Rhythm Flashcards
All automaticity foci pace with
A regular rhythm
Sinus arrhythmia represents normal, minimal variations in the SA nodes pacing rate in association with the phases of
Respiration
The atrial conduction system consists of 4 tracts
3 internodal right atrial tracts (anterior, middle, posterior) and one tract known as bachmanns bundle that innervates the left atrium
The slowed conduction through the AV node produces a
Pause on the EKG between the P wave and the QRS
The final phase of purkinje repolarization may record a small hump following the T wave on the EKG known as
A U wave
Irregular atrial rhythms are usually cause by
Multiple active atrial automaticity sites
Wandering pacemaker is from pacemaker activity wandering from the SA node to nearby atrial automaticity foci and causes
Irregular rhythm, p wave shape variations, atrial rate less than 100
Multifocal atrial tachycardia is a rhythm of patients with COPD and causes
Irregular rhythm, p wave shape variations, HR exceeds 100 bpm
Atrial fibrillation is caused by rapid firing of multiple atrial foci, and only an occasional random foci Rachel the AV node to be conducted to the ventricles is causes
Irregular rhythm, continuous chaotic atrial spikes, irregular ventricular rhythm
An automaticity focus that escapes overdrive suppression to pace at its inherent rate
Escape rhythm
An automaticity focus transiently escape overdrive suppression to emit one beat
Escape beat
When in sinus arrest an atrial focus quickly escapes overdrive suppression to become the dominant pacemaker at its inherent rate
Atrial escape rhythm
With absent regular pacing stimuli from above, an automaticity focus in the AV junction may escape overdrive suppression to become an active pacemaker
Junctions escape rhythm
A junctional automaticity focus may cause retrograde atrial depolarization causing
Retrograde p wave immediately before QRS, retrograde p wave after each QRS, retrograde p wave buried within each QRS
A ventricular automaticity focus is not regularly stimulated by paced depolarization from above causing
Ventricular escape rhythm
Pacing from a ventricular focus is often so slow that blood flow to the brain is significantly reduced causing unconsciousness. This is called
Stokes- Adams syndrome
One missed pacing cycle is known as a
Transient sinus block
A sinus block with an atrial automaticity focus is known as an
Atrial escape beat
A sinus block with a junctional automaticity focus is known as
A junctional escape beat
A sinus block with a ventricular automaticity focus is known as a
Ventricular escape beat
An irritable focus spontaneously fires a single stimulus known as
A premature beat
Ventricular automaticity are the worlds most sensitive sensors of…
Low O2
Atrial and junctional foci become irritable because …
Epinephrine released by adrenal glands,
increased sympathetic stimulation, presence of caffeine, amphetamines, cocaine
Excess digitalis, some toxins occasionally etoh
Hyperthyroid
Stretch
An irritable atrial automaticity focus, producing a p wave earlier than expected
Premature atrial beat
If a premature atrial beat reaches the SA node it is depolarized as well the SA node will then…
Reset itself to a new rhythm with the PAB being the first beat of the new rhythm
An aberrant ventricular contraction is created sometimes with a PAB because ..
One of the ventricles is not completely repolarized and therefore temporarily unable to be depolarized causing a widened QRS
When the AV node is completely unreceptive to premature atrial depolarization causes
A nonconducted premature atrial beat
A premature atrial beat after every normal beat
Atrial bigeminy
A premature atrial beat after two normal cycles is
Atrial trigeminy
When an irritable automaticity focus in the AV junction suddenly fires a premature stimulus that depolarized the ventricles
Premature junctional beat
A ventricular focus can be made irritable by
Low O2
Low K
Pathology- mitral valve prolapse, stretch, myocarditis
An irritable ventricular automaticity focus that produces giant complexes on EKG
Premature ventricular contraction
The most likely reason for a ventricular automaticity focus to become irritable is
Under-oxygenation
How many PVCs per minute is considered pathological?
6
A ventricular automaticity focus that suffers from entrance block (is not irritable) so it paces at its inherent rate
Ventricular parasystole
A run of 3 or more PVCs in rapid succession is really a run of
Ventricular tachycardia
Each irritable focus produces its own
Distinctive looking PVC
What causes PVCs, including runs of VT and multifocal PVCs but is considered a benign condition
Mitral valve prolapse
Paroxysmal means
Sudden
Rapid rate with more than one p wave for every QRS
Paroxysmal atrial tachycardia with AV block
A continuous reentry circuit develops which includes the AV node and lower atria and rapidly paces the atria and ventricles
AV nodal reentry tachycardia
Paroxysmal Supra ventricular tachycardia
A very irritable automaticity focus that originates above the ventricles
A very irritable ventricular focus that suddenly paces in 150-250 bpm with a characteristic pattern of enormous, consecutive PVC like complexes
Paroxysmal ventricular tachycardia
The QRS in SVT even if widened by aberrant ventricular conduction is usually
0.14 sec or less
Ventricular complexes in VT are very wide
Greater than .14 sec
A single ventricular automaticity focus firing to produce smooth sine-waves or similar amplitude
Ventricular flutter
Multiple focus discharging rapidly
Fibrillation
An abnormal, accessory AV conduction which can short circuit the usual delay of ventricular conduction in the AV node
Bundle of Kent
The AV node is bypassed by an extension of the anterior internodal tract by passing the conduction delay by the James bundle in this syndrome
Lown-ganong- Levine syndrome
