Essentials Quiz 5

• 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 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.
• • 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)