A B H I L A S H

SURGERY IN PATIENTS WITH ICD AND PACEMAKERS

• Interactions between the pacemaker and current generated by electrocautery.• Metabolic derangements, antiarrythmic agents

and anaesthetic agents on pacing and sensing thresholds.

EMI – ELECTROMAGNETIC INTERFERENCE

• Depends on the proximity of the ICD/ pacemaker.• Amount of current generated• Axis of the electrocautery and the pacemaker.

AFFECTS OF ELECTROCAUTERY ON THE ICD OR PACEMAKER

1) temporary or permanent resetting to a different pacing mode.2) temporary or permanent inhibition of pacemaker output; 3) an increase in pacing rate due to activation of the rate-responsive sensor; 4) ICD firing due to activation by electrical noise;

IMPACT TO THE PATIENT

• Depends on • patient is pacemaker dependent? • whether the pacemaker has unipolar or bipolar leads.• electrocautery is bipolar or unipolar• relative distance from and orientation of the

electrocautery relative to the pacemaker and pacemaker lead

EVALUATION OF A PATIENT ON PACEMAKER

• 1) determining the type of device• 2) determining whether the patient is pacemaker

dependent for antibradycardia pacing• 3) determining device programmed settings and

battery status

• pacemaker dependent- reprogram to an asynchronous mode during surgery ,or a magnet should be placed over the device during surgery• ICD-  tachyarrhythmia treatment

algorithms programmed off before surgery and turned on after surgery to prevent unwanted shocks due to spurious signals that the device might interpret as ventricular tachycardia or fibrillation

MEASURES TO REDUCE EMI

• 1) bipolar electrocautery • 2) short and intermittent bursts of electrocautery

at the lowest possible energy levels• 3) maximization of the distance between the

electrocautery and the device• 4) if a unipolar cautery is to be used, placement of

the ground patch in a position so as to minimize current flow through the pacemaker or ICD device

• If cardioversion is needed keep the paddles as far as possible from the pacemaker and preferrably perpendicular to the axis of the pacemaker leads.

EFFECTS OF MAGNET PLACED

• FOR PACEMAKER – changes it to asynchronous mode- delivers preprescribed pace.• In dependent patients apply before operation to

be certain.• Magnets will not change pacing function of ICD.• In some cases magnets turn off the shock

function of the ICD.

AFTER SURGERY

• If reprogrammed for surgery should be programmed back.• Formal assessment of pacemaker/ICD by an

expert.