Cardiac Pacing In Elderly

Cardiac Pacing in elderly has its unique challenges. Although pacing is now a straightforward procedure with minimal complications, certain aspects of pacing need to be given unique consideration when faced with elderly patients.

Most of cardiac pacing is done in mid to late adulthood. Degenerative disease & ischemia are the predominant conditions which lead to indications for pacing in adults. Since general medical care has improved, many patients with other cardiac conditions (e.g. Coronary artery disease) and non cardiac disease (e.g Diabetes, renal disease) survive to late adulthood allowing time for manifestation of conduction defects necessitating pacing. Some adults by virtue of good lifestyle live very well up to their 80s and 90s but develop conduction defects due to ageing and degeneration. Fall prevention is a major goal of cardiac pacing in elderly and even a mild sick sinus or a very rare intermittent AV block might need pacing solely to prevent a fall.

Elderly patients (>8O years) have poor cardiovascular reserve  i.e. – they do well in usual day to day activities but when stressed their cardiovascular reserve is inadequate and complications develop rapidly. Certain aspects need to be considered when pacing an elderly patient to minimizing stressing his or her reserve.

Before Permanent Cardiac Pacing

This is the most neglected aspect of pacing in elderly. A proper pre-pacing plan is essential to prevent complications.

Potential Sources of Problems

Side of Implantation : If upper limb hemiplegia is present, its best to implant the device onto the affected side.  This recommendation is based on the fact that the patient will mostly depend on the normal limb and there is a high chance of acute lead dislodgment if implanted to this side. (Author has witnessed a case where this happened)  Presence of a pacemaker on the effected side has no implication for physiotherapy to that side as physiotherapy movements are controlled movements compared to active self supportive movements from the non-affected side. The non – affected side must be free for movements to facilitate rehabilitation.

Hemostasis issues : Coagulopathy (pathological or therapeutic), thrombocytopenia – all predispose to difficult intra-operative haemostasis and increase the chance of post op haematoma formation. If there is an absolute need for anti-coagulation (e.g. prosthetic valve) we continue anti-coagulation with warfarin and keep the INR just below 2.5  – otherwise we stop warfarin and bring the INR < 1.5 before operating. Ideally the platelet count needs to be >100,000 before surgery although can be done between 50,000-100,000.

Antiplatelets : If there is no absolute acute indication for an antiplatelet agent (e.g. stent), it’s best to stop all antiplateles few days prior to the operation. Elderly are more susceptible to haematoma formation and antiplatlets increase this risk substantially. Operating on a patient with dual antiplatlet therapy  can be a haemostatic disaster and if there is no choice (e.g patient on a recent  stent) – the most experienced (and least messy !!!) operator should do the implantation. A dilute adrenaline (1:20,000) wash in the pocket before closure and application of a post procedure pressure dressing for few hours have helped me in preventing haematoma in such patients.

Heparin / LMWH : Permanent pacing on a patient on heparin or low-molecular weight heparin is a guaranteed way to ask for a haematoma. We don’t touch such patients until at least 24 hrs have expired after the last dose. For a patient who needs anti-coagulation (e.g. prosthetic valve), the patient should be on a therapeutic warfarin (INR just below 2.5) before pacing rather than heparin or LMWH. Author has seen many cases with haematomas when patients have been on heparin and none when operated while on warfarin. The biggest disaster is when one gets a big haematoma when there is a need for anti-coagulation – because now all anti-coagulation has to be stopped (because of haematoma) but yet there is a need for anti-coagulation (e.g. prosthetic valve). Bridging therapy with heparin has NO place in pacing

In the unusual event of a needing a permanent pacemaker while on heparin or recently was on heparin, application of a dilute adrenaline wash (1:20,000) to pocket after meticulous diathermy haemostasis and application of a post procedure pressure dressing for couple of hours can minimize the risk of a haematoma.

Peri-procedure Issues

Operator experience : Pacing in elderly should be undertaken by experienced operators as elderly tolerate complications poorly.

Sedation :  Elderly patients tolerate sedation poorly. However they do tolerate the procedure well with local anaesthesia alone. Hence its always better to attempt permanent pacing without any sedation. For patient with cognitive issues, slight sedation may be helpful but one must be aware of paradoxical worsening of agitation with benzodiazepines. My experience is that a tiny dose of midazolam (0.5 mg) is more than sufficient to keep them comfortable while minimizing the risk of paradoxical agitation.  Opioids generally do not have this problem but opiods can cause enhanced respiratory depression in elderly. Stroke patients are exquisitely sensitive for sedation and care must be taken to avoid over sedation. A pre-op chest x-ray will be valuable to assess diaphragmatic paralysis and this subset of patients have the highest risk of de-saturation. A local anesthesia only strategy is the best approach. If sedation is surely anticipated, its best to have a dedicated anesthetist experienced in elderly patients.

Timing  : Authors preference is to do elderly cases (or other complicated cases) as the second case in a morning list. This minimizes fasting time for the patient. From a operator and theatre perspective, the staff is fresh and less fatigued in the morning which helps in case of a complication. Additionally in state sector hospitals where there is pressure to do more cases in a given list, early morning cases receive most attention and time compared to late cases. Why  second case ? – an uncomplicated straightforward  first cases get the theater going for the rest of the day ! Cardiac Pacing in Elderly / complicated  patients should not be operated in late afternoon.

Venography: The threshold to do a venogram should be low. (I personally always do one)  Veins tend to be more medial and arterial punctures are not infrequent – therefore vascular access may be difficult – reinforcing the fact that the most experienced operator should do the case.

Dual Chamber vs Single Chamber Pacing : Dual Chamber pacing is undoubtedly more physiologic – but in frail elderly, where syncope / fall prevention is the main goal, dual chamber pacing may not be the ideal solution. Longer operating time, more leads, large pocket, increased risk of complications and higher costs need to be balanced with the pacing requirements and patient’s long term outlook.  In our experience, most elderly patients do very well with single chamber ventricular pacing. An occasional active patient or a patient with LV impairment may benefit from dual chamber pacing. Another consideration is the severity of the bardy-arrhythmia – for confirmed intermittent issues (e.g intermittent AV block) where most of the time there won’t be any pacing, it would be unwise to implant a dual chamber device as there would be significant continuous tracking and ventricular pacing – which is unnecessary. In these subsets, a VVI pacemaker is more than adequate to prevent syncope and a fall.

Site of Ventricular Pacing : After witnessing two cases of lead dislodgment (and critical bradycardia leading to significant morbidity) , the author’s personal preference is now to pace the lowest possible place on the septum rather than  mid septum when pacing in elderly with critical bradycardia. One of the problems of septal pacing is increased chance of lead dislodgement – and in a patient needing critical life sustaining pacing, a dislodged lead can lead to catastrophe. Apical leads are very stable but again in elderly the RV apex is very thin and an active fixation lead can perforate. A safe compromise is the lowest septum.

Type of lead : A re-operation for a displaced lead or need for intervention from a lead perforation causes significant morbidity in elderly. Therefore safety trumps physiologic or other strategies in pacing. Active atrial leads are notorious to get displaced and also cause perforations. In most elderly patients an atrial lead is not necessary abut if needed, a passive atrial lead is a more safe option – minimal risk of perforation and if displaced – generally can be managed conservatively as it is unlikely to get displaced to the ventricle. An active lead displaced to the ventricle might need intervention – even if the lead is considered not necessary – as they can cause ventricular tachyarrhythmia by physical irritation.

For ventricular leads the main concern is perforation. As the perforation risk is minimal in the septum, my preference is to use an active lead as I almost exclusively pace in the septum. However in the rare case of not getting suitable parameters on the septum and I have to go to the apex, I would use a passive lead to minimize the risk of perforation. Nevertheless, I have seen several cases of passive leads causing ventricular perforation, and therefore I make a significant effort to place an active lead somewhere in the septum.

Anchoring of leads and device : Another possible mechanism that helps lead dislodgement in elderly may be the frail tissue in the pocket. Leads are kept in place by the active fixation screw but there is a limit that the screw can hold – after a certain tension, the lead may get dislodged from the myocardium. Anchoring of lead by the sleeve at the pocket is the critical factor that prevents tension on the lead at the myocardium. Meticulous attention to anchoring and leaving a generous curve of lead inside helps to mitigate lead dislodgement from a lead pull. Feeble pocket tissue gives minimal support to the device and once the patient gets up and mobilizes, the weight of the device is gradually leads to caudal migration of the device with subsequent tension on the lead. Therefore the anchoring stitch for the device has to be properly applied to prevent device migration