Cardiovascular Pathology II Flashcards
What is ischemic heart disease?
Coronary heart disease, damage to the arteries of the heart
What is present in more than 90% of IHD cases?
Coronary atherosclerosis
What are the four basic forms of ischemic heart disease?
Angina pectoris, myocardial infarction, chronic ischemia leading to CHF, sudden death from arrhythmia
What are risk factors for ischemic heart disease?
Hypertension, hypercholesterolemia, diabetes, smoking, lifestyle, diet, genetic
What is myocardial infarction?
Heart attack, death of cardiac muscle from ischemia
What are 90% of myocardial infarctions caused by?
Thrombosed artery
Disruption of the atherosclerotic plaque leading to formation of thrombus
Results in total occlusion
What are the symptoms of myocardial infarction?
Crushing pain in chest, sweating, nausea, vomiting, dyspnea
What are complications of myocardial infarction?
Coagulative necrosis, cardiogenic shock (sudden loss of pumping strength), cardiac failure, arrhythmias, mural thrombosis, valvular dysfunction (due to rupture of papillary muscle), rupture, tamponade or death
Describe the gross morphological changes associated with myocardial infarction.
18-24 hours: pallor of myocardium
24-72 hours: pallor with some hyperaemia
3-7 days: hyperaemic border with central yellowing
10-21 days: minimally yellow and soft with vascular margins
7 weeks: White fibrosis
What are two types of myocardial infarctions?
Transmural infarction and subendocardial infarct
What is a transmural infarction?
Ischemic necrosis of full or nearly full thickness of ventricular wall in distribution of single coronary artery
What causes a transmural infarction?
Coronary atherosclerosis, acute plaque change, superimposed thrombosis
What is a subendocardial infarct?
Necrosis limited to inner on third or half of the ventricular wall, localised or circumferential
What causes a subendocardial infarct?
Acute coronary thrombosis, hypotension
How are myocardial infarctions diagnosed?
Symptoms, ECG pattern, cardiac biomarkers
What is different about an ECG in myocardial infarction?
ST elevation, new Q waves in silent infarction
Which cardiac biomarkers indicate recent myocardial infarction?
Raised cardiac troponin (T and I): remain elevated for up to two weeks
CK-MB: MB subtype of creatine kinase raised
What is congestive heart failure?
Diminished pumping ability of left ventricle
What is the result of congestive heart failure?
Inadequate supply of blood and oxygen to cells, back up of blood in pulmonary vasculature leading to pulmonary edema, peripheral edema
What is heart failure?
Diminished out volume of either ventricle, often due to loss of contractility of myocardium
What is forward failure?
Diminished cardiac output
What is backward failure?
Damming of blood in venous system
What is systolic failure?
Loss of pumping strength leading to backup of blood and atherosclerosis leading to chronic ischemia
What is diastolic failure?
Reduced ability of ventricle to fill, constriction or trapping of ventricle
What are adaptations to congestive heart failure?
Activation of neurohumoral systems (sympathetic mediated peripheral vasoconstriction, renin-angiotensin-aldosterone system and ANP), Frank-Starling mechanism (cardiac output increases or decreases in response to changes in HR or SV), hypertrophy
Why does congestive heart failure cause edema?
Increased hydrostatic pressure due to backup of blood resulting in water being driven into interstitial spaces
What causes the clinical symptoms of congenital heart diseases?
Mixing of blood
What causes congenital heart diseases?
Environmental/developmental factors, eg. maternal infection, foetal alcohol syndrome; genetic factors are rare
What are three types of congenital heart diseases?
Left-to-right shunts, right-to-left shunts, obstructive anomalies
What are three left-to-right shunt congenital heart diseases?
Atrial septal defect (ASD), ventricular septal defect (VSD), patent ductus arteriosus (PDA)
What is a right-to-left shunt congenital heart disease?
Tetralogy of Fallot: transposition of great arteries (aorta from RV, pulmonary artery from LV), present with cyanosis
What are three congenital obstructive anomalies?
Coarction of the aorta, pulmonary stenosis and atresia, aortic stenosis and atresia
