Endovascular therapeutic hypothermia adjunctive to percutaneous coronary intervention in acute myocardial infarction: realistic simulation as a game changer.

Background: Endovascular therapeutic hypothermia (ETH) reduces the damage by ischemia/reperfusion cell syndrome in cardiac arrest and has been studied as an adjuvant therapy to percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI). New available advanced technology allows cooling much faster, but there is paucity of resources for training to avoid delays in door-to-balloon time (DTB) due to ETH and subsequently coronary reperfusion, which would derail the procedure. The aim of the study was to describe the process for the development of a simulation, training & educational protocol for the multidisciplinary team to perform optimized ETH as an adjunctive therapy for STEMI.

Effect of Low-Frequency Therapeutic Ultrasound on Induction of Nitric Oxide in CKD: Potential to Prevent Acute Kidney Injury.

Introduction: Post-contrast acute kidney injury (PC-AKI) develops in a significant proportion of patients with CKD after invasive cardiology procedures and is strongly associated with adverse outcomes.

Objective: We sought to determine whether increased intrarenal nitric oxide (NO) would prevent PC-AKI.

Methods: To create a large animal model of CKD, we infused 250 micron particles into the renal arteries in 56 ± 8 kg pigs.

Cooling as an Adjunctive Therapy to Percutaneous Intervention in Acute Myocardial Infarction: COOL-MI InCor Trial.

Endovascular Therapeutic hypothermia (ETH) reduces the damage caused by postischemia reperfusion injury syndrome in cardiopulmonary arrest and has already established its role in patients with sudden death; however, its role in ST-segment elevation myocardial infarction (STEMI) remains controversial. The objectives of this study were to investigate the safety, feasibility, and 30-day efficacy of rapid induction of therapeutic hypothermia as adjunctive therapy to percutaneous coronary intervention (PCI) in patients with anterior and inferior STEMIs. This was a prospective, controlled, randomized, two-arm, prospective, interventional study of patients admitted to the emergency department within 6 hours of angina onset, with anterior or inferior STEMI eligible for PCI.

Effects of endovascular cooling on infarct size in ST-segment elevation myocardial infarction: A patient-level pooled analysis from randomized trials.

Objectives: This study sought to examine the relationship between temperature at reperfusion and infarct size.

Background: Hypothermia consistently reduces infarct size when administered prior to reperfusion in animal studies, however, clinical results have been inconsistent.

Methods: We performed a patient-level pooled analysis from six randomized control trials of endovascular cooling during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) in 629 patients in which infarct size was assessed within 1 month after randomization by either single-photon emission computed tomography (SPECT) or cardiac magnetic resonance imaging (cMR).

Automatic TAC extraction from dynamic cardiac PET imaging using iterative correlation from a population template.

This work describes a new iterative method for extracting time-activity curves (TAC) from dynamic imaging studies using a priori information from generic models obtained from TAC templates. Analytical expressions of the TAC templates were derived from TACs obtained by manual segmentation of three (13)NH3 pig studies (gold standard). An iterative method for extracting both ventricular and myocardial TACs using models of the curves obtained as an initial template was then implemented and tested.

Approach to assessing myocardial perfusion in rats using static [13N]-ammonia images and a small-animal PET.

Purpose: Semi-quantitative, static positron emission tomography (PET) has been used to perform an initial approach to the assessment of [13N]-ammonia perfusion studies aimed to elucidating the effect of injecting human embryonic stem cell-derived (hES) hemangioblasts on infarcted rat hearts.

Procedures: Female NIH nude rats underwent occlusion of the left anterior descending coronary artery for 30 min before reperfusion. Either one million hES-derived hemangioblasts (n = 5) or control media (n = 4) were injected into the site of the infarct 1 day post-myocardial infarction (MI) under high-resolution echocardiography guidance.

Combining dynamic and ECG-gated ⁸²Rb-PET for practical implementation in the clinic.

Objectives: For many cardiac clinics, list-mode PET is impractical. Therefore, separate dynamic and ECG-gated acquisitions are needed to detect harmful stenoses, indicate affected coronary arteries, and estimate stenosis severity. However, physicians usually order gated studies only because of dose, time, and cost limitations.

Targeted in vivo extracellular matrix formation promotes neovascularization in a rodent model of myocardial infarction.

Background: The extracellular matrix plays an important role in tissue regeneration. We investigated whether extracellular matrix protein fragments could be targeted with antibodies to ischemically injured myocardium to promote angiogenesis and myocardial repair.

Methodology/principal Findings: Four peptides, 2 derived from fibronectin and 2 derived from Type IV Collagen, were assessed for in vitro and in vivo tendencies for angiogenesis.

Percutaneous implantation of an intraventricular device for the treatment of heart failure: experimental results and proof of concept.

Background: A percutaneous system to implant a ventricular partitioning device (VPD) has been developed to partition the left ventricular (LV) cavity for treating regional wall motion abnormalities associated with post-left anterior descending (LAD) infarction, dilated left ventricle, and systolic dysfunction. The hemodynamic effects of this novel approach were evaluated in an ovine model with an anteroapical infarction created by a coil placed in the LAD.

Methods And Results: LV anteroapical infarction (MI) was induced in 10 animals.

Localization of ventricular tachycardia exit site and subsequent contraction sequence and functional effects with bedside radionuclide angiography.

Objectives: In an effort to better understand the clinical effects of ventricular tachycardia (VT), we sought to characterize function and conduction during VT in patients.

Background: The image evaluation of VT has been limited by the lack of technical tools and its often-dramatic hemodynamic effect. Objective bedside imaging of VT-induced changes in contraction pattern, synchrony, and volumes has never been performed but could aid in the understanding of rhythm tolerance.

Pediatric nuclear cardiology.

Echocardiography, magnetic resonance imaging and, more recently, multidetector computed tomography, have led to major advances in noninvasive image assessment of anatomy in pediatric cardiology. The radionuclide methods often lack sufficient resolution to precisely characterize complex morphology in congenital heart lesions. However, these methods provide an accurate and reproduceable quantitative assessment of the physiological consequences of structural heart disease.

Rodent brain imaging with SPECT/CT.

We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining.

Prospective analysis of prevalence, distribution, and rate of recovery of left ventricular systolic dysfunction in patients with subarachnoid hemorrhage.

Object: Subarachnoid hemorrhage (SAH) has been associated with cardiac injury and left ventricular (LV) dysfunction. The incidence and natural history of neurocardiogenic injury after SAH remains poorly understood. The objective of this study was to describe the incidence, time course, recovery rate, and segmental patterns of LV dysfunction after SAH.

Acute neurocardiogenic injury after subarachnoid hemorrhage.

Background: Left ventricular (LV) systolic dysfunction has been reported in humans with subarachnoid hemorrhage (SAH), and its underlying pathophysiology remains controversial. Possible mechanisms include myocardial ischemia versus excessive catecholamine release from sympathetic nerve terminals.

Methods And Results: For 38 months, echocardiography and myocardial scintigraphy with technetium sestamibi (MIBI) and meta-[(123)I]iodobenzylguanidine (MIBG) were performed on 42 patients admitted with SAH to assess myocardial perfusion and sympathetic innervation, respectively.

Age and aneurysm position predict patterns of left ventricular dysfunction after subarachnoid hemorrhage.

Cardiac injury, including left ventricular dysfunction, frequently occurs in patients with subarachnoid hemorrhage. Patterns of left ventricular dysfunction often do not follow coronary artery distributions, and may correlate with myocardial sympathetic innervation. Left ventricular dysfunction of the anterior and anteroseptal walls that spares the apex is unusual for patients with myocardial infarction and may represent a neurally mediated pattern of injury.

Combined effects of mild hypothermia and glycoprotein IIb/IIIa antagonists on platelet-platelet and leukocyte-platelet aggregation.

Endovascular cooling was assessed as a potential treatment for percutaneous coronary intervention in patients with acute myocardial infarction. Here we show that mild hypothermia: (1) inhibits platelet aggregation; (2) augments eptifibatide- and tirofiban- but not abciximab-induced inhibition of platelet aggregation; (3) increases the formation of adenosine diphosphate-induced leukocyte-platelet aggregates; and (4) diminishes the glycoprotein IIb/IIIa antagonist-induced decrease in leukocyte-platelet aggregates.

Hypothermia during reperfusion limits 'no-reflow' injury in a rabbit model of acute myocardial infarction.

Objective: Reflow following coronary artery occlusion is an important predictor of clinical outcome. This study tests the effects of regional hypothermia, initiated late during ischemia and maintained for 2 h of reperfusion, on the no-reflow phenomenon.

Methods: Anesthetized, open-chest New Zealand White rabbits received 30 min of coronary artery occlusion and 3 h reperfusion.

Pinhole single-photon emission computed tomography for myocardial perfusion imaging of mice.

Objectives: Although transgenic mice have emerged as powerful experimental models of cardiovascular disease, methods for in vivo phenotypic assessment and characterization remain limited, motivating the development of new instruments for biologic measurement.

Background: We have developed a single-photon emission computed tomography system with a pinhole collimator (pinhole SPECT) for high-resolution cardiovascular imaging of mice. In this study, we describe a protocol for myocardial perfusion imaging of mice using technetium-99m ((99m)Tc)-sestamibi and demonstrate the feasibility for measurement of perfusion defect size from pinhole SPECT images.

Safety and efficacy of endovascular cooling and rewarming for induction and reversal of hypothermia in human-sized pigs.

Background And Purpose: Numerous studies indicate that mild hypothermia provides substantial neuroprotection. However, current systems transfer insufficient heat to rapidly vary core temperature. We thus evaluated the safety and efficacy of endovascular cooling and rewarming for the induction and reversal of hypothermia.

Performance evaluation of a pinhole SPECT system for myocardial perfusion imaging of mice.

The increasing use of transgenic mice as models of human physiology and disease has motivated the development of dedicated in vivo imaging systems for anatomic and functional characterization of mice as an adjunct to or a replacement for established ex vivo techniques. We have developed a pinhole single photon emission computed tomography (SPECT) system for high resolution imaging of mice with cardiovascular imaging as the primary application. In this work, we characterize the system performance through phantom studies.

Induction of mild systemic hypothermia with endovascular cooling during primary percutaneous coronary intervention for acute myocardial infarction.

Objectives: The purpose of this study was to evaluate the safety and feasibility of endovascular cooling during primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).

Background: In experimental models of AMI, mild systemic hypothermia has been shown to reduce metabolic demand and limit infarct size.

Methods: In a multi-center study, 42 patients with AMI (<6 h from symptom onset) were randomized to primary PCI with or without endovascular cooling (target core temperature 33 degrees C).

Effect of endovascular cooling on myocardial temperature, infarct size, and cardiac output in human-sized pigs.

Mild hypothermia reduces myocardial infarct size in small animals; however, the extent of myocardial protection in large animals with greater thermal mass remains unknown. We evaluated the effects of mild endovascular cooling on myocardial temperature, infarct size, and cardiac output in 60- to 80-kg isoflurane-anesthetized pigs. We occluded the left anterior descending coronary artery for 60 min, followed by reperfusion for 3 h.

Effect of endomyocardial laser channels on regional innervation shown with (125)I-MIBG and autoradiography.

Unlabelled: The aim of this study was to map regional innervation against regional flow early after laser channel placement using autoradiography in a porcine model.

Methods: Four juvenile male swine underwent left ventricular mapping using a catheter-based mapping system and laser treatment with 20-30 channels to the mid and distal anterior wall of the left ventricle. Three days later animals were injected with 37 MBq (125)I-metaiodobenzylguanidine (MIBG) followed in 3 h with 1,110 MBq (99m)Tc-sestamibi; 1 h later the animals were killed.