…degeneration (Barlow's disease), degeneration associated with connective tissue disorders (Marfan syndrome, Ehlers Danlos syndrome), osteogenesis imperfecta typically causes prolapse of P2 (Figure 1). Myocardial…

…may take hours to days. It is generally stated that myocardium resists 20 minutes of severe hypoxia before cell death begins. It appears that neurons…

…overdoses, etc.). Among victims in whom the cardiac arrest was caused by VT or VF (e.g acute or chronic myocardial ischemia, heart failure, etc…

…Increased intracranial pressure Irreversible causes of sinus node dysfunction Age related degenerative disease (fibrosis) Myocardial ischemia/infarction Lesions due to heart surgery Myocarditis Collagen disease…

…anomaly (Figure 1). Carcinoid heart disease. Endocarditis (common in intravenous drug addicts). Myxomatous degeneration. Rheumatic heart disease. Dilatation of the right ventricle. Dilatation of the…

…are caused by calcification of the aortic valve. Calcification has traditionally been considered a passive degenerative process, but emerging evidence suggests it is propelled by…

…those with LAFB, however, have significant heart disease. Myocardial infarction, coronary artery disease, left ventricular hypertrophy, dilated cardiomyopathy, hypertrophic cardiomyopathy, degenerative disease, hypertension, hyperkalemia, myocarditis…

Myocardial ischemia and infarction Pharmacology & dosing Definition and pathophysiological basis Secondary prevention after myocardial infarction (MI) encompasses long term interventions intended to reduce recurrent infarction…

…the past century. Initial post mortem observations in the late 19th century first linked thrombotic occlusion of a coronary artery with myocardial necrosis. Although early…

…of acute coronary syndrome (ACS), biochemical evidence of myocardial injury with corroborating evidence of infarction caused by ischaemia, and no obstructive stenosis in a major…

…ischaemia and presumed new ischaemic ECG changes. The distinction between myocardial injury and type 2 infarction is particularly important. Type 2 infarction requires clinical evidence…

…appears to act through a redistribution of blood from non ischemic to ischemic myocardium (i.e an increase in blood flow in the ischemic area…

…based on the principle that flow limiting coronary disease limits the ability of a myocardial territory to augment blood flow during exercise or pharmacological vasodilation…

…the criteria for type 1 MI. Procedural myocardial injury may also occur without satisfying the diagnostic threshold for periprocedural MI. This distinction is clinically important…

…As mentioned above, posterior myocardial infarction may be accompanied by inferior infarction if the occlusion affects both vascular territories. This will result in ST segment…

Myocardial ischemia and infarction ECG Definition and Pathophysiology Acute coronary syndromes (ACS) encompass a spectrum of clinical conditions characterized by a recent change in symptoms…

…of underlying coronary artery disease (CAD) and structural cardiac abnormalities. Mechanisms involving reduced myocardial perfusion include fixed coronary atherosclerosis without plaque rupture, coronary artery spasm…

…requires continuous blood flow to maintain cellular function. Myocardial ischemia occurs when there is insufficient oxygen available. Insufficient oxygen supply results in diminished ATP production…

Echocardiography Structure and contractile function of myocardial fibers The left ventricular wall can be subdivided into several layers. These layers are similar to those seen…

Cardiology Myocardial ischemia and infarction Definition and Purpose Cardiac rehabilitation is a comprehensive, multidisciplinary secondary prevention intervention for patients with cardiovascular disease, including those recovering…

…distribution [4, 5]. In contrast to acute myocardial infarction, pericarditis lacks prominent reciprocal ST depression and does not evolve into pathologic Q waves [4]. Additionally…

…repeated ischemic episodes or chronic reductions in perfusion. The amount and distribution of both viable and nonviable myocardium, together with coronary anatomy and the feasibility…

Echocardiography Myocardial ischemia and infarction Definition and pathophysiology Left ventricular (LV) thrombus is an intracavitary clot attached to the LV endocardium, typically overlying an akinetic…

…may manifest as reciprocal ST segment depression rather than apparent ST segment elevation. Posterior involvement is commonly associated with inferior or lateral myocardial infarction. Consequently…

…process: acute, evolving or chronic The severity of ischaemia and whether infarction has occurred The extent and degree of myocardial involvement The anatomical territory, including…

…from risk factors to acute coronary syndromes. It also presents a classification of acute coronary syndromes and myocardial infarctions. The reader should study this chart…

ECG Myocardial ischemia and infarction Use of ECG in acute coronary syndromes & chest pain patients An ECG must be performed on all patients seeking medical…

…normal persons. In 2017 it was possible to detect myocardial infarctions 100 times smaller than what was possible to detect in year 2000. This explains…

…The relation between the action potential and the ECG curve. Myocardial ischemia primarily affects repolarization, which is reflected in ST T changes on the ECG…

…leads. Localization of myocardial infarction / ischemia is done by using ECG changes to determine the affected area and subsequently the occluded coronary artery (culprit). Figure…

…due to extensive subendocardial infarction (NSTEMI). If pathological Q waves occur as a result of myocardial infarction, the infarction may be classified as Q wave…

…is slightly simplified. In reality, the course in acute myocardial infarction (AMI) is modified by several factors. The most important of these, and their implications…

…complete coronary artery occlusion, which results in the complete stop of blood flow and thus more extensive myocardial ischemia (referred to as transmural ischemia). Yet…

…factors– including the severity of the stenosis/occlusion, microvascular function, myocardial oxygen extraction, presence of collateral circulation, etc –ischemia may also develop during resting conditions…

…exhibit ST segment elevations, but the condition should be managed as STEMI (ST Elevation Myocardial Infarction) in terms of treatment and interventions. As discussed previously…

ECG Myocardial ischemia and infarction ST segment depression due to acute myocardial ischemia ST segment depressions caused by ischemia are characterized by a horizontal or…

…Indeed, a dynamic (varying) ST segment is suggestive of myocardial ischemia. It is wise to connect the patient to continuous ECG (ST) monitoring in order…

…patients with acute STEMI. Although ECG changes in acute STEMI have been discussed previously (refer to ECG Changes in Acute Myocardial Infarction), a rehearsal is…

Echocardiography Myocardial deformation: strain, strain rate, speckle tracking As previously discussed, the left ventricular wall can be subdivided into three layers: the inner lining ( endocardium…

…oxygen from the blood in the ventricular cavity. The right bundle branch then runs deeper into the myocardium, where roughly one third of its length…

…available. Recall that ST segment elevations also become normalized as a part of the natural course of myocardial infarction (refer to Figure 2 below). However…

…Indeed, the atrial myocardium consists of such a thick layer that much of it may receive oxygen directly from the blood within the atrial cavity…

…the diagnostic method. Myocardial bridging has been identified in approximately 0.5–12% of angiographic series and up to 5–75% of CT series; other…

Critical care Myocardial ischemia and infarction Definition and Pathophysiology Cardiogenic shock is a state of inadequate tissue and end organ perfusion caused by cardiac insufficiency…

…the absence of evidence of ischaemia. Classification of myocardial infarction The Fourth Universal Definition separates MI into five principal types. Type Mechanism or setting Type…

…Absolute contraindications Acute myocardial infarction (MI) within 48 hours Ongoing unstable angina Uncontrolled cardiac arrhythmia with hemodynamic compromise Active endocarditis Symptomatic severe aortic stenosis Decompensated…

…Image acquisition and evaluation Stress Imaging : Initially performed using exercise or pharmacologic agents to elevate myocardial oxygen demand (or simulate increased demand using vasodilatory agents)…

…Implications of left bundle branch block in myocardial ischemia and infarction A summary of the issues that arise when facing a patient with left bundle…

…typically platelet rich and less occlusive, often presenting clinically as Non ST Elevation Myocardial Infarction (NSTEMI) rather than STEMI [4] . Calcified Nodules: A less common…

…medications such as nitrates, beta blockers, or calcium channel blockers Recent acute myocardial infarction (AMI) Pharmacologic agents in perfusion imaging Vasodilators (adenosine, dipyridamole, regadenoson) These…

…of blood flow using PET Quantitative PET perfusion imaging offers precise measurements of myocardial blood flow in milliliters per minute per gram of tissue (mL…

…conditions. MPI uses radiotracers in combination with single photon emission computed tomography (SPECT) or positron emission tomography (PET) to assess myocardial perfusion and blood flow…

…fundamental pathophysiological substrate for acute coronary syndromes (ACS), including ST Elevation Myocardial Infarction (STEMI) [1] . Historically viewed as a simple plumbing problem characterized by the…

…syndromes with persistent ST segment elevations (i.e STEMI, ST segment elevation acute myocardial infarction). 1 Initial diagnosis of STEMI ECG Management Recommendation Level of…

…stress testing, myocardial ischemia and ischemic symptoms Understanding the basic principles of exercise physiology is essential to conduct and evaluate the exercise stress test. Exercise…

…and cost. The pathophysiological substrate of angina may differ between patients. Myocardial ischaemia may result predominantly from obstructive epicardial coronary disease, coronary vasospasm, microvascular dysfunction…

Myocardial ischemia and infarction Pharmacology & dosing Definition and pathophysiology Atherosclerosis and acute coronary syndromes have important inflammatory components. Inflammation contributes to atherothrombosis through activation of…

Myocardial ischemia and infarction Definition and pathophysiology In acute coronary syndrome (ACS) with multivessel coronary artery disease (MVD), revascularization may be directed exclusively at the…

Myocardial ischemia and infarction Procedurer Definition and scope Coronary angiography is an invasive fluoroscopic procedure in which contrast media are injected selectively into the epicardial…

Myocardial ischemia and infarction Pharmacology & dosing Definition and pathophysiological rationale Dual antiplatelet therapy (DAPT) denotes treatment with aspirin plus a P2Y12 receptor inhibitor. In the…