Atrial
Fibrillation (AF) is a rhythm associated with increasing prevalence alongside aging. It is often quoted in
our literature that the prevalence of AF is about 2-5% as you hit age 60yrs old
and above. This is the most common stable arrhythmia we cardiologists and
medical practitioners see in our practice. AF is very well tolerated and
patients can do their usual chores but, unknown to many, the ugly side of AF is
the risk for stroke. Stroke is very unforgiving and can be potentially
life changing with disabilities of various severity.
Facts about the
strong association of AF and aging are well established, yet despite all these,
not much is done to unmask AF and prevent stroke. Our college is
silent just as our guidelines are muted on how we could preempt this ugly side
of this arrhythmia. It is often quoted that as much as 30% of all strokes are
secondary to cardiac arrhythmia called Atrial Fibrillation. At present, we as
medical practitioners simply play the waiting game and wait for the next stroke
patient. We scratch our head once we are presented with a patient coming into
the ER and only then will a series of tests ordered to find the cause.
One of the tests usually done is called holter monitoring. Holter monitor is a
gadget that records your heart's electrical activity continuously for a fixed
duration of time ranging from 24hrs to 72hrs or even up to a week depending on
the gadget you use. The question that begs to be answered is why not use it to
screen our at risk patients and help unmask AF rather than do it only after the
fact when damage has already been done?
I challenged and
asked myself how and my conscience answered....why not? It is precisely for
this reason I routinely do "stroke screening" sans guidelines
recommendation. Since it is a largely benign and noninvasive test,
I routinely advise patients at risk most importantly those
with a known family history of stroke to get screened NOW! and not wait
another day as history will repeat itself if we continue to ignore. I
have also come to realize that patients who denies having any family
history of stroke may not necessarily mean "NONE at ALL" but,
may simply be that they just don't know or not aware. The best
recourse therefore is to deploy such a readily available and noninvasive tool to all
patients whom I think are at risk and wants to be screened.
As I have been
doing this, I came to realize that I may have inadvertently
opened a can of worms when I started to frequently encounter short bursts of
Supraventricular Tachycardia or abnormal heart beats for which there are no clear guidelines regarding management at the present time. My instinct however, tells me to intervene and take
it seriously despite paucity of information to support such action. Interestingly, in the last Asia Pacific Congress of Cardiology in May of
2019, I attended, the talk by Professor John Camm, MD from UK entitled
"Changing Lanes: AF Risk Assessment". He presented a new concept
called Micro-AF, from the study of Dr. Fredrikkson et. al. July 2018 Am.
J. Cardiology as a risk for AF. Patients with Micro-AF (4 supraventricular beats up to less than 30secs. ) followed up for 2 years had a 50% risk of getting full blown AF on that study. Our current guideline defines AF when irregular supraventricular beats last up to 30 seconds duration and unknown to many that this is simply based on consensus. Consensus recommendations are devoid of evidence as they are based on how the experts in the field want us to believe and follow. Furthermore, in the STROKESTOP Study published in the
Circulation, June 2015 showed that Micro-AF was associated with stroke 1.5% of
the time. It became obvious to me that the frequently encountered arrhythmias currently ignored by many are actually a double-edged sword....that it is not only a risk for developing AF but, may actually be associated with stroke as well. I felt relieved, vindicated and happy when all these came to fore for obvious
reasons. If all these gets the validation from large randomized clinical trials
in the future, then my patients are not only getting the lucky break ahead
of the pack but, most importantly some of my patients may have actually dodged the ugly twin called STROKE.
I do this
because I strongly believe that almost all, if not all catastrophic events
start small when the early warning signs are either missed or simply ignored. That
these little short bursts of abnormal beats could be a harbinger of something
big that would eventually lead to catastrophic events if taken for granted. I always ask myself if I should just sit and wait for stroke to happen? or should I proactively look out
for them with the hope of preventing the dreaded stroke from happening in the first
place? Whenever I see these rhythm abnormalities, I discuss with the
patients my sentiment, what we know at this time and plan of action. In most cases they do trust me and go
along and accede with my preconceived plan and that is to intervene. Most of the time, the seemingly asymptomatic
patients are treated and much to my surprise, many would come back
feeling better for which I have a simple and logical explanation. These rhythm
abnormalities are chronic and longstanding where patients eventually
adapt or get used to and eventually consider it as part of normal. When the arrhythmias are fixed and they start feeling good, they start to recognize the difference and more often than not, they voice it out to me on their next office visit. This is obviously a subjective feel and considered
anecdotal at best since only the patient can feel it. I took all these
with a grain of salt initially and relegated it as maybe due to chance, however, as
soon as many more patients would come back echoing the same, I started to pause, look back and took it seriously as real. This is a very
interesting finding if true as this is an area that is largely unexplored in the field of cardiology. Subjective feelings generally don't hold much ground in medicine to defend and used as proof of concept
but, I will take this positivity anytime despite the absence of support from randomized clinical trials.
While 24-hr Holter monitoring is the norm, I routinely
recommend doing 72-hr Holter instead on patients I
consider at risk for AF as it has been shown to be far superior in detecting
silent AF vs 24hrs Holter recording on the study by Martin Grond et. al. published in Stroke, 2013. In
this study, 24-hr Holter monitoring missed up to 70% of arrhythmias
vs 72-hrs recording.
I believe and
abide by our hippocratic oath, that is "Do no Harm", and this will always be my guiding principle as a physician in my
day to day practice.
