Cardiology Part 1 Flashcards
Alpha - 1
Vascular Smooth Muscle (vasoconstriction), use as an agonist for hypotension. Use as antagonist for hypertension and benign prostatic hyperplasia (BPH)
Alpha - 2
CNS synapses (inhibitory effects), agonist use is for hypertension and spasticity while antagonistic has no clinical use
Beta - 1
Heart (increased HR and force of contraction),
agonist use for cardiac decompensation and antagonistic use for HTN, arrhythmia, angina pectoris, heart failure, prevention of reinfarction
Beta - 2
Lungs (bronchodilation), agonist use to prevent bronchospasms and no clinical use for antagonist
Alpha 1 Epinephrine
Topically or Intradermal
Local effects
Control bleeding
Intravenously
Vasoconstriction
Hypotension (vasopressor)
Beta 1 epinephrine
Intravenously
Myocardium
Cardiac arrest
Beta 2 epinephrine
Inhalation/IM
Target lungs
Anti-Asthmatic / Anaphylaxis
Midodrine
Alpha-1 agonist -> vasoconstriction of vascular smooth muscle, used for OH and prevention of hypotension, well tolerated
Orthostatic Hypotension
Also known as postural hypotension
Abnormal drop in BP when changing positions
-≥20 mm Hg systolic and/or≥10 mm Hg diastolic
Due to delayed/inadequate baroreceptor reflex
Risk factors:
Age >60, Parkinson’s disease, medications
Diuretics
MOA: Increase renal excretion of water and sodium, decreased plasma volume
↓ Blood volume =↓ SV =↓ CO
3 groups based on where they act in nephron:
-Thiazides(First line therapy)
-Loop
-Potassium-sparing
Diuretics: Adverse Effects
electrolyte imbalances, increased urination, orthostatic hypotension
Sympatholytics
In general work to decrease sympathetic drive
Classified based on where they work:
-Beta blockers
-Alpha blockers
-Centrally acting agents
Beta-blockers
MOA: Bind toβ receptors in heart/lung blocking binding of catecholamines
↓Contractility =↓SV = ↓ CO
↓HR = ↓CO
Adjunct therapy – need compelling indication – not first line
Cardioselective beta blockers
Atenolol
Metoprolol
Nebivolol (Bystolic)
Mixed alpha/beta beta blockers
Carvedilol
Labetalol
Nonselective beta blockers
Propranolol
Beta-blockers adverse effects
Generally well-tolerated, after adjusting to ADE
Bronchoconstriction
Orthostatic hypotension
Mask hypoglycemia
Exercise intolerance
Alpha blockers
MOA: Bind to α1 receptorson vascular smooth muscle, blocking binding of catecholamines
↓Vasoconstriction =↓ TPR
Adjunct therapy
Alpha Blockers: Adverse Effects
Reflex tachycardia (Caution in patients with cardiac disease)
Orthostatic hypotension (Take at night to lower risk)
Dizziness
Centrally Acting Agents
MOA: Alpha 2 agonist: Stimulate α2 receptors in brainstem which decreases sympathetic activity
↓HR/SV = ↓ CO
Adjunct therapy
Exception: methyldopa in pregnancy
Centrally Acting Agents: Adverse Effects
Dry mouth
Dizziness
Sedation
Rebound hypertension/tachycardia with abrupt withdrawal
-Due to rebound sympathetic activity
Vasodilators
MOA: Vasodilate the peripheral vasculature directly at cell
IncreasedcGMP = ↓contractility of smooth muscle cells =↓TPR
Adjunct therapy
Vasodilators: Adverse Effects
Reflex tachycardia
-Baroreceptor reflex compensation
Orthostatic hypotension
-Warm pool will worsen
Angiotensin Converting Enzyme Inhibitors (ACE-I)
Lisinopril
Ramipril
Benazepril
Captopril
Angiotensin II Receptor Blockers (ARBs)
Losartan
Olmesartan (Benicar)
Valsartan (Diovan)
RAS Inhibitors MOA
↓Fluid/Sodium Retention =↓SV =↓CO
↓Angiotensin II =↓Vasoconstriction =↓TPR
First line therapy (ACE inhibitors/ARBs)
ACE-I/ARBs: Adverse Effects
Generally well-tolerated
Hyperkalemia
Dry cough (ACE-I)
Angioedema (ACE-I)
Kidney injury
CCBs MOA
Blocks calcium entry into vascular smooth muscle, First line therapy
Vasculature: ↓SVR Vasodilation
Heart: ↓HR/SV =↓CO
CCBs Adverse effects
Peripheral edema
Orthostatic hypotension
Reflex tachycardia (dihydropyridine only)
CCB (dihydropyridine)
Amlodipine
Nifedipine
Nicardipine
CCB (nondihydropyridine)
Diltiazem
Verapamil
