Cardiology Rhythms Flashcards
Sinus bradycardia
Slower than 60 Bpm
All p waves are identical
All PR intervals are identical
Sinus Tachycardia
Faster than 100 Bpm
All p waves are identical
All PR intervals are identical
Sinus Arrhythmia
Can have a normal rate, a brady or tachy rate
All p waves are identical
All PR intervals are identical
Irregular heart rate.
What do all sinus rhythms have in common?
They all originate from the SA node
Cycle 1 of the heart
Majority of the heart is at rest. SA node is preparing to depolarize
Cycle 2 of the heart
SA node has fired and the signal is being spread through the intermodal pathways on the way to the AV node
cycle 3 of the heart
Right atria has depolarizer and the signal has reached the AV node
Cycle four of the heart
Both atria have depolarized completely. SA node and surrounding area have begun to depolarize.
Cycle 5 of the heart
Depolarization of the left atria is almost complete and repolarization of the right atria is happening
Normal PR interval time
0.12 - 0.2 seconds
What is a sign of a Sinus Block?
The cadence of the rhythm will remain the same and continues to fire on schedule.
In a sinus block what is never present?
P wave
What is a sinus pause?
It is a caused delay in the formation of a sinus impulse in the sinus node itself.
What is a tall tale sign of a sinus pause?
The cadence of the rhythm can possibly reset. They never have an exact multiple of normal P - P intervals.
What is the rule of thumb when trying to asses a Block between a pause?
Pause = 3x time shorter than the P-P Block = 3x longer than the P-P
What is normally the regularity with Sinus Arrhythmia?
Regular with events
What is a Premature Atrial Contraction?
PAC refers to an impulse or complex that occurs earlier than expected and originates in an atrial focus, not in the SA node.
Normal Sinus Rhythm
60 - 100 Bpm
All p waves are identical
All PR intervals are identical
Regular heart rate
1st Degree AV Block
Prolonged PR interval longer than .2 which is one big box
2nd Degree AV Block (Wenckebach) (mobitz II)
In which the PR interval become progressively longer until AV node is not penetrated (No QRS).
The PR interval become gradually longer from cycle to cycle until the final P wave doesn’t elicit a response.
1st Degree AV Block
Prolonged PR interval longer than .2 which is one big box
2nd Degree AV Block (Wenckebach) (mobitz II)
In which the PR interval become progressively longer until AV node is not penetrated (No QRS).
The PR interval become gradually longer from cycle to cycle until the final P wave doesn’t elicit a response.
