Pulse irregular

Main differential diagnoses and typical outline evidence

Atrial fibrillation caused by ischaemic heart disease, thyrotoxicosis, etc.	Suggested by: irregularly irregular pulse.
	Confirmed by: ECG showing no P waves, and irregularly irregular normal QRS complexes.
	Management: OHCM p130.
Atrial flutter with variable heart block caused by ischaemic heart disease, etc.	Suggested by: irregularly irregular pulse.
	Confirmed by: ECG showing ‘saw tooth’ F waves, and irregularly irregular normal QRS complexes.
	Management: OHCM p130.
Atrial or ventricular ectopics caused by ischaemic heart disease, etc.	Suggested by: regular rate with irregular dropped beat.
	Confirmed by: ECG showing normal sinus rhythm with irregular QRS complexes not preceded by P wave, and then compensatory absence of subsequent QRS.
	Management: OHCM p132.
Wenkenbach heart block caused by ischaemic heart disease, etc.	Suggested by: regular rate with regular dropped beat.
	Confirmed by: ECG showing progressive prolongation of P-R interval with normal QRS complex followed by an absent QRS complex.