Author/Authors :
Stewart ، نويسنده , , Simon and Haste، نويسنده , , Mark، نويسنده ,
Abstract :
Objective
ermine the value of routine versus selective use of the 18-lead electrocardiogram in determining the size of an acute inferior myocardial infarction (MI).
ctive, quasi-experimental, random assignment.
g
ronary care unit (CCU) of a major teaching hospital in South Australia.
ts
two patients admitted to the CCU with acute evolving inferior MI.
e measures
ation and comparison of the predictions of right ventricular (RV) and posterior wall (PW) lead ST elevation with prospectively chosen markers on the 12-lead electrocardiogram—ST elevation in lead III>II and precordial ST depression, and the predictions by coronary care nurses.
ure
sults of 18-lead electrocardiograms of 52 consecutive patients admitted to the CCU with acute evolving inferior MI were classified according to prospectively chosen criteria. Coronary care nurses were randomly assigned four 12-lead electrocardiograms and asked to “blindly” predict ST elevation in the concurrent RV and PW leads.
s
vation in lead III>II demonstrated a sensitivity and positive predictive accuracy of 86% to 1 mm of ST elevation in the RV leads. ST depression in V1, V2, and V3 similarly demonstrated a 75% sensitivity and 89% positive predictive accuracy to 1 mm of ST elevation in the PW leads. In comparison, coronary care nurses proved to be as accurate in their predictions of additional PW ST elevation (p=0.73), but were significantly less able to predict RV ST elevation (p=0.049). These predictions were independent of the level of experience and qualifications.
sions
minating between smaller and larger types of inferior MIs has the potential to alter patient management: Thirty-two percent of patients in the study demonstrated additional ST elevation in both the RV and PW leads. Both of the 12-lead electrocardiogram markers used in this study proved reasonably accurate in predicting additional ST elevation in the leads that normally comprise the 18-lead electrocardiogram. Recognition of these markers has the potential to expedite the need for the additional 18-lead electrocardiogram when rapid assessment of infarction size is required. However, the routine use of the 18-lead electrocardiogram is supported by this study.