: Department of Cardiology, Hospital General Universitario Gregorio Marañón, Facultad de Medicina, Universidad Complutense de Madrid, and Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain;
authors.forename: Javier
authors.initials: J
authors.lastname: Bermejo
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Benito
authors.forename: Marta
authors.initials: M
authors.lastname: Alhama
authors.forename: Raquel
authors.initials: R
authors.lastname: Yotti
authors.forename: Pablo
authors.initials: P
authors.lastname: Martínez-Legazpi
authors.forename: Candelas Pérez
authors.initials: CP
authors.lastname: Del Villar
authors.forename: Esther
authors.initials: E
authors.lastname: Pérez-David
authors.forename: Ana
authors.initials: A
authors.lastname: González-Mansilla
authors.forename: Cristina
authors.initials: C
authors.lastname: Santa-Marta
authors.forename: Alicia
authors.initials: A
authors.lastname: Barrio
authors.forename: Francisco
authors.initials: F
authors.lastname: Fernández-Avilés
authors.forename: Juan C
authors.initials: JC
authors.lastname: Del Álamo
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D018618:Echocardiography, Doppler, Color; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011237:Predictive Value of Tests; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left; D017725:Ventricular Pressure; D020257:Ventricular Remodeling
keywords: diastolic function; doppler echocardiography; fluid dynamics