How to differentiate Atrial Fibrillation (Afib) from a Pacemaker (placed)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 2, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

To distinguish atrial fibrillation (AFib) from a paced rhythm, focus on the rhythm pattern and symptoms, and use electrocardiographic documentation as the primary diagnostic tool, as recommended by the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1. When checking a pulse, AFib feels chaotic and unpredictable, whereas a paced rhythm may feel regular. Symptoms can help differentiate as well - AFib often causes persistent palpitations, shortness of breath, fatigue, and sometimes chest discomfort. Definitive diagnosis requires an ECG, which shows chaotic atrial activity without P waves in AFib, versus a regular rhythm with P waves in a paced rhythm. Some key points to consider when evaluating a patient with suspected AFib or a paced rhythm include:

  • The clinical history and physical examination, which can suggest AFib on the basis of irregular pulse, irregular jugular venous pulsations, variation in the intensity of the first heart sound, or absence of a fourth sound heard previously during sinus rhythm 1.
  • The use of ambulatory rhythm monitoring, such as telemetry, Holter monitor, or event recorders, to confirm the diagnosis of AFib 1.
  • The importance of assessing cardiac and extracardiac factors pertinent to the etiology, tolerability, and management of AFib 1.
  • The need for thyroid, renal, and hepatic function tests, as well as serum electrolyte and hemogram measurements, to evaluate the underlying cause of AFib 1.
  • The use of 2-dimensional, Doppler echocardiography to assess left atrial and left ventricular dimensions, left ventricular wall thickness, and function, and to exclude occult valvular or pericardial disease and hypertrophic cardiomyopathy 1.

From the Research

Diagnostic Evaluation of Atrial Fibrillation

  • The diagnostic evaluation of atrial fibrillation (Afib) involves a review of symptoms, past medical history, quality of life, and physical exam findings, as discussed in 2.
  • Diagnostic tools are then used to confirm the diagnosis, but the provided studies do not specifically discuss how to differentiate Afib from a pacemaker.

Differentiation from Pacemaker

  • There is no direct evidence in the provided studies on how to tell Afib from a pacemaker.
  • However, studies such as 3, 4, and 5 discuss the treatment and management of Afib, which may be relevant in understanding the condition, but do not provide information on differentiation from a pacemaker.
  • Study 6 discusses the use of metoprolol in patients with permanent pacemaker implantation, but does not provide information on how to differentiate Afib from a pacemaker.

Treatment and Management

  • The treatment and management of Afib involve the use of medications such as metoprolol and diltiazem, as discussed in 3, 4, and 5.
  • These studies compare the effectiveness and safety of these medications in controlling heart rate and preventing complications, but do not provide information on how to differentiate Afib from a pacemaker.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.