Dubin Flashcards
What binds to β1 receptors in the heart
Norepinephrine
What does NE binding to the heart do
Increase rate of SA node pacing
Increase rate of conduction
Increase force of contraction
The parasympathetic system acts on the heart via what nerve and what receptor
Vagus; cholinergic
The parasympathetic system does what to the heart
Decreases rate of SA node pacing
Decreases rate of contraction
Decreases force of contraction
What receptor and system is responsible for constricting arteries
α1; sympathetic and it is more sensitive to NE
What effect does the constriction of arteries have on blood? What is responsible
Blood flow and pressure increase; α1 receptors and sympathetic system
What effect does vasodilation have on blood? What causes this
Decreases flow and pressure; parasympathetic system
Carotid massage and gag reflex may stimulate what response
Parasympathetic
Failure of sympathetic response to standing can cause what
Orthostatic hypotension followed by possible syncope
What is neurocardiogenic syncope
Standing for too long can cause a sympathetic response in the elderly in which peripheral vasoconstriction is inadequate -> contracting ventricles that are not filled cause parasympathetic response -> arteries dilate and BP drops
What can be used to confirm the diagnosis of neurocardiogenic syncope
HUT (head up tilt) test
What is the normal pacemaker and where is it located
SA node; posterior RA
What is normal HR? Above? Below?
60-100; tachycardia; bradycardia
When the SA node fails to fire and another pacemaker takes over, what is this pacemaker called
Ectopic pacemaker (they are the latent pacemakers)
Junctional pacemakers function at what rates
40-60 bpm
Ventricular pacemakers function at what rate
20-40 bpm
(Non SA nodal) atrial pacemakers function at what rate
60-80 bpm
What is the order of pacemakers used by the body if the SA node fails
Atrial->Junctional->Ventricular
“Sinus arrhythmia” is a normal but minimal increase in HR during ____________ and minimal decrease during ___________
Inspiration; expiration
What are the 4 tracts that leave the SA node? Which go to the AV node
Posterior internodal, middle internodal, anterior internodal, and bachmans to the LA; posterior, middle, and anterior
PR interval changes represent a change in what conduction area
Through the AV node
Wandering pacemaker arrhythmia manifests as changes to
The shape and direction of the p wave and rate less than 100
The multifocal atrial tachycardia is associated with changes in
P wave and a rate greater than 100
What other diseases are associated with multifocal atrial tachycardia
Digitalis toxicity and COPD patients
A-fib is shown by
Staticky periods between QRS complexes
Each atrial depolarization doesn’t necessarily lead to a QRS
Where do we look for a LBBB
V5-6
Where do we look for a RBBB
V1-2
Significant Q wave is a sign of
Necrosis
ST elevation is a sign of
Acute injury
T wave inversion is a sign of
Ischemia
Atrial hypertrophy is shown by
Biphasic P wave
R: initial component larger
L: final component larger
Delta wave is a sign of
WPW syndrome
RBBB is shown by
rSR’ in V1
qRs in V6
LBBB is shown by
rS in V1
R in V6
