When Should Hospitalists Order Continuous Cardiac Monitoring?

Bottom line: AHA guidelines recommend use of CCM in patients with a higher likelihood of developing a life-threatening arrhythmia, including those with an ACS, those experiencing post-cardiac arrest, or those who are critically ill. Medical ward patients who should be monitored include those with acute or subacute congestive heart failure, syncope of unknown etiology, and uncontrolled atrial fibrillation.¹

Ischemia surveillance. Computerized ST-segment monitoring has been available for high-risk post-operative patients and those with acute cardiac events since the mid-1980s. When properly used, it offers the ability to detect “silent” ischemia, which is associated with increased in-hospital complications and worse patient outcomes.

Computerized ST-segment monitoring is often associated with a high rate of false positive alarms, however, and has not been universally adopted. Recommendations for its use are based on expert opinion, because no randomized trial has shown that increasing the sensitivity of ischemia detection improves patient outcomes.

Bottom line: AHA guidelines recommend ST-segment monitoring in patients with early ACS and post-acute MI as well as in patients at high risk for silent ischemia, including high-risk post-operative patients.¹

QT-interval monitoring. A corrected QT-interval (QTc) greater than 0.50 milliseconds correlates with a higher risk for torsades de pointes and is associated with higher mortality. In critically ill patients in a large academic medical center, guideline-based QT-interval monitoring showed poor specificity for predicting the development of QTc prolongation; however, the risk of QTc prolongation increased with the presence of multiple risk factors.⁸

Bottom line: AHA guidelines recommend QT-interval monitoring in patients with risk factors for QTc-prolongation, including those starting QTc-prolonging drugs, those with overdose of pro-arrhythmic drugs, those with new-onset bradyarrhythmias, those with severe hypokalemia or hypomagnesemia, and those who have experienced acute neurologic events.¹

Recommendations Outside of Guidelines

Patients admitted to medical services for noncardiac diagnoses have a high rate of telemetry use and a perceived benefit associated with cardiac monitoring.³ Although guidelines for noncardiac patients to direct hospitalists on when to use this technology are lacking, there may be some utility in monitoring certain subsets of inpatients.

Sepsis. Patients with hemodynamically stable sepsis develop atrial fibrillation at a higher rate than patients without sepsis and have higher in-hospital mortality. Patients at highest risk are those who are elderly or have severe sepsis.⁷ CCM can identify atrial fibrillation in real time, which may allow for earlier intervention; however, it is important to consider that other modalities, such as patient symptoms, physical exam, and standard EKG, are potentially as effective at detecting atrial fibrillation as CCM.

Bottom line: Our recommendation is to use CCM in patients who are at higher risk, including elderly patients and those with severe sepsis, until sepsis has resolved and/or the patient is hemodynamically stable for 24 hours.

Alcohol withdrawal. Patients with severe alcohol withdrawal have an increased incidence of arrhythmia and ischemia during the detoxification process. Specifically, patients with delirium tremens and seizures are at higher risk for significant QTc prolongation and tachyarrhythmias.⁹

Bottom line: Our recommendation is to use CCM in patients with severe alcohol withdrawal and to discontinue monitoring once withdrawal has resolved.

COPD. Patients with COPD exacerbations have a high risk of in-hospital and long-term mortality. The highest risk for mortality appears to be in patients presenting with atrial or ventricular arrhythmias and those over 65 years old.¹⁰ There is no clear evidence that beta-agonist use in COPD exacerbations increases arrhythmias other than sinus tachycardia or is associated with worse outcomes.¹¹

Bottom line: Our recommendation is to use CCM only in patients with COPD exacerbation who have other indications as described in the AHA guidelines.