Perioperative management of patient with pacemaker undergoing non cardiac surgery

Abstract

The heart is endowed with a specialized system for generating rhythmical impulses to cause rhythmical contraction of the heart muscle and conducting these impulses rapidly throughout the heart. The structures that make up the conduction system are the sinoatrial node (SA node), the internodal atrial pathways, the atrioventricular node (AV node), the bundle of His and its branches and the purkinje system. Conduction delay and block can result in either bradyarrhythmias when the propagating impulses are blocked and followed by asystole or a slow escape rhythm, or tachyarrhythmias when the impulse delay or block produce re-entrant excitation. Patients with cardiac disease presenting for noncardiac surgery pose a considerable challenge to the anesthesiologists. Many patients especially of the elderly age group are detected to have electrophysiological disorders. Pacemakers are being used with greater frequency for both conduction and arrhythmia problems in such patients. Indications for Pacing 1. Pacing for Bradycardia Due to Sinus and Atrioventricular Node Dysfunction 1.1. Sinus Node Dysfunction 1.2. Acquired Atrioventricular Block in Adults 1.3. Chronic Bifascicular Block 1.4. Pacing for Atrioventricular Block Associated With Acute Myocardial Infarction 1.5. Hypersensitive Carotid Sinus Syndrome and Neurocardiogenic Syncope 2. Pacing for Specific Conditions 2.1. Cardiac Transplantation 2.2. Neuromuscular Diseases 3. Prevention and Termination of Arrhythmias by Pacing 3.1. Pacing to Prevent Atrial Arrhythmias 3.2. Long-QT Syndrome 4. Pacing for Hemodynamic Indications 4.1. Cardiac Resynchronization Therapy Generic Codes of Pacemaker The first letter indicates the chamber being paced, the second letter designates the chamber being sensed, third position designates response to sensing (I and T indicates inhibited or triggered responses, respectively), the fourth and fifth positions describe programmable and antitachyarrhythmia functions, but these two are rarely used. An R in fourth position indicates that the pacemaker incorporates a sensor to modulate the rate independently of intrinsic cardiac activity such as with activity or respiration. Care of the pacemaker during surgery as well as understanding its anesthetic implications is crucial in the management of these patients. Special attention must be paid to patients with implantable pacemaker during anaesthetic management, good preoperative preparation, premedication, induction, intraoperative procedure and postoperative care there are different anaesthetic agents and techniques better than others in patients with pacemaker. Preoperative Evaluation Preoperative evaluation is an important aspect of the anaesthetic management of a patient with permanent pacemaker undergoing noncardiac surgery. It includes evaluation of the patient and the pacemaker. It should include not only detailed evaluation of the underlying cardiovascular disease responsible for the insertion of pacemaker, but also other associated medical problems. It is important to evaluate the function of pacemaker in the preoperative period. Assistance from the cardiologist and the manufacturer’s representative may be obtained for the purpose. Most of the information about the pacemaker, such as type of pacemaker (fixed rate or demand rate), time since implanted, pacemaker rate at the time of implantation, and half- life of the pacemaker battery can be taken from the manufacture’s book kept with the patient.