When Should Hospitalists Order Continuous Cardiac Monitoring?

Case

Two patients on continuous cardiac monitoring (CCM) are admitted to the hospital. One is a 56-year-old man with hemodynamically stable sepsis secondary to pneumonia. There is no sign of arrhythmia on initial evaluation. The second patient is a 67-year-old man with a history of coronary artery disease (CAD) admitted with chest pain. Should these patients be admitted with CCM?

Overview

CCM was first introduced in hospitals in the early 1960s for heart rate and rhythm monitoring in coronary ICUs. Since that time, CCM has been widely used in the hospital setting among critically and noncritically ill patients. Some hospitals have a limited capacity for monitoring, which is dictated by bed or technology availability. Other hospitals have the ability to monitor any patient.

Guidelines from the American College of Cardiology (ACC) in 1991 and the American Heart Association (AHA) in 2004 guide inpatient use of CCM. These guidelines make recommendations based on the likelihood of patient benefit—will likely benefit, may benefit, unlikely to benefit—and are primarily based on expert opinion; rigorous clinical trial data is not available.^1,2 Based on these guidelines, patients with primary cardiac diagnoses, including acute coronary syndrome (ACS), post-cardiac surgery, and arrhythmia, are the most likely to benefit from monitoring.^2,3

In practical use, many hospitalists use CCM to detect signs of hemodynamic instability.³ Currently there is no data to support the idea that CCM is a safe or equivalent method of detecting hemodynamic instability compared to close clinical evaluation and frequent vital sign measurement. In fact, physicians overestimate the utility of CCM in guiding management decisions, and witnessed clinical deterioration is a more frequent factor in the decision to escalate the level of care of a patient.^3,4

Guideline Recommendations

(Click for larger image)Figure 1. Advantages and Disadvantages of CCM

CCM is intended to identify life-threatening arrhythmias, ischemia, and QT prolongation (see Figure 1). The AHA guidelines address which patients will benefit from CCM; the main indications include an acute cardiac diagnosis or critical illness.¹

In addition, the AHA guidelines provide recommendations for the duration of monitoring. These recommendations vary from time-limited monitoring (e.g. unexplained syncope) to a therapeutic-based recommendation (e.g. high-grade atrioventricular block requiring pacemaker placement).

The guidelines also identify a subset of patients who are unlikely to benefit from monitoring (Class III), including low-risk post-operative patients, patients with rate-controlled atrial fibrillation, and patients undergoing hemodialysis without other indications for monitoring.

Several studies have examined the frequency of CCM use. In one study of 236 admissions to a community hospital general ward population, approximately 50% of the 745 monitoring days were not indicated by ACC/AHA guidelines.⁵ In this study, only 5% of telemetry events occurred in patients without indications, and none of these events required any specific therapy.⁵ Thus, improved adherence to the ACC/AHA guidelines can decrease CCM use in patients who are unlikely to benefit.

Life-threatening arrhythmia detection. Cleverley and colleagues reported that patients who suffered a cardiac arrest on noncritical care units had a higher survival to hospital discharge if they were on CCM during the event.⁶ However, a similar study recently showed no benefit to cardiac monitoring for in-hospital arrest if patients were monitored remotely.⁷ Patients who experience a cardiac arrest in a noncritical care area may benefit from direct cardiac monitoring, though larger studies are needed to assess all potential confounding effects, including nurse-to-patient ratios, location of monitoring (remote or unit-based), advanced cardiac life support response times, and whether the event was witnessed.

(Click for larger image) Figure 2. Abbreviated AHA Guidelines for CCMa.Abbreviations: AHA, American Heart Association; CCM, continuous cardiac monitoring; ICD, Internal Cardioverter-Defibrillator; AV, Atrioventricular; MI, Myocardial Infarction; TdP, torsades de pointesaAdapted from Drew, et al.1bST-segment monitoring recommendedcQT-interval monitoring recommended