Path-ischemia Flashcards
Risk factors for atherosclerosis and IHD
Family hx Age Men>women Hypercholesterolemia Diet Smoking DM Lack of exercise Obesity Stress
Clinical syndromes of IHD
- Acute coronary syndromes:
a. Angina pectoris (stable, prinzmetal, or unstable)
b. MI
c. Sudden cardiac death - Chronic IHD, resulting in HF
Substernal or precordial chest pain from transient myocardial ischemia lasting from 15 seconds to 15 minutes
Angina pectoris
Angina pectoris is most common in ____. Pain is described as ____
- Middle aged and older males (women are usually affected after menopause)
- Constricting, squeezing, choking, or knife-like. May radiate, or may be diffuse. Not related to breathing
What is the most common variant of angina?
Stable angina
Angina with exercise, excitement, or other sudden increase in cardiac load with subsequent in trade in demand for blood flow.
Stable angina
True or false:
Myocardial ischemia is usually irreversible
False
Only irreversible if there is myocyte necrosis. Otherwise it is reversible
\_\_\_\_ angina is usually associated with >70% chronic stable stenosis of a coronary a. It is (usually/not usually) associated with plaque disruption. And (is/is not) relieved with rest or a vasodilator.
Stable
Not usually
Is
Within a year of dx, how many people with stable angina will develop unstable angina or MI?
20%
Episodic angina at rest due to intense coronary a. vasospasm. Unrelated to exercise, heart rate, or BP
Variant (Prinzmetal) Angina
Variant (Prinzmetal) Angina typically responds to ___
Nitroglycerin (vasodilator)
Ca channel blockers
Things that can cause vasospasms
Primary Raynaud disease
A lot of vasoactive mediators
Elevated TSH
Autoantibodies and T cells in scleroderma
Extreme psycho stress and release of catecholamines
Occurs with progressively lower levels of physical activity or at rest
Increases in frequency over time
Often of prolonged duration
Unstable (Crescendo) Angina
Aka Preinfarction Angina
Unstable (Crescendo) Angina is usually caused by ___
Disruption of plaque and superimposed partial thrombosis and possibly embolization or vasospasm or both
Sequence of events in coronary a. occlusion
- Sudden change in atheromatous plaque
- Collagen exposed, causing platelet adhesion and aggregation to form thrombus
- Vasospasm
- Tissue factor activates coag pathway, increasing size of thrombus
- Thrombus evolves to occlude lumen
- Occlusion causes ischemia, dysfunction, and potentially myocyte death
Vasospasm is initiated by ___
Mediators from platelets
Prolonged ischemia for greater than ___ causes damages to microvasculature
1 hour
Reperfusion injury probably results from ___.
Free radical damage to the microvascular circulation
Potential complications of MI
DARTH VADER Death Arrhythmia Rupture Tamponade HF Valve disease Aneurysm of ventricle Dressler's syndrome Embolism Recurrence/Regurgitation
Progressive congestive heart failure as a result of long term ischemic damage to myocardium.
Chronic ischemic heart disease
Aka ischemic cardiomyopathy
Chronic ischemic heart disease often results in ___
Cardiomegaly
LV hypertrophy
Ventricular dilation
Some degree of obstructive coronary a. atherosclerosis
In ___ of sudden cardiac death cases you will see coronary artery atherosclerosis with critical (>___%) stenosis involving one or more of the three major coronary vessels
80-90%
75%
True or false: most cases of sudden cardiac death are associated with acute MI
False
Sudden cardiac death is thought to result from ___
Ischemia-induced myocardial irritability that initiates dangerous arrhythmias
