The authors of this article claim that the San Francisco Syncope Rule – which we’ve already put out to pasture – has simple EKG criteria that “can help predict which patients are at risk of cardiac outcomes”.
And, they’re only possibly partly right. Out of the 644 patients in their cohort they followed for syncope, they had 42 cardiac events within their 7-day follow-up period. Of those 42, 36 met the criteria for “abnormal EKG”. If you had a completely normal EKG, it was 6 out 428 that had a cardiac event, which gave them a 99% NPV upon which they base the quoted statement above.
But the positive criteria wasn’t adequately predictive enough to be helpful in making hospitalization decisions – 216 patients had abnormal EKGs, but only 36 had a cardiac outcome. And then, there are significant differences in the patients who had abnormal EKGs, and even more differences with the patients who had cardiac outcomes – the cardiac outcome cohort had an average age of 78.6 compared to the noncardiac outcome cohort average age of 61.0, with probably even more comorbid differences they don’t tell us about.
So, a normal EKG is probably helpful in making your decision – but being younger and healthier probably accounts for more of the differences between their groups.
“Electrocardiogram Findings in Emergency Department Patients with Syncope”
www.ncbi.nlm.nih.gov/pubmed/21762234