Advantage of atrial rather than ventricular pacing

1. Physiological pacing

a) ‘Pacing the heart while maintaining the normal atrial ventricular activation sequence and a physiological heart rate similar to that of the SA node’

2. Ventricular pacing with the loss of AV synchrony has an adverse effect on haemodynamics which is more significant in the sick heart

a) Should be considered in all patients with pump failure requiring pacing

3. Ventricular (VVI) pacing problems:

a) Ventricular pacing wastes the atrial contribution to cardiac output

b) This may drop the cardiac output by 25% or more

c) Due to AV dissociation, or worse, retrograde conduction from ventricle to atria, the atrium may contract against closed AV valves with a consequent fall in blood pressure

i) There is a regurgitation of blood into the pulmonary veins with an increase in pulmonary capillary pressure and possibly pulmonary oedema

4. Dual pacing has been shown in practice to make a significant haemodynamic improvement