Cardiology Flashcards
Fick principle
CO = (rate of O2 consumption) / (arterial O2 content - venous O2 content)
Mean arterial pressure
MAP = CO * TPR
= 2/3 diastolic pressure + 1/3 systolic
Laplace’s law
relationship of wall thickness and afterload
Wall tension = (pressureradius)/(2wall thickness)
Resistance
R = Delta P / Q
= 8viscositylength / pi * r^4
S3
Increased filling pressures.
2/2 CHF, MR
S4
Stiff ventricle during atrial systole.
Cardiac and vascular tone curves
Change inotropy: CO changes (same x intercept)
Change volume, venous tone: Venous return changes (including x-intercept)
Change TPR, both change (same x intercepts).
Ventricular action potential
0: Na current
1: Na current
2: K + Ca current
3: Ca current
4: K current
Pacemaker action potential
4: Na current, funny
0: Ca current
3: K current
Conduction spead
Purkinje > atria > ventricles > AV node.
Rheumatic fever
Fever Erythema marginatum Valvular damage ESR up Red-hot joints (migratory polyarthritis) Subcutaneous nodules St. Vitus' dance (Sydenham chorea)
Hsto: Aschoff bodies (granulomas with giant cells), which include Anitschkow cells (enlarged marcophages with ovoid waxy rod like nucleus).
Temporal arteritis
Large vessel
focal granulomatous inflammation
Associated with polymyalgia rheumatica
Polyarteritis nodosa
Medium vessel
Young adults, hep B positive in 30%.
Abdominal pain, melena, fever, weight loss, HTN,
Neuro dysfunction, cutaneous eruptions
Typically renal and visceral vessels.
Immune complex mediated.
Histo: transmural inflammation of arterial wall.
Microaneurysms.
Kawasaki dz
Medium vessel
Fever, cervical lymphadenitis, conjunctival injection, changes in lips/oral mucosa (strawberry tongue), hand-food erythema, desquamating rash.
May develop coronary artery aneurysms.
Tx: IVIG, ASA
Buerger dz (thromboangitis obliterans)
Medium-vessel
Smokers.
Intermittent claudication, possible gangrene and ulcers, superficial nodular phlebitis.
Segmental thrombosing vasculitis.
Sensitive to intradermal tobacco extract
