EKG review: Arrhythmia rules

Rhythms: sinus, atrial, junctional, ventricular, paced, heart blocks

Sinus exit block

absence of cardiac cycle(s); P-P intervals still march out across the rhythm once activity resumes

Sinus pause

absence of cardiac cycles(s); P-P intervals will not march out across rhythm strip due to SA node restarting

Sinus arrest

absence of at least 3 cardiac cycles; P-P intervals will not march out across the rhythm strip due to SA node restarting

normal sinus rhythm

RRR, intervals map out evenly

sinus bradycardia

regular rhythm, HR < 60

sinus tachycardia

regular rhythm; HR > 100

sinus arrhythmia

benign variation in beat intervals; regular rate, irregular rhythm

premature atrial complex (PAC)

arrive early in the cardiac cycle → longer PR; have different morphologies than normal waves

wandering atrial pacemaker (WAP)

pacemaker site shifts → at least 3 different P wave morphologies

multifocal atrial pacemaker (MAT)

pacemaker site shifts → at least 3 different P wave morphologies ; HR > 100

atrial flutter (A-flutter)

sawtooth pattern; no P waves; irregular

atrial fibrillation (A-fib)

no P waves; irregularly irregular, HR usually > 100;

AV nodal reentrant tachycardia (AVNRT) (SVT)

regular, narrow, HR >100 (usually >150); no P or retrograde P waves

Premature junctional complex (PJC)

early in the cardiac cycle; no P, inverted P, or post-QRS P wave

Junctional escape beat (JEB)

late in the cardiac cycle -where next R wave should’ve been; no P, inverted P, or post-QRS P wave

Junctional escape rhythm (Junctional rhythm)

regular rhythm; HR 40-60 bpm; no P, inverted P, or post-QRS P wave

Accelerated junctional rhythm

regular rhythm; HR 60-100 bpm; no P, inverted P, or post-QRS P wave

Junctional tachycardia

regular rhythm; HR >100 bpm; no P, inverted P, or post-QRS P wave

Premature ventricular complex (PVC)

early in the cardiac cycle; R on T; wide QRS; can be grouped

Ventricular escape complex

come late in the cardiac cycle, past when next expected R wave; wide QRS

Idioventricular rhythm (IVR)

regular, HR 20-40, wide QRS, no P waves

Accelerated idioventricular rhythm

regular, HR 40-100, wide QRS, no P waves

ventricular tachycardia (V-tach)

regular, wide; HR >100; no P; can be polymorphic or monomorphic

ventricular fibrillation (V-fib)

irregular; no P waves, QRS complexes, or T waves

asystole

flat line, no pulse; lack of electrical activity

ventricular standstill

P waves only; can be present in paroxysmal episdoes

atrial paced

pacer spike followed by normal PQRST cycle

ventricular paced

pacer spike followed by a wide QRS complex and contralateral T wave

AV paced

pacer spike preceding P wave; 2nd pacer spike followed by a wide QRS and contralateral T wave

First degree AV block

RRR, long PR interval (>0.2 sec)

2nd degree AV block Type 1 (Wenckebach)

irregular, increasing PR intervals followed by a dropped beat -cycle repeats

2nd degree AV block Type 2 (Mobitz II)

constant PR intervals, QRS usually wide; occasional dropped QRS complexes

3rd degree AV block (complete heart block)

regular R-R unrelated to regular P-P; P & QRS don’t line up