Pacemaker Essentials: Complications You Must Know

Incidence: 0.5-3% ^​1​

Description:

Most patients who undergo pacemaker insertion have minimal bleeding and the hematoma risk is low. Those who are on antithrombotic or anticoagulant therapy have slightly higher rates of bleeding and hematoma, but it still relatively rare.^​1​

Management:

• Most hematomas are treated conservatively with a local compressive dressing.
• Exploration is ONLY indicated if the hematoma expands significantly and causes wound dehiscence and/or necrosis. However, exploring or draining a hematoma significantly increases the risk of infection so it should not be done haphazardly.^​1​
• If you are concerned about a hematoma, you should consult cardiology and never attempt drainage by yourself in the ED.

Incidence: 1-3.4% ^​2,3​

Description:

Luckily infections are rare, but they can be detrimental to patients, especially if missed. Patients can have a pocket infection (where the pacemaker generator sits subcutaneously), systemic infection (e.g. endocarditis or bacteremia), or both. You should consider a systemic pacemaker infection in any patient with unexplained fever, bacteremia, pulmonary infiltrates or a pocket infection.^​4​ Staphylococcus aureus or epidermidis are common culprit organisms.^​4–6​

Management:

• Three sets of blood cultures 
• Intravenous antibiotics (e.g. ceftriaxone and vancomycin)
• Cardiology consult –patients may require transesophageal echocardiography and removal and replacement of their pacemaker.

Tip 1: A pocket infection is endocarditis or bacteremia until proven otherwise!^​5​

Incidence: 30-50%^​7​

Description:

You may be surprised to find out how prevalent phlebitis and thrombophlebitis are with pacemakers. However, symptomatic presentations are rare because patients develop collateral blood flow (0.5-3.5%).^​7​ If a patient presents with pain, swelling, or erythema to the ipsilateral arm (usually right-sided where pacemakers are often inserted) then a DVT must be considered.

Management:

• Usually, no treatment is needed for phlebitis or thrombophlebitis. 
• Doppler ultrasound to rule out a DVT
• If the patient is confirmed to have a DVT, then they should be started on anticoagulation with the usual follow up for venous thromboembolism at your centre.

Incidence: 5-80%^​8​

Description:

This syndrome is caused by the loss of atrioventricular (AV) synchrony. It is most commonly seen in VVI pacemakers where the atria and ventricles are not communicating. The atria contract against closed tricuspid and mitral valves resulting in increased jugular and pulmonary venous pressures, respectively. Patients can present with many, often vague, symptoms including fatigue, exercise intolerance, weakness, dizziness, palpitations, pre-syncope/syncope, and neck pulsations.^​7,8​ Rarely, they can present in congestive heart failure (CHF).^​7​

Management:

• All patients should receive cardiology follow-up as they usually require pacemaker interrogation. The severity of symptoms and clinical findings will determine whether the patient needs to be seen in the ED.
• If mild, patients may adjust to these new symptoms over time. Otherwise, they may require pacemaker parameter changes to decrease these symptoms.
• Some patients will go on to have their pacemaker changed to another type (e.g. VVI to a DDD). 
• If the patient is in CHF, treat accordingly and consider other more common causes.

Incidence: 16%^​9​

Description:

Tricuspid regurgitation (TR) is a common pacemaker-related complication. It can occur from damage to the valve during pacemaker insertion or from the prevention of tricuspid valve closure during systole.^​9​ Though it is not overly important for us to identify in the ED, it should be considered in those presenting with CHF. This problem should become less common if leadless cardiac pacemakers become more widely used (yes, you read that correct!).^​10​ 

Management

• Loop diuretics (e.g. furosemide) are the first-line treatment for TR causing CHF.
• Consider consulting cardiology if the patient is not suitable for discharge. Otherwise, they should follow up with their cardiologist as an outpatient.

Incidence: 1-5%^​11​

Description:

Lead displacement is not as rare as you may think. However, it is a rare reason for a patient to present to the ED. Patients can displace their pacemaker lead and even have myocardial perforation but remain asymptomatic! A chest x-ray (CXR) and ECG are two necessary investigations that may aid in diagnosis. There are two important caveats, however. First, if the patient’s native rhythm is normal, the pacemaker is inhibited so an ECG will not tell you about lead displacement. Secondly, a displaced lead may still be able to pace the endocardium so you could still see a paced rhythm. One helpful hint is if the patient’s paced morphology has changed from prior paced ECGs. Another helpful tip is if the paced ECG shows signs of malfunction, especially failure to capture, then lead displacement should be on your differential. A CXR can also be helpful for diagnosis. So carefully inspect the leads for any discontinuity in both your PA and lateral views.

Management:

• Any suspected lead displacement should be assessed by cardiology.
• Depending on the patient, they may adjust the lead, replace it, or leave it alone.

Tip 2: Consider lead displacement or perforation if the QRS morphology changes from a patient’s previously paced ECG.

Incidence: 0-6%^​12,13​

Description:

If a patient with a pacemaker presents with chest pain, shortness of breath, or an equivalent, you should consider myocardial perforation on your differential diagnosis. As mentioned above, patients can even present asymptomatically! Patients can have perforation from the procedure itself or from the lead over time. Again, both an ECG and CXR are good starting points, with a CT scan being more sensitive than a CXR for detecting perforation if needed. For those who are savvy in point-of-care ultrasound, you may see a pericardial effusion and/or a lead floating outside the myocardium in the pericardial space. 

Management:

• All perforations should be referred to cardiology and/or cardiac surgery. Evidence suggests that if a patient is asymptomatic no intervention is needed.^​14​ Otherwise, it may be removed percutaneously or surgically depending on the case.

Incidence: Symptomatic malfunction <5%^​7​

Description:

Pacemaker malfunction is a global term used when a pacemaker is not working properly. It usually involves failure of the pulse generator or the lead(s). It presents as failure to pace, failure to capture, inappropriate sensing (over- or under-sensing), or dysrhythmia. Inappropriate sensing and failure to capture are the two most common malfunctions.^​7​ Life-threatening situations are rare with modern pacemakers due to longer lasting batteries, better fail-safe mechanisms, and frequent follow-up.^​7​ Again, start with an ECG and CXR when considering malfunction. See Part 2 for more on pacemaker malfunction. 

Management

• Pacemaker malfunction can be difficult to identify in the ED so patients should undergo a pacemaker interrogation if you are suspicious.
• If the patient is unstable, get the crash cart, place pads on the patient (at least 10 cm away from the pacemaker pocket), and proceed as per the ACLS algorithm.