Gradient variability in hypertrophic cardiomyopathy: New insights from computer-assisted, high fidelity, rest and exercise hemodynamic analysis.

Objectives: This study examines the intrapatient variability in peak instantaneous left ventricular outflow tract (LVOT) gradients and aortic pulse pressures during rest, exercise, and after ventricular ectopy.

Background: Although the variability in LVOT gradients in patients with hypertrophic cardiomyopathy (HCM) is well known, the predictors of such variation are not. We hypothesized that quantitative invasive analysis of gradient variation could identify useful predictors of maximal gradients.

Rest and exercise hemodynamic and metabolic findings in active duty soldiers referred for cardiac catheterization to exclude heart disease: Insights from past invasive cardiopulmonary exercise testing using multisensor high fidelity catheters.

Objective: This study describes results of iCPET from the past, which used submaximal stress and multisensor high-fidelity catheters to exclude heart disease in a unique population of young adults.

Background: There has been resurgence in comprehensive hemodynamic evaluation of complex cardiovascular patients. Although dynamic assessments during cardiac catheterization have become commonplace, there remains limited information regarding left and right heart hemodynamic changes during supine exercise in young adults.

Location of a reflection site is elusive: consequences for the calculation of aortic pulse wave velocity.

Aortic pulse wave velocity (PWV), a measure of aortic stiffness, is an important indicator of cardiovascular risk. Derivation of PWV from uncalibrated proximal aortic or carotid pressure alone has practical advantages. However, when the time of return of the reflected wave, (Delta)t, is used to calculate PWV, inaccurate data are obtained.

Assessment of Renal Perfusion in a Canine Model Using FS069, A New Transpulmonary Echocontrast Agent.

We have previously demonstrated the safety and efficacy of FS069, a new transpulmonary echocontrast agent, for myocardial opacification. To our knowledge, no information exists regarding the use of this agent for transcutaneous assessment of renal perfusion. We studied 14 mongrel dogs using intravenously administered FS069.

Identification of Perfusion Abnormalities Using FSO69, a Novel Contrast Agent, in Conscious Dogs.

Recent advances in the production of echocardiographic contrast agents has resulted in the ability to delineate areas of hypoperfusion after coronary occlusions and stenoses following their intravenous injection. Most of these studies though have been done in open chest animals. This study was done to determine if we could assess myocardial perfusion following the intravenous administration of FSO69, a suspension of perfluoropropane filled albumin microspheres (3.

Is a Full Digital Echocardiography Laboratory Feasible for Routine Daily Use?

To determine the feasibility and accuracy of digital echocardiography for routine interpretation of two-dimensional and Doppler echocardiography, we studied 93 consecutive patients chosen at random from our daily workload. The parameters studied included cavity sizes, biventricular regional and global systolic and diastolic function, valvular structure and function, and presence or absence of pericardial disease. The results were first interpreted using quad screen, digital format cine loops.

On-Line Myocardial Tissue Characterization with a New Commercially Produced Software.

Myocardial tissue characterization has been performed using various ultrasonic techniques, one of which is the cyclic variation of integrated backscatter, a method that analyzes the acoustic properties of the myocardium using backscattered radiofrequency signals to provide information about myocardial structure and function. Previous studies using prototype equipment have demonstrated a reduction in the cardiac cycle variation of integrated backscatter in various pathologic states. Recently, a commercially produced software package that allows online analysis of cyclic variation of integrated backscatter has been made available for testing by various investigators.