TOPIC-1-MT-HANDOUT.pdf

HEART FAILURE I. Heart failure (HF) is a complex, progressive disorder in which the heart is unable to pump sufficient blood to meet the needs of the body. II. Cardinal Symptoms: Dyspnea Fatigue Lethargy Fluid Retention...

HEART FAILURE I. Heart failure (HF) is a complex, progressive disorder in which the heart is unable to pump sufficient blood to meet the needs of the body. II. Cardinal Symptoms: Dyspnea Fatigue Lethargy Fluid Retention (Edema), Congestion 1 III. Compensatory physiological responses in HF 1. Increased sympathetic activity 2. Activation of the RAAS 3. Myocardial hypertrophy IV. Types of heart failure 1. Left-sided HF - Pulmonary edema 2. Right-sided HF - Peripheral Edema 3. DIASTOLIC HEART FAILURE (Preserved Ejection Fraction) a. Inability of the ventricles to fill with blood during diastole, or ventricular relaxation due to stiffness of the cardiac muscle 4. SYSTOLIC HEART FAILURE (Reduced Ejection Fraction) a. Impaired degree of ventricular contraction resulting in a decrease of cardiac inotropy (contractility) and cardiac stroke volume V. New York Heart Association (NYHA) classification of heart failure Class I: No or very little limitation of physical activity in which more than the ordinary physical activity leads to fatigue, palpitation, dyspnea, or anginal pain; the person is comfortable at rest Class II: Slight limitation of physical activity in which ordinary physical activity leads to fatigue, palpitation, dyspnea, or anginal pain; the person is comfortable at rest 2  Class III: Marked limitation of physical activity in which less-than-ordinary activity results in fatigue, palpitation, dyspnea, or anginal pain; the person is comfortable at rest Class IV: Inability to carry on any physical activity without discomfort but also symptoms of heart failure or the anginal syndrome even at rest, with increased discomfort if any physical activity is undertaken VI. ACC/AHA VII. Therapeutic goals 1. Increase force of myocardial contraction 2. Decrease workload of the heart VIII. Drugs for heart failure 1. Unloaders a. ACE inhibitors b. ARBs c. Aldosterone antagonist d. Diuretics i. decreases preload (veins, blood volume) ii. **** FUROSEMIDE e. Vasodilators i. decreases afterload ii. Hydralazine + ISDN 1. HZN (dec. afterload), ISDN (dec.preload) iii. Nesiritide – a synthetic form of the endogenous peptide brain natriuretic peptide (BNP) 1. MOA: increases cGMP in smooth muscle cells and reduces venous and arteriolar tone; causes diuresis 2. For ACUTE HF iv. f. Beta-blockers 3  2. Inotropic agents a. Digitalis glycosides b. β-Adrenergic agonists c. Phosphodiesterase inhibitors/Bipyridines Cardiac glycosides MOA: inhibits Na/KATPase Pump (for extrusion of Ca from the myocardiocyte) Sources: 1. Digoxin - Digitalis lanata a. low protein binding; renal clearance; long half-life 2. Digitoxin - Digitalis purpurea a. high protein binding Digoxin Digitoxin Lipid Solubility Medium High Half-Life Short Long Excretion Renal Hepatic ***Note: Digoxin – very narrow therapeutic index A/E: – Nausea and vomiting – Yellowish vision (xanthopsia) – Cardiac arrhythmias Management of toxicity Correct electrolyte imbalance (KCL) hypokalemia Hypomagnesemia hypercalcemia hypoxia Digifab/Digibind Antiarrhythmic drugs β-Adrenergic agonists ❖ Dobutamine - 1st line in acute heart failure (ROA: IV) ❖ Dopamine ❖ MOA: B1 activation in the heart (inc. cAMP = [+] inotropy) ❖ Use: management of acute heart failure 4  management of CHF with acute exacerbation Phosphodiesterase inhibitors ❖ Bipyridine (Amrinone, Milrinone) ❖ MOA: Inhibit PDE3 (inactivates the degradation of cAMP to AMP) ❖ Use: management of acute heart failure & exacerbation of CHF (SHORT TERM) ❖ SE: Hypersensitivity, Arrhythmia First Line Therapies 1. ACEis 2. Beta Blockers * Carvedilol, Metoprolol, Bisoprolol ** Start low, slow titration **Reduced cardiovascular remodeling (reduced sympathetic activation) 3. Loop Diuretics - Fluid Retention 4. Digoxin – Atrial Fibrillation Other Treatment Options 1. Aldosterone antagonists * Spironolactone, Eplerenone **S/E Gynecomastia, Hyperkalemia 2. ARBS – if intolerant to ACEi 3. Nitrates (ISDN) and Hydralazine – if unable to take ACEi and ARBs UNLOAD FAST!! U pright position N itrates (low dose) L asix (Furosemide) O xygen therapy A minophylline D igoxin F luid (decrease) A fterload (decrease) S odium restriction T ests (monitor) – ABG, potassium level, Glucose _________________________________________________________________________________________ 5  ANTIARRHYTHMICS Heart rhythm problems (heart arrhythmias) occur when the electrical impulses that coordinate your heartbeats do not work properly, causing your heart to beat too fast, too slow, or irregularly. Conduction System of the Heart I. Treatment goals 1. Na+ channel blockade 2. Inhibiting sympathetic innervation 3. Prolongation of effective refractory period (K+ channel blockade) 4. Ca+2 channel blockade II. Drugs A. Vaughan-Williams classification 6 A. Class I – Sodium channel blockers a. Class IA (Double Quarter Pounder) i. Disopyramide 1. HF, torsades de pointes, atropine-like activity (urinary retention in BPH, dry mouth, blurred vision, constipation, glaucoma) ii. Quinidine (PO) 1. Diarrhea (Most common) 2. Causes cinchonism (tinnitus, headache, and dizziness iii. Procainamide 1. acute treatment of AF, VF, and VT (in MI) 2. A/E: SLE-like syndrome b. Class IB (Too Much Love is Painful) i. Phenytoin ii. Tocainide iii. Mexiletine iv. Lidocaine 1. 1st line in the management of digoxin induced ventricular tachycardia 2. AE: Seizure: treat w/ diazepam c. Class IC (More Fa, Papi Enchong) i. Moricizine ii. Flecainide iii. Propafenone 1. A/E: metallic taste, constipation iv. Encainide B. Class II – Beta Blockers a. Beta blockers (-olol) i. except – sotalol C. Class III – Potassium Channel Blockers i. Amiodarone 19 – 32% by weight of iodine ii. Dronedarone iii. Sotalol iv. Bretylium v. Ibutilide vi. Dofetilide b. Use: 1st line for ventricular tachycardia (VT) c. AE: i. Hepatotoxicity ii. Pulmonary fibrosis iii. Wolff-Chaikoff Effect (initially hypothyroid, final rxn is hyperthyroidism) 7 D. Class IV - CCBs a. Diltiazem (PO) i. SVT ii. less cardiac ADRs than verapamil b. Verapamil (PO, IV) i. Use: management of paroxysmal supraventricular tachycardia (SVT) ii. SE: Constipation, hypotension, AV block 1. AV block: treated with atropine, β-agonists E. Miscellaneous agent a. Adenosine i. DOC for SVT ii. AE: Bronchoconstriction, Chest burning, Pulmonary FIbrosis 1. Pulmonary fibrosis: treated with glucocorticoids b. Magnesium Sulfate i. management of Torsades de Pointes ii. For digitalis-induced arrhythmia iii. Eclampsia 8