150 Reversal of fortunes: right arm-left arm ECG lead misplacement

Conclusion Highly statistically significant ECG features of RA-LA misplacement are inverted P waves and inverted QRS complexes in lead I and the presence of R waves in lead aVR Their absence does not exclude the diagnosis. In this study ECG machines failed to detect almost half of all RA-LA misplacements. Education and training is required to recognise ECG lead misplacements. ECG interpretative software should incorporate these findings into their diagnostic algorithms. Abstract #150 Table 1 Inverted P waves Inverted QRS lead I Inverted T waves lead I R in aVR 95% CI 95% CI 95% CI 95% CI Sensitivity 88.0% 80.7 – 93.3% 100% 97.5 – 100% 77.6% 69.9 – 84.2% 79.0% 71.4 – 85.4% Specificity 98.3% 93.9 – 99.8% 100% 97.5 – 100% 95.1% 90.2 – 98% 98.6% 95 – 99.8% LR + 51.5 13.0 – 203.8 15.9 7.7 – 32.8 56.5% 14.2 – 224.% LR - 0.12 0.1 – 0.2 0 0.24 0.2 – 0.3 0.2% 0.15 – 0.29% PPV 98.1% 92.9 – 99.5% 100% 97.5 – 100% 94.1% 88.5 – 97% 98.3% 93.4 – 99.6% NPV 89.2% 83.4 – 93.1% 100% 97.5 – 100% 81% 75.8 – 85.3% 82.5% 77.4 – 86.6% Accuracy 93.2% 89.1 – 96.0% 100% 97.5 – 100% 86.4% 81.8 – 90.1% 88.8% 84.6 – 92.2% Fisher’s exact test p<0.00001 p<0.00001 p<0.00001 LR = Likelihood ratio, PPV = Positive predictive value, NPV = Negative predictive value, CI = Confidence intervals 2-tailed Fisher’s e...
Source: Emergency Medicine Journal - Category: Emergency Medicine Authors: Tags: Oral Presentations Source Type: research