BACKGROUND AND IMPORTANCE Hemodynamics play an important role in the mechanisms of aneurysm formation, growth, and rupture. However, little is known about the hemodynamics of rupture sites. CLINICAL PRESENTATION We incidentally acquired 3-dimensional images before and at the moment of rebleeding of a cerebral aneurysm in a patient. Comparison of these 2 images enabled precise identification o...

The survival rate from ventricular fibrillation is very high for short-duration fibrillation (<30 secs) but decreases to approximately 3% to 30% in out-of-hospital conditions. During short-duration fibrillation, action potentials occur rapidly with no intervening period of electrical diastole; a shock defibrillates by interacting with the fibrillation action potential to produce a uniformly lon...

BACKGROUND Two-dimensional (2D) perfusion cardiovascular magnetic resonance (CMR) remains limited by a lack of complete myocardial coverage. Three-dimensional (3D) perfusion CMR addresses this limitation and has recently been shown to be clinically feasible. However, the feasibility and potential clinical utility of quantitative 3D perfusion measurements, as already shown with 2D-perfusion CMR ...

Magnetic resonance imaging (MRI) is a biomedical imaging modality that provides high resolution images and excellent soft tissue contrast [1]. This makes MRI a preferable imaging modality for many applications. One limitation of MRI is slow data acquisition. MRI acquires data in the Fourier domain one point at a time, usually until enough data has been collected to approximately satisfy Nyquist...

Using a needle-probe videomicroscope with a charge-coupled device (CCD) camera, we measured the diameter of subendocardial arterioles and venules during prolonged diastole beyond the time point at which coronary blood flow reached zero. In seven open-chest heart-blocked dogs, a sheathed needle probe with a doughnut-shaped balloon was introduced from the left atrial appendage and advanced into t...

BACKGROUND The effective aortic regurgitant orifice area varies with aortic pressure in animal models of acute aortic regurgitation. The purpose of this study was to determine whether the aortic regurgitant orifice area changes during diastole in patients with chronic aortic regurgitation. METHODS AND RESULTS Two-dimensional and Doppler echocardiography were performed immediately before and a...

Continuous-wave Doppler echocardiography was used to estimate pulmonary artery pressures by measuring pulmonary regurgitant flow velocity in 21 patients with pulmonary hypertension (mean pulmonary artery pressure greater than or equal to 20 mm Hg) and 24 patients without pulmonary hypertension. The pulmonary regurgitant flow velocity patterns, characterized by a rapid rise in flow velocity imme...

OBJECTIVE To obtain normal M mode (one dimensional) echocardiographic values in a substantial sample of normal infants and children. DESIGN Data were obtained over three years from a single centre in central Europe. PATIENTS 2036 healthy infants and children aged one day to 18 years. METHODS In line with recommendations for standardising measurements from M mode echocardiograms, and using...

Sato et al. (Electronic Letters 32, 949-950, 1996) reported that one can obtain a non-invasive estimate of left ventricular (LV) pressure at around end-diastole in an isolated canine preparation. In this study we examined whether this method can be applied to humans. Using the method proposed by Kanai et al. (IEEE. Trans. UFFC, 43, 791-810,1996), we detected small amplitude LV vibration from an...

Integrated ultrasonic backscatter from normal myocardium has been shown to vary with the phase of cardiac contraction (decreasing from end-diastole to end-systole) in previous studies of open-chest dogs. If confirmed, this finding would have important implications for clinical application of ultrasonic tissue characterization. Our hypothesis was that a cardiac cycle-dependent variation in regio...