Cardio and Renal 4 Flashcards
What happens in heart failure?
Heart fails to pump blood, so heart will dilate (to compensate), which will result in an increased force of contraction
After compensation, the heart fails to compensate further, so it’ll lead to decompensation, decreased contraction, and thus, decreased cardiac output
What are the three conditions that lead to heart failure?
- Coronary Artery Disease
- MI
- Valvular disease
Decrease Cardiac Output Consequence: Increase Venous Pressure
Which leads to
- Increased BP, and thus Increased Preload
- Increased capillary filtration, leading increased salt and water retention (edema)
Decrease Cardiac Output Consequence: Decreased Renal Blood Flow
Which leads to increase Renin-Angiotensin, and then increased Aldosterone, and then ultimately
Increased salt and water retention (edema)
Decrease Cardiac Output Consequence: Decreased BP
Which leads to
Increase symps, which leads to increased vasoconstriction, which finally leads to increase afterload
NYHA Classification of Heart Failure: Class I
No limitation of physical activity, ordinary physical activity doesn’t cause fatigue or dyspnea
NYHA Classification of Heart Failure: Class II
Slight limitation of physical activity.
Comfortable at rest, but ordinary physical activity will result in fatigue and dyspnea
NYHA Classification of Heart Failure: Class III
Marked limitation of physical activity
NYHA Classification of Heart Failure: Class IV
Unable to carry out any physical activity without discomfort.
Symptoms of cardiac insufficiency at rest
Left Sided Heart Failure
- Dyspnea
- Orthopnea
- Paroxysmal Nocturnal Dyspnea
Diaphoresis - Cool extremities
Pathologic S3 gallop
Right Sided Heart Failure
- Edema
- Ascites
- JVD
- Hepatomegaly
Epistaxis
Goal of Heart Failure Treatment (4)
- Drugs that increase contractility
- Drugs that decrease preload
- Drugs that decrease afterload
- Drugs that reduce edema
Drugs for Heart Failure (1 of 5): Positively Inotropic Drugs (3)
- Digitalis Glycoside: Digoxin
- Adrenoreceptor Agonist: Dobutamine
- Phosphodiesterase Inhibitors: Milrinone
Drugs for Heart Failure (2 of 5): Vasodilators (3)
- ACE Inhibitors: Enalapril, Lisnopril
- ARB: Valsartan, Candesartan
- Other Vasodilators: Hydralazine, Isosorbide, Nesiritide
Drugs for Heart Failure (3 of 5): Aldosterone Antagonists (2)
Spironolactone
Eplerenone
Drugs for Heart Failure (4 of 5): Beta Adrenoreceptor Blocker (3)
Carvedilol
Metoprolol
Bisoprolol
Drugs for Heart Failure (5 of 5): Diuretic (3)
Furosemide
Bumetanide
Torsemide
Drugs that Increase Contractility: Digitalis
Aka Cardiac Glycosides
Drugs that Increase Contractility: Digitalis MOA
Inhibits Na/K ATPase Pump
Troponin/tropomysin complex form a barrier between actin and myosin
Ca2+ binds to troponin and break the complex
Myosin interacts with actin producing muscle contraction
Drugs that Increase Contractility: Digitalis - Direct Effect (5)
Inhibits Na/K ATPase pump leading to
Intracellular Na+, which increases Ca2+, causing increased force of contraction
Atria: Decreased APD and ERF (causing arrhythmia)
AV node: Decrease conduction velocity***
Ventricles and Purkinje: Decrease APD and ERP
Drugs that Increase Contractility: Digitalis - Indirect Effect (a and b)
a. Cholinergic effect through vagal stimulation
Atria: decrease SA node rate
AV node: Increase ERP, decrease velocity
Ventricles and Purkinje: No effect
b. Sympathomimetic Effect (B1)
Atria: INCREASE SA rate
AV node: DECREASE refractory period
Ventricles and Purkinje: Increase conduction velocity and abnormal automaticity
What is most commonly prescribed digitalis?
Digoxin
Drugs that Increase Contractility: Digitalis - Digoxin Info
+ve ionotropic
-ve chronotropic
t1/2: 20-40 hours
Clearance: renal
Protein binding: 25%
Vd: 6.3L/kg
Should be avoided in WPW
Drugs that Increase Contractility: *Digitalis Side Effects (5)
RENAL CALCULI
- CV: PVCs, Tachyarrhythmias, AV block, sinus bradycardia
- GI: ANV & Diarrhea
* 3. CNS: Headache, visual halos, hallucinations
**4. EKG: Prolonged PR interval, decrease QT interval, T wave inversion