Arrhythmia

A monitor can show a dramatic rhythm while perfusion is intact, or a slower rhythm can quietly reduce cardiac output. Recognition therefore starts with the patient, not the monitor: determine whether a pulse is present, whether perfusion is adequate, and whether symptoms are caused by the rhythm. Hypotension, acute mental-status change, shock, ischemic chest discomfort, or acute heart failure turns rhythm identification into an immediate resuscitation problem. When perfusion is stable, classify the rhythm by its origin, ventricular rate, regularity, and QRS width. Then ask whether it is the cause of the patient's deterioration or a response to hypoxia, ischemia, sepsis, acid-base disturbance, electrolyte abnormality, or a drug effect. That distinction prevents an antiarrhythmic from being used to mask a reversible physiological problem. The practical model is simple: identify the electrical pattern, connect it to mechanical perfusion, correct the substrate, and escalate according to risk.