Emergency Care of Patients with Pacemakers and Defibrillators

a,b b, Michael G. Allison, MD , Haney A. Mallemat, MD *

KEYWORDS Pacemaker Implantable cardioverter-defibrillator Electrical storm Cardiac arrest Magnet

KEY POINTS

The traditional categories of pacemaker malfunction (failure to pace, failure to capture, failure to sense) do not provide sufficient insight or description for the emergency care provider; in the emergency department, the focus needs to be on correcting hemody- namic instability. A magnet causes a pacemaker to go into an asynchronous mode and a defibrillator to stop delivering shocks without affecting the pacing function of the device. In patients with pacemakers and implantable cardioverter-defibrillators who present in cardiac arrest, defibrillation pads should be placed in an anterior-posterior configuration. Patients who present after the single discharge of a defibrillator can be sent home with close cardiology follow-up for device interrogation. Electrical storm is defined as more than 3 episodes of ventricular tachycardia in 24 hours. In refractory cases, b-blockers can be used to treat the malignant arrhythmia.

INTRODUCTION Implantable cardiac devices are used to reduce morbidity and mortality among patients with, or at risk for, rhythm disturbances. Permanent pacemakers and implantable cardioverter-defibrillators (ICDs) can be lifesaving. The invasive nature of their insertion and the way they affect cardiac electrophysiology make troubleshooting problems

Funding sources: Nil. Conflict of interest: Nil. The article was copyedited by Linda J. Kesselring, MS, ELS, the technical editor/writer in the Department of Emergency Medicine at the University of Maryland School of Medicine. a Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Maryland School of Medicine, 110 South Paca Street, 2nd Floor, Baltimore, MD 21201, USA; b Department of Emergency Medicine, University of Maryland School of Medicine, 110 South Paca Street, 6th Floor, Baltimore, MD 21201, USA * Corresponding author. E-mail address: [email protected]

associated with these devices a necessary skill for emergency physicians. When problems with the devices arise, patients typically present to the emergency department (ED). Reports from the US Food and Drug Administration and device registries estimate 26.5 ICD malfunctions and 1.3 pacemaker malfunctions per 1000 person years (likely an underestimate of the true incidence of device malfunction).1,2 All practicing emergency physicians should understand the possible problems associated with implantable cardiac devices and have a framework for addressing their malfunction.

PERMANENT PACEMAKERS In 2009, more than 185,000 pacemakers were inserted in the United States.3 Eighty- two percent of them were dual-chamber pacemakers, an increase of 20% compared with the previous 16 years. The North American Society of Pacing and Electrophysi- ology and the British Pacing and Electrophysiology Group settled on a common lan- guage to describe pacemaker terminology and settings (Table 1).4 Pacemakers are fully described by a 5-position code. The first 3 positions define the function of the device and should be understood by every emergency physician. The first 3 positions of pacemaker code can be remembered by the mnemonic PaSeR. The first position (Pa) describes the pacing function of the device, the second position (Se) describes the sensing position of the device, and the third position (R) describes the pacemaker’s response to sensing. Pacing and sensing can be set to one of 4 settings: ventricle (V), atrium (A), dual (D), or no pacing (O). Response to sensing can be set to one of 4 settings as well: inhibited (I), triggered (T), dual (D), or no response (O). The most common setting for dual-chamber devices is DDD. The pacemaker paces and senses the atria and the ventricle. If a native cardiac beat is sensed, the pacemaker is inhibited; if no native beat is sensed after a set interval, the pacemaker delivers a triggered beat.

INDICATIONS FOR PACEMAKER PLACEMENT The indications for placement of permanent pacemakers are varied and complex. Pro- fessional societies have created guidelines to assist electrophysiologists in deter- mining the need for these devices. Guidelines issued jointly by the American College of Cardiology Foundation (ACCF [formerly the ACC]), the American Heart As- sociation (AHA), and the Heart Rhythm Society (HRS) were first published in 2008 and were updated in 2012.5,6 The European Society of Cardiology (ESC) and the European Heart Rhythm Association (EHRA) have also published guidelines to assist clinicians.7 Patients with persistent bradycardia, intermittent bradycardia, syncope with a bundle branch block, and reflex syncope with long sinus pauses can be considered for pacemakers in the right clinical context. The 2 sets of recommendations and levels of ev- idence for various cardiac rhythm disturbances are summarized in Table 2.

Table 1 Uniform pacemaker code

Position I II III IV V Function Chamber Chamber Response Programmability Antitachycardia Paced Sensed to Sensing Function Code V V I O: none O: none A A T P: simple programmable P: pacing D D D M: multiprogrammable S: shock O O O C: communicating D: dual R: rate responsive Download English Version: https://daneshyari.com/en/article/3236699

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