12. Cardiac Pathology Flashcards
What is ischemic heart disease?
Cardiac ischemia usually secondary to coronary artery disease (CAD).
What is angina pectoris?
Transient cardiac ischemia without cell death resulting in substernal chest pain.
What is a stable angina?
The most common type of angina, caused by coronary artery atherosclerosis with luminal narrowing greater than 75%. Chest pain is brought on by increased cardiac demand (exertional or emotional).
What is Prinzmetal variant angina?
Caused by coronary artery vasospasm, episodic chest pain often occuring at rest.
What is unstable or crecendo angina?
Caused by formation of a nonocclusive thrombus in an area of coronary atherosclerosis. Increasing frequency, intensity and duration of episodes. Occurs at rest. It has a high risk for myocardial infarction.
What is a myocardial infarction (MI)?
Localized area of cardiac muscle necrosis due to ischemia caused by coronary artery atherosclerosis with plaque rupture and superimposed thrombus formation or caused by coronary artery spasm.
Which arteries are the most affected during a myocardial infarction?
I. Left anterior descending (LAD) = 45%. II. Right coronary artery (RCA) = 35%. III. Left circumflex coronary artery (LCA) = 15%.
Which type of infarction is the most common?
Transmural infarction. Caused by ischemic necrosis of >50% of myocardial wall.
What are the clinical symptoms of a myocardial infarction?
Sudden onset of severe “crushing” substernal chest pain, often radiates to the left arm, jaw, and neck. Chest heaviness, tightness and shortness of breath. Diaphoresis, nausea, and vomiting. Jugual venous distension (JVD) could be seen. Anxietey and often have a feeling of impending doom.
In which type of patients do we see atypical presentations of MI with little or no chest pain?
Elderly patients, diabetics, women, and postsurgical patients.
At what time after the myocardial infarction do Q waves representing myocardial necrosis develop?
In 24 to 48 hours.
What can we see in the EKG in transmural ischemia?
ST segment elevation.
What can we see in the EKG in subendocardial ischemia?
ST segment depression.
What gross changes we see in the heart 18-24 hours later after a myocardial infarction?
Vague pallor and softening.
What gross changes we see in the heart 1-7 days later after a myocardial infarction?
Yellow pallor.
What gross changes we see in the heart 7-28 days later after a myocardial infarction?
Central pallor with a red border.
What gross changes we see in the heart months later after a myocardial infarction?
White, firm scar.
When does serum marker CK-MB elevate by, peak, and returns to normal?
Elevated by 4-8 hours, peaks by 18 hours, returns to normal by 2-3 days.
When does serum marker Troponin I and T elevate by, peak, and returns to normal?
Elevated by 3-6 hours, peaks by 16 hours, returns to normal by 7-10 days.
When does serum marker LDH elevate by, peak, and returns to normal?
Elevated by 24 hours, peaks by 3-6 days, returns to normal by 8-14 days.
What do we see microscopically 1-4 hours later following a myocardial infarction?
Wavy myocyte fibers.
What time after a myocardial infarction do we see coagulative necrosis microscopically?
4-24 hours later.
What do we see microscopically 1-4 days later following a myocardial infarction?
Neutrophilic infiltrate.
What time after a myocardial infarction do we see macrophage infilatrion microscopically?
4-7 days later.