cardiac action potential
Depolarization
na+ rushes in, membrane potential rises sharply
calcium
contraction
blocked by verapamil and diltiazem
venticles
where bundle of his bifurcates, cells occasionally demonstrate automaticity, acts as pacemaker if no impulse from sa or av nodes at rate 20-40 bpm
a-fib causes
Pulmonary conditions, post op
Ischemic heart disease, IV central line
Rheumatic heart disease
Anemia, alchohol, age
Thyroid disease
Elevated BP, electrocution
Sleep apnea, surgury, sepsis
left sided
pulmonary congestion
early repolarization
k+ leaves breifly, small drop in membrane potential. cl out
sodium
depolarization
p- wave
atrial depolarization
adult tachyarythmias with a pulse
is it causing hypotension altered mental status, signs of shock, ischemic chest discomfort, acute heart failure
yes
-synchronized cardioversionno but wide qrs yes
-adenosine
right sided
systemic dysfunction
plateau
ca2+ enters, so k+ left but ca in so balance
potassium
repolarization
pr interval
depolarization of right and left atria and impulse delay through the av node
should be 0.12-0.20 seconds long
meds for rate controlled chronic a-fib
beta blockers (-olol)
calcium channel blockers( verapamil, diltiazem)
digoxin
systolic dysfunction
impaired contractility
thin weak heart muscle
low ejection fracture
chronic hypertension
ischemic heart disease
dilated cardiomyopathy
repolarization
k+ leaves the cell, membrane potential falls
sa node
pacemaker of heart, spontansously generate impulses at 60-100 bpm
qrs complex
ventricular depolarization
should be <0.10 seconds
meds for rhythm control, new onset a-fib
amiodarone, electric cardioversion
diastolic dyscfunction
imapaired filling/relaxation
stiff/think heart muscle
s4 gallop
normal ejection fracture
resting state
stable resting potential ready for next impulse
av node
gatekeeping between atria and ventricles, impulse is delyaed at av node to allow atrial kick and prevents extra impulse from getting through
the t wave
late ventricular repolarization
ventricular tachycardia
Toxic drugs
Rythm disturbances
Ischemia/infarction
Cardiomyopathy
Y sYndromes
Cardiovascular surgury
Low ejection fracture
Electlye abnormalities