Cardio and respiratory Flashcards
Chronotropic
affecting heart rate
inotropic
affecting force of cardiac contraction
what is cardiac output
the amount of blood heart is capable of pumping per min (mulitply rate by stroke vol)
what are the 4 cardiac reserve or compesations
- Increasing heart rate - increases output to point that rate is so fast, there is inadequate time for ventricular filling
- Increasing stroke volume - increaseed fore of contraction results in increase in amount of blood pumped
- Increasing efficiency of heart muscle -
- Physiologic heart enlargement - muscle responds to work by increasing its size
What category of drugs is digoxin, epinephrine and pimobendan
Positive inotropic drugs
What do antiarrhytmics do
slow down electrical impulses in the heart so it can beat regularly again
what are Class 1 antiarrhytmics
**Sodium channel blockers **
slow electrical impulse conduction in heart muscle
Class 1drugs
- procainamide (Procane)
What are Class 2 antiarrhytmics
**Beta blockers **
Slow heart rate by slowing electrical impulse conduction at the sinoatrial and atrioventricular node
CLass 2 drugs
- atenolol (ApoAtenol, Act-atenolol)
- metoprolol (Apotex)
- propranolol (Inderal)
What are class 3 antiarrhytmics
**Potassium channel blockers
**
slow electrical impulse conduction in all heart cells
Class 3 drugs
- amiodarone
- dronedarone (Mutlaq)
What are class 4 antiarrhytmics
**calcium channel blockers
**
depresses the calcium dependent action potentials in slow channel tissues. Decreases the rate of automaticiity which is the capacity of a cell to generate a spontaneous action potential without external stimulus and prolongs refractoriness
Class 4 drugs
- amlodipine
- diltiazem
- verapamil
