Duplex ultrasound imaging to detect limb stenosis or kinking of endovascular device.

Objective: We attempted to correlate duplex ultrasound (DU) findings with the clinical outcome of graft limb stenosis or kinking after endovascular aneurysm repair (EVAR).

Methods: Between 1998 and 2010, 248 patients underwent EVAR and postoperative DU surveillance of 496 graft limbs in our accredited noninvasive vascular laboratory by one of three experienced technologists. Routine DU surveillance was performed 1 week, 6 months, and annually after EVAR.

Deformation analysis of 3D tagged cardiac images using an optical flow method.

Background: This study proposes and validates a method of measuring 3D strain in myocardium using a 3D Cardiovascular Magnetic Resonance (CMR) tissue-tagging sequence and a 3D optical flow method (OFM).

Methods: Initially, a 3D tag MR sequence was developed and the parameters of the sequence and 3D OFM were optimized using phantom images with simulated deformation. This method then was validated in-vivo and utilized to quantify normal sheep left ventricular functions.

Ventricular restraint prevents infarct expansion and improves borderzone function after myocardial infarction: a study using magnetic resonance imaging, three-dimensional surface modeling, and myocardial tagging.

Background: Infarct expansion is associated with impaired borderzone function, adverse remodeling, and poor long-term prognosis. We hypothesized that left ventricular restraint early after myocardial infarction limits infarct expansion, preserves borderzone function, and reduces remodeling.

Methods: We used an ovine model as well as high spatial and temporal resolution cardiac magnetic resonance imaging to quantify total and infarcted left ventricular epicardial surface area at baseline and 1 week and 12 weeks after anterior wall infarction in 10 animals.

The surgical treatment of end-stage heart failure.

Cardiac failure remains the leading cause of death in the Western World today. After myocardial insult, as the heart remodels and dilates, an increase in wall tension occurs secondary to increased radius of curvature, leading to increased myocardial oxygen consumption, decreased subendocardial blood flow, impaired energetics, and increased arrhythmias. Poor prognosis directly correlates with the degree of remodeling.

Early postinfarction ventricular restraint improves borderzone wall thickening dynamics during remodeling.

Background: Early infarct expansion impairs function of normally perfused borderzone myocardium (BZM), initiates adverse remodeling, and portends a poor long-term outcome. Early ventricular restraint has been demonstrated to improve global remodeling but its effect on BZM function has not been assessed. Using an ovine model of infarct induced remodeling and MRI, we tested the hypothesis that ventricular restraint early after MI preserves BZM function and reduces remodeling.

Infarct size reduction and attenuation of global left ventricular remodeling with the CorCap cardiac support device following acute myocardial infarction in sheep.

Background: Whether mechanical restraint of the left ventricle (LV) can influence remodeling following myocardial infarction (MI) remains poorly understood. The following discussion details three studies examining the effects of surgically placing a cardiac support device (CSD) over the entire epicardial surface, on infarct expansion, global cardiac function and myocyte geometry and function post-MI.

Methods: The effects of passive constraint on infarct expansion and global cardiac function/myocardial energetics were investigated in 10 sheep (5 MI only; 5 MI + CSD) using pressure-volume analysis and magnetic resonance imaging (MRI).

Cardiac support device modifies left ventricular geometry and myocardial structure after myocardial infarction.

Background: Whether mechanical restraint of the left ventricle (LV) can influence remodeling after myocardial infarction (MI) remains poorly understood. This study surgically placed a cardiac support device (CSD) over the entire LV and examined LV and myocyte geometry and function after MI.

Methods And Results: Post-MI sheep (35 to 45 kg; MI size, 23+/-2%) were randomized to placement of the CorCap CSD (Acorn Cardiovascular, Inc) (MI+CSD; n=6) or remained untreated (MI only; n=5).

Passive ventricular constraint to improve left ventricular function and mechanics in an ovine model of heart failure secondary to acute myocardial infarction.

Objective: This study investigated the effects on global cardiac function and myocardial energetics of limiting progressive dilatation after infarction by means of a woven polyester jacket cardiac support device. We hypothesized that placement of the cardiac support device results in a decrease in myocardial wall stress and improvement in cardiac function and myocardial energetics.

Methods: To investigate the effect of passive constraint on left ventricular function and mechanics, a total of 10 sheep were studied with pressure-volume analysis and magnetic resonance imaging.

Ventricular constraint using the acorn cardiac support device reduces myocardial akinetic area in an ovine model of acute infarction.

Background: Left ventricular remodeling secondary to acute myocardial infarction (AMI) is characterized by ventricular dilatation and regional akinesis. In this study, we investigated the effect of passive constraint on akinetic area development.

Methods And Results: The effect of passive constraint on akinetic area was investigated in 10 sheep using tissue-tagging magnetic resonance imaging (MRI).