Tachyarrhythmias
For an abnormal-origin tachyarrhythmia, first decide whether there is a pulse, then whether life-threatening adverse signs make the patient unstable; only a stable patient proceeds to classification by QRS width and regularity, while sinus tachycardia is treated by correcting its cause.
Definition
Tachyarrhythmias are abnormal fast cardiac rhythms arising from atrial, atrioventricular-junctional or ventricular mechanisms. The acute framework applies to abnormal-origin rhythms and separates cardiac arrest, unstable tachyarrhythmia with a pulse and stable ECG branches; sinus tachycardia is a response to an underlying driver and is managed by treating that driver.
First principles
This is a peri-arrest decision framework, not a rate threshold
The Resuscitation Council UK algorithm addresses tachyarrhythmias of abnormal origin that may require immediate rhythm treatment. It does not apply to sinus tachycardia, where fever, pain, hypovolaemia, hypoxia, sepsis, pulmonary embolism, thyrotoxicosis or another driver should be treated rather than trying to normalise the heart rate with an antiarrhythmic drug or cardioversion.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.