Pacemakers in 2nd or 3rd degree heart block

• single lead ventricular pacing may be indicated if heart block occurring as brief episodes in patients usually in sinus rhythm
• dual chamber pacing is preferred in patients with chronic heart block
  • dual-chamber pacing and single-chamber atrial pacing (in patients with sick sinus syndrome without atrioventricular block), as opposed to single-chamber ventricular pacing, are considered to be ‘physiological’ pacing modes because AV synchrony is maintained and the frequency of contractions of the atria and ventricles varies with metabolic demand, mimicking the heart’s natural rhythm
  • dual-chamber pacing is recommended for the management of symptomatic bradycardia due to sick sinus syndrome, atrioventricular block, or a combination of sick sinus syndrome and atrioventricular block, except:
    • in the management of sick sinus syndrome in patients in whom, after full evaluation, there is no evidence of impaired atrioventricular conduction; in this situation, single-chamber atrial pacing is appropriate
    • in the management of atrioventricular block in patients with continuous atrial fibrillation; in this situation, single-chamber ventricular pacing is appropriate
    • in the management of atrioventricular block (atrioventricular block alone, or in combination with sick sinus syndrome), when patient-specific factors, such as frailty or the presence of comorbidities, influence the balance of risks and benefits in favour of single-chamber ventricular pacing

Reference:

1. NICE (February 2005).Dual-chamber pacemakers for symptomatic bradycardia due to sick sinus syndrome and/or atrioventricular block