Title USMLE-World-Step-3-High-Yield-Notes-90-Pages.pdf ✅

Biostats Hazards Ratio: Measure of how much effect something actually had. Value of 1.00 means there is no difference between the two groups. A ratio < 1 indicates a protective effect, and > 1 indicates a detrimental effect. If the confidence interval of the hazard ratio includes 1.00 (null value), then the effect wasn’t statistically significant. If the interval doesn’t include the value, the difference was significant. Cardiology Community Health Centers LDL levels: keep < 100 in pt w/ known CHD risk equivalent (CAD, MI, PVD, or inpatient DM). If pt has none of these problems, can keep below < 160 if 0-1 RF, < 130 if >=2 RF. Consider drug therapy only ay 30 above the threshold, unless > 2 RF. Initial DOC for newly diagnosed HTN is thiazide diuretic. Common side effect is photosensitivity, leading to a rash in sun exposed areas. Rx by stopping med, or avoid sun exposure. Thus, this is a common side efx of meds in newly diagnosed HTN. Best RF to modify to reduce risk of CAD is LDL. HTN is also good but not as good as LDL. Other stuff helps too (exercise, stop smoke, control DM), but they don’t lower risk as much as LDL and HTN. Secondary HTN: Consider it in a young patient w/ high blood pressure. 90% of secondary HTN is d/t unidentified cause. Otherwise, the MCC is renovascular HTN. Look for abd or flank bruit in pt with renovascular HTN. Other causes: peho (headaches, tachy), Cushing’s disease (edema), advanced renal disease (edema). Retinal abnormalities is a long term effect of HTN, not seen early in disease. DM is the single most important predictor of adverse CV outcomes. Such a good predictor that DM is considered a CHD equivalent. In women, the prediction is evn more important. For people with DM, keep BP < 130/85, versus 140/90 in a healthy person. AAA: Cutoff for surgery is > 5 cm diameter. If smaller, do periodic imaging. Rapid growth can also need surgery. Big time RF is smoking. Other RF don’t have as much impact as smoking cessation does. Office Amlodipine side efx: fluid retention and urticarial rash. ACEI side efx: angioedema, urticaria. Rash is usually psoriatic, not photosensitivity in nature. Note that ARB might also cause angioedema if a pt has bad experience w. ACEI. Paroxysmal a fib: present w/ EPISODIC palpitation possibly associated w/ symptoms. Same CVA risk as normal afib, so need warfarin. Either rate or rhythm control is effective if asymptomatic. If there are marked or persistent symptoms (palpitation, dizzy, dyspnea) rhythm control is better. Amiodarone is the preferred drug for rhythm control if pt also has some other structural heart disease (cardiomyopathy, CHF, CAD). Flecainide can work ONLY if pt has NO structural heart disease. It can lead to fatal arrhythmias if you give it to pt w/ structural heart disease. Ibutilide: use for acute termination of a-fib. Fibrinogen: associated w/ increased CV risk. > 3.43 is a double risk. > 2.7 is high. Drug therapy to decrease fibrinogen hasn’t been shown to be preventative. However, stopping further increase helps. Within statins, lovastatin and atorvastatin increase levels, while prava and simva don’t increase. Thus,
if someone is at a high level for fibrinogen, must think about which statin to use if pt also has high LDL. Nonsusstained ventricular tachy: >=3 consecutive ventricular beat w/ rate > 120, and the episode lasts < 30 sec. If you see this, pt most likely has structural heart diease. Ex. Prior MI scarring, ventricular hypertrophy, mitral valve prolapse (midsystolic click). If you pick up this rhythm on EKG, next step is to get echo and stress test to r/o ischemia. CHF: ACEI are the main therapy. Improve survival and delay progression of disease. Indicated even if pt is asymptomatic. Only contraindications are poor tolerance to drug, or renal failure or hyperkalemia. CHF: standard therapy is diuretic, ACEI, bb, digoxin, or spironolactone. ACEI is the best, and won’t exacerbate confusion in a pt. digoxin could worsen confusion. If ACEI isn’t well tolerated (angioedema), then hydralazine and isosorbide dinitrate is a common combination. Side efx might include drug induced lupus. Manifest as flu like symptoms (fever, malaise, myalgia, facial rash). LAD, splenomegaly can also happen. Antihistone antibody is marker of drug induced lupus. Rx is to stop drug. Hydralazine is safe in pregnancy (as are dopa, labetalol) CHF as a cause of hypoNa. The decreased CO and SBP decreases perfusion P at carotid baroreceptor, so body stimulates ADH and rennin angiotensin despite volume overload. This causes even more fluid retention, leading to hypoNa. Must correct levels gradually, not acutely. Best Rx is water restriction. CHF: syndrome which results from impaired ventricular emptying (systolid) or relaxation (diastolic). Symptoms: fatigue, weakness (d/t reduced CO), edema (d/t fluid retention). Exertion exacerbates all symptoms. Its’s a syndrome, so it’s a clinical diagnosis based on H and P. PND, orthopnea, raised JVP, rales, S3, CXr findings (increased vascular congestion or silhouette) are major criteria. Dx is 2 major or 1 major + 2 minor. Minor criteria: bilateral LE edema, hepatomegaly, dyspnea on exertion, nocturnal cough). Digoxin toxicityL N/V, anorexia, confusion, visual disturb, cardiac abnormalities. Drugs that can cause toxicity: verapamil, quinidine, amiodarone, spironolactone. Hypercholesteremia + hypertriglyceridemia (>200): DOC is a statin. . If statin isn’t good alon,e add gemfibrozil or niacin. Lone a fib: a-fib which occurs w/o any other signs of clinical heart disease (r/o CAD, TH, PE, HTN, DM, CHF). Warfarin is not necessary, just aspirin is good enough. Unstable angina: no matter what, need a coronary angio ASAP to look at blockage and see it’s severity. If angio reveals pt to be high risk, consider percutaneous coronary intervention (PCI) or CABG. Remember that DM will increase rate of progression a lot. Evaluating heart ischemia in pt w/ prior CABG, poor heart function, or if there already exist baseline EKG changes: use adenosine or dipyramidole to induce ischemia and watch the technetium-99. (sestamibi). Stress echo should only be done if adenosine cant be used for some reason. Remember that arthritis can also impair exercise. Adenosine can induce bronchospasm, so if pt has COPD or asthma, adenosine is contraindicated. Use dobutamine instead. Orthostatic HypotensionL dx with fall or 20 SBP or 10 DBP. Can happen after standing up or even eating. Drop in BP must happen within 2-5 min of standing. 2 MCC ortho hytpo: autonomic dysfunction or intravascular volume depletion. Autonomic dysfunction (DM neuropathy). Drugs: antihyptrtensives, vasodilators, anti-angina drugs.
Ca channel blocker: peripheral edema is common side efx. The –dipines are common, but diltiazem can also cause it. Exercise stress test is FSOM in pt w/ angina symptoms.. Weight loss is the best non-drug way to decrease BP. Benefit in overall CV risk is unclear but probably helps. Other firstline drug for HTN besides ACEI is b-blocker. Positive stress test: > 1 mm downsloping ST depression. NSOM is to do cardiac cath to see where the lesions are, and to possibly to balloon stenting. Right sided endocarditis: commonly see R sided involvement or septic pulmonary emboli. Septic emboli manifests as scattered bilateral rales. Pulmonary infiltrates on both sides. IVDU is the likely cause. Otherwise, R sided disease is very uncommon. Coumadin management: If INR > 3 but < 5, just hold drug for a few days to get level to therapeuritic. If INR > 5 but < 9, stop drug and give small dose of vit K (1-2 mg). If > 9 but < 20, higher dose of vit K. If > 20, consider FFP. If at anytime pt is bleeding, give FFP. Drug interaction w/ warfarin: Amiodarone increases warfarin action. If need to have the two together, reduce warfarin by 25%. MVP: MC valve abnormality in industrialized nations. Mid to late systolic click, most easily heard over LV. Mitral regurg: holosystolic decrescendo murmur (can be 2ndary to MVP) heard in apex, radiates to axilla. Increases w/ grip, decrease w/ valsalva. Systolic <> in LU sternal border: pulmonic stenosis. Mitral stenosis: low pitched diastolic rumble heard over the apex best when pt is lying L lat decubitis. The narrowing of the valve leads to increased P in LA, which backflows into increased P in pulmonary vasculature and R side of heart. MCC is rheumatic fever. May present as hemoptysis. LA can enlarge, leading to elevation of L mainstem bronchus, and flattening of L heart border. Mitral stenosis: opening snap with diastolic rumble. Best heard mid clavicular on L side between 5th and 6th ribs. MC congenital heart malformation: VSD. If large enough, may be symptomatic. Murmus is pansystolic murmur at LL sternal border. Should get an echo. VSD is not congenitally cyanotic, only if its big enough. Polypharmacy: Using too many diuretics, a-blocker, or nitrates can induce ortho hypo. MCC perioperative mortality: cardiac death. Highest risks: unstable angina and critical aortic stenosis. Exercise angina and MI < 6 mo ago are also decently big RF, but less than the other two. Amiodarone induced lung toxicity: MC presentation is as a chronic interstitial pneumonitis. Nonprod cough, fever, pleuritic CP, focal or diffuse interstitial opacity on CXR. Rx with d/c drug. If really bad, consider steroids. Inpt facility Metformin: higher chance of lactic acidosis (contraindicated) if renal insufficiency, hepatic dysfunction, or CHF. Thus, if pt goes to a procedure that needs contrast (ex. Cardiac cath), you must d/c metformin a bit before the procedure.