Acoustic Activation Imaging With Intravenous Perfluoropropane Nanodroplets Results in Selective Bioactivation of the Risk Area.

Background: Acoustically activatable perfluoropropane droplets (PD) can be formulated from commercially available microbubble preparations. Diagnostic transthoracic ultrasound frequencies have resulted in acoustic activation (AA) predominately within myocardial infarct zones (IZ).

Objective: We hypothesized that the AA area following acute coronary ischemia/reperfusion (I/R) would selectively enhance the developing scar zone, and target bioeffects specifically to this region.

Delayed Echo Enhancement Imaging to Quantify Myocardial Infarct Size.

Background: Perfluoropropane droplets formulated from commercial microbubbles exhibit different acoustic characteristics than their parent microbubbles, most likely from enhanced endothelial permeability. This enhanced permeability may permit delayed echo-enhancement imaging (DEEI) similar to delayed enhancement magnetic resonance imaging (DE-MRI). We hypothesized this would allow detection and quantification of myocardial scar.

The START App: a web-based RNAseq analysis and visualization resource.

Summary: Transcriptional profiling using RNA sequencing (RNAseq) has emerged as a powerful methodology to quantify global gene expression patterns in various contexts from single cells to whole tissues. The tremendous amount of data generated by this profiling technology presents a daunting challenge in terms of effectively visualizing and interpreting results. Convenient and intuitive data interfaces are critical for researchers to easily upload, analyze and visualize their RNAseq data.

Screening entire healthcare system ECG database: Association of deep terminal negativity of P wave in lead V1 and ECG referral with mortality.

Background: Each encounter of asymptomatic individuals with the healthcare system presents an opportunity for improvement of cardiovascular disease (CVD) awareness and sudden cardiac death (SCD) risk assessment. ECG sign deep terminal negativity of the P wave in V1 (DTNP) was shown to be associated with an increased risk of SCD in the general population.

Objective: To evaluate association of DTNP with all-cause mortality and newly diagnosed atrial fibrillation (AFib) in the large tertiary healthcare system patient population.

Feasibility of Using Electronic Medical Record Data for Tracking Quality Indicators in Adults with Congenital Heart Disease.

Background: In order to determine the feasibility of tracking quality of care in adults with congenital heart disease (ACHD), we aimed to estimate the availability of relevant data in electronic medical records (EMR) used in North American ACHD centers.

Methods: Previously proposed quality indicators (QIs) were reviewed to consider what types of data would be required for each. ACHD program directors were surveyed about the nature of electronic data in existing EMRs.

Cyclic variation in ultrasonic myocardial integrated backscatter is due to phasic changes in the number of patent myocardial microvessels.

Objective: We tested the hypothesis that the cyclic variation in ultrasonic myocardial integrated backscatter (IBS) is due to cardiac contraction-induced changes in the number of patent myocardial microvessels.

Methods: We performed experiments in open-chest dogs in which we increased the number of patent myocardial microvessels without changing cardiac contraction. We achieved this either by direct intracoronary administration of adenosine (group 1; n = 10) or by producing a noncritical coronary stenosis (group 2; n = 7).

Automated quantification of the spatial extent of perfusion defects and viability on myocardial contrast echocardiography.

The spatial extent of hypoperfusion or viability is important in the treatment of patients with coronary artery disease. We hypothesized that computerized pixel intensity threshold analysis (PITA) could be used for the automated analysis of perfusion defect size during myocardial contrast echocardiography (MCE). For calibration studies, MCE was performed in 6 dogs undergoing ischemia and reperfusion.

Role of collateral blood flow in the apparent disparity between the extent of abnormal wall thickening and perfusion defect size during acute myocardial infarction and demand ischemia.

Objectives: The aim of this study was to test the hypothesis that the apparent disparity between the circumferential extent of abnormal wall thickening (WT) and that of infarct size (IS) at rest or size of ischemic zone (IZ) during demand ischemia (DI) is principally due to the effects of collateral blood flow (CollBF).

Background: A disparity has been reported between the circumferential extent of abnormal WT and that of IS at rest or IZ size during DI.

Methods: Wall thickening and CollBF were measured in 18 dogs: at 6 h after coronary occlusion (Group 1, n = 6), and during 40 microg x kg x min(-1) of dobutamine in the presence of either one-vessel (Group 2, n = 6) or two-vessel stenosis (Group 3, n = 6).

Molecular imaging identifies regions with microthromboemboli during primary angioplasty in acute coronary thrombosis.

Unlabelled: Microthromboemboli (MTE) may contribute to the no-reflow phenomenon in acute myocardial infarction (AMI) either spontaneously or after primary percutaneous transluminal coronary angioplasty (PTCA). We hypothesized that myocardial MTE in acute coronary syndromes can be identified on imaging by in vivo (99m)Tc labeling of the coronary thrombus with a compound that binds to the glycoprotein IIb/IIIa present on activated platelets (DMP-444).

Methods: Fifteen dogs underwent left anterior descending coronary artery (LAD) injury in to produce thrombus, whereas 5 control dogs had LAD ligation.

Imaging tumor angiogenesis with contrast ultrasound and microbubbles targeted to alpha(v)beta3.

Background: Angiogenesis is a critical determinant of tumor growth and metastasis. We hypothesized that contrast-enhanced ultrasound (CEU) with microbubbles targeted to alpha(v)-integrins expressed on the neovascular endothelium could be used to image angiogenesis.

Methods And Results: Malignant gliomas were produced in 14 athymic rats by intracerebral implantation of U87MG human glioma cells.

Microvascular rheology of Definity microbubbles after intra-arterial and intravenous administration.

The microvascular rheology and extent of pulmonary retention of second-generation microbubble ultrasound contrast agents has not previously been well characterized. We assessed the microvascular behavior of Definity, a lipid-shelled microbubble agent containing perfluoropropane gas, using intravital microscopy of either rat spinotrapezius muscle or mouse cremaster muscle. Immediately after intra-arterial injection, which was performed to model pulmonary retention, larger microbubbles (> 5 microm) were entrapped within small arterioles and capillaries.

Automated, nonrigid alignment of clinical myocardial contrast echocardiography image sequences: comparison with manual alignment.

Analysis of myocardial contrast echocardiography (MCE) images is currently done by manual techniques. The development of computationally efficient methods for aligning images provides an important first step toward the automation of MCE analysis. This is challenging because a nonrigid transformation correction is required.