Cardiac Flashcards
(93 cards)
What is preload?
The amount of blood returning to the right side of the heart AND the muscle stretch that the volume causes.
What is released by the atria in response to preload stretch?
ANP
What is afterload?
The pressure in the aorta and peripheral arteries that the left ventricle has to pump against to deliver blood to the body. High after load decreases cardiac output.
What is stroke volume?
The amount of blood pumped out of the ventricles with each beat.
What is cardiac output?
The amount of blood delivered by the heart to perfuse the body. CO = SV X HR
What are some medications that reduce preload?
Diuretics (furosemide) and Nitrates (nitroglycerin). They vasodilate (nitrates) or diverse to reduce preload.
What are some medications that decrease afterload?
ACE inhibitors (“pril”), ARBS (“sartan”), hydralazine, nitrates (nitroglycerin). They vasodilate to decrease after load.
What are medications that improve contractility?
Inotropes (dopamine, dobutamine, milrinone)
What are medications that control cardiac rate?
Beta blockers (“lol”), calcium channel blockers (diltiazem, verapamil, amlodipine), digoxin
What are medications that control rhythm?
antiarrhythmics (amiodarone)
What are the 3 arrhythmias that are always a big deal?
1) pulseless ventricular tachycardia
2) ventricular fibrillation
3) asystole
What is the most common type of cardiovascular disease?
Coronary Artery Disease (CAD). This is a broad term that includes chronic stable angina and acute coronary syndrome.
What causes Chronic Stable Angina?
Intermittent/decreased blood flow to the myocardium leading to ischemia.
What brings on the pain of chronic stable angina?
Low 02 usually brought on by exertion.
What relieves the pain of chronic stable angina?
Rest and/or nitroglycerin SL
How is nitroglycerin given and how often?
sublingually (do not swallow), every 5 minutes for a max of 3 doses. May cause headache.
What medication must be kept in a dark glass bottle and be kept dry and cool?
Nitroglycerin
What does nitroglycerin do?
Causes venous and arterial dilation, decreasing preload and afterload and increasing blood flow to the heart. May cause headache.
What happens to the BP after nitroglycerin is given?
It drops
What is used for prevention of angina?
Beta blockers, calcium channel blockers, aspirin
What do beta blockers do?
They block beta cells, which are receptor sites for catecholamines (epinepherine and norepinephrine) which causes reduction in BP, HR, and myocardial contractility. This decreases cardiac workload BUT it can also decrease cardiac output!
note always assess BP and HR before administration of beta blockers!
What do calcium channel blockers do?
They block calcium receptor channels in smooth muscle. By prohibiting the entry of calcium (which stimulates muscle contraction) the smooth muscle relaxes, causing vasodilation of the arteries. This decreases afterload and increases oxygen to the heart muscle.
What kind of exercise should those with unstable angina avoid? What should they use?
Avoid isometric exercises (weight lifting) and walk. Do everything possible to REDUCE workload of the heart!
What is a cardiac catheterization?
Catheter inserted in artery or vein for diagnostic and treatment purposes.