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