Cardiac Flashcards
1
Q
Drugs that are selective vasodilators of coronary vessels (aka coronary steal)?
A
Adenosine and dipyridamole (coronary perfusion studies therefore pretty precise)
2
Q
VSD murmur
A
Holosystolic murmur over L mid-sternal border
3
Q
Mucosal cyanosis and fingernail clubbing found in what defects?
A
Cyanotic congenital heart diseases (like Tetralogy) or late features 2/2 Eisenmengers
4
Q
Fixed, wide splitting of S2?
A
ASD! L-to-R shunt –> delayed closure of the pulmonary valve all the time.
5
Q
Pulsus paradoxus
A
Dec. in systolic pressure of > 10 mmHg w/ inspiration. Conditions that impair expansion of pericardial space (tamponade, constrictive pericarditis, obstructive lung disease, restrictive cardiomyopathy), causes the inter ventricular septum to move into the left and reduce SV during inspiration.
6
Q
Cardiac tamponade exam?
A
Beck’s triad - hypotension, JVD, distant/muffled heart sounds; tachycardia
7
Q
Fick principle?
A
CO = rate of O2 consumption/arteriovenous O2 difference. Derived from the idea that flow * concentration difference = amount of substance consumed.
8
Q
Concentric LV hypertrophy associated with?
A
Chronic HTN, aortic stenosis
9
Q
Extended consumption of appetite suppressants leading to?
A
Pulmonary hypertension
10
Q
Aortic regurgitation murmur
A
Diastolic decrescendo, heard loudest in early diastole (increased pressure gradient). Left sternal border w/ pt leaning forward at END-expiration.
11
Q
Perivascular infiltrate with abundant eosinophils in cardiac tissue?
A
Hypersensitivity myocarditis
12
Q
Light micro path after MI
A
Minimal change < 4h. Up to day 5 becomes coagulation necrosis (edema, wave fibers -> band necrosis -> neurophils). Days 5-10 = macrophage. Days 10-14 = granulation tissue and neovasc. 2 wk-2mo = collagen deposition/scar
13
Q
Selective beta-blockers?
A
Metoprolol, atenolol, acebutolol, and esmolol. Preferred in patients with COPD or asthma b/c won’t B2 blockade -> bronchoconstriction
14
Q
How does nitroglycerin relieve angina?
A
DECREASED cardiac preload (LV diastolic volume) via venodilation leading to retention of blood in venous system. Modest coronary arteriolar dilation, but high doses -> coronary steal
15
Q
Phase 0 pacemaker?
A
Upstroke. Opening of L-type (long-lasting dihydropyridine-sensitive Ca2+ channels leading to slow influx
16
Q
Phase 3 pacemaker?
A
Repolarization. Opening of K+ channels and efflux. Closure of L-type Ca2+ channels.
17
Q
Phase 4 pacemaker?
A
Pacemaker potential. Slow influx of Na+ occurring at end of 3. Also slow decrease in K+ efflux. At -50 mV, T-type (Transient) Ca+ opens leading to depolarization. At -40, L-types open until we get AP.
18
Q
Effects of adenosine on cardiac pacemakers?
A
Adenosine activates K+ channels and prolongs K+ efflux leading to longer time NEGative, while also inhibiting L-type Ca+ channels prolonging time to reach threshold -> decreased HR.
19
Q
Digoxin toxicity treatment
A
Oral activated charcoal, mgmt of K+ w/ insulin, kayexelate, or dialysis (avoid Ca gluconate), digoxin-specific Ab fragments
20
Q
Digoxin toxicity
A
AV nodal block -> brady -> junctional escape -> ventricular tachyarrhythmias. HyperK leads to increased susceptibility. Anorexia, n/v, abdominal pain, fatigue, confusion, weakness, COLOR VISION change
21
Q
Effects of an arteriovenous shunt on preload and after load?
A
Decreased after load but increased preload.
22
Q
ADP-mediated drugs?
A
Clopidogrel and ticlopidine
23
Q
Two QT prolongation congenital syndromes?
A
Romano-Ward (AD, no defaness) and “Jervell and LAnge-Nielsen syndrome” (AR, neurosensory deafness) —> torsades at young age. K+ channel mutations -> delayed rectifier current
24
Q
Paradoxical embolism
A
Cerebrovascular event in setting of known thromboembolic disease is suspicious for an intracardiac or intrapulmonary shunt (patent foramen ovale, ASD, VSD, plum AV malformations). Even if L-R shunt, transient reversal during elevated R-sided pressure periods –> embolization
25
Phase 0 myocyte
SODIUM (not Ca+ as in pacemaker) inward (voltage-gated)
26
Phase 1 myocyte
Initial rapid repol b/c of Na+ channel closure
27
Phase 2 myocyte
Plateau (only seen here). Opening of L-type Ca+ channels and closure of some K+ channel.
28
Phase 3 myocyte
Late rapid depolarization b/c of closure of Ca+ channel and OPENING of K+ channels
29
Phase 4 myocyte
Resting potential. Mostly b/c of K+ permeability.
30
Inspiration affecting murmurs
Intrathroacic pressure drops, increased blood flow to right heart. Inc. RV SV, decreased LV return. Increased TR murmur.
31
Myxomatous degeneration
Often seen in connective tissue disease for the MV --> prolapse.
32
Pulsus alternans
Beat to beat variation in magnitude of pulse pressure. LV dysf(x)
33
Pulsus paradoxus
Decrease in systolic > 10 mmHg upon inspiration vs. expiration. Associated with cardiac tamponade.
34
Dicrotic pulse?
Pulse w/ two distance peaks - one in systole, the other in diastole. Best palpated in CAROTIDs and associated with severe SYSTOLIC dysf(x)
35
Pulsus parvus et tardus
Aortic stenosis. Low magnitude w/ delayed peak.
36
Most reliable auscultatory indicator of degree of mitral stenosis?
A2-OS interval. Shorter = more SEVERE b/c increased LA pressures.
37
Degree of cyanosis in TOF determined by?
Degree of pulmonic stenosis. (TOF = pulmonic stenosis, VSD, RVH, overriding aorta). If severe, blood goes across the VSD and does not oxygenate.
38
Post-MI pericarditis
Early-onset pericarditis develops in 10-20% of patients between days 2-4 following STEMI b/c of inflammation overlying necrotic segment. Short-lived, 1-3 days with ASA. Late-onset post-MI pericarditis = Dressler's syndrome = autoimmune reaction starting 1 week to few months after MI
39
Atrial myxoma
Most common primary cardiac neoplasm. Constitutional symptoms, mid-diastolic rumble at apex, positional dyspnea, large pedunculated mass of LA. Path - scattered cells within mucopolysaccharide stroma, normal blood vessels (VEGF) and hemorrhaging
40
Antihypertensive that has minimal effect on AV conduction?
Nifedipine. Vasodilator. a CCB.
41
What part of the cardiac electrical conduction system is the slowest and why?
The AV node. B/c after P-wave fires from SA node, want to give time for ventricles to fill before firing off for systole.
42
Fastest to slowest cardiac tissue conduction?
Purkinje, Atrial tissue, Ventricular Tissue, AV node. Purk At Ventricle Ave.
43
Nitroglycerin's effect
Venodilates>arteriodilates -> decreasing PRELOAD. Reflexive increased HR NOT overcome by overall decreased volumes -> decrease O2 consumption by cardiac muscle
44
Atrial septation
First the septum primum forms superiorly to inferiorly. At some point, a foramen secundum forms in the septum primum before the foramen primum is obliterated. The septum secundum then forms superiorly to partially cover the foramen secundum allowing a R-L shunt. When LA increases at birth, the septa will fuse to form the atrial septum.
45
Fetal erythropoiesis
Young Liver Synthesizes Blood. Yolk sac (3-8wk), Liver (6 wk-birth), spleen (10-28 weeks), bone marrow (18 weeks to adult)
46
The three major shunts in fetal circulation
Ductus venosus bypasses the liver form umbilical vein to IVC. Patent foramen ovale allows said oxygenated blood to R-L shunt into the aorta. Finally, deoxygenated blood moving into RV go mostly into the aorta via ductus arteriosus instead of going into the pulmonary vasculature, which has high resistance.
47
What keeps PDA open (and what can close it?)
Prostaglandins E1 and E2. Indomethacin can help close it.
48
Ductus arteriosus and ductus venosus turn into?
Ligamentum arteriosum and ligamentum venosum
49
Umbilical vein and umbilical arteries turn into?
Ligamentem teres hepatis and mediaL umbilical ligaments. MediaL for umbiLical.
50
Median vs medial umbilical ligament?
ONE median umbilical ligament from the allantois. TWO medial umbilical ligaments from umbiLical arteries.
51
Interventricular septum perfusion?
PDA/posterior interventricular artery supplies the posterior 1/3. LAD supplies anterior 2/3.
52
MAP equations (2)
MAP = 2/3 diastolic + 1/3 systolic = CO x TPR; (V=IR w/ V ~ Pa b/c Pv ~ 0)
53
Pulse pressure equation; what does it mean?
Pulse pressure = Psystolic - Pdiastolic ~ Stroke volume / arterial compliance (b/c difference in pressure ~ change in volume / compliance). Therefore, pulse pressure is proportional to SV but INVERSELY proportional to arterial compliance. (Inc. pulse pressure in athersclerosis)
54
Pulse pressure increased when?
Atherosclerosis, hyperthyroidism, AR (inc. SV), OSA (sympathetic tone), exercise (Transient)
55
Pulse pressure is decreased when?
Aortic stenosis (dec. SV), cardiogenic shock, cardiac tamponade, HF
56
Digoxin mechanism
Blocks the Na+/K+ channel, which increases intracellular Na+, which prevents Na+/Ca2+ exchanger -> INC. intracellular Ca2+
57
Approximaters for preload and afterload?
Preload ~ EDV. Afterload ~ MAP.
58
How relate LV structural parameters with afterload?
LaPlace's law. Wall tension = pressure x radius / (2 x wall thickness). LV seeks to decrease wall tension in HTN by increasing wall thickness.
59
Ejection fraction equation
SV / EDV = (EDV - ESV) / EDV.
60
Which way does the Starling curve go with increased contractility?
Y axis = SV. X axis = pre-load. Soooo, left-shift the curve with increased contractility
61
Vascular resistance components (equation)
R ~ viscosity x length / r^4
62
Jugular venous pulsations?
a wave (atrial kick), c wave (RV Contraction), x descent (atrial relaXation), v wave (RA pressure due to filling against closed tricuspid Valve)
63
Wide split S2?
P2 comes after A1 b/c of delayed RV emptying (e.g. pulmonic stenosis, RBBB)
64
Fixed split S2?
Seen in ASD b/c the Left-Right shunt delays RV emptying constantly regardless of breath
65
Paradoxical split S2?
P2 comes before A2 b/c of delayed LV emptying (aortic stenosis, LBBB). On inspiration, no split, but split on EXPiration!
66
Hand grip maneuver increases intensity of what murmurs?
Hand grip increases SVR. Increased - MR, AR, VSD. Catch the regurgitation w/ your hand! Decreased - AS, HCOM.
67
Valsalva or standing increases intensity of what murmurs?
Decreased venous return. Increased HOCM.
68
Rapid squatting increases intensity of what murmur?
AS
69
Where do you hear the HOCM murmur?
Left sternal border
70
Mitral valve prolapse murmur?
Late systolic crescendo murmur with mid systolic click (sudden tensing of chordae tendinae).
71
MS vs. AR murmurs?
MS follows an opening snap with "rumbling" late diastolic murmur. AR is high-pitched early diastolic decrecending.
72
What does U wave look like and what does it signify?
A small positive deflection following T-wave that may indicate hyPOkalemia or bradycardia
73
Meds that can prolong QT?
Some Risky Meds Can Prolong QT: Sotalol, Risperidone (antipsychs), Macrolides, Chloroquime, Protease inhibitors (-navirs), Quinidine (Ia AND III), Thiazides
74
Two congenital long QT syndromes
Romano-Ward (AD, pure cardiac phenotype) and Jervell and Lange-Nielsen syndrome (AR w/ sensorinueral deafness)
75
WPW can lead to what?
A re-entery circuit -> supraventricular tachycardia; Delta wave
76
Atrial-flutter sinus conversion with what and rate-control with what?
IA, IC, III anti-arrhythmics; Rate-control with beta-blocker or CCB
77
Mobitz type I vs. type II
Type I is lengthening PR until dropped whereas type II is dropped QRS. Both are 2nd degree AV blocks. II must be treated.
78
ANP vs. BNP
Atrial release vs. ventricular release. Increased blood volume and atrial pressure vs. increased tension. BNP used for negative predictive value for HF.
79
ANP/BNP physiological effects
Vasodilation, decreased Na+ resorption, dilates afferent and constricts efferent via cGMP to promote diuresis.
80
Nerve transmission differences between aortic arch and carotid sinus baroreceptors?
Aortic arch receptor via vagus nerve (to solitary nucleus) and only reports on INCreased pressure. (The aorta is above hypotension apparently). Carotid sinus baroceptors via CN IX to solitary and reports both increased and decreased blood pressure.
81
Peripheral vs. central chemoreceptors
Peripherals (carotid and aortic) stimulated by low PO2, high PCO2, low pH BUT central only responds to PCO2 and pH.
82
Organs that rely on local metabolites for auto-regulation of perfusion?
Heart (CO2, adenosine, NO), brain (CO2 via pH), and skeletal muscle (lactate, adenosine, K+, H+, CO2)
83
Tetralogy of Fallot
RVOT stenosis, VSD, aorta dextropositin (over-riding aorta), and RV hypertrophy. "Tet" spells (episodes of blush pale skin during crying or feeding. Harsh systolic ejection murmur.
84
Neural crest cell abnormal migration cyanotic diseases?
ToF, transposition, truncus arteriosus (namely aorticopulmonary septation).
85
Cardiac effects of carcinoid syndrome.
Overproduction of serotonin -> endocardial fibrosis on the RIGHT heart (b/c pulmonary system inactivates serotonin and bradykinin). Pulmonic stenosis and restrictive cardiomyopathy. Corelated with urinary excretion of 5-hydroindoleacetic acid (serotonin-metbaolite)
86
Right to left shunts?
Truncus arteriosus, Transposition, Tricuspid atresia, Tetralogy of Fallot, Total anomalous pulmonary venous return (TAPVR)
87
Tetralogy of Fallot
Abnormal anterior and cephalic displacement of infundibular portion of inter ventricular septum: VSD, pulmonic stenosis, overriding aorta (receiving blood flow from both ventricles), and RV hypertrophy. "Tet" spells following exertion b/c systemic VASOdilation -> increased right to left shunt. Associated with diGeorge.
88
Transposition of great vessels
Aorta is ANT and leaves RV while pulmonary artery is POSTerior and leaves LV. Requires shunt to support life. Failure of aorticopulmonary septum to spiral. Most common cause of cyanosis in NEONATE period. Associated with diabetic mother.
89
VSD
Left to right shunt. Asymptomatic at birth. Most self resolve but large lesion -> LV overload and HF
90
ASD
Wide, fixed split S2 (2/2 constant P2 late). Usu. septum secundum. NOT patent foramen ovale b/c septa are missing not unfused.
91
Patent ductus arteriosus
Indomethicin closes, PGE2 keeps open. Machine-like continuous murmur. Differential cyanosis.
92
Eisenmenger syndrome
An uncorrected Left-to-right shunt can cause pulmonary vasculature to be remodeled and increased resistance eventually leading to a REVERSAL to a R-L shunt -> cyanosis (clubbing, and polycythemia)
93
TAPVR
Total anomalous pulmonary venous return. Pulmonary veins drain into Right heart circulation. Associated with ASD +/- PDA.
94
Coarctation of the aorta
Infantile type is PRE-ductal (before ductus arteriosus) and is associated with XO Turner's. PGE2 to prevent closure. Adult type is post-ductal (after ligamentem arteriosum), associated with rib notching (collateral circulation), HTN of UPPER limbs and weak pulses in lower extremities, cerebral aneurysms and circle of Willis deformities
95
Truncus arteriosus
No septation. Often associated with a VSD. Seen in diGeorge
96
Congenital rubella is associated with what cardiac defects?
Septal, PDA, pulmonary artery stenosis
97
Turner syndrom is associated with what cardiac defects?
Bicuspid valve, coarctation of the aorta
98
Monckeberg arteriosclerosis
Medial calcific sclerosis. Calcification of then media NOT intima of blood vessels. Usu. benign. X-rays of radial or ulnar arteries.
99
What type of people would you expect to get an abdominal aortic aneurysm vs. a thoracic aortic aneurysm?
Abdominal - 50's smoker. Thoracic - Marfan syndrome, tertiary syphilis. Associated with cystic medial degeneration in the older population
100
Aortic dissection Sanford type A vs. B?
A involves ascending aorta (+/- descending) while B does not.
101
Prinzmetal angina
2/2 to coronary spasm. Triggers include tobacco, cocaine, triptans, ergot alkaloids (ergonovine - an abortifacent/placental delivery drug). Tx = CCB, nitrates, smoking sessation
102
MI days 3-14: what do I need to know?
Macrophages doing their thing. Granulation tissue. Hyperemic border with central yellow-brown softening on gross. Free wall rupture, papillary muscle rupture, IV septal rupture (macrophage-mediated structural degradation). LV pseudoaneurysm = mural thrombus plugs hole = a time bomb
103
How long after occlusion does it take for histological or gross changes to occur in a MI?
FOUR hours. Coincedentally (or not), it takes four hours for troponin I to start rising (most specific cardiac marker)
104
Why use CK-MB?
Found in myocardium and skeletal muscle (less specific). BUT, it goes back to normal after 48 hours (troponins rise for 7-10 days). Therefore , it's used for diagnosing re-infarction
105
Anteroseptal vs. Anterolateral leads?
V1-V2 vs. V4-V6
106
Dressler syndrome
autoimmune, takes several weeks to months (true ventricular aneurysm timeline)
107
Etios of dilated cardiomyopathy
Alcohol, wet Beriberi, Coxsackie B myocarditis, chronic Cocaine, Chagas, Doxorubicin toxicitiy, hemochromatosis, peripartum cardiomyopathy. Idiopathic and congenital.
108
Hypertrophic cardiomyopathy
LV ONLY. Most are familial and AD (Beta-myosin heavy chain mutation) although rarely associated with Friedreich ataxia. Can syncopize if septum to close to mitralm leaflet. Diastolic dysfunction. S4. Myofibrillar disarray and fibrosis. Tx = Cessation of high-intesnsity, Beta-block or non-di CCB.
109
Explain night symptoms of HF?
Orthopnea and PND are due to increased venous return 2/2 to the gradual reabsorption of pooled blood toward the lungs.
110
Physical signs of bacterial endocarditis
Fever, new murmur, Roth spots, Osler nodes, Janeway lesions, splinter hemorrhages on nail bed
111
Acute vs. subacute etios of endocarditis?
Acute - Staph aureus. Subacute - Viridians strep.
112
Culture negative bacterial endocarditis?
Coxiella burnetii, Bartonella. Or 2/2 malignancy, hpercoagulable state, lupus
113
Rheumatic fever histo findings
Aschoff bodies (granuloma with giant cells), Anitschkow cells (enlarged macrophages w/ ovoid nucleus).
114
Fibrinous vs. serous pericarditis?
Fibrinous is usu. Dressler, uremia, radiation. Serous is usually viral or inflammatory/auto-immune
115
Findings in cardiac tamponade
Beck's triad (hypotension, distended neck veins, distant hear sounds). Tachy. Pulsus paradoxes, Kussmaul sign (rise of JVP on inspiration), ECG electrical alternans
116
Pathogenesis of syphilitic heart disease
In tertiary syphilis, disruption of the vasa vasorum of the aorta -> atrophy of wall and dilation. "Tree bark" aorta. Aneurysm.
117
Myxoma vs. rhabdomyoma
Myxoma - most common primary. LA. Associated with syncopal episodes associated with obstruction of valve. Rhabdo - mostly in children (i.e. tuberous sclerosis)
118
Cherry vs. strawberry hemangiomas?
Strawberries are for kids! Regress by 5-8. Cherries are for old people. Don't regress.
119
Pyogenic granuloma
Hemangioma that can ulcerate and bleed. Associated with trauma and pregnancy.
120
Glomus tumor
Benign, PAINful, red-blue tumor under fingernails. From mod SMC's of glomus body (temp. regulation)
121
Bacillary angiomatosis
Like Kaposi, associated with AIDS. But looks uglier and caused by Bartonella henselae.
122
Angiosarcoma
Rare blood vessel malignanty of the H&N and breast. Eldelry, sun-exposed. Radiation and arsenic. Agressive
123
Lymphangiosarcoma
Lymphatic malignancy associated with too much lymph (e.g. post-mastectomy)
124
Large vessel vasculitis
Temporal (Giant cell) and Takayasu
125
Medium-vessel vasculitides
Polyarteritis nodosa, Kawasaki disease, Buerger disease
126
Small-vessel vasculitides
Granulomatosis with polyangiitis, microscopic polyangiitis, Churg-Strauss syndrome, Henoch-Schonlein purpura
127
Temporal arteritis
Elderly women with unilateral HA and jaw claudication. Treat with corticosteroids before temporal a. biopsy to prevent irreversible blindness 2/2 opthalmic artery occlusion. Associated with polymyalgia rheumatic. Path - focal granulomatous inflammation.
128
Takayasu arteritis
Asian women < 40. "Pulseless disease." Weak upper extremity PULSE, fever, night sweats, arthritis, myalgias, skin nodules, ocular. Path - granulomatous thickening and narrowing of aortic arch and great vessels. Tx = steroids
129
Polyarteritis nodosa
Young adults with abdominal pain, melena, HTN, neuro, cut. eruptions, renal damage w/ Hep B seropositivity in 30%. IC-mediated. Transmural inflammation of wall w/ fibrinoid necrosis. MICROaneurysms. Renal and visceral vessels. Tx = steroids, cyclophosphomide
130
Kawasaki disease
Asian children < 4 w/ fever, cervical nymphs, RED (conjuctiva, strawberry tongue, hand-foot), desquamating rash. Comps include coronary artery ANEURYSM -> MI,rupture. Tx = IVIG and ASA
131
Buerger disease
Smoking men < 40 w/ claudication that can lead to gangrene and autoamputation.
132
Granulomatosis with polyangitis
Perf'd nasal septum, chronic sinusitis, hemoptysis, cough, hematuria. Necrotizing vascultisi, granulomas of lung, glomerulonephritis. PR3-ANCA/c-ANCA. Tx - cyclophosamide, corticosteroids.
133
Microscopic polyangitis
Kidney, lung, skin. Hemoptysis, cough, hematuria. NO granulomas. MPO-ANCA/p-ANCA. Tx = cyclophosphamide, corticosteroids
134
Churg-Strauss
Asthma, sinusitis, palpable purpura, peripheral neuropathy. Granulomatous, necrotizing vasculitis with EOSinophilia. MPO-ANCA/p-ANCA.
135
Henoch-Schonlein purpura
IgA complex deposition often following a URI. Palpable purport, arthralgia, GI.
136
Dihydropyridine CCBs?
Amlodopine, nimodipine, nifedipine. HTN, angina, Raynauds. Nimodipine in particular used to decrease vasospasm following SAH.
137
Non-dihydropyridine CCB's?
Verapamil, Diltiazem. Used for HTN, angina, AFIB/FLUTTER.
138
Vascular smooth muscle vs. heart effects by CCBs?
For smooth muscle: amlodopine = nifedipine > dilt > verp. For heart, Verapamil > dilt > amlodopine = nifedipine.
139
CCB toxicities?
Cardiac depression, AV block, peripheral edema, flusshing, dizziness, hyperprolactinemia, constiation
140
Hydralazine mech and use?
Increases cyclic GMP -> vasodilating arterioles > veins. Used fo rsevere HTN, CHF. 1st line for pregnancy with methyldopa. Often administered with Beta-blockers to prevent reflex tachy. B/c of reflex tachy, contra'd in angina/CAD
141
Nitroprusside
Increases cGMP via direct NO release. But releases cyanide. Used for hypertensive emergencies. Balanced veno and arteriodilator.
142
Fenoldopam
A D1 receptor agonist -> coronary, peropheral, renal, splanchnic vasodilation.
143
Nitrates
Venodilation > arteriolardilation via increased cGMP. Decreased preload is mechanism as anti-anginal. Isosorbide mono nitrate has best oral availability. Nitroglycerin is given SL. Sodium nitroprusside is the only one given IV.
144
Bile acid resins
Cholestyramine, colestipol, colesevelam. Prevents intestinal reabsorption of bile forcing the liver to use more cholesterol. Decreases LDL. GI discomfort, decreased absorption of fat-soluble vitamins. Cholesterol gallstones.
145
Cholesterol absorption blockers
Ezetimibe. Only affects LDL (lowers)
146
Niacin mech and side effecst
Inhibits lipolysis in adipose tissue and reduces hepatic VLDL synthesis. SE include flushing (dec. by aspirin), hyperglycemia, and hyperuricemia.
147
Fibrates
Upregulate lipoprotein lipase to increase triglyceride clearance. (Suppresses cholesterol 7alpha-hydroxylase activity). Activates PPAR-alpha to induce HDL synthesis. Best TG lowering drug. Myositis (inc. with statins), hepatotoxicity, cholesterol gallstones (inc. with resins)
148
Important digoxin pharmacokinetics
RENAL excretion. 75% bio. 20-40% protein bound. t1/2 of 40 hours.
149
Digoxin mech?
Inhibits Na/K ATPase -> indirect inhibition of Na/Ca exchanger -> increased Ca intracellular -> positive isotropy. Also stimulates vagus nerve -> bradycardia.
150
Digoxin Tox and Tx?
Cholinergic tox, increased PR, decreased QT, ST scooping, TWI, arrhythmia, AV block. HyperKalemia. Renal failure, hypokalemia, verapamil, amiodarone, quinidine all predispose. Tx = fix K+ slowly, pacer, anti-digoxin Fab-fragments, Mg2+
151
Class IV antiarrhythmics
Non-dihydropyridine CCBs = verapamil and diltiazem. Decrease conduction velocity, increase effective refractory period, increase PR. Slowed rise of AP, prolonged depolarization. Used for nodal arrhythmias and rate control in AFib.
152
Class III anti-arrhythmic names
Amiodarone (all class effects), Ibutilide, Dofetilide, Sotalol. AIDS is Potassium on Three.
153
Class III anti-arrhythmics mechanism and usage
K+ channel blocker -> markedly prolong depolarization. Increased AP duration, increased refractory period. Increased QT. Used for Afib, A-flutter, ventriclear tachy
154
Amiodarone toxicities
pulmonary fibrosis, hepatotoxicity, hypothyroidism/ hyperthyroidism, corneal depositis, skin deposits (blue/gray), neurological, constipation, brady, heart block, CHF. Therefore, must check PFTs, LFTs, TFTs.
155
Class II antiarrhythmics mechanism and usage
Decreased cAMP -> dec. nodal activity. Decrease the phase 4 depolarization slope AND prolong repoarlization. Used for SVTs, rate control
156
Class II antiarrhythmics tox
Impotence, exacerbate COPD/asthma, brady, AV block, CNS. Metoprolol can cause DLD. Propanolol can exacerbate vasopasm. Contra'd in COCAINE (b/c of risk of unopposed alpha-adrenergic receptor). Tx with glucagon.
157
Class IA antiarrhythmics mech and usage
Quinidine, Procainamide, Disopyramide. Na+ channel bicker that decreases rate of depolarization -> inc. AP duration, inc. refractory, inc. QT. Used of atrial and ventricular arrhythmias.
158
Class IB mech and usage
Lidocaine, Mexiletine. Decreased AP duration. Preferentially affects ischemic or depolarized tissue. Used for acute ventricular arrhythmias (post-MI), digitalis-induced.
159
Class IC mech and usage
Flecainide, Propafenone. Significantly prolongs refractory period in AV node. Used for SVTs, AFib. "Use-dependence" - Na+ blocking gets more prominent as HR increases b/c medication has less time to dissociate from receptor
160
Adenosine mech
K+ out of cells -> hyper polarizing and decreased Ca2+ current. Used to abolish and dx SVTs. Flushing, hypotension, CP. Blocked by theophylline and caffeine.
161
Fatty streak composition
Composed of intimal lipid-filled foam cells derived from macrophages and SMCs that have engulfed LDL's.
162
Drug-induced lupus drugs
Procainamide, Hydralazine, INH. (Quinidine and minocycline). ANA and anti-histone Ab's present in > 95% of cases
163
Supine hypotension?
Aortocaval compression syndrome. Pregnant woman lies supine - sweating, nausea, dizziness.
164
Isolated atrial amyloidosis
Due to deposition of ANP-derived peptides. Senile cardiac amyloidosis -> inc. risk of A-fib.
165
Isolated systolic hypertension
Frequent among people > age 50. Thought to be due to decreased compliance of the aorta.
166
Cardiac defects associated with down syndrome?
Endocardial cushion defects (ostium primum ASD [lower down], regurgitant AV valves)
167
Mitral valve prolapse?
Mid-systolic click with short late-systolic murmur. Diminishes on squatting b/c increased preload and rise in afterload -> increased LV volume, which helps close the valve. Etio - connective tissue defects -> myxomatous degeneration
168
Ebstein's anomaly
Atrialization of R ventricle, atrial displacement of the tricuspid valve, and decreased RV volume.
169
Mechanism of statins
HMC-CoA reductase inhibitors. Decreased hepatic cholesterol synthesis -> increased expression of hepatic LDL receptor -> receptor-mediated endocytosis of more LDL particles --> lowered LDL. (Also helps to lower TG's and increase HDL).
