Chapter 28
Intraoperative Arrhythmias

The ability to recognize and manage arrhythmias efficiently is a core skill for any anesthesia provider. Your approach in the OR should begin with this commonly taught, practical framework:

Stable vs. unstable
Wide vs. narrow
Regular vs. irregular

As anesthesiologists, we add one crucial question:

What is the context of this arrhythmia?

Identifying the underlying trigger. Whether surgical, anesthetic, or physiologic, context is essential to guiding timely and appropriate management.

The most common intraoperative arrhythmias are bradycardia due to anesthetic/vagal factors, sinus tachycardia due to concurrent illness or surgical stimulation, Afib in a patient with paroxysmal Afib, or short runs of VT in patients with coexisting cardiac disease.

Supraventricular tachycardia (SVT) is less common. The 2015 AHA guidelines for SVT are a useful reference, especially for simplifying acute management without getting lost in terminology like AVNRT or MAT [7].

This section will focus on sinus tachycardia and atrial fibrillation.

Sinus Tachycardia

Sinus tachycardia is easy to diagnose but difficult to manage. Sinus tachycardia is almost never the primary pathology, and, outside of rare SVTs, rarely the cause of hypotension. Most often, it is a sign of something else, a “check engine” light, signaling stress or imbalance. The causes are numerous, but here are some common perioperative ones.

Common Causes of Sinus Tachycardia in the Perioperative Period

Pain
Surgical stimulation
Hypovolemia
Bleeding
Hypoxemia
Hypercarbia (to consider during MAC cases where ETCO₂ is only partially recorded)
Sepsis, infection, or systemic inflammation
Acidosis
Fever
Stimulant use
Beta-blocker withdrawal
Anemia
Chronic malnutrition
Myocardial ischemia
Elevated ICP (presents as tachycardia initially, bradycardia is later)
Pregnancy
Tumor-related cytokine storm
Pulmonary embolism
Chronic critical illness
Young age, particularly with acute illness (higher baseline sympathetic tone, more pronounced heart rate response to stressors)

Key Management Principles

Treat the underlying cause, not the tachycardia alone. The first two causes (pain and stimulation) on the list above are easy to treat with opioids or deeper anesthetic planes. For the rest of the items on the list, focus on correction of the underlying physiology. Avoid reflexively giving beta-blockers or other rate-control agents unless the cause is clearly identified and modifiable causes have been ruled out.

In MAC cases, tachycardia may be your first clue of hypoventilation or hypercarbia. The priority in this case is to fix the airway. In pediatrics, heart rate is tightly linked to cardiac output. Consider the normal heart range for age before reflexively treating with opiates and deeper anesthesia. Do not treat tachycardia in pediatric cases with a beta-blocker without a clear indication and a discussion with your attending.