What rhythms have no P waves?

A junctional rhythm is characterized by QRS complexes of morphology identical to that of sinus rhythm without preceding P waves.

Absence of P waves suggests either. No normal atrial depolarization , e.g., atrial fibrillation, atrial standstill. The P waves are hidden within the QRS complexes, e.g., ventricular tachycardia, junctional tachycardia.

This is because the P waves (flutter waves) in atrial flutter occur at about 250-350 per minute (usually around 300) . At this rate, it can appear that there is a P wave in front of each QRS and a T wave after each QRS.15 Kas 2016

A lack of visible P waves preceding QRS complexes suggests a lack of sinus beats; this may occur with sinus dysfunction or in the presence of fibrillation or flutter waves. The P wave may also be hidden within the QRS complex. … Absence of P Waves. AtriaVentriclesAtrial FlutterRegular ~300bpmRegular ~150bpmThe P Wave | ECG Basics – MedSchool medschool.co › Investigations › ECG Basics