EKG - Rhythms (part 1)

basic sinus (SA node) rhythms

P-waves upright in leads I, II, III, and aVF

most common AV conduction in AFlutter

2:1 (A-rate 300 and V-rate 150)

Atrial Fibrillation (AFib) with a controlled response

AFib with rate 70-110 bpm

Atrial Fibrillation (AFib) with a slow ventricular response

AFib with rate <60 bpm

Atrial Fibrillation (AFib) with a rapid ventricular response

AFib with rate >120 bpm

junctional rhythms

AV nodal rhythms with either a negative "retrograde" P wave (PR <0.12), no P wave (hidden in QRS), or P after QRS

escape beats

QRS occurs after expected

premature beats

QRS occurs before expected

when thinking of accelerated junctional rhythm, think ...

digitalis toxicity

supraventricular arrhythmias

electrical impulse originates at or above the AV node

AV Nodal Reentry Tachycardia (AVNRT)

impulse continues to circulate within the AV node until reentry pathway is interrupted OR stops spontaneously

"sawtooth" "F waves" are best seen in which leads?

inferior (II, III, aVF) and V1

calculate atrial rate

number of P waves in one minute or number of P waves x10 in a six second strip

calculate ventricular rate

number of QRS complexes in one minute or number of QRS x10 in a six second strip

Paroxysmal Supraventricular Tachycardia (PSVT)

rate - 150-240 bpm rhythm - regular P waves - ? (most of the time, the retrograde P wave is not seen because it is hidden within the QRS) P:QRS ratio - ? PR interval - ? QRS width - narrow AKA - paroxysmal atrial tachycardia (PAT)

Junctional Rhythm (JR)

rate - 40-60 bpm rhythm - regular P waves - variable (Before, During, or After) QRS P:QRS ratio - none OR 1:1 if before QRS PR interval - none OR short if before QRS QRS width - normal escape beat because the SA node was delayed or failed

Wandering Atrial Pacemaker (WAP)

rate - 60-100 bpm rhythm - irregularly irregular P waves - AT LEAST 3 DIFFERENT MORPHOLOGIES P:QRS ratio - 1:1 PR interval - variable depending on focus (because the P waves vary) QRS width - normal

Accelerated Junctional Rhythm (AJR)

rate - 60-100 bpm rhythm - regular P waves - during QRS P:QRS ratio - none OR 1:1 if before QRS PR interval - none OR short if before QRS QRS width - normal

Normal Sinus Rhythm (NSR)

rate - 60-100 bpm rhythm - regular P waves - upright P wave in lead II P:QRS ratio - 1:1 PR interval - normal (0.12-0.20 sec) QRS width - normal (0.04-0.10 sec)

Sinus Arrhythmia (SA)

rate - 60-100 bpm rhythm - varies with respiration (normal variant) by at least 0.08-0.12 sec (2-3 little boxes) P waves - upright P wave in lead II P:QRS ratio - 1:1 PR interval - normal (0.12-0.20 sec) QRS width - normal (0.04-0.10 sec)

Atrial Flutter (AFlutter)

rate - atrial commonly 250-350 bpm, ventricular commonly 125-175 bpm rhythm - usually regular P waves - "sawtooth" "F waves" P:QRS ratio - variable, most commonly 2:1 (A-rate 300 and V-rate 150) PR interval - variable QRS width - normal

Premature Junctional Contraction (PJC)

rate - depending on underlying rhythm rhythm - irregular P waves - variable (Before, During, or After) QRS P:QRS ratio - none OR 1:1 if before QRS PR interval - none OR short if before QRS QRS width - normal grouping - usually none

Premature Atrial Contraction (PAC)

rate - depending on underlying sinus rate rhythm - irregular P waves - P-wave may be a different shape or hidden in T-wave P:QRS ratio - 1:1 PR interval - varies in PAC QRS width - normal grouping - sometimes non-compensatory pause - sinus rhythm returns "out of sync" after PAC

Junctional Escape Beat

rate - depends on underlying rhythm rhythm - irregular (occurs after the expected beat) P waves - variable (Before, During, or After) QRS P:QRS ratio - none OR 1:1 if before QRS PR interval - none OR short if before QRS QRS width - normal dropped beats - yes

Sinus Bradycardia (SB)

rate - less than 60 bpm rhythm - regular P waves - upright P wave in lead II P:QRS ratio - 1:1 PR interval - normal to prolonged QRS width - normal to prolonged

Multifocal Atrial Tachycardia (MAT)

rate - more than 100 bpm rhythm - irregularly irregular P waves - AT LEAST 3 DIFFERENT MORPHOLOGIES P:QRS ratio - 1:1 PR interval - variable QRS width - normal

Ectopic Atrial Tachycardia (EAT)

rate - more than 100 bpm rhythm - irregularly irregular P waves - ectopic focus morphology different (negative/inverted P-wave in leads I, II, III, or aVF, than not from SA node) P:QRS ratio - 1:1 PR interval - ectopic focus has different interval (>0.12 sec) QRS width - normal, but aberrant at times

Sinus Tachycardia (ST)

rate - more than 100 bpm rhythm - regular P waves - upright P wave in lead II P:QRS ratio - 1:1 PR interval - normal to short QRS width - normal to short

Junctional Tachycardia (JT)

rate - over 100 bpm rhythm - regular P waves - variable (Before, During, or After) QRS P:QRS ratio - none OR 1:1 if before QRS PR interval - none OR short if before QRS QRS width - normal

Atrial Fibrillation (AFib)

rate - variable, ventricular response can be fast or slow rhythm - IRREGULARLY IRREGULAR P waves - none (chaotic atrial activity, no distinct P-waves) P:QRS ratio - none PR interval - none QRS width - normal (0.04-0.10 sec)

respiratory variation in sinus arrhythmia

slightly irregular rate, usually related to breathing...when you inhale, the rate goes up and when you exhale, the rate goes down

common causes of regular SVT

• Sinus Tachycardia (but you can't see P wave) • Atrial Flutter (but you can't see P wave) • PSVT (AV nodal reentry tachycardia)