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
Granulomatosis with polyangitis (wegener)
Small vessel
Triad:
- Focal necrotizing vasculitis
- Necrotizing granulomas in lung and upper airway
- Necrotizing glomerulonephritis
c-ANCA
Microscopic polyangitis
Small vessel
Similar to granulomatosis with poly angitis without nasopharyngeal involvement.
MPO-ANCA/p-ANCA
Churg-strauss
Small vessel
Asthma, sinusitis, palpable purpura, peripheral neuropathy
Also can involve heart, GI, kidnes (pauciimmune glomerulonephritis)
Histo: granulomatous, necrotizing vasculitis with eosinophilia
p-ANCA, elevated IgE
Henoch-Shonlein purpura
Small vessel
2/2 IgA complex deposition. Often post-URI
Abdominal pain
Purpura
Arthralgia
P450 inducers/inhibitors
Induce:
- carbamazapine
- phenobarbital
- Phenytoin
- Rifampin
- Griseofulvin
Inhibitors: Cimetidine -Cipro -Erythromycin/clarithromycin -Azoles -Grapefruit juice -Isoniazid -Ritonavir (protease inhibitors)
Antiarrhythmics
Ia
Double Quarter Pounder
Disopyramidine
Quinidine
Procainamide
Increase AP time.
Atrial and ventricular
Antiarrhythmics
Ib
Lettuce, Mayo, Tomato
Lidocaine
Mexiletine
Tocainide
Decrease AP time.
Ventricular
Especially post-MI
Antiarrhythmics
Ic
More fries please
Moricizine
Flecainide
Propafenone
AP the same.
SVTs
Antiarrhythmics
II
beta-blockers
SVT,
Slow ventricle during a-fib/flutter
Antiarrhythmics
III
K+ blockers
Amiodarone, ibutilide, dofetilide, sotalol (also beta blocker)
a-fib/flutter
V-tack (amiodarone, sotalol)
Antiarrhythmics
IV
Ca2+ blockers
Verapamil, diltiazem
prevent nodal arrhythmias (e.g. SVT)
Rate control in a-fib with RVR
Drugs that induce lupus
hydralazine procainamide isoniazid minocycline quinide
