Cardiovascular Disorders Flashcards
acute hypoxemia on ECMO; 3 possibilities
- patient
- MV
- ECMO circuit
acute hypoxemia on ECMO if it’s the ECMO circuit
- large clot in oxygenator
- poor O2 source
- significant recirculation
indications for surgery for tricuspid endocarditis
- failure of medical therapy (persistent bacteremia or enlarging vegetation)
- large vegetation, > 1 cm
- fungal endocarditis
- HF d/t TR
when should you worry about fungal endocarditis in IVDU?
delayed growth of Candida species in BCs
causes of dampened (smooth contours) arterial line waveform
- air bubbles
- catheter kinking
- tubing kinking
- intraluminal thrombus
what is a distinguishing feature of a properly functioning arterial line system?
presence of 1-3 beats of pressure overshoot or oscillation
four phases of myocyte action potential
- phase 4 (repolarization) = resting potential
- phase 0 (rapid depolarization) = Na+ influx
- phase 1 = K+ efflux
- phase 2 (plateau) = Ca++ influx
- phase 3 (repolarization) = K+ efflux
- phase 4 (repolarization) = resting potential
arrhythmias are initiated and maintained by what 3 main mechanisms?
- automaticity
- afterdepolarizations
- reentry
which arrhythmias are a/w automaticity?
- sinus tachycardia
- atrial premature complexes
- some atrial tachycardias
afterdepolarizations are a/w an increase in cellular
Ca++ accumulation
afterdepolarizations are a/w an increase in cellular Ca++ accumulation, leading to what?
repeated myocardial depolarization
- EADs if between phase 2 and phase 3 of the action potential (prolongs action potential and QT on ECG)
- DADs if between phase 3 and phase 4 of the action potential
which arrhythmia may be related to early afterdepolarization?
initiation of torsades de pointes
which arrhythmias may be related to delayed afterdepolarization?
- digoxin toxicity
- catecholamine-induced ventricular tachycardia
which arrhythmias are a result of reentry?
most supraventricular and ventricular tachycardias
class 1 antiarrhythmics
- work on what phase of the action potential
- block what channel
- phase 0
- Na+ channel blocker
what are the class 1A antiarrhythmics?
- quinidine
- procainamide
- disopyramide
when are the class 1A antiarrhythmics used?
- AF
- AFl
- SVT
- ventricular tachyarrhythmias (VTs)
what are the class 1B antiarrhythmics?
- lidocaine
- tocainide
- mexiletine
when are the class 1B antiarrhythmics used?
VTs
what are the class 1C antiarrhythmics?
- flecainide
- propafenone
- moricizine
when are the class 1C antiarrhythmics used?
life-threatening SVT and VTs
quinidine distinguishing characteristic
moderate anticholinergic
quinidine AEs
- cinchonism (blurred vision, tinnitus, headache, psychosis)
- cramping and nausea
- enhances digitalis toxicity
procainamide distinguishing characteristics
- weak anticholinergic
- relatively short half-life
procainamide AE
lupus-like syndrome (25-30%)
disopyramide distinguishing characteristic
strong anticholinergic
disopyramide AE
negative inotropic effect
lidocaine distinguishing characteristic
good efficacy in ischemic myocardium
tocainide distinguishing characteristic
orally active lidocaine analog
tocainide AE
pulmonary fibrosis
mexiletine distinguishing characteristic
- orally active lidocaine analog
- good efficacy in ischemic myocardium
flecainide used for
SVT
flecainide AE
can induce life-threatening VT
propafenone used for
SVT and VT
propafenone AE
can worsen HF d/t beta and Ca++ channel blockade
moricizine distinguishing characteristic
also has class 1B activity
what are the class 2 antiarrhythmics?
- nadolol
- propranolol
- sotalol
- timolol
- acebutolol
- atenolol
- betaxolol
- bisoprolol
- esmolol
- metoprolol
nadolol distinguishing characteristic
long acting
propranolol distinguishing characteristic
- membrane stabilizing activity
- prototypical beta-blocker
timolol distinguishing characteristic
primary used for glaucoma
acebutolol distinguishing characteristic
intrinsic sympathomimetic activity
betaxolol distinguishing characteristic
membrane stabilizing activity
esmolol distinguishing characteristic
ultra-short acting
metoprolol distinguishing characteristic
membrane stabilizing activity
class 3 antiarrhythmics
- work on what phase of the action potential
- block what channel
- phase 3
- K+ channels
what are the class 3 antiarrhythmics?
- amiodarone
- dronedarone
- bretylium
- sotalol
- ibutilide
- dofetilide
amiodarone therapeutic uses
- VT
- VF
- AF and AFl (off-label)
amiodarone distinguishing characteristic
- very long half-life (25-60 days)
- has class 1, 2, 3, and 4 activity
amiodarone AEs
- pulmonary fibrosis
- hypothyroidism
- bradycardia and AVB
dronedarone therapeutic uses
- AF (non-permanent)
- AFl
dronedarone distinguishing characteristic
- structurally related to amiodarone
- CI in severe or recently decompensated symptomatic HF
dronedarone AE
risk for severe liver injury
bretylium therapeutic uses
life-threatening VT and VF
bretylium distinguishing characteristic
initial sympathomimetic effect (NE release) followed by inhibition which can lead to hypotension
sotalol therapeutic uses
- VT
- AF
- AFl
sotalol distinguishing characteristic
also has class 2 activity
ibutilide therapeutic uses
- AF
- AFl
ibutilide AE
can cause life-threatening ventricular arrhythmias
dofetilide therapeutic uses
- AF
- AFl
dofetilide distinguishing characteristic
- very selective K+ channel blocker
dofetilide AE
can cause life-threatening ventricular arrhythmias
what are the class 4 antiarrhythmics?
- verapamil
- diltiazem
what are the 3 classes of CCBs?
- dihydropyridines
- phenylalkylamine (non-dihydropyridine)
- benzothiazepine (non-dihydropyridine)
what are the dihydropyridine CCBs?
- amlodipine
- felodipine
- isradipine
- nicardipine
- nifedipine
- nimodipine
- nitrendipine
which CCB is the phenylalkylamine class?
verapamil
which CCB is the benzothiazepine class?
diltiazem
how do CCBs work as antiarrhythmics?
- decrease firing rate of aberrant pacemaker sites w/i the heart
- decrease conduction velocity, especially at AV node
- prolong repolarization, especially at AV node
initial treatment of RV infarction
ivf w/o overdistention of RV
treatment of RV infarction if no improvement w/ ivf
inotrope
clinical findings of primary RCM
skeletal myopathy
What causes endomyocardial fibrosis (EMF)
h/o parasitic infestation, hematologic malignancy, or AI d/o
clinical findings of amyloidosis
- macroglossia
- periorbital ecchymosis
- orthostatic hypotension
clinical findings of drug-induced
h/o chloroquine or hydroxychloroquine use
What causes post-radiation RCM?
h/o mediastinal radiation
clinical findings of hemochromatosis
- hyperpigmentation
- liver failure
- DM
What causes Anderson-Fabry
reduced alpha-galactosidase
clinical findings of Danon/Pompe/PRKAG2
skeletal myopathy
clinical findings of Friedreich’s ataxia
- ataxia
- DM
clinical findings of constrictive pericarditis
- fluid overload; ranges from peripheral edema to anasarca
- decreased CO in response to exertion
if;
- fever
- AMS
- AF w/ RVR
- HF
after coronary angiography, consider what condition?
thyroid storm
Jod-Basedow syndrome
thyroid storm in a patient w/ subclinical hyperthyroidism precipitated by administration of iodinated contrast
clinical hallmarks of cardiac amyloidosis
- biventricular HF
- pAF
- carpal tunnel syndrome
3 main types of amyloidosis
- amyloid light-chain (AL) amyloidosis
- amyloid A (AA) amyloidosis
- amyloid transthyretin (ATTR) amyloidosis
AL amyloidosis diagnosis
measuring serum immunoglobulin light chains and finding a monoclonal spike
what test is highly sensitive for ATTR amyloidosis in the presence of HF w/ a compatible TTE?
technetium-labeled bone scintigraphy compared w/ the bone signal
what class of medications used to treat non-small cell lung cancer can cause myocarditis?
checkpoint inhibitors, eg pembrolizumab
how to distinguish between true aortic stenosis and pseudostenosis?
dobutamine stress test
if dobutamine increases CO and the aortic valve gradient is unchanged, then calculated valve area will INCREASE, indicating what?
pseudostenosis
if dobutamine increases CO and the aortic valve gradient increases PROPORTIONALLY, then what is confirmed?
true aortic stenosis
if dobutamine does NOT increase CO (that is, the patient lacks contractile reserve), the test is what?
indeterminate regarding the severity of aortic stenosis
if a dobutamine stress test is indeterminate regarding the severity of aortic stenosis, what does that mean regarding prognosis?
POOR prognosis with or w/o valve replacement
what test is contraindicated in the presence of critical aortic stenosis?
exercise stress testing
dipyridamole administration w/ myocardial perfusion imaging may be used to diagnose what?
myocardial ischemia
is TEE good at evaluating AS?
no
how is aortic valve gradient calculated?
flow/AVA
- AVA = aortic valve area
what tachyarrhythmia should be considered when these 3 criteria are present?
- wide complex tachyarrhythmia
- irregularly irregular rhythm
- varying widths of QRS complexes
preexcited AF or AF in a patient w/ an accessory conduction pathway AKA WPW syndrome
patients w/ WPW syndrome have an accessory conduction pathway that directly connects what to what?
atria w/ ventricles and bypasses the AV node