There are three pathological irregular rhythms:
- ectopic beats - these may be atrial, junctional or ventricular
- atrial or ventricular ectopics - 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
- atrial fibrillation
- suggested by: irregularly irregular pulse. Confirmed by: ECG showing no P waves, and irregularly irregular normal QRS complexes
- second degree heart block
Examples of causes of irregularly irregular rhythms include:
- atrial or ventricular ectopics
- atrial fibrillation
- note that atrial flutter with variable heart block might also present with an irregularly irregular pulse
- suggested by: irregularly irregular pulse. Confirmed by: ECG showing 'saw tooth' pattern, and irregularly irregular normal QRS complexes
Examples of causes of regularly irregular rhythms include:
- sinus arrhythmia
- second degree heart block
- Wenkenbach heart block- 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
For more information about Supraventricular Arrhythmias and example ECGs then click here
For more information about Ventricular Arrhythmias and example ECGs then click here