HLK Week 2 Flashcards
What limits the ability of a blood vessel to expand and accommodate blood?
The connective tissue layer surrounding it.
What are the 4 layers in a blood vessel (not present in all vessels)?
- Endothelial layer
- Elastic layer
- Smooth muscle layer
- Fibrous tissue layer
How does arterial compliance work to accommodate a pressure pulse?
Blood exerts a perpendicular pressure on the walls of the artery, which expand to accommodate it and then further propel it forward as the vessel returns to normal. As compliance decreases with age/pathology, pressure in the artery rises.
Total peripheral resistance is determined in large part by what type of vessel?
Arterioles
How is resistance related to viscosity and the length and radius of vessels?
- Proportional to viscosity and length
- Inversely proportional to 4th power of radius
What is responsible for most of the control of vasoconstriction in peripheral vascular beds?
Neurally secreted norepinephrine acting on alpha receptors
Give an example of how local control can overrule sympathetic activity:
Exercising one arm: sympathetic activity is the same throughout the body, but because of local control blood flow is only increased in the muscle being exercised.
Contrast the actions of norepinephrine and epinephrine in regards to smooth muscle activity:
- Neurally secreted norepinephrine acts on alpha adrenergic receptors in peripheral arteries to cause vasoconstriction
- Epinephrine secreted into plasma by adrenal medulla acts on beta adrenergic receptors in the heart and lungs to cause vasodilation
What two forces drive capillary exchange?
- Diffusion: concentration gradients across capillary wall
- Bulk flow: hydraulic gradients due to pressure differences across capillary wall
What is oncotic pressure?
Osmotic pressure due to the presence of colloids in a solution.
What is Starling’s hypothesis?
It says that the flow across a capillary wall is proportional to the difference in pressure across the wall. The pressure on each side is a compound pressure made up of hydrostatic and oncotic pressures.
With pitting edema, explain how pushing on a patient’s tissue causes edema to disappear:
By pushing on the tissue, you increase the tissue pressure, which forces fluid back into the veins. This is why compression stockings are recommended for people with edema.
What two things do cardiovascular homeostasis mechanisms preserve blood flow to above all others?
Brain and kidneys
In terms of improving cardiac function, which is more important to treat, preload (through diuresis) or afterload (through SBP reduction)?
Afterload. LV performance is afterload dependent but relatively preload independent.
In patients with CHF, what category of hemodynamic status is correlated with poor outcomes?
Both cold (low perfusion) types: cold and wet (volume overload but still low output) or cold and dry (volume depleted with low output).
True or false: In patients with CHF, both Digoxin and diuretics (with the exception of aldosterone inhibitors) are good for keeping patients out of the hospital but don’t reduce mortality.
True
Which classes of HF drugs reduce mortality?
- Beta blockers
- ACE’s/ARB’s
- Aldosterone inhibitors
- Combination Hydralazine and Isordil
Describe the use of beta blockers in CHF:
- Never use in cold & wet patients
- Only use in warm & dry patients
- In the long term, improves long term ventricular responsiveness to adrenergic stimulation
- Shields cardiac muscle from long term effects of norepinephrine
- Improves LV performance and reduces mortality
What sort of patient would combination Hydralazine and Isordil be good for in reducing mortality?
African Americans
Mesenteric ischemia:
Should be suspected in elderly, atherosclerotic patients complaining of frequent indigestion.
Amaurosis fugax:
Temporary blindness causes by thromboembolism in the carotid artery that ends up in the arterioles feeding the eye.
SSx of chronic arterial insufficiency:
- Intermittent claudication
- Sparse or absent distal leg hair
- Dependent rubor
- Distal ulceration
- Diminished or absent pulses
- Delayed capillary refill with thickened nails
- Cool extremities
Drug tx for arterial insufficiency:
- Aspirin or Clopridogrel as anti-platelet therapy
- Rheologic modifier such as Pentoxifylline to decrease viscosity and platelet adhesion
- Phosphodiesterase inhibitor such as Cilostasol to suppress platelet activation and increase vasodilation
SSx of acute arterial insufficiency:
- 50% have severe, unrelenting leg pain
- 50% have insidious onset of pain over several hours
- Compartment syndrome (remember the 5 P’s)
5 P’s of compartment syndrome:
- Pain
- Pallor
- Paresthesias
- Pulselessness
- Paralysis
Thromboangiitis obliterans:
- AKA Buerger’s Disease
- Occlusive inflammatory disease of small/medium distal arteries of extremities
- Prevalence higher in men from southeast Asia, India and Japan who smoke
SSx of Buerger’s disease:
- Most of the SSx of chronic arterial insufficiency, occurring in upper as well as lower extremities
Biggest non-genetic risk factor for developing varicose veins:
Pregnancy
How is the Trendelenberg test used in the workup of varicose veins?
- Used to distinguish superficial venous insufficiency due to saphenofemoral valve incompetence from perforator vein incompetence
- Compress saphenous vein with leg elevated, then have patient stand while maintaining compression
- If varicosities return, problem is perforator incompetence
Describe Virchow’s triad:
- Stasis, hypercoagulability and vessel damage
- = increased risk of phlebitis
What is Trousseau’s sign (of malignancy)?
Superficial migratory thrombophlebitis, often occurring in unusual locations, that may be the 1st indication of a cancer, esp. pancreatic and lung cancer
What’s the DDx for chest pain in the primary care setting?
- ~1.5 % MI or ACS
- 20 % chest wall pain
- 13 % reflux esophagitis
- 13 % costochondritis
- Other systems (GI, pulmonary, psych, CV)
What is the definition of likelihood ratio?
It’s the ratio of true positives to false positives
What kinds of surgery do not require interruption of anticoagulant therapy?
- Dental, dermatologic or ophthalmologic surgeries, which are considered minor risks for bleeding
- All others are considered major risks for bleeding.
What is the MOA of vorapaxar?
Blocks thrombin receptors on platelets
Indication for Aggrenox (ASA + ER dipyrimadole)
To prevent recurrent stroke in patients who have had a TIA or ischemic stroke
What is the MOA of aspirin?
Irreversibly blocks thromboxane A2 production in platelets, decreasing their ability to aggregate.
What would you expect to see on exam of a patient with myocarditis?
- Tachycardia
- Pleural or pericardial chest pain
- Gallop
- Signs of HF
- Conduction defects
- Cardiomegaly
- Pulmonary edema/hypertension
On exam, pericardial rub, dyspnea, and chest pain that is worse when supine would indicate:
Pericarditis
How would you treat myocarditis?
- NSAIDS for pain
- Abx for pathogen, if identifiable
- ACE/Beta blocker if left ventricular EF is less than 40%
What’s the typical patient population for congenital bicuspid-related aortic stenosis?
Male, 40’s to 60’s
Which type of murmur is typically associated with a “crescendo-decrescendo” sound?
Aortic stenosis
Murmur due to aortic stenosis:
- Opening click just after S1
- Followed by crescendo decrescendo murmur
Murmur due to mitral regurgitation:
- Murmur begins at S1
- Followed by holosystolic murmur
Murmur due to mitral valve prolapse:
- Mid systolic click
- Followed by flat murmur
Murmur due to aortic regurgitation:
- Murmur begins at S2
- Followed by decrescendo only murmur
Murmur due to mitral stenosis:
- Opening snap
- Followed by decrescendo with pre-systolic accentuation (due to atrial kick)
- Described in class as mid diastolic rumble with pre-systolic murmur
What physiologic condition is associated with S3?
Volume overload (sound made by chordae tendinae tensing due to rapid filling, which in the elderly or sick is due to volume overload)
What physiologic condition is associated with S4?
Pressure overload (sound made by atrial kick pumping blood into a stiff (due to hypertrophy) ventricle)
What is the treatment for hypertrophic cardiomyopathy?
- Beta blockers
- Septal ablation
- Myectomy or alcohol injection
SSx of acute vs. chronic aortic regurgitation:
Acute: patients usually present with HF and shock
Chronic: Sx of HF develop slowly over time
Describe the pulse pressure in a patient with aortic regurgitation. How does this affect the carotid pulses?
- Very wide
- Carotid pulses are often very visible
Patient population for mitral stenosis:
Women in their 40’s and 50’s from developing countries with Hx of rheumatic heart disease
Treatment for mitral stenosis:
- Manage A-fib with digoxin
- Anticoagulate for stroke risk
- Can do surgery to break apart stenotic valve, with regurgitation as a sequela
What other electrolyte must be administered prior to administering calcium or potassium?
Magnesium if it’s also deficient
Normal ranges for BMP:
- Glucose (65 - 100)
- Sodium (135 - 145)
- Potassium (3.5 - 5)
- Calcium (8.5 - 10.5)
- BUN (8 - 20)
- Creatinine (0.8 - 1.4)
- Bicarb (22 - 27)
- Chloride (95 - 105)
What is the importance of chloride and bicarbonate ions in a BMP?
Common anions used to regulate acid base balance and osmotic pressure
What is the importance of BUN and creatinine in a BMP?
Good indicators of renal function
What should you think if you see a patient with profound carotid pulses and a wide pulse pressure?
Aortic regurgitation
