Enabling Reliable Visual Detection of Chronic Myocardial Infarction with Native T1 Cardiac MRI Using Data-Driven Native Contrast Mapping.

Purpose To investigate whether infarct-to-remote myocardial contrast can be optimized by replacing generic fitting algorithms used to obtain native T1 maps with a data-driven machine learning pixel-wise approach in chronic reperfused infarct in a canine model. Materials and Methods A controlled large animal model (24 canines, equal male and female animals) of chronic myocardial infarction with histologic evidence of heterogeneous infarct tissue composition was studied. Unsupervised clustering techniques using self-organizing maps and -distributed stochastic neighbor embedding were used to analyze and visualize native T1-weighted pixel-intensity patterns.

Microvascular Obstruction and Intramyocardial Hemorrhage in Reperfused Myocardial Infarctions: Pathophysiology and Clinical Insights From Imaging.

Microvascular injury immediately following reperfusion therapy in acute myocardial infarction (MI) has emerged as a driving force behind major adverse cardiovascular events in the postinfarction period. Although postmortem investigations and animal models have aided in developing early understanding of microvascular injury following reperfusion, imaging, particularly serial noninvasive imaging, has played a central role in cultivating critical knowledge of progressive damage to the myocardium from the onset of microvascular injury to months and years after in acute MI patients. This review summarizes the pathophysiological features of microvascular injury and downstream consequences, and the contributions noninvasive imaging has imparted in the development of this understanding.

Utilization of Shock Team and Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) in the Management of Cardiogenic Shock in Northern Ontario.

Background: Despite advancements in critical care and coronary revascularization, cardiogenic shock (CS) outcomes remain poor. Implementing a shock team and use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) have been associated with improved CS outcomes, but its feasibility in remote and rural areas remains unknown.

Methods: This retrospective study included patients with CS who required mechanical circulatory support (MCS) at Health Sciences North, Sudbury, Ontario.

The Canadian Cardiovascular Society Classification of Acute Atherothrombotic Myocardial Infarction Based on Stages of Tissue Injury Severity: An Expert Consensus Statement.

Myocardial infarction (MI) remains a leading cause of morbidity and mortality. In atherothrombotic MI (ST-elevation MI and type 1 non-ST-elevation MI), coronary artery occlusion leads to ischemia. Subsequent cardiomyocyte necrosis evolves over time as a wavefront within the territory at risk.

Intramyocardial hemorrhage drives fatty degeneration of infarcted myocardium.

Sudden blockage of arteries supplying the heart muscle contributes to millions of heart attacks (myocardial infarction, MI) around the world. Although re-opening these arteries (reperfusion) saves MI patients from immediate death, approximately 50% of these patients go on to develop chronic heart failure (CHF) and die within a 5-year period; however, why some patients accelerate towards CHF while others do not remains unclear. Here we show, using large animal models of reperfused MI, that intramyocardial hemorrhage - the most damaging form of reperfusion injury (evident in nearly 40% of reperfused ST-elevation MI patients) - drives delayed infarct healing and is centrally responsible for continuous fatty degeneration of the infarcted myocardium contributing to adverse remodeling of the heart.

Intramyocardial Hemorrhage and the "Wave Front" of Reperfusion Injury Compromising Myocardial Salvage.

Background: Reperfusion therapy for acute myocardial infarction (MI) is lifesaving. However, the benefit of reperfusion therapy can be paradoxically diminished by reperfusion injury, which can increase MI size.

Objectives: Hemorrhage is known to occur in reperfused MIs, but whether hemorrhage plays a role in reperfusion-mediated MI expansion is not known.

Rare case of iatrogenic aortic valve leaflet tear following a diagnostic coronary angiogram.

We report a rare case of a 44-year-old male who underwent a diagnostic coronary angiogram following a non-ST elevation myocardial infarction complicated by an aortic valve leaflet tear requiring surgical intervention. Routine transthoracic echocardiogram demonstrated a mobile echogenic structure prolapsing into the left ventricular outflow tract. An intraoperative transesophageal echocardiogram confirmed that the structure originated from the ventricular side of left coronary cusp, causing malcoaptation between left and right coronary cusps, and subsequent moderate to severe aortic regurgitation.

An Unusual Case of Cardiac Tamponade Secondary to an Elevated Right Hemidiaphragm.

Diaphragmatic eventration in old age is a rare phenomenon. Typically, it is thought to originate as a result of failure of development of the muscles of the diaphragm. Less commonly, it can occur secondary to acquired conditions resulting from spinal cord or phrenic nerve injury and is only detected incidentally when the patient presents with dyspnea, chest infection, or cardiac compression symptoms.

Recent Advances in Cardiovascular Magnetic Resonance: Techniques and Applications.

Cardiovascular magnetic resonance imaging has become the gold standard for evaluating myocardial function, volumes, and scarring. Additionally, cardiovascular magnetic resonance imaging is unique in its comprehensive tissue characterization, including assessment of myocardial edema, myocardial siderosis, myocardial perfusion, and diffuse myocardial fibrosis. Cardiovascular magnetic resonance imaging has become an indispensable tool in the evaluation of congenital heart disease, heart failure, cardiac masses, pericardial disease, and coronary artery disease.

Persistent Microvascular Obstruction After Myocardial Infarction Culminates in the Confluence of Ferric Iron Oxide Crystals, Proinflammatory Burden, and Adverse Remodeling.

Background: Emerging evidence indicates that persistent microvascular obstruction (PMO) is more predictive of major adverse cardiovascular events than myocardial infarct (MI) size. But it remains unclear how PMO, a phenomenon limited to the acute/subacute period of MI, drives adverse remodeling in chronic MI setting. We hypothesized that PMO resolves into chronic iron crystals within MI territories, which in turn are proinflammatory and favor adverse remodeling post-MI.

Cardiac magnetic resonance in clinical cardiology.

Over the last decades, cardiac magnetic resonance (CMR) has transformed from a research tool to a widely used diagnostic method in clinical cardiology. This method can now make useful, unique contributions to the work-up of patients with ischemic and non-ischemic heart disease. Advantages of CMR, compared to other imaging methods, include very high resolution imaging with a spatial resolution up to 0.

Acute myocarditis triggering coronary spasm and mimicking acute myocardial infarction.

A 24-year-old healthy man consulted to our center because of typical on-and-off chest-pain and an electrocardiogram showing ST-segment elevation in inferior leads. An urgent coronary angiography showed angiographically normal coronary arteries. Cardiovascular magnetic resonance imaging confirmed acute myocarditis.

Usefulness of cardiac resonance imaging in Churg-Strauss syndrome.

: Churg-Strauss syndrome (CSS) is a rare entity that is characterized by widespread vasculitis, which affects both small and medium-sized blood vessels of nearly all organs. More than 50% of these cases have cardiac involvement, which is the major cause of morbidity and mortality. We describe a case of a patient with cardiac biopsy proven CSS, and we discuss the usefulness of cardiovascular MRI for its diagnosis.

Detection of acute reperfusion myocardial hemorrhage with cardiac MR imaging: T2 versus T2.

Purpose: To evaluate T2 and T2* changes in acute reperfused hemorrhagic and nonhemorrhagic myocardial infarctions and to determine which technique is more suitable in the detection of intramyocardial hemorrhage at 1.5 T.

Materials And Methods: Patient studies were approved by the institutional review board and were HIPAA compliant.

Chronic manifestation of postreperfusion intramyocardial hemorrhage as regional iron deposition: a cardiovascular magnetic resonance study with ex vivo validation.

Background: Intramyocardial hemorrhage frequently accompanies large reperfused myocardial infarctions. However, its influence on the makeup and the ensuing effect on the infarcted tissue during the chronic phase remain unexplored.

Methods And Results: Patients (n=15; 3 women), recruited after successful percutaneous coronary intervention for first segment-elevation myocardial infarction, underwent cardiovascular magnetic resonance imaging on day 3 and month 6 after percutaneous coronary intervention.

Late gadolinium enhancement in cardiac transplant patients is associated with adverse ventricular functional parameters and clinical outcomes.

Background: Heart transplant recipients (HTRs) experience multiple cardiac complications, many of which might produce myocardial fibrosis. Cardiovascular magnetic resonance imaging (CMR) can image myocardial fibrosis using late gadolinium enhancement (LGE) imaging. We hypothesized that the presence and volume of LGE in heart transplant recipients correlates with left ventricular (LV) functional parameters and clinical outcomes.

Sudden cardiac arrest due to subtotal absence of left-sided pericardium--case report and review of the literature.

Congenital absence of the pericardium is a very rare cardiac malformation, usually diagnosed fortuitously on autopsy or surgery. Symptoms related to these abnormalities are usually benign, and fatalities reported in the literature are almost exclusively secondary to herniation of the heart through a partial defect. We present the unusual case of a 44-year-old woman admitted for sudden cardiac arrest.

Detection and quantification of myocardial reperfusion hemorrhage using T2*-weighted CMR.

Objectives: The purpose of this study was to validate T2*-weighted cardiac magnetic resonance (T2*-CMR) for the detection and quantification of reperfusion hemorrhage in vivo against an ex vivo gold standard, and to investigate the relationship of hemorrhage to microvascular obstruction, infarct size, and left ventricular (LV) functional parameters.

Background: Hemorrhage can contribute to reperfusion injury in myocardial infarction and may have significant implications for patient management. There is currently no validated imaging method to assess reperfusion hemorrhage in vivo.

CMR imaging of edema in myocardial infarction using cine balanced steady-state free precession.

Objectives: The aim of this study was to investigate the capabilities of balanced steady-state free precession (bSSFP) cardiac magnetic resonance imaging as a novel cine imaging approach for characterizing myocardial edema in animals and patients after reperfused myocardial infarction.

Background: Current cardiac magnetic resonance methods require 2 separate scans for assessment of myocardial edema and cardiac function.

Methods: Mini-pigs (n = 13) with experimentally induced reperfused myocardial infarction and patients with reperfused ST-segment elevation myocardial infarction (n = 26) underwent cardiac magnetic resonance scans on days 2 to 4 post-reperfusion.

The emerging clinical role of cardiovascular magnetic resonance imaging.

Starting as a research method little more than a decade ago, cardiovascular magnetic resonance (CMR) imaging has rapidly evolved to become a powerful diagnostic tool used in routine clinical cardiology. The contrast in CMR images is generated from protons in different chemical environments and, therefore, enables high-resolution imaging and specific tissue characterization in vivo, without the use of potentially harmful ionizing radiation.CMR imaging is used for the assessment of regional and global ventricular function, and to answer questions regarding anatomy.