Editing Pacemaker (section)

=== Complications ===
[[File:UOTW 15 - Ultrasound of the Week 1.webm|thumb|[[Ultrasound]] showing non capture of a pacemaker<ref>{{cite web|title=UOTW #15 |first1=Ben |last1=Smith |url=https://www.ultrasoundoftheweek.com/uotw-15/|website=Ultrasound of the Week|access-date=27 May 2017|date=26 August 2014 |url-status=unfit |archive-url=https://web.archive.org/web/20181106201010/https://www.ultrasoundoftheweek.com/uotw-15/ |archive-date= Nov 6, 2018 }}</ref>

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Complications from having [[surgery]] to implant a [[Pacemaker failure|pacemaker]] are uncommon (each 1–3% approximately), but could include: infection where the pacemaker is implanted or in the bloodstream; [[allergy|allergic reaction]] to the dye or [[anesthesia]] used during the procedure; swelling, bruising or bleeding at the generator site, or around the heart, especially if the patient is taking [[blood thinners]], elderly, of thin frame or otherwise on chronic [[steroid]] use.<ref>{{Cite web|url=http://www.mayoclinic.org/tests-procedures/pacemaker/details/risks/cmc-20198664|title=Risks – Pacemaker |website=Mayo Clinic |access-date=2016-12-01 |url-status=live |archive-url=https://web.archive.org/web/20170218212112/http://www.mayoclinic.org/tests-procedures/pacemaker/details/risks/cmc-20198664 |archive-date= Feb 18, 2017 }}</ref>

A possible complication of dual-chamber artificial pacemakers is 'pacemaker-mediated tachycardia' (PMT), a form of reentrant tachycardia. In PMT, the artificial pacemaker forms the anterograde (atrium to ventricle) limb of the circuit and the atrioventricular (AV) node forms the retrograde limb (ventricle to atrium) of the circuit.<ref name=Olshansky>{{EMedicine|article|159645|Pacemaker-Mediated Tachycardia}}</ref> Treatment of PMT typically involves reprogramming the pacemaker.<ref name="Olshansky" />

Another possible complication is "pacemaker-tracked tachycardia," where a [[supraventricular tachycardia]] such as [[atrial fibrillation]] or [[atrial flutter]] is tracked by the pacemaker and produces beats from a ventricular lead.<ref>{{cite book |doi=10.1016/B978-1-4377-1616-0.00029-1 |chapter=Pacemaker Troubleshooting and Follow-up |title=Clinical Cardiac Pacing, Defibrillation and Resynchronization Therapy |date=2011 |last1=Love |first1=Charles J. |pages=844–888 |isbn=978-1-4377-1616-0 }}</ref> This is becoming exceedingly rare as newer devices are often programmed to recognize supraventricular tachycardias and switch to non-tracking modes.<ref>{{cite journal |last1=Kamalvand |first1=Kayvan |last2=Tan |first2=Kim |last3=Kotsakis |first3=Athanasios |last4=Bucknall |first4=Cliff |last5=Sulke |first5=Neil |title=Is Mode Switching Beneficial? A Randomized Study in Patients With Paroxysmal Atrial Tachyarrhythmias |journal=Journal of the American College of Cardiology |date=August 1997 |volume=30 |issue=2 |pages=496–504 |doi=10.1016/S0735-1097(97)00162-9 |pmid=9247524 |s2cid=23092273 }}</ref>

It is important to consider leads as a potential nidus for [[Thrombosis|thromboembolic]] events. The leads are small-diameter wires from the pacemaker to the implantation site in the heart muscle, and are usually placed intravenously through the [[subclavian vein]] in order to access the right atrium. Placing a foreign object within the venous system in such a manner may disrupt blood-flow and allow for thrombus formation. Therefore, patients with pacemakers may need to be placed on  anti-coagulation therapy to avoid potential life-threatening thrombosis or embolus.<ref>{{cite journal |last1=Noheria |first1=Amit |last2=DeSimone |first2=Christopher V. |last3=Asirvatham |first3=Samuel J. |title=Cardiac Implantable Electronic Device Lead Thrombus as a Nidus for Pulmonary and Systemic Embolization |journal=JACC: Clinical Electrophysiology |date=November 2018 |volume=4 |issue=11 |pages=1437–39 |doi=10.1016/j.jacep.2018.08.019 |doi-access=free |pmid=30466849 }}</ref><ref>{{cite book |doi=10.1007/978-88-470-2139-6_66 |chapter=Pacemaker/ICD Patients: To Anticoagulate or Not to Anticoagulate? |title=Cardiac Arrhythmias 1999 - Vol.1 |date=2000 |last1=Santomauro |first1=M. |last2=Costanzo |first2=A. |last3=Ottaviano |first3=L. |last4=Cresta |first4=R. |last5=Minichiello |first5=S. |last6=Prastaro |first6=M. |last7=Chiariello |first7=M. |pages=494–500 |isbn=978-88-470-0071-1 }}</ref>

These leads may also damage the [[Tricuspid valve|tricuspid valve leaflets]], either during placement or through wear and tear over time. This can lead to [[tricuspid regurgitation]] and [[right-sided heart failure]], which may require [[Valve replacement|tricuspid valve replacement]].<ref>{{cite journal |last1=Lin |first1=Grace |last2=Nishimura |first2=Rick A. |last3=Connolly |first3=Heidi M. |last4=Dearani |first4=Joseph A. |last5=Sundt |first5=Thoralf M. |last6=Hayes |first6=David L. |title=Severe Symptomatic Tricuspid Valve Regurgitation Due to Permanent Pacemaker or Implantable Cardioverter-Defibrillator Leads |journal=Journal of the American College of Cardiology |date=May 2005 |volume=45 |issue=10 |pages=1672–75 |doi=10.1016/j.jacc.2005.02.037 |doi-access=free |pmid=15893186 }}</ref>

Sometimes leads will need to be removed. The most common reason for lead removal is infection; however, over time, leads can degrade due to a number of reasons such as lead flexing.<ref name="Wilkoff">{{cite journal |last1=Wilkoff |first1=Bruce L. |last2=Love |first2=Charles J. |last3=Byrd |first3=Charles L. |last4=Bongiorni |first4=Maria Grazia |last5=Carrillo |first5=Roger G. |last6=Crossley |first6=George H. |last7=Epstein |first7=Laurence M. |last8=Friedman |first8=Richard A. |last9=Kennergren |first9=Charles E.H. |last10=Mitkowski |first10=Przemyslaw |last11=Schaerf |first11=Raymond H.M. |last12=Wazni |first12=Oussama M. |title=Transvenous Lead Extraction: Heart Rhythm Society Expert Consensus on Facilities, Training, Indications, and Patient Management |journal=Heart Rhythm |date=July 2009 |volume=6 |issue=7 |pages=1085–1104 |doi=10.1016/j.hrthm.2009.05.020 |pmid=19560098 }}</ref> Changes to the programming of the pacemaker may overcome lead degradation to some extent. However, a patient who has several pacemaker replacements over a decade or two in which the leads were reused may require lead replacement surgery.

Lead replacement may be done in one of two ways. Insert a new set of leads without removing the current leads (not recommended as it provides additional obstruction to blood flow and heart valve function) or remove the current leads and then insert replacements. The lead removal technique will vary depending on the surgeon's estimation of the probability that simple traction will suffice to more complex procedures. Leads can normally be disconnected from the pacemaker easily, which is why device replacement usually entails simple surgery to access the device and replace it by simply unhooking the leads from the device to replace and hooking the leads to the new device. The possible complications, such as perforation of the heart wall, come from removing the lead{s} from the patient's body.

The free end of a pacemaker lead is actually implanted into the heart muscle with a miniature screw or anchored with small plastic hooks called tines. The longer the leads have been implanted (starting from a year or two), the more likely that they will have additional attachments to the patient's body at various places in the pathway from device to heart muscle, since the body tends to incorporate foreign devices into tissue. In some cases, for a lead that has been inserted for a short amount of time, removal may involve simple traction to pull the lead from the body. Removal in other cases is typically done with a laser or cutting device which threads like a cannula with a cutting edge over the lead and is moved down the lead to remove any organic attachments with tiny cutting lasers or similar device.<ref>{{Cite web |title=What is Laser-Assisted Lead Extraction? {{!}} DFW |url=https://www.heartplace.com/services-laser-lead-extraction |access-date=2022-09-16 |website=HeartPlace |language=en |archive-date=2022-09-20 |archive-url=https://web.archive.org/web/20220920165250/https://www.heartplace.com/services-laser-lead-extraction |url-status=dead }}</ref><ref>{{cite journal |last1=Gaca |first1=Jeffrey G. |last2=Lima |first2=Brian |last3=Milano |first3=Carmelo A. |last4=Lin |first4=Shu S. |last5=Davis |first5=R. Duane |last6=Lowe |first6=James E. |last7=Smith |first7=Peter K. |title=Laser-Assisted Extraction of Pacemaker and Defibrillator Leads: The Role of the Cardiac Surgeon |journal=The Annals of Thoracic Surgery |date=May 2009 |volume=87 |issue=5 |pages=1446–51 |doi=10.1016/j.athoracsur.2009.02.015 |pmid=19379883 }}</ref>

Pacemaker lead malposition in various locations has been described in the literature. Treatment varies, depending on the location of the pacer lead and symptoms.<ref>{{cite journal |last1=Kalavakunta |first1=Jagadeesh Kumar |last2=Gupta |first2=Vishal |last3=Paulus |first3=Basil |last4=Lapenna |first4=William |title=An Unusual Cause of Transient Ischemic Attack in a Patient with Pacemaker |journal=Case Reports in Cardiology |date=2014 |volume=2014 |pages=265759 |doi=10.1155/2014/265759 |pmid=24826308 |pmc=4008350 |doi-access=free }}</ref>

Another possible complication called [[twiddler's syndrome]] occurs when a patient manipulates the pacemaker and causes the leads to be removed from their intended location and causes possible stimulation of other nerves.

Overall life expectancy with pacemakers is excellent, and mostly depends upon underlying diseases, presence of atrial fibrillation, age and sex at the time of first implantation.<ref>{{cite journal |last1=Brunner |first1=M |title=Long-term survival after pacemaker implantation Prognostic importance of gender and baseline patient characteristics |journal=European Heart Journal |date=January 2004 |volume=25 |issue=1 |pages=88–95 |doi=10.1016/j.ehj.2003.10.022|pmid=14683747 |doi-access=free }}</ref>