Coronary perfusion from the aorta takes place during diastole
What are the various types of anginas?
Variant Angina
Stable Angina
Unstable Angina
Angina refers specifically to the uncomfortable sensation in the chest that arises from an imbalance between myocardial oxygen supply and demand
Cardiac Ischemia is when results form an imbalance between myocardial oxygen supply and demand. The most common symptom is “angina pectoris” (chest pain).
Angina Pectoris: Uncomfortable sensation in the chest and neighboring anatomic structures produced by myocardial ischemia
Stable Angina:
Chronic pattern of transient angina pectoris
Precipitated by physical activity or emotional upset
Relieved by rest within a few minutes
Episodes often associated with temporary depression of the ST segment, but permanent myocardial damage does not result
Myocardial Oxygen Demand is determined by:
Ventricular wall stress
Heart rate
Contractility
Ventricular wall stress:
Increase in wall tension
Increase in wall “thickness” decreases stress (hypertrophied heart)
Directly proportional to LV systolic pressure
Heart rate:
Increase in heart rate leads to an increase in oxygen consumption and oxygen demand
Medications can control heart rate, e.g., Ace inhibitors decrease HR
Contractility:
Refers to the force of contraction (inotropic + state)
Diagnostic studies of ischemia include:
Electrocardiogram
Stress testing
Coronary angiography
Noninvasive imaging of coronary arteries
Electrocardiogram Diagnostic Studies:
Subendocardial ischemia causes ST-segment depressions and/or T-wave flattening or inversions
Severe transient transmural ischemia can result in ST-segment elevations, similar to the early changes in acute myocardial infarction
When transient ischemia resolves, so do the electrocardiographic changes
Stress Testing Diagnostic Studies:
Standard Stress Testing
Nuclear Imaging Studies
Exercise Echocardiography
Pharmacologic Stress Tests (Nuclear and Echocardiographic)
Coronary Angiography (gold standard)
Subendocardial ischemia causes ST-segment depressions and/or T-wave flattening or inversions.
Severe transienttransmural ischemia can result in ST-segment elevations, similar to the early changes in acute myocardialinfarction. When transient ischemia resolves, so do the electrocardiographic changes.
Diagnostic Studies - Stress Testing
Standard Stress Testing (less useful w/baseline abnormalities)
Nuclear Imaging Studies
Exercise Echocardiography
Pharmacologic Stress Tests
Nuclear
Echocardiographic
Coronary Angiography (gold standard)
What are the diagnostic studies of ischemia? Electrocardiogram, stress testing, coronary angiography, and noninvasive imaging of coronary arteries
What are the O2 demand determinants? Organic Nitrates, Calcium Channel Blockers, and β-Blockers
What does PTCA stand for? percutaneous transluminal coronary angioplasty
What type of treatment is PTCA? A procedure to open blocked coronary arteries, being a revascularization treatment.
What are the drug types and their example medicine?
Organic nitrates - Nitroglycerin
β-Blockers - Metoprolol
Calcium Channel Blockers - Amlodipine
Ranolazine - Ranexa
Variant Angina:
Typical anginal discomfort
usually at rest, which develops because of coronary artery spasm rather than an increase of myocardial oxygen demand
episodes often associated with transient shifts of the ST segment, usually ST elevation (also termed Prinzmetal angina)