Cardio Flashcards
What are the indications for Amlodipine?
Amlodipine is a dihydropyridine Calcium antagonist (CCB).
First line for isolated systolic HTN (often seen in elderly)
What are the side effects of Amlodipine?
Flushing and peripheral edema
What are the symptoms of brachiocephalic obstruction?
Brachiocephalic vein drains the ipsi jugular and subclavian veins >
One sided face and arm swelling + engorgement of subcutaneous veins on that side
Much like SVC syndrome, but one-sided
What part of the heart is closest to the esophagus?
Left atrium.
- Most of the posterior surface
- TEE visualizes LA well
- LA enlargement > dysphagia
EKG shows A-V dissociation with narrow QRS complex. What location is responsible for pacing the patient’s ventricles?
AV node.
Blockage between SA and AV in complete heart block. But if the QRS are narrow (normal), the AV has taken over (not the His Purkinje system, which would produce wider QRS).
What are fatty streaks?
The earliest lesion of atherosclerosis.
Lipid filled foam cells (macrophages that have engulfed lipoproteins).
Some progress to atherosclerotic plaques, but the location doesn’t predict location of atherosclerosis.
What are three drugs commonly used for invasive MRSA (ex. causing bacterial endocarditis)?
Vancomycin
Daptomycin
Linezolid
Which drug used to treat MRSA can cardiac side effects?
Daptomycin
- Myopathy and CPK elevation
- Also inactivated by pulm surfactant
What does ‘a’ indicate in the JVP?
R atrial contraction
What does ‘c’ indicate in the JVP?
Bulge of tricuspid into R atrium during RV contraction
What does ‘x’ indicate in the JVP?
R atrial relaxation
What does ‘v’ indicate in the JVP?
Continued venous blood (R atrium filling)
What does ‘y’ indicate in the JVP?
Passive emptying of R atrium after tricuspid valve opens
When does an S4 heart sound occur, and what does it indicate?
Right before S1.
Inidcates reduced ventricular compliance (hypertensive heart disease, aortic stenosis, hypertrophic cardiomyopathy).
This is diastolic dysfunction. Atrium is contracting against a a ventricle with reduced compliance.
What does an abnormal S4 sound like?
Low frequency, late diastolic sound (right before S1).
Why does mean arterial pressure only rise a little bit during strenuous exercise?
Adaptive decrease in systemic vascular resistance.
Exercising muscle releases local vasodilatory factors.
Does coronary blood flow occur during systole or diastole?
Diastole.
In systole, the open aortic valve partially blocks coronary blood flow.
What is the major side effect of drugs that relax arterioles but not veins (minidoxil and hydralazine)?
Sodium and fluid retention
Vasodilation > reduced arterial pressure > baroreceptors > RAAS
Causes reflex tachycardia and edema
What is holiday heart syndrome?
AFib (irregular tachyarrhythmia) precipitatied by binge alcohol.
EKG shows absent P waves because there are no coordinated atrial contrations
What is a drug that increases arteriolar dilation, increases renal perfusion, and promotes natriuresis?
Fenoldopam
- D1 receptor agoinst
- Improves renal perfusion and lowers BP
- Indicated for short term management of severe HTN
What is the mechanism of action of nitroglycerin?
Dilates large VEINS, leading to decreased preload, lessening myocardial O2 demand.
What is a good alternative to ASA in case of allergy?
Clopidogrel
Antithrombotic agent that binds & irreversibly blocks the platelet surface ADP receptors needed for platelet activation
What is the mechanism of isoproterenol?
Increases cardiac contractility through action on B1 adrenergic receptors. (high doses)
Relaxation of vascular smooth muscle through action on B2 receptors. (low doses)
What is the most common cardiac anomaly in Turner’s Syndrome?
Bicuspid aortic valve.
- May occur w aortic coarctation
- Aortic ejection sound: early systolic, high frequency click over R 2nd intercostal space
- Risk for stenosis, insufficiency, and infection
What does a tall (upsloping) left atrial ‘v’ wave during cardiac cath indicate?
Mitral Regurge
V wave measure atrial filling in systole.
Atrial pressure is increased if blood is entering from across the ventricle in addition to passive filling.
A class of medications used to treat depression cannot be taken with foods such as aged cheeses and wines, or else will cause severe hypertension and other signs of sympathetic hyperactivity.
What is this class of drugs? How do they work?
MAO inhibitors (traylcypromine, phenelzine)
They prevent monoamine degradation, including that of tyramine.
What adverse effect is associated with taking beta blocker and non-dihydropyridine CCBs (verapimil, diltiazem) together?
Negative chronotropy (decreased HR)
Cardiac assoc. with Down’s Syndrome?
Endocardium cushion defects:
- ASD
- AV valve regurge
Cardiac assoc. with DiGeorge?
Tetralogy of Fallot
Aortic arch abnormalities
Cardiac assoc. with Friedreich’s Ataxia?
Hypertrophic cardiomyopathy
Cardiac assoc. with Marfan’s?
Cystic medial necrosis of the aorta
- Aortic dissection
- Aortic aneurysm
Mitral valve prolapse
Cardiac assoc. with Tuberous Sclerosis?
Valvulvar obstruction due to cardiac rhabdomyomas
Cardiac assoc. with Turner’s Syndrome?
Aortic coarctation
Bicuspid aortic valve
Changes to myocardium 0-4hrs post MI:
Minimal change/none
Changes to myocardium 4-12hrs post MI:
Early coagulation necrosis
Edema
Hemorrhage
Wavy fibers
Changes to myocardium 12-24hrs post MI:
Coagulation necrosis
Marginal contraction band necrosis
Changes to myocardium 1-5days post MI:
Coagulation necrosis
Neutrophilic infiltrate
Changes to myocardium 5-10days post MI:
Macrophage phagocytosis of dead cells
Changes to myocardium 10-14days post MI:
Granulation tissue
Neovascularization
Changes to myocardium 2wks-2mo post MI:
Collagen deposits
Scar formation
In which types of vasculitis are giant cells found?
Takayasu
Giant Cell Arteritis
In which types of vasculitis is segmental fibrinoid necrosis found?
Leukocytoclastic vascultis:
-MPA, microscopic polyarteritis, hypersensitivity vasculitis
PAN
What are the steps in forming an atheroma?
- Endothelial cell injury
- HTN, hyperlipidemia, smoking, diabetes, homocysteine, toxins (alcohol), viruses, immune - Monocyte and lymphocyte adhesion and migration to the intima
- Exposure of subendothelial collages promotes platelet adhesion.
- Growth factors from monocytes and platelets stimulate medial smooth muscle cell migration and proliferation in the intima
- Increased endothelial cell permeability allows LDL cholesterol into the intima, where it accumulates in macrophages and SMCs to produce foam cells
What are the sequelae of severe aortic stenosis?
- Impaired LV output
- LV hypertrophy
- Atrial contraction necessary to fill LV
AFib!
- Reduced LV filling >
- Hypotension &
- Pulm edema
What type of cell responds to endothelial injury through fibrosis?
Smooth muscle cells
- Reactive cells that migrate from the media to the intima
- Produce collagen
When there is a PE, what do you expect to find in terms of:
- pH
- PaO2
- PaCO2
- Plasma HCO3-
Respiratory alkalosis (hyperventilation)
- pH: high
- PaO2: low
- PaCO2: low
- Plasma HCO3-: normal or low to compensate
What are the effects of dobutamine?
Dobutamine is a selective B1 agonist:
- Increases HR (chronotrophy
- Increases conduction velocity (inotropy)
- Increases myocardial O2 consumption because of positive inotropy
What type of nitrate has the highest oral bioavailability?
Isosorbide mononitrate (metab in the liver)
In what form are each of the following nitrates administered?
NTG Isosorbide dinitrate Isosorbide mononitrate Amyl nitrate Sodium nitroprusside
NTG: sublingual
Isosorbide dinitrate: PO, but parent compound to mono
Isosorbide mononitrate: PO, metab in liver
Amyl nitrate: inhalant
Sodium nitroprusside: IV
What is statin myopathy?
Statins are lipid lowering agents commonly prescribed after MI because they lessen incidence of 2nd MI.
Myalgia occurs at lower doses of statins.
Myopathy including elevated creatinine kinase occurs at higher doses.
Myopathy increased when fibrates and/or niacin are used at same time.
Is nifedipine useful in brady or tachycardia?
Bradycardia.
Nifedipine causes peripheral vasodilation (and has minimal effect on AV conduction).
Vasodilation results in reflex tachycardia.
What is normal P in RA?
0-8
What is normal P in the RV
4-25
What is normal P in the PA
9-25
What is normal P in the LA?
2-12
What is normal P in the LV?
9-130
What is normal P in the aorta?
70-130
What is nonbacterial thrombotic endocarditis?
NBTE is small, sterile, non-destructive, fibrinous cardiac valve vegetations that often involve a hypercoagulable state.
- May be the result of procoagulants circulating as products of a cancer
- Strong association with adenocarcinomas of the pancreas and lung
What causes coronary sinus dilation?
Coronary sinus is the confluence of deoxygenated blood that has supplied the heart and drains into the RA.
Anything dilating the RA will dilate the sinus.
- Most common = pulmonary HTN
What organs are associated with vessel damage from PAN?
Kidneys
Liver
GI
Heart
NOT lungs
Think: what parts of an animal can be eaten? What would you cook in the PAN? Kidney, liver, intestines, and heart, but NOT LUNGS
What is the conduction velocity of the various cardiac tissues?
Fast > Slow =
Purkinje > Atrial Muscle > Ventricular Muscle > AV node
Mnemonic: Park at Ventura Avenue
What are 2 formulas to calculate cardiac output?
CO = SV x HR
CO = O2 consumption/arteriovenous O2 difference
What maneuvers increase the murmur associated with left ventricular outflow tract (LVOT) obstruction?
Sudden standing, Valsalva, or NTG will decrease preload, thereby decreasing chamber size, increasing the LVOT, and increasing the murmur
What maneuver decrease the murmur associated with LVOT obstruction?
Sustained hand grip or passive leg raise increase preload, thereby increasing chamber size, decreasing the LVOT and the murmur
What is hyperplastic arteriosclerosis?
Result of malignant hypertension.
Onion-like concentric thickening of arteriolar walls.
What is hyaline arteriosclerosis?
Associated with low level HTN.
Homogenous, acellular thickening of arteriolar walls.
When does ventricular free wall rupture generally occur after an MI?
3-7 days after, when coagulative necrosis, neutrophilic infiltration, and enzymatic degradation of connective tissue have weakened the infarcted myocardium
What is the most common cause of in-hospital death due to MI?
LV failure/cardiogenic shock
What is pulsus paradoxus?
Defined by decrease in systolic BP of > 10 mmHg with inspiration
Occurs in the setting of acute cardiac tamponade, constrictive pericarditis, severe obstructive lung disease, and restrictive cardiomyopathy
Path:
- More volume returns to the R heart with inspiration
- If the heart can’t expand more (restriction) the BP falls
This triad of symptoms:
- Hypotension
- JVD (or distended neck veins)
- Distant/muffled heart sounds
indicates…?
Cardiac Tamponade
(beck’s triad)
Other sx:
- Tachycardia
- Pulsus Paradoxus (drop of BP > 10 on inspiration)
What are the changes in preload and afterload expected in the case of an AV fistula?
Communication between the arterial and venous systems causes blood to rush from A to V.
- Increased preload (more volume in the venous bed)
- Decreased afterload (less resistance in the arterial bed)
On a PV loop, this would cause a wider, shorter box.
What are the 3 major cyanotic heart diseases that can be caused by abnormal migration of neural crest cells through the primitive truncus ateriosus and bulbus cordis?
Tetralogy
TGA
Truncus Arteriosus
What is the effect of dopamine (on the kidney and heart) at low, medium, and high doses?
Low: stimulate D1 receptors in renal and mesenteric vasculature > vasodilation and increased blood flow
Medium: stimulate B1 receptors in the heart > increased cardiac contractility
High: stimulate a1 receptors > vasoconstriction
What is indicated by a mid-systolic click followed by a murmur during systole?
Mitral valve prolapse
What are the main causes of mitral valve prolapse?
Myxomatous degeneration
Some connective tissue disorders:
- Marfan’s
- Ehler Danlos
What does a prolonged QT indicate in terms of the cardiac action potential (what phase and channels are affected)?
QT corresponds to ventricular repolarization
This is phase 3, marked by K+ efflux
Class III antiarrythmics (and Sotalol, a beta blocker with III activity) can cause this effect.
What is a strawberry hemangioma and what is it’s natural progression?
Unencapsulated aggregate of closely packed blood vessels, common in children
Will increase in size as the child grows and usually regress spontaneously between 1-3 years of age, completely gone by age 7
What do siderophages indicate?
Siderophages are macrophages that have ingested hemosiderin, leaked from erythrocytes in a pulmonary capillary bed
They indicate pulmonary congestion and edema, consistent with chronic left sided heart failure
Test: hemosiderin turns blue with Prussian blue stain
What are the most lethal arrhythmias in patients with acute MI?
Vtach and Vfib
Atrial flutter and fib do not result in sudden cardiac death
What is the mechanism of nitrates?
Conversion into NO at vascular smooth muscle cell
Stimulates guanylate cyclase to convert CTP to CGMP
Increased cGMP
Decreased Ca
Decreased myosin light chain kinase
Myosin dephosphorylation
Smooth muscle relaxation
What is indicated by a holosystolic murmur best heard at the apex of the heart and radiating to the axilla?
Mitral regurge
What indicates the severity of mitral regurge?
High regurge and left ventricular volume overload is marked by a left-sided S3 gallop
A child has severe chest pain and is diagnosed with MI. Labs show increased serum methionine. What is the condition?
Homocystinuria
Homocysteine cannot be converted to cysteine because of a complete lack of cystathione beta synthetase.
Homocysteine comes from methionine, so both of these build up.
Sx: premature atherosclerosis, lens subluxation, osteoporosis, mental retardation
What is the treatment for prosthetic valve endocarditis?
Staph epidermiditis is the most common pathogen.
Assume it is methicillin resistant –> Vancomycin.
If it’s not resistant, nafcillin or oxacillin. Few strains are susceptible to penicilin!
Where are the leads placed on a 2 lead pacemaker?
Right atrium, right ventricle
Where are the leads placed on a 3 lead pacemaker?
RA, RV, and the LV lead in a “biventricular” pacemaker goes through the coronary sinus to rest in the atrioventricular groove.
What is the most common cardiac neoplasm?
Myxoma
- Most commonly in the LA
- Scattered cells within a mucopolysaccharide stroma
- Abnormal bvs and hemorrhage
- Produce VEGF –> angiogenesis
- Produce IL-6 –> weight loss, fever
- Look gelatinous, pedunculated, large
- Present with emboli or CV sx secondary to valve obstruction by the myxoma
How do Class IA antiarrhythmics change the AP?
Phase 0 inhibition: intermediate
Length of AP: prolonged
How do class IB antiarrhythmics change the AP?
Phase 0 inhibition: weak
Length of AP: shortened
How do class IC antiarrhythmics change the AP?
Phase 0 inhibition: strong
Length of AP: no change
What does S4 sound like?
Low frequency sound heard at the end of diastole, just before S1
What conditions is S4 associated with?
S4 is the atrial kick, so it is due to decreased left ventricular compliance:
- Restrictive cardiomyopathy
- LVH
What is the sodium channel binding strength of Class I antiarrhythmics?
IC > IA > IB
This reflects “use dependence,” the idea that higher rates of depolarization lead to increased sodium channel blockade due to the channels spending less time in the resting state.
What is the differential for holsystolic murmurs?
Mitral regurge
Tricuspid regurge
VSD
A holosystolic murmur that increases with inspiration is likely:
Tricuspid regurge
- Increased venous return during inspiration
A tricuspid regurge murmur is best heard in what location of the heart?
Left lower sternal border
A mitral regurge murmur is best heart in what location of the heart?
Apex, best heard in left lateral decubitus
What is the pattern of mitral stenosis murmur?
Mid-DIASTOLIC, low pitched murmur that starts after S2 and ends before S1
What is the pattern of aortic stenosis murmur?
Mid-SYSTOLIC ejection murmur that starts after S1 and ends before S2. Crescendo-decrescendo pattern.
What is the pattern of pulmonic regurge murmur?
Early diastolic murmur.
Crescendo-decrescendo config. May increase in intensity during inspiration.
High-pitched blowing sound over 2nd and 3rd intercostal spaces.
What does deficiency of LPL cause?
Familial chylomicronemia
- LPL binds chylomicrons and releases FFAs into tissues
- Without LPL, body cannot hydrolyze chylomicrons or release lipid loads
Symptoms:
- Acute pancreatitis
- Lipemia retinalis (milky retinal vasculature)
- Eruptive xanthomas
- Not at increased risk for premature CAD!
What does deficiency/defects of LDL receptor cause?
Familial hypercholesterolemia
- Defects in LDL receptor or its ApoB-100 ligand
- Super elevated LDL
Sx:
- Ischemic chest pain
- Tendon xanthomas
- Xanthalesmas
- High risk for accelrated CAD
What pathologic processes are associated with an S3?
- Forceful, rapid filling of ventricle that has normal or elevated compliance
- Normal or even decreased filling rate when ventricular compliance is low
- Blood flowing into an overfilled ventricle with high end-systolic volume
Basically, associated with left ventricular systolic failure.
What is a contraindication for ACEI?
Bilateral renal artery stenosis or unilateral with only 1 fx kidney
- Need ACE mediated efferent arteriolar constriction to maintain renal perfusion and GFR
What are the signs of Digitalis toxicity?
Hyperkalemia
Bradycardia
What is the Kussmaul sign?
JVP usually drops during inspiration, but it rises paradoxically in patients with constrictive pericarditis.
This is because the volume-restricted Rv is unable to accommodate the inspiratory increase in venous return.
What is a side effect of varicose veins?
Skin ulcerations!
Also painful thromboses, stasis dermatitis, poor wound healing, superficial infections
What is phelgmasia alba dolens?
“Painful white leg” or “milk leg” result of iliofemoral venous thrombosis
- Occurs in peripartum women
- Pregnancy predisposes to DVT because of pressure of the gravid uterus on deep pelvic veins
- Also increased hyeprcoagulability
What is the greatest risk factor for aortic dissection?
Hypertension is the single most important risk factor for the development of intimal tears leading to aortic dissection.
What is the genetic cause of HCM?
AD mutations in cardiac sarcomere proteins
- Mostly a single point missense mutation in the genes for beta-myosin heavy chain.
The dystrophin gene is associated with DCM.
What are signs specific to left heart failure?
Orthopnea
- Supine dyspnea relieved by sitting up (Because of lung congestion)
Productive cough, wheezing, chest tightness (nonspecific)
What are signs specific to right heart failure?
Bilateral lower extremity edema
Congestive hepatomegaly
What kind of drug is dofetilide?
Class III antiarrhythmic that blocks K efflux from cardiac myocytes and prolongs phase 3 of the mycoyte AP
In AFib, what determines the number of atrial impulses that reach the ventricle?
AV node refractory period
In AFib, the AV node is stimulated a lot. Each time it’s excited, it enters a refractory period in which additional atrial impulses are not transmitted to the ventricles. So the majority of atrial impulses do not reach the ventricles.
What does the PR interval on the EKG correspond to in terms of depolarization?
The time between atrial depolarization and ventricular depolarization.
How do beta blockers affect the EKG?
They prolong the PR interval because they slow AV conduction (increasing the time between atrial depol and ventricular depol).
What is the most common cause of death in acute rheumatic fever?
Severe myocarditis.
Death due to ARF is rare.
- ARF occurs 10 days - 6 weeks post Strep pharyngitis
- 3% of patients get ARF
- 1% of those with ARF die from it
What are 3 factors that distinguish heart circulation from blood flow to skeletal muscle and viscera?
- Volume: heart muscle consumes 5% of cardiac output (a lot!)
- Local regulation by metabolic factors (like hypoxia and adenosine)
- Diastolic perfusion
VoLoDiasto
What does pulsus alternans indicate?
Left ventricular dysfunction
Beat to beat variation in the magnitude of pulse pressure
What does dicrotic pulse indicate?
Severe systolic dysfunction
The pulse has two distinct peaks, one during systole, another during diastole
What does pulsus parvus et tardus indicate?
Aortic stenosis
Pulse of low magnitude with delayed peak
What does a hyperkinetic pulse indicate?
Rapid ejection of large stroke volume against decreased afterload
- Exercise in normal subjects
- High output conditions (PDA, AV fistula)
What is pulsus paradoxus associated with?
Cardiac tamponade
Decrease in systolic BP of 10mmHg or more during inspiration
(Radial pulse disappears on inspiration)
What is the effect of nitroprusside?
Balanced venous and arterial vasodilator
- Decreases preload
- Decreases afterload