ABSTRACT
What are the causes of intra-operative tachyarrythmias?
Patient factors: All patients undergoing anaesthesia and surgery are at risk of intra-operative arrhythmias. However, certain patients are at increased risk:
Pre-existing cardiac disease, e.g. ischaemic heart disease or valvular heart disease
Pre-existing arrhythmia, e.g. atrial fibrillation or Wolff–Parkinson–White syndrome
Pre-existing electrolyte disturbances, e.g. diuretic-induced hypokalaemia and hypomagnesaemia
Endocrine disease, e.g. thyrotoxicosis.
Anaesthetic factors: General and regional anaesthetic techniques can have significant effects on cardiac function:
Drug-induced alteration in cardiac preload, contractility and afterload
Effects on coronary perfusion pressure
Effects on myocardial irritability
Effects on autonomic nervous system
Effects of hypoxia and hypercapnia
Electrolyte disturbances (either pre-existing or iatrogenic from fluid therapy)
Effects of intravascular devices (e.g. central venous lines) advanced too far and entering the right atrium
Surgical factors:
Effects of pneumoperitoneum related to laparoscopic surgery, e.g. vagal response, reduced venous return, fall in cardiac index or rise in SVR
Effects of hypercapnia related to laparoscopic surgery, e.g. arrhythmias
Effects of rapid fluid shifts
Systemic inflammatory response syndrome (SIRS) induced by tissue trauma