Exam 2 - Hypertension, heart failure, arrhythmias Flashcards
Desribe the categories of blood pressure?
What are the 4 factors that effect blood pressure?
- Peripheral reistance
- Vessel elasticity
- Blood volume
- CO (SVxHR)
Where are the 4 anatomic sites of blood pressure control?
- Resistance - arterioles
- Capacitance - venules
- Pump output - heart
- Volume - kidneys
What are the 4 major groups of antihypertensives?
- Diuretics - deplete sodium
- Sympathoplegics - deacrease PVR, reduce CO (alpha and beta blockers)
- Direct vasodilators - relax vascular smooth muscle
- Anti-angiotensins - block activity or production
What is the only available drug that acts on renin to decrease blood pressure?
Aliskiren
What are the targets for centrally acting sympathoplegics? What 2 drugs are in this category?
- Methyldopa - alpha 2 agonist in brainstem
- Clonidine - alpha 2 agonist in brainstem and alpha 1 agonist in arterioles
What is the primary indication for methyldopa?
Pregnancy induced hypertension, does not cross the placenta
What are the uses of clonidine? Side effects?
- Back up hypertensive
- ADHD, Tourettes, anxiety, PTSD
- Causes sedation
What is the side effects of alpha 1 blockers? What is the treatment?
- Retention of salt and water (less flow to renal tubules)
- More effective when used with beta blocker or diuretic
How do vasodilators work in general?
They cause relaxation of smooth muscle of arterioles and veins causing reduction in PVR and MAP.
Describe how vasodilators elicit compensatory responses and require combination therapy?
Describe the MOA of hydralazine? Whats a side effect?
Dilates arterioles by inducing NO production in the endothelium
Cause a rash that looks like SLE
Describe the MOA of minoxidil?
Opens K+ channels in smooth muscles (hyperpolarizes, less likely to contract) leading to dilation of arteries and arterioles
Well absorbed orally and topically (Rogaine)
What is the MOA of sodium nitroprusside? What is a treatment concern?
- Dilates arterial and venous vessels by NO release and increasing cGMP (relaxes smooth muscle)
- In high doses can cause CN toxicity, worse in pt’s with renal insufficency
What are the 4 classes of vasodilators and some examples?
- Oral - hydralazine and minoxidil
- Parenteral - nitroprusside and fenoldopam
- Combination - CC blockers
- Nitrates
What is the MOA of fenoldopam?
Peripheral arteriolar dilator, agonizes D1 receptors in renal arterial bed.
Acts as a diuretic by increaseing BF to kidneys
What are the 3 classes of CCB and their targets?
- Verapamil - Heart arterioles
- Diltiazem - peripheral and heart arerioles
- Dihydropyridines - peripheral arterioles (-pine)
Draw the RAAS pathway and the targets of treatment.
What are the differences between the two types of angiotensin antagonists?
- ACE inhibitors (-pril) - prevent the conversion of angiotensin I to angiotensin II, prevents metabolisim of bradykinin
- Angtiotensin Receptor Blockers (ARB, -sartan) - prevents binding of angtiotensin II, preventing vasoconstriction and aldosterone secretion.
What are the drugs used to treat pulmonary hypertension and their MOA?
- Prostaglandins (Epoprostanol) - continuous IV infusion that prevents formation of ET-1 which is responsible for vasoconstriction proliferation
- Endothelin receptor antagonists (-sentan) - block binding of ET- 1 to receptors
What is the suggested treatment for mild hypertension?
- Weight loss and reduction in sodium intake
- First line drugs: diuretic, BB, CCB
What are hypertensive urgency and hypertensive crisis?
- Urgency is BP >180/110 without acute end organ damage
- Emergency - BP >180/110 with acute end organ damage
What are the treamtents for hypertensive emergencies?
- Parenteral drugs to reduce BP quickly: sodium nitroprusside and fenoldopam
What are the differences between arteriolar, capillary, and venous tone?
- Arteriolar - have ability to squeeze tightly due to increased amount of smooth muscle
- Capillaries - no real tone
- Veins - some tone, much less than arteries
What is classic angina or angina of effort?
- Chest pain induced by increased O2 demands (exercise)
- Coronary artery flow not being increased proportionately leads to ischemia
- Relieved after rest
What is vasospastic angina?
- O2 delivery is decreased due to coronary vasospasm
What is unstable angina?
- Angina at rest due to small clots in the vicinity of atherosclerotic plaque