Angina drugs Flashcards
Is angina a symptom or a dz?
Symptoms
- heaviness, squeezing, pressure and tightness
What is the cause of angina pectoris?
Imbalance between supply and demand
What are some causes of Prinzmental angina?
- Underlying atheromas
- Nocturnal episodes because of venous return increase which triggers neurogenic a-adrenergic coronary vasospasm
What is silent or ambulatory ischemia?
Ischemia without pain
What is the cause demand or supply for classic angina?
Demand
- decrease cardiac work
- Shift myocardial metabolism
What is the cause demand or supply for variant angina?
Supply
- Reverse spasm
- treat the atherosclerosis
What is the cause demand or supply for unstable angina?
Supply and demand
S1. Reverse spasm
S2. treat the atherosclerosis
D1. decrease cardiac work
D2. Shift myocardial metabolism
What are the some determinants of myocardial 02 demand?
Ventricular wall stress
HR
Contractility
Basal metabolism
What is LaPlaces relationship and what is it used for?
T=(P*r)/2h
Where r is radius and h is thickness
- Calculates Tension which is a tangible force action o the myocardial fibers
What are some things that increase pressure and radius?
P- AS and HTN
R- Increase ventricular filling
Both lead to increase O2 consumption
What is the relationship between wall thickness and O2 consumption?
Inverse
- Hypertrophied heart muscle has lower wall stress and O2 consumption per gram
What doe arteriolar tone and venous tone synomonous with in terms of stress?
Systolic and diastolic wall stress respectively
What are some things that affect supply?
- Total coronary blood flow (aortic diastolic pressure and duration of diastole)
- LV EDP (ejection fraction)
- pAO2 (Hematocrit and saturation, anemia)
- Membrane diffusion (thickness)
What are some things that affect demand?
HR
Intraventriular wall stress (preload, after, contractility and wall thickness)
What are the classic anginal drugs?
Nitrates
B-blockers
Ca-blockers
What are the physiologic effects of nitrates?
Venodilation
- decrease preload
- decrease pulmonary vascular r
- decrease LV EDP
Minimal change in total coronary blood flow
main effects are decrease preload and LV EDP
What are the phosphodiesterase type 5 inhibitors?
Viagra
Cialis
Levitra
What are the physiologic affects of Ca channel blockers?
- Increase total coronary blood flow by decreasing aortic diastolic pressure
- Decrease in contractility
What are the clinical uses of Ca channel blockers?
Prophylaxis of angina
HTN
Others
What is a classical management for classical angina?
B- blockers
What is the physiological affects of beta blockers?
Decrease HR and contractility
Decrease Aortic diastolic pressure.
Slightly raise CA pressure and LV EDP.
Which are more b1 selective, Atenolol, metoprolol or propranolool?
Aten and Metoprolol
What are the MOA of the new drugs for angina?
- Target Na+/Ca2+ Exchanger
- Shift myocardial metabolism
- Inhibit “funny current” Na+ channels
- Inhibit Rho Kinase
What is Ranolazine?
Reduces late Na channel that facilitates Ca entry via NCX
Reduction in intracellular Ca reduces contractility
Trimetazidine MOa?
pFOX inhibitor which reduces fatty acids oxidation and shifts metabolism towards glucose oxidation. Which lowers oxygen demand
Not approved
What is the MOA of Ivabradine?
Selective If Na channel blocker
- slows cardiac rate
What is the MOA of Fasudil?
Inhibitor of SM Rho kinase
Reduces coronary vasospasm
