Cardiologist or Computer: Who Can Read EKG Better?

Nowadays most of the ECGs have computerized interpretation and overall, a diagnosis is also provided by the computer algorithm. Most of the time, these EKG interpretations are correct. However there are times when the computer algorithm misses the diagnosis completely or gives a wrong diagnosis altogether. In this contemporary time of medicine, most internists and family physicians have started to rely so much more on the computers that they are losing the EKG interpretative skills. We would like to demonstrate through this article that we need to get back that skill so urgently.

recently one night with epigastric distress and abdominal pains. He was diagnosed with GERD (Gastroesophageal reflux disease) and a treatment protocol was advised. His resting 12-lead ECG as per the computer interpretation revealed 'atrial fibrillation' (Figure 1). He was given subcutaneous heparin for a few days followed by Warfarin to be started for anticoagulation.

INTRODUCTION
The first human electrocardiograms (EKGs) were recorded more than 125 years ago. The first attempts to automate EKGs go back to the late 1950s [1].
At least one person per 5 annual health examinations gets an ECG. As per the latest evidence, there are about 300 million EKGs performed in the US annually. The market expenditure for the year 2015 for the EKGs was expected to reach about $200 Million [2].
Based on these two case reports as mentioned above, one can imagine the extent and severity of under-and over-diagnosis, wrong treatment, adverse outcome and possible malpractice case scenarios. Now you multiply all that knowing that there are 300 million EKG performed annually in the US! "To err is human; to really foul things up requires a computer!" "Computers have lots of memory but no imagination!" Computer is only as good as its programming.

DISCUSSION
EKG is certainly the most performed test in the practice of clinical cardiology. For the last six decades, more and more clinical medicine and its procedures are being computerized including EKG interpretation. In spite of so much advancement in computer technology, the ECG interpretation by the computer remains far from being perfect. As early as mid-70s, there was a study [3] evaluating the accuracy of computer interpretation of EKGs?
There were 5 different computer programs interpreting the EKGs. The study concluded that computers were not as accurate in reading EKGs when compared with experienced cardiologists.
Overall accuracy of computer reading of EKGs was 80% and the computer was often quite poor in arrhythmia interpretation.
That study made a recommendation that all computer-read ECGs should be over-read by an experienced physician.
A large international study compared the performance of 9 computer read ECGs programs with that of cardiologists in interpreting EKGs in clinically validated cases of cardiac conditions [4]. Overall sensitivity of the computer programs was significantly lower than that of the cardiologists in diagnosing left ventricular hypertrophy, right ventricular hypertrophy, anterior myocardial infarction and inferior myocardial infarction. The median accuracy was 6.6% lower for the computer programs (69.7%) than for the cardiologists (76.3%; p<0.001).
The questions: What are the sensitivity and specificity of computer-generated EKG interpretation? Comparisons of the accuracy of computer EKG analysis with that of expert electrocardiographers demonstrate 58-94% of disorders are classified correctly, with arrhythmias being the most problematic diagnosis. Sensitivity is lowest for ST-segment or wave changes (83.1%). This represents the most common category of misinterpretation, with a false-negative rate of nearly 17% [5].
Due to the variations in interpretation, there can be more than one common disagreement. interpreted non-sinus rhythms with a sensitivity of 72%, a specificity of 93%, and a positive predictive value of 59.3% [6].
Speaking about the rhythm, atrial fibrillation is undoubtedly the most common arrhythmia seen in clinical cardiology practice.
Computer-interpreted EKG (CIE) programs have a frequent tendency to over-diagnose atrial fibrillation, especially in elderly people potentially leading to inappropriate administration of harmful medications. In one study [7], the computer made the wrong diagnosis of atrial fibrillation in 19% cases! In 10% cases, the physicians did not rectify the diagnosis by ordering repeat EKGs thus leading to unnecessary antiarrhythmic Rx and anticoagulation. Based on this wrong diagnosis, additional unnecessary tests were ordered in 24% of these cases.
In addition, the computer interpreted EKG (CIE) programs have wide variability for reading ST-segment myocardial infarction. The false positive rate can be 0-42% and false negative can be 22-42%. Therefore CIE cannot be recommended as a sole means of activating an emergent cardiac cath lab. EKG artifacts and non-ischemic causes of ST elevation could be the most common reasons for incorrect interpretation of STEMI [8].
Does it matter if the EKG is being read by non-cardiologist vs a cardiologist? Well, it could! One study [9]  Automated computer interpretation may significantly affect physicians' EKG reading abilities. It improves their diagnostic capabilities when the interpretation is correct, however it will increase the probability of error when the diagnosis is incorrect. One study has shown that these wrong diagnoses may account for up to 10,000 adverse effects or avoidable deaths worldwide annually [10].
Additionally CIE programs may decrease analysis time by up to 24-28% for experienced readers. Also, computerized archives allow rapid access to serial EKG comparisons. It improves interpretation accuracy, for example, in acute coronary syndromes [11].
Medical residents have a low proficiency and self-perceived confidence in interpreting EKGs. Cardiologists as primary readers more often correct the misinterpreted EKGs, as compared with internists or others specialists. In the United States, cardiology fellows are required to interpret about 3,000-3,500 EKGs during their standard 3-year training program to acquire competence in EKG interpretation. Training to review, edit, and amend EKGs generated by the computerized system that provides preliminary interpretation is part of their training [12].

SUMMARY
CIE programs are supposed to help us interpret the EKGs; these programs are not a substitute for an experienced physician.
Algorithms and diagnostic criteria will need to be universally standardized throughout the world. For now, all the EKGs will need to be over-read by the cardiologists or experienced internists and other physicians. I can never forget that day when I felt so embarrassed and humiliated. I promised to myself that one day I will have the ease and experience of reading EKGs without any difficulties.
That day in the emergency room was one reason I choose cardiology as my specialty and I have taught EKGs to hundreds of medical students, the residents and the internists since then. I have read thousands of EKGs myself ever since! If that EKG was computer-read and the reading was correct, it is quite likely that I might not have become a cardiologist!