Relias Dysrhythmia Basic A – Essential Cardiac Rhythm Concepts for Medical & Nursing Exams, 2026

RELIAS DYSRHYTHMIA BASIC A, ESSENTIAL CARDIAC RHYTHM
CONCEPTS FOR MEDICAL & NURSING EXAMS (2026 UPDATE)
Normal sinus rhythm - Regular

Rate: 60-100

P Wave: Present, upright

PR Interval: 0.12-0.20 sec

QRS: <0.12 sec



Sinus Bradycardia - Regular

Rate: <60

P Wave: Present, upright

PR Interval: 0.12-0.20 sec

QRS: <0.12 sec



Sinus Tachycardia - Regular

Rate: 100-150

P Wave: Present, upright

PR Interval: 0.12-0.20 sec

QRS: <0.12 sec



Premature Atrial Contraction - IRREGULAR

Rate: depends on underlying rhythm

P wave: Present or hidden in T wave

PR Interval: 0.12-0.20 sec

QRS: <0.12 sec

, Atrial Fibrillation - IRREGULAR

Atrial rate: UNMEASURABLE

Ventricular rate: variable

P wave: unable to see

PR Interval: N/A

QRS: <0.12 sec



A fib RVR - IRREGULAR

Ventricular rate: 100-175

P wave: unable to see

PR Interval: N/A

QRS <0.12 sec



Atrial Flutter - Usually REGULAR can be irregular

Atrial rate: 250-350

Ventricular rate: variable BUT < atrial rate

P Wave: Flutter

PR Interval: N/A

QRS: <0.12 sec



Supraventricular Tachycardia - Regular

Rate: 150-350

P wave: Hidden in QRS or T wave

PR: unable to determine

QRS: <0.12 sec