Patients with antitachycardia pacemakers and automatic implantable defibrillators may not dive.
Patients with pacemakers implanted for treatment of bradyarrhythmias may dive under certain circumstances.
(a) Since implantation of the pacemaker the patient should have been free of cardiac symptoms – notably syncope, dizziness, chest pain and inappropriate dyspnoea.
(b) The patient should be free of significant cardiac disease other than sinus or atrioventricular node disease. There should be no suggestion of significant coronary artery disease, valvular disease or cardiomyopathy.
(c) The patient should be able to mount an appropriate response to exercise, i.e. should usually be able to achieve a heart rate of 80% of (220 minus age in years) and at least 9 minutes (3 stages) of the Bruce protocol (or equivalent).
(d) Pacemaker implantation should not have caused any other contraindication to diving, e.g. serious lung damage during subclavian vein puncture.
(e) The pacemaker should be a modern resin filled pacemaker rather than a gas filled model which could result in pacemaker compression at depth.
(f) The pacemaker should have been tested under hyperbaric conditions to ensure reliability.
(g)The depth limit for the diver should be set at 10 metres shallower than the manufacturer’s tested pressure or depth rating on the pacemaker model.
Kratz JM, Blackburn JG, Leman RB, Crawford FA. Cardiac pacing under hyperbaric conditions. Annals Thoracic Surg 1983; 36: 66-8.