Step 1 Flashcards
(128 cards)
The most common cause of pericarditis is ______
Coxsackie B virus, which causes inflammation of the pericardial membrane. This is a picornovirus, the smallest RNA virus. Positive, single-stranded, naked, icosohedral virus.
Tertiary syphilis can cause what cardiac problems?
Tertiary syphilic disrupts the vasa vasorum of the aorta, dilating the aortic root and the aortic valve ring. This can lead to aneurysm and aortic valve insufficiency. “Tree barking” of the aorta may also occur which is due to the wrinkling of the tunica intima.
Cystic fibrosis
Autosomal recessive causing a defect in CFTR gene, leading to dysfunctional chloride channel that secretes Cl- into lungs and GI tract and reabsorbs Cl- in sweat glands. This often leads to mucus plugging and recurrent pulmonary infections, chronic bronchitis, and bronchiectasis. Often present with meconium ileus in newborns. N-acetylcysteine can be used to loosen mucus plugs (it cleaves disulfide bonds within mucus glycoproteins).
CF can lead to problems associated with absorption of fat-soluble vitamins. Which condition can arise from this?
Fat soluble vitamins include A, D, E, and K. Deficiency in D can cause rickets in children due to decreased bone formation. Hypocalcemic tetany and muscle spasm can also occur. Vitamin A deficiency can result in night-blindness and dry skin. Deficiency in E and K can lead to RBC dysfunction and defective coagulation, respectively.
Which antitumor antibiotic can cause pulmonary fibrosis?
Bleomycin - it induces free radical formation resulting in breaks in DNA strands. It is used to treat testicular cancer and Hodgkin’s lymphoma. Skin changes may also occur on this drug such as darkening.
What is osteomalacia?
It is a disorder of bone mineralization/calcification of osteoid in adults. It is often due to vitamin D deficiency (rickets in children), which leads to low to normal levels of calcium, low vitamin D, and low phosphate. Bone matrix can be laid down but it cannot be mineralized. These patients have reduced bone densities and prone to pathologic fractures. Lab profiles might show elevated alkaline phosphatase or increased PTH secretions (this decreased phosphate levels in serum and tries to increase calcium levels). There is a hyperactivity of osteoblasts which require an alkaline environment hence why alkaline phosphatase is increased.
What is osteoporosis?
This is a decreased synthesis of new bone matrix, which is contrasted from osteomalacia, where bone matrix is laid down but not mineralized.
What time of chronic gastritis (nonerosive) affects the first part of the stomach?
Type A - it affects the fundus/body of stomach and spares the antrum. It is an autoimmune condition where antibodies attack parietal cells in the stomach.
What is Gerstmann’s syndrome?
(1) an inability to distinguish right from left; (2) an inability to identify fingers; (3) a writing disability known as agraphia or dysgraphia; and (4) a lack of understanding the rules for calculation or arithmetic known as acalculia or dyscalculia. Reading ability remains intact. The syndrome results from damage to the visual association cortex (angular gyrus).
Name one enzyme responsible for renal gluconeogenesis.
Fructose-1,6-bisphosphatase
Stable angine usually presents at what percentage of artery stenosis?
75% and greater.
What is most likely cause of death a few hours post-MI?
Fatal arrythmia, specifically polymorphic ventricular tachycardia. Cardiac arrythmia is an important cause of death before reaching hospital. Cardiogenic shock may also arise when heart completely fails and cannot supply vital organs.
What causes arrythmia post-MI?
It is due to a disruption of the vascular supply to the conduction system, combined with myocardial irritability after injury.
What are some etiologies of dilated cardiomyopathy?
ABCCCD: Alcohol abuse, Beriberi (lack of thiamine pyrophosphate - active form of thiamine or B1), Coxsackie B myocarditis (direct toxicity via receptor-mediated entry of virus into cardiac myocytes), chronic Cocaine use, Chagas’ disease, and Doxorubicin toxicity.
What is the S3 heart sound?
S3, or ventricular gallop, occurs in early diastole, following opening of the AV valves during rapid ventricular filling phase. In adults, it is a sign of volume overload owing to congestive heart failure, or increased transvalvular flow that accompanies advanced mitral or tricuspic regurgitation.
What is the S4 heart sound?
S4, or atrial gallop, occurs in late diastole and coincides with contraction of atria. It is generated by the left or right atrium contracting vigorously against stiffened ventricle. It is a sign of decreased compliance due to ventricular hypertrophy or MI.
A cocaine user is exeriencing an MI. Physicians decide not to give a beta-blocker. Why?
Beta blockers are not given with cocaine use due to unopposed alpha effects. By blocking presynaptic uptake of norepinephrine and increased release of catecholamines from the adrenal gland, cocaine results in a high degree of adrenergic activity. Beta blockers will isolate these effects to a-receptors amplifying the a-1-agonists activity leading to vascular smooth muscle contraction.
Which beta blockers are nonselective antagonists?
Think “N to Z” for “n”onselective: nadolol, pindolol, propranolol, timolol
What is a classic histologic finding of rheumatic fever?
It can lead to damage of the heart valves (mitral > aortic»_space; tricuspid). Aschoff bodies (granulomas with giant cells), Anitschkow cells (enlarged macrophages with ovoid, wavy, rod-like nucleus) are commonly seen. The murmur is usually a late diastolic murmur with delayed rumbling.
Which heart valve is most likely damaged in IV drug users?
The tricuspid valve, usually tricuspid regurgitation due to tricuspid endocarditis. This results in a holosystolic, high-pitched blowing murmur. It is enhanced by maneuvers that increase RA return (like inspiration).
What are characteristics of septic shock?
Patients generally have high cardiac output and low SVR. The low SVR is due to inflammatory mediators released causing vasodilation, often presenting as flushing of the skin. Cardiac output is generally 4-8 L/min.
Which lipid-lowering agent results in most significant decrease in triglycerides?
Fibrates (like gemfibrozil). The are ligands for the peroxisome proliferator-activated receptor-alpha (PPAR-alpha) protein, a receptor that regulates the transcription of genes involved in lipid metabolism. Increase PPAR results in increased expression of LPL on endothelial cells and thus increased clearance of TG-rich lipoproteins. Also has the effect of increasing HDL synthesis.
What is the mechanism of calcium-channel blockers?
Amlodipine, nimodipine, nifedipine (dihydropyridine); diltiazem, verapamil (non-DHP) - block voltage-gated Ca++ channels (L-type) of cardiac and smooth muscle, thereby reducing muscle contractility. They close the channels during Phase 2 of the AP. Drugs like verapamil slows conduction through AV node via calcium channel blocking.
What is Kawasaki’s disease?
It is an acute necrotizing vasculitis of medium to small muscular arteries, usually affecting children <5 years old. This is the only condition in which you should given children aspirin with a high fever. IV immunoglobins should also be considered. The condition can present with fever, cervical lymphadenitis, conjuctival infection, strawberry tongue, and hand-foot erythema.
