Bradyarrhythmias

Overview of sinus node dysfunction

Sinus Bradycardia

Regular RR interval with normal PR interval and normal axis

Sinus Arrhythmia

Irregular PP / RR intervals, otherwise sinus rhythm

Sinus Arrest

No P waves or QRS complexes for >3 seconds, with or without an escape rhythm

Sinoatrial Exit Block

Missed P waves due to delayed sinoatrial conduction

Tachy-Brady Syndrome

Alternating bradycardia and supraventricular tachycardia

Atrial Fibrillation with Slow Ventricular Response

Reduced transmission of fibrillatory waves due to defective conduction

Atrial Flutter with Variable Block

Sawtooth flutter waves with irregular ventricular rhythm

Atrial Escape Rhythm

Ventricular rate <60bpm with abnormal P waves

Atrioventricular (AV) Block

Missed P waves due to delayed sinoatrial conduction

Junctional Escape Rhythm

Narrow QRS complexes without P waves at 40-60bpm

Ventricular Escape Rhythm

Wide complexes at <40bpm with dissociated or absent P waves