Cardiovascular Flashcards
Tx primary (essential) HTN
Diuretics
ACEI
ARBs
CCBs
Tx HTN with CHF
Diuretics
ACEI/ARBs
B-blockers (compensated CHF)
Aldosterone antagonists (spironolactone)
B-blockers contraindicated in cardiogenic shock
Tx HTN with DM
ACEI/ARBs = protective against diabetic neuropathy CCBs Diuretics B-blockers a-blockers
Dihydropyridine CCBs (3)
Amlodipine
Nimodipine
Nifedipine
Non-dihydropyridine CCBs (2)
Diltiazem
Verapamil
CCBs
Block voltage-dependent L-type Ca channels of cardiac and smooth muscle = reduce muscle contractility
CCB effect on vascular smooth muscle
___ = ___ > ___ > ___
amlodipine = nifedipine > diltiazem > verapamil
CCB effect on heart
___ > ___ > ___ =
verapamil > diltiazem > amlodipine = nifedipine
verapamil = ventricle
Dihydropyridine use (except nimodipine)
HTN
Angina (including Prinzmetal)
Raynaud phenomenon
Nimodipine = subarachnoid hemorrhage (prevents cerebral vasospasm)
Non-dihydropyridine use
HTN
Angina
Atrial fibrillation/flutter
Hydralazine
Increases cGMP = smooth muscle relaxation
Vasodilates arterioles > veins
AFTERLOAD reduction
Severy HTN, CHF
First line HTN in pregnancy (with methyldopa)
Coadmin with B-blocker to prevent reflex tachycardia
Hydralazine toxicity
Compensatory tachycardia (contraindicated in angina/CAD)
Fluid retention
Nausea, headache, angina
Lupus-like syndrome
Tx hypertensive emergency
Nitroprusside Nicardipine Clevidipine Labetalol Fenoldopam
Nitroprusside
Short acting
Increases cGMP via direct release of NO
Cyanide toxicity (releases cyanide)
Fenoldopam
Dopamine D1 receptor agonist = coronary, peripheral, renal, and splanchnic vasodilation
Decreases BP and increases natriuresis
Nitroglycerin, isosorbide dinitrate
Vasodilate by increasing NO in vascular smooth muscle = increase in cGMP and smooth muscle relaxation
Dilates veins»_space; arteries
Decreases PRELOAD
Tx angina, acute coronary syndrome, pulmonary edema
Nitroglycerin, isosorbide dinitrate toxicity
Reflex tachycardia (treat with B-blockers)
Hypotension, flushing, headach
“Monday disease” = industrial exposure; tolerance for vasodilating action during work week and loss of tolerance over weekend leads to tachycardia, dizziness, and headache upon reexposure
What are 4 determinants of myocardial O2 consumption (MVO2)?
End-diastolic volume
Blood pressure
Heart rate
Contractility
Lipid lowering drug classes (5)
HMG-CoA reductase inhibitors (statins)
Niacin (vitamin B3)
Bile acid resins (cholestyramine, colestipol, colesevelam)
Cholesterol absorption blockers (ezetimibe)
Fibrates (gemfibrozil, clofibrate, bezafibrate, fenofibrate)
Lovastatin, pravastatin, simvastatin, atorvastatin, rosuvastatin
MOA
SE (3)
HMG-CoA reductase inhibitors
Inhibit conversion of HMG-CoA to mevalonate (cholesterol precursor)
Hepatotoxicity (increased LFTs)
Rhabdomyolysis (esp when used with FIBRATES and NIACIN)
Myalgias
Niacin
MOA
SE (3)
Vitamin B3
Inhibits lipolysis in adipose tissue; reduces hepatic VLDL synthesis
Red, flushed face (decreased by ASA)
Hyperglycemia (acanthosis nigricans)
Hyperuricemia (exacerbates gout)
Cholestyramine, colestipol, colesevelam
MOA
SE (4)
Bile acid resins
Prevent intestinal reabsorption of bile acids; liver must use cholesterol to make more
Bad taste
GI discomfort
Decreased absorption of fat-soluble vitamins
Cholesterol gallstones
Ezetimibe
MOA
SE (2)
Cholesterol absorption blocker
Prevents cholesterol absorption at small intestine brush border
Rare increase in LFTs
Diarrhea
Gemfibrozil, clofibrate, bezafibrate, fenofibrate
“fib”
MOA
SE (3)
Fibrates
Upregulate LPL = increased TG clearance
Activates PPAR-a to induce HDL synthesis
Myositis (increased risk with concurrent STATINS)
Hepatotoxicity (increased LFTs)
Cholesterol gallstones (esp with concurrent BILE ACID RESINS)
Statin effects
Decrease (3) LDL
Increase (1) HDL
Decrease (1) triglycerides
Niacin effects
Decrease (2) LDL
Increase (2) HDL
Decrease triglycerides
Bile acid resin effects
Decrease (2) LDL
Slightly increase HDL
Slightly INCREASE TRIGLYCERIDES
Cholesterol absorption blocker effects
Decrease (2) LDL
No effect on HDL or triglycerides
Fibrate effects
Decrease (1) LDL
Increase (1) HDL
DECREASE (3) TRIGLYCERIDES
Digoxin
Cardiac glycoside
Direct inhibition of Na/K ATPase = indirect inhibition of Na/Ca exchanger/antiport
Increased Ca concentration = positive inotropy
Stimulates vagus nerve to decrease HR
Digoxin toxicity
Cholinergic = n/v/d, blurry yellow vision ECG = increased PR, decreased QT, ST scooping, T wave inversion, arrhythmia, AV block Hyperkalemia = poor prognosis
Factors predisposing to digoxin toxicity
Renal failure (decreased excretion)
Hypokalemia (permissive for digoxin binding at K binding site on Na/K ATPase)
Verapamil, amiodarone, quinidine (decrease clearance; displace digoxin from tissue binding sites)
Digoxin antidote
Normalize K, cardiac pacer, anti-digoxin Fab fragments, Mg
Class I antiarrhythmics
Na channel blockers
Slow or block conduction
Decrease slope of phase 0 depolarization and increase threshold for firing in abnormal pacemaker cells
Hyperkalemia causes increased toxicity
Class IA
Na blockers
Quinidine
Procainamide
Disopyramide
INCREASE AP duration, effective refractory period, and QT interval (risk torsades)
Quinidine, Procainamide, Disopyramide
Class and Toxicity
Class IA = Na channel blockers
CINCHONISM (headache, tinnitus with quinidine)
Reversible SLE like syndrome (procainamide)
Heart failure (disopyramide)
Thrombocytopenia
Torsades de pointes due to increase QT interval
Class IB
Na blockers
Lidocaine Mexiletine (Phenytoin can also fall into category)
DECREASE AP duration
Preferentially affect ischemic or depolarized Purkinje and ventricular tissue
Best for post-MI
Lidocaine, Mexiletine
Class and toxicity
Class IB = Na channel blockers
CNS stimulation/depression
Cardiovascular depression
Class IC
Flecainide
Propafenone
Significantly prolongs refractory period in AV node
Minimal effect on AP duration
Flecainide, Propafenone
Class and toxicity
Class IC
Proarrhythmic, especially post-MI (contraindicated in structural and ischemic heart disease)
Class II antiarrhythmics
Beta-blockers
Decrease SA and AV nodal activity by decreasing cAMP and Ca currents
Suppress abnormal pacemakers by decreasing slope of phase 4 (nodal tissue)
AV node particularly sensitive
Class II B-blockers
Metoprolol Propranolol Esmolol Atenolol Timolol Carvedilol
B-blocker toxicity
Impotence
Exacerbation of COPD and asthma
Cardiovascular effects (bradycardia, AV block, CHF)
CNS effects (sedation, sleep alterations)
May MASK SIGNS of HYPOGLYCEMIA
Metoprolol = dyslipidemia
Propranolol = exacerbate vasospasm in Prinzmetal angina
Contraindicated in COCAINE users (risk of unopposed a-adrenergic receptor agonist activity)
B-blocker antidote
Glucagon
Class III antiarrhythmics
K channel blockers
Increase AP duration and effective refractory period
Used when other antiarrhythmics fail
Increase QT interval (risk torsades)
Class III K channel blockers
Amiodarone
Ibutilide
Dofetilide
Sotalol
Amiodarone, Ibutilide, Dofetilide, Sotalol
Class and toxicity
Class III K channel blockers
Sotalol = torsades de pointes, excessive B blockade
Ibutilide = torsades de pointes
Amiodarone = pulmonary fibrosis, hepatotoxicity, hypothyroidism/hyperthyroidism (amiodarone is 40% iodine), corneal deposits, skin deposits (blue/gray) resulting in photodermatitis, neurologic effects, constipation, cardiovascular effects (bradycardia, heart block, CHF)
What tests should you always check when using amiodarone?
PFTs
LFTs
TFTs
Amiodarone has class I, II, III, and IV effects and alters the lipid membrane
Class IV antiarrhythmics
Ca channel blockers
Decrease conduction velocity
Increase effective refractory period and PR interval
Slow rise of action potential (phase 0 nodal) Prolonged repolarization (at AV node)
Class IV Ca channel blockers
Verapamil
Diltiazem
Non-dihydropyridine
Verapamil, Diltiazem
Class and toxicity
Class IV non-dihydropyridine CCBs
Constipation, flushing, edema, CV effects (CHF, AV block, sinus node depression)
Adenosine
Increase K out of cells = hyperpolarize cell and decrease Ca current
Drug of choice = supraventricular tachycardia dx/tx
Short acting = 15 seconds
Adenosine adverse effects
Flushing
Hypotension
Chest pain
Effects blocked by theophylline and caffeine
Magnesium is effective in the treatment of which two conditions?
Torsades de pointes
Digoxin toxicity
Drugs prolonging QT interval
“Some Risky Meds Can Prolong QT”
Sotalol Risperidone (antipsychotics) Macrolides Chloroquine Protease inhibitors (-navir) Quinidine (class Ia; also class III) Thiazides
Treatment for torsades de pointes
Magnesium sulfate