Day 3 Cardiology Flashcards
What happens during phase 0 of a cardiac action potential?
Phase 1? Phase 2? Phase 3?
Phase 4?
Rapid Na channels open, Slow Ca channels open.
Na channels close. Plateau phase, K channels open, Ca influx continues. Repolarizaion, Ca channels close, K outflux continues.
resting state, K channels close, active transport of K and Ca ions.
What starts your cardiac action?
What does automaticity lack?
Which wave responds to atrial depolarization?
Hyperpolarization-activated cation current is activated at low potentials, resulting in automaticity of the SA-node. Epinephrine up and Acetylcholine lowers.
Phase 1 and 2, sodium channels.
P wave
Which wave responds to atrial repolarization and ventricular depolarization?
What does nitric oxide do?
Prostacyclin function?
QRS
predominates, vasodilator, released in response to acetylcholine. Ach–>NOS–> L-Arginine–> NO–>released to smooth muscles–> activates guanylate cyclase–> converts GTP to cGMP–> causes relaxation by sequestering interstitial calcium.
vasodilator, inhibits platelet aggregation, AA is changed to prostacyclin through cox-2.
Endothelin-1 function?
Basic difference between arteries and veins?
What does ACE do?
Most potent vasoconstrictor, high levels in people with htn related disease, can induce smooth muscle proliferation, can be released or increased by angiotensin 2, epinephrine, vasopressin, insulin, thrombin, and LDL cholesterol.
Veins have valve, thinner elastic membrane and smooth muscle layer, thicker connective tissue layer.
found on endothelial cell surface, converts angiotensin to angiotensin 2.
What does thromboxane do?
When alpha receptors are activated sympathetically you get vasoconstriction and beta receptors you get vasodilation true or false?
What happens if you take betablocker to alpha? Add mixed alpha beta blocker?
produced by the interaction of AA with cox 1, Primarily in platelets.
True
You get increased blood pressure due to vasoconstriction. You get vasodilation.
Anticoagulant factors?
Procoagulant factors?
BP formula?
Protein S, Heparin Sulfate, Thrombomodulin, tPA, tissue factor pathway inhibitor.
Tissue Factor, platelet activating factor, PAI-I, Von willebrands factor.
SVR x CO
Pressure formula?
CO formula?
What terms to know?
flow x resistance
HR x Stroke Volume. There for BP = SVR X HR X Stroke Volume
End diastolic volume, end diastolic pressure, end systolic volume, end systolic pressure
Stroke Volume formula?
What is preload?
Cardiac Output?
EDV-ESV, related to contractility of the heart, force of the contraction on the heart.
amount of blood returning to the heart, directly proportional to venous return
Amount of blood leaving the heart. Stroke volume x heart rate.
What is after load?
frank startling law?
What is contractility?
pressure in the wall of the left ventricle during ejection, directly proportional to total peripheral resistance.
stroke volume therefore cardiac output, is direclty proportional to preload.
relates to stroke volume, the intrinsic ability of cardiac muscle to develop force is related to the intracellular calcium and its use. Intrinsic to the cardiac muscles/ventricle. Independent of external conditions.
What is inotropy?
Force of contraction?
What is ejection fraction?
changes in muscle contraction.
Influenced by extrinsic factors
Proportion of blood pumped out of ventricles with each heart beat. Normal range is 55-70%.
What is tissue perfusion?
What is a chronotrope?
What is an inotrope?
flow of blood through arteries and capillaries. Depends on cardiac output, local tissue blood flow(depends on bp). Ischemia is decrease tissue perfusion.
Agent that affects the rate at which a heart contracts.D Dilitiazem(negative), Epinephrine(positive).
Agent that effects the strength of muscle contraction. Dobutamine(positive) Metoprolol(negative).
What is a domotrope?
Affects AV node conduction, Atropine(positive), Digoxin(negative)
