Arrhythmia 'Fake News'
On March 22, 2018, I posted this Implantable Loop Recorder (ILR) tracing on LinkedIn. I concurrently showed the tracings to multiple individuals who routinely review ILR tracings including Device-Industry Reps, device data technicians and even physicians. Much to my chagrin, but not necessarily to my surprise, the recurring interpretation of this tracing was that this patient has Ventricular Tachycardia and ‘clearly' needs a Defibrillator. Fortunately for the patient, this is neither Ventricular Tachycardia nor does the patient need a Defibrillator; this tracing demonstrates Noise Artifact, in other words there is no arrhythmia rather just electrical interference which looks like an arrhythmia.
On one level, the fact that multiple different levels of care providers uniformly misread this tracing is distressing however this observation may not be all that surprising. The clinical professionals who read implantable device reports range from medical assistants to highly trained Device-Industry representatives to Electrophysiologists. Having now practiced in this industry for over 18 years, I am bewildered by the breadth of knowledge and skill which these care providers may possess. When it comes to interpretation quality I have seen ‘rock-star’ medical assistants and ‘dive-bar’ Electrophysiologists and I have not witnessed any level of ‘certification’ as a reliable differentiator of interpretation skill. I can only surmise how often the data output of these devices is misinterpreted with patients subsequently receiving interventions (either pacemakers, defibrillators or ablation) which are completely unnecessary and/or potentially harmful to their care. Diagnostic implantable devices are extremely clinically valuable; however, the value of these devices is derived by having appropriately trained, focused and conscientious clinical professionals interpret the data output from these devices.
At the present time, the implantation of the Implantable Loop Recorders is limited to implantation in the inpatient setting and is generally performed by care providers with Cardiology expertise. On January 1st, 2019, these devices will begin to be implanted within the outpatient, office-based setting. Coincident with this 'progress', I fully expect that implantation of these devices to extend beyond those with Cardiology expertise and extend out to Primary Care, Emergency Care and even Neurology providers. The challenge of these devices does not lie in their implantation. The challenge of these devices lies in the accurate and thoughtful interpretation of the continuous flow of data emanating from these marvels of engineering.
This is but one example of a Pseudo-Arrhythmia emanating from Implantable Loop Recorders, I will be posting additional tracings demonstrating similar ‘fake arrhythmia news’ in short order. For those interested, I have attached the education which was provided to our Geneva Remote Care Coordinators for this tracing as part of our continuing education program, now termed Geneva University.
Geneva University Case #30
As always, start with what you know to be true.
The top line clearly demonstrates a regular rhythm with noise. We can see that there is a wobble in the underlying rhythm, which likely is sinus rhythm despite the fact that we cannot clearly see P waves. Irrespective of the wobble, if we march our calipers through the rhythm we can see that the QRS complexes line up at or near the anticipated time on the tracing.
On the second strip we clearly see continuation of sinus rhythm on the initial third of the strip. Thereafter we see what could be construed as a narrow complex tachycardia. However, notice the marked irregularity in both the rate and character of the 'QRS complexes'. Notice also that if this were tachycardia, it's onset would be coincident with the patient's Baseline QRS, which is a nonexistent presentation for tachycardia initiation. Additionally, appreciate the fact that the rate of this tachycardia, if true, would be between 250-300 bpm, which is quite impressive for a narrow complex tachycardia (while I have all seen these, they are not common). Also notice the noise at the very onset of this potential arrhythmia which is not dissimilar from the noise on the top strip. If we carry out the same exercise that we did on the top strip, we can identify complexes which represent the same Baseline QRS that can be appreciated throughout the rest of the tracing. Ideally we would have liked to have seen the termination of this 'toothbrush tachycardia' and seen the baseline QRS appear unfettered, however we do not have this luxury given the suspension of the ECG on the tracing.
On the third strip, after an 8 second suspension of ECG signals, we once again see QRS complexes which march through the noise.
Commonly we will have to look at one area of the tracing to help us make the diagnosis in another point on the tracing. In this case, we had to "Read Between the Lines" to identify the QRS complexes. These QRS complexes, while more suggestive than definitive evidence of the rhythm marching through the noise, when added to the fact that we already see noise on other parts of the tracing and the inconsistencies which would be present for both the initiation and presentation of a potential SVT lend us to conclude that this is in fact noise.
Sadly, if I had to venture a guess I would expect that based on this tracing perhaps at least quarter of the time the patient would be treated with medications or a procedure based on the strip being diagnosed as a true tachycardia.