Cardiovascular Diseases Commons^™

A Study Of Acoustically Activated Nanodroplets, Songita Choudhury

Theses & Dissertations

Current treatment of acute myocardial infarction (AMI), which is the main pathophysiological event leading to death in the United States, has advanced considerably with the introduction of emergent percutaneous interventions, but there remains an urgent need for novel techniques to rapidly and accurately detect infarcted or ischemic tissue that results from AMI. Ultrasound contrast agents, also known as microbubbles (MB), have become commonplace in echocardiography. However, MBs are purely intravascular tracers and unable to cross endothelial barriers due to size. The limitations of MBs, namely size and short circulation times within the human body, led to the development of phase-change …

Longitudinal Measures Of Deformation Are Associated With A Composite Measure Of Contractility Derived From Pressure-Volume Loop Analysis In Children., Shahryar M. Chowdhury, Ryan J. Butts, Carolyn L. Taylor, Varsha M. Bandisode, Karen S. Chessa, Anthony M. Hlavacek, Arni Nutting, Girish S. Shirali, G Hamilton Baker

Manuscripts, Articles, Book Chapters and Other Papers

Aims: The relationship between echocardiographic measures of left ventricular (LV) systolic function and reference-standard measures have not been assessed in children. The objective of this study was to assess the validity of echocardiographic indices of LV systolic function via direct comparison to a novel composite measure of contractility derived from pressure-volume loop (PVL) analysis.

Methods and results: Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. A composite invasive composite contractility index (ICCI) was developed using data reduction strategies to combine four measures of contractility derived from PVL analysis. Echocardiograms …

Echocardiographic Detection Of Increased Ventricular Diastolic Stiffness In Pediatric Heart Transplant Recipients: A Pilot Study., Shahryar M. Chowdhury, Ryan J. Butts, Anthony M. Hlavacek, Carolyn L. Taylor, Karen S. Chessa, Varsha M. Bandisode, Girish S. Shirali, Arni Nutting, G Hamilton Baker

Manuscripts, Articles, Book Chapters and Other Papers

Background: Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients.

Methods: Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, β, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional …

Validation Of Noninvasive Measures Of Left Ventricular Mechanics In Children: A Simultaneous Echocardiographic And Conductance Catheterization Study., Shahryar M. Chowdhury, Ryan J. Butts, Carolyn L. Taylor, Varsha M. Bandisode, Karen S. Chessa, Anthony M. Hlavacek, Girish S. Shirali, G Hamilton Baker

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children.

METHODS: Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different …