Entity

Time filter

Source Type


Russo C.,Columbia University | Palmieri V.,Unit of Cardiovascular Imaging | Homma S.,Columbia University | Rundek T.,University of Miami | And 3 more authors.
Hypertension | Year: 2012

Increased arterial stiffness and wave reflection have been reported in heart failure with normal ejection fraction (HFNEF) and in asymptomatic left ventricular (LV) diastolic dysfunction, a precursor of HFNEF. It is unclear whether women, who have higher frequency of HFNEF, are more vulnerable than men to the deleterious effects of arterial stiffness on LV diastolic function. We investigated, in a large community-based cohort, whether sex differences exist in the relationship among arterial stiffness, wave reflection, and LV diastolic function. Arterial stiffness and wave reflection were assessed in 983 participants from the Cardiovascular Abnormalities and Brain Lesions study using applanation tonometry. The central pulse pressure/stroke volume index, total arterial compliance, pulse pressure amplification, and augmentation index were used as parameters of arterial stiffness and wave reflection. LV diastolic function was evaluated by 2-dimensional echocardiography and tissue-Doppler imaging. Arterial stiffness and wave reflection were greater in women compared with men, independent of body size and heart rate (all P<0.01), and showed inverse relationships with parameters of diastolic function in both sexes. Further adjustment for cardiovascular risk factors attenuated these relationships; however, a higher central pulse pressure/stroke volume index predicted LV diastolic dysfunction in women (odds ratio, 1.54; 95% confidence intervals, 1.03 to 2.30) and men (odds ratio, 2.09; 95% confidence interval, 1.30 to 3.39), independent of other risk factors. In conclusion, in our community-based cohort study, higher arterial stiffness was associated with worse LV diastolic function in men and women. Women's higher arterial stiffness, independent of body size, may contribute to their greater susceptibility to develop HFNEF. © 2012 American Heart Association, Inc. Source


Bachler P.,University of Santiago de Chile | Bachler P.,Biomedical Imaging Center | Valverde I.,University of Santiago de Chile | Valverde I.,Kings College London | And 9 more authors.
Radiology | Year: 2013

To validate the use of particle traces derived from fourdimensional (4D) flow magnetic resonance (MR) imaging to quantify in vivo the caval flow contribution to the pulmonary arteries (PAs) in patients who had been treated with the Fontan procedure. Materials and Methods: The institutional review boards approved this study, and informed consent was obtained. Twelve healthy volunteers and 10 patients with Fontan circulation were evaluated. The particle trace method consists of creating a region of interest (ROI) on a blood vessel, which is used to emit particles with a temporal resolution of approximately 40 msec. The flow distribution, as a percentage, is then estimated by counting the particles arriving to different ROIs. To validate this method, two independent observers used particle traces to calculate the flow contribution of the PA to its branches in volunteers and compared it with the contribution estimated by measuring net forward flow volume (reference method). After the method was validated, caval flow contributions were quantified in patients. Statistical analysis was performed with nonparametric tests and Bland-Altman plots. P < .05 was considered to indicate a significant difference. Results: Estimation of flow contributions by using particle traces was equivalent to estimation by using the reference method. Mean flow contribution of the PA to the right PA in volunteers was 54% 6 3 (standard deviation) with the reference method versus 54% ± 3 with the particle trace method for observer 1 (P = .4) and 54% ± 4 versus 54% ± 4 for observer 2 (P = .6). In patients with Fontan circulation, 87% ± 13 of the superior vena cava blood flowed to the right PA (range, 63%-100%), whereas 55% 6 19 of the inferior vena cava blood flowed to the left PA (range, 22%-82%). Conclusion: Particle traces derived from 4D flow MR imaging enable in vivo quantification of the caval flow distribution to the PAs in patients with Fontan circulation. This method might allow the identification of patients at risk of developing complications secondary to uneven flow distribution. © 2013 RSNA. Source


Riesenkampff E.,Unit of Cardiovascular Imaging | Mengelkamp L.,Unit of Cardiovascular Imaging | Mueller M.,Saarland University | Kropf S.,Otto Von Guericke University of Magdeburg | And 8 more authors.
American Journal of Physiology - Heart and Circulatory Physiology | Year: 2010

The atria play an important role in cardiac performance. We evaluated their function and the atrioventricular interaction in operated patients with tetralogy of Fallot (TOF). Twenty patients who had undergone surgical repair of TOF and seven controls were investigated. Patients had residual pulmonary but no major tricuspid valve insufficiency. Atrial and ventricular strain rates were obtained by echocardiographic speckle tracking. Cine MRI-derived volumetric analysis provided atrial and ventricular time volume and time volume change curves yielding emptying and filling parameters. In addition, at the atrial level, reservoir, conduit and pump function, and cyclic volume change were calculated. At the atrioventricular valve level, tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE, respectively) were measured by two-dimensional echocardiography. In the patients compared with controls, right ventricular end-diastolic volumes were increased and biventricular ejection fraction was decreased (all P < 0.05). Biventricular measures of early diastolic ventricular filling were at control levels, but in late diastole, right ventricular filling parameters and strain rates were decreased (P < 0.001). The maximal right atrial size was slightly but not significantly diminished, but cyclic volume change was significantly reduced (P < 0.0001). Pump and reservoir function were decreased (P < 0.05), and conduit function was elevated (P < 0.001). The left atrium showed reduced reservoir function and cyclic volume change (P < 0.05). TAPSE and MAPSE were also decreased (P < 0.05). There were statistically significant interdependencies between RV ejection fraction, TAPSE, and right atrial filling and emptying parameters (all P < 0.05). In TOF patients, moderate systolic and diastolic right ventricular dysfunction is associated with clearly impaired right atrial function. The left atrium is affected to a lesser extent. Copyright © 2010 the American Physiological Society. Source


Riesenkampff E.,Unit of Cardiovascular Imaging | Nordmeyer S.,Unit of Cardiovascular Imaging | Al-Wakeel N.,Unit of Cardiovascular Imaging | Kropf S.,Otto Von Guericke University of Magdeburg | And 3 more authors.
Cardiology in the Young | Year: 2014

Background and objectives Flow profiles are important determinants of fluid-vessel wall interactions. The aim of this study was to assess blood flow profiles in the aorta and pulmonary trunk in patients with transposition and different ventriculoarterial connection, and hence different mechanics of the coherent pump. Methods In all, 29 patients with operated transposition- concordant atrioventricular and discordant ventriculoarterial connection, and no other cardiac malformation-and eight healthy volunteers were assessed with cardiac magnetic resonance imaging: n = 17 patients after atrial redirection, with a morphologic right ventricle acting as systemic pump and a morphologic left ventricle connected to the pulmonary trunk, and n = 12 patients after the arterial switch procedure, with physiologic ventriculoarterial connections. Flow-sensitive four-dimensional velocity-encoded magnetic resonance imaging was used to analyse systolic flow patterns in the aorta and pulmonary trunk, relating to helical flow and vortex formation. Results In the aorta, overall helicity was present in healthy volunteers, but it was absent in all patients independent on the operation technique. Partial helices were observed in the ascending aorta of 58% of patients after arterial switch. In the pulmonary trunk, mostly parallel flow was seen in healthy volunteers and in patients after arterial switch, whereas vortex formation was present in 88% of patients after atrial redirection. Conclusion Blood flow patterns differ substantially between the groups. In addition to varying mechanics of the coherent pumping ventricles, the absent overall helicity in all patients might be explained by the missing looping of the aorta in transposition. © 2013 Cambridge University Press. Source


Palmieri V.,Unit of Cardiovascular Imaging | Manganelli F.,Unit of Cardiovascular Imaging | Russo C.,Columbia University | Gagliardi B.,Azienda Ospedaliera San G. Moscati di Rilevanza Nazionale e di Alta Specialita | And 4 more authors.
American Journal of Cardiology | Year: 2013

Calculation of left ventricular (LV) ejection fraction (EF) by Doppler stroke volume and end-diastolic volume (EDV) derived from LV diastolic diameter (LVIDD) could be reliable and feasible in clinical practice. In subjects with a wide range of LV volumes and EFs, magnetic resonance imaging (MRI) was used to evaluate the accuracy of common formulas (Teichholz and Z method) to estimate EDV from LVIDD (EDVTeich; EDVZ) versus volumetric EDV. The accuracy of simplified Doppler-EF was tested in a separate study sample versus real-time 3-dimensional (RT3D) echocardiography and versus bidimensional Simpson's method. A new equation to calculate EDV from LVIDD was derived using MRI and tested in the RT3D echo samples. Feasibility of Doppler-EF was tested in a third sample of consecutive inpatients and outpatients. In the MRI sample, EDVTeich was greater whereas EDVZ was smaller than volumetric EDV (both p <0.01); however, a quadratic equation estimated EDV from LVIDD with accuracy (R 2=0.97). In the echocardiographic sample, independent of severe segmental wall motion abnormalities, EDVTeich was greater whereas EDV using Simpson's method was smaller than RT3D EDV (all p <0.05); Doppler-EF using EDVTeich was lower compared with EF by Simpson's rule or byRT3D-EF (all p <0.01). However, RT3D-EF showed no differences compared with Doppler-EF when EDV was calculated by the novel MRI-derived equation. Feasibility was 95% for Doppler-EF and 72% using Simpson's method. In conclusion, equations estimating EDV from LVIDD affect the accuracy of simplified Doppler-EF. However, Doppler-based EF may be accurate and feasible even in the presence of LV contractile asynergy. © 2013 Elsevier Inc. All rights reserved. Source

Discover hidden collaborations