Magnetic resonance imaging provides an accurate method for the measurement of left and right ventricular volume. The ratio of left ventricular stroke volume to right ventricular stroke volume was calculated from contiguous transverse magnetic resonance images and was used to measure the severity of regurgitation in 18 patients with aortic regurgitation and 10 with mitral regurgitation. Cardiac ...

BACKGROUND Patients with heart failure have modified myocardial expression of nitric oxide synthase (NOS), as is evident from induction of calcium-insensitive NOS isoforms. The functional significance of this modified NOS gene expression for left ventricular (LV) contractile performance was investigated in patients with dilated nonischemic cardiomyopathy. METHODS AND RESULTS In patients with ...

BACKGROUND AND PURPOSE The National Institutes of Health Stroke Scale (NIHSS) includes minimal assessment of cognitive function, particularly in right hemisphere (RH) stroke. Descriptions of the Cookie Theft picture from the NIHSS allow analyses that (1) correlate with aphasia severity and (2) identify communication deficits in RH stroke. We hypothesized that analysis of the picture description...

• The sudden injection indicator dilution method for the estimation of ventricular volumes J has been applied both in the experimental animal ~ and in man.This method presupposes effective uniform distribution of indicator in each end diastolic volume (EDV), a circumstance which may not occur. Further, it has not yet been practical to evaluate in vivo the possible effects of "nonmixing" on the ...

The outflow of blood from the chest during the phases of the cardiac cycle is found to be nearly equaled by a phasic inflow. The net volume change exerts very small pressure changes in the intrathoracic (intrapulmonary) air. This is not due to the distensibility of the chest wall because when allowance is made for this factor and the intrathoracic blood volume change is calculated, it is found ...

While simultaneous acquisition of electrocardiography (ECG) data during MRI is a widely used clinical technique, the effects of the MRI environment on impedance cardiography (ICG) data have not been characterized. We collected echo planar MRI scans while simultaneously recording ECG and thoracic impedance using carbon fiber electrodes and customized amplifiers. Here, we show that the key change...

Due to the absence of a sub-pulmonary ventricle, the Fontan circulation is sensitive to respiration-induced changes in intrathoracic pressure. However, the importance of a ‘respiratory pump’ in creating forward flow remains controversial. We aimed at evaluating the effect of respiration on ventricular filling during exercise using clinical data and computational modeling predictions.Ten Fontan ...

A biplane cinefluorographic technic for measuring ventricular volume is described and its accuracy and limitations are assessed. Although rather complicated and time-consuming at present, the method permits construction of volume curves and estimation of stroke volume of the left ventricle for several successive contractions in the intact animal or man. This method may prove ultimately for diag...

This study aimed to examine the effect of caffeine on hemodynamics after a resistance exercise session. Fifteen subjects completed two randomly ordered experimental resistance exercise sessions 45 min after the ingestion of either caffeine (4 mg.kg(-1)) or placebo. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were measured before consuming caffeine; SBP, DBP, MAP, heart rate, ...

An examination has been made of the relationship between stroke volume measured by dye dilution and left ventricular isovolumetric contraction and ejection times as measured by the vibrocardiogram. These studies were performed in 10 normal subjects under postural alterations, and in 11 patients recovering from acute myocardial infarction. gression analyses of the data showed that ejection t h e...