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Question 3#

Regarding electrocardiographic (ECG) monitoring in the ICU:

A. A standard 3-lead ECG will detect 95% of ischemia, whereas a 12-lead ECG will detect greater than 98%
B. Lead V₄ is the most sensitive for detecting perioperative ischemia
C. A standard 3-lead ECG will detect ischemia at the same rate as a12-lead ECG; however, it is inferior at identifying dysrhythmias
D. Lead V₂ is the most sensitive for detecting perioperative ischemia

Correct Answer is B

Comment:

Continuous monitoring of the 12-lead ECG is now available in many ICUs and is proving to be beneficial in certain patient populations. In a study of 185 vascular surgical patients, continuous 12-lead ECG monitoring was able to detect transient myocardial ischemic episodes in 20.5% of the patients. This study demonstrated that the precordial lead V₄, which is not routinely monitored on a standard 3-lead ECG, is the most sensitive for detecting perioperative ischemia and infarction. To detect 95% of the ischemic episodes, two or more precordial leads were necessary. Thus, continuous 12-lead ECG monitoring may provide greater sensitivity than 3-lead ECG for the detection of peri operative myocardial ischemia, and may become standard for monitoring high-risk surgical patients.