What is the most frequent cause of death in developed countries?
Coronary heart disease
What is the approximate distribution of Resistance between large coronary vessels and their small vessel branches? How does this affect their ability to respond to a stenosis in the large vessel?
5% in large vessels 95% in small vessels
At what % of occlusion of a large coronary does its resting and maximal flow begin to decrease?
At 50% occlusion maximal flow begins to drop At 80% occlusion resting flow rate begins to drop.
What other factors are involved besides a stenosis to evoke CHD?
Dysfunction of the endothelial cells near the stenosis. -Inappropriate vasoconstriction or impaired vasodilation. Impaired NO or Adenosine release. -Loss of antithrombotic properties. Impaired NO or prostacyclin release.
What is Angina Pectoralis? What are the types?
Severe, dull/pressing pain in the chest, of limited duration. Often radiates, typically to left arm. Usually provoked by physical activity, cold, or a large meal. Classic and Prinzmetal angina, Stable and Unstable angina.
Describe classic angina
Stress induced, ST depression Alleviated by nitrates Caused by coronary occlusion Common type
Describe Prinzmetal angina
Occurs at rest or sleep
Not very responsive to nitrates
Caused by Coronary Spasm
Describe Stable angina
Has a good prognosis
Caused by a quiescent plaque
Has stable characteristics
Occurs at a predictable level of physical activity
Usual frequency and usual pain amount
Describe unstable angina
Caused by a Ruptured Plaque
occurs more frequently,
caused by lower levels of physical activity
Describe Acute Coronary Syndrome
May be from either AMI or Unstable Angina
Sypmtoms indicate ACS if:
1) it is the first angina-pain occurence
2) in a CHD patient, the angina is not relieved by nitrates or is unusually severe.
May occur with ST elevation: ST-elevation Mycardial Infarct (STEMI) or Q-Wave Myocardial Infarct QMI
or without ST elevation: unstable angina, Non-ST-Elevated MI (NSTEMI), or Non-Q MI (NQMI)
What are the effects of hypoxia in AMI?
Decreased pump activity
Increased intracellular Na+
Increased intracellular Ca++
Altered membrane potential
Anaerobic glycolysis, lowered pH
Complications that can result from AMI
-stasis and thrombus generation
-vent fibrillation, death
- Papillary muscle or valve defect --> regurgitation and congestive heart failure
- subsequent decreased contractility --> congestive heart failure,
- pericarditis -->pericardial effusion, cardiac tamponade
- Ventricle rupture --> cardiac tamponade
How is ACS managed?
Acute Coronary Syndrome:
ECG is performed --> Is there ST elevation?
Yes, ST elevation: STEMI, immediate percutaneous coronary intervention (PCI), also called coronary angioplasty, using a ballon catheter or stent.
No, Unstable Angina or Non-STEMI: Check if Troponin levels are elevated
Yes, troponin is elevated:
What are ways to prevent CHD?
Do not smoke
Physical exercise, avoiding sedentary lifestyle
In CHD patients, what precautions are taken to prevent AMI?
Prophylactic anticoagulants, Aspirin
Monitor the CHD
Hospitalize if angina occurs, especially unstable angina
Surgery or angioplasty, stents if needed