Wide qrs tachycardia often evoke a OCD like reaction among many cardiologists (Obsessive compulsive disorder). Whenever we are given a strip of wide qrs tachycardia we are compelled to initiate a conscious or subconscious debate , whether it is VT or SVT . Tens of thousands of articles, seminars, CMEs , have been conducted for over 30 years for decoding wide qrs tachycardias . The fact that the confusion is still widely prevalent indicate only two things
- Either , it is not possible to arrive at a simple fool proof bed side modality to confirm either VT or SVT
- Or it is a too trivial electrophysiological issue that need not be worried about as we have broad spectrum antiarrhythmics (Like antibiotics ! , where we rarely bother about identity of the culprit bacteria )
The power of statistics and commonsense have never been applied in the management this vital cardiac entity .While a 75% sensitive exercise stress test (EST) has a huge following in clinical cardiology , a 99 % sensitive clinical criteria* for diagnosing VT is not respected .
*All wide QRS tachycardia in patients with with history of CAD/STEMI would be VT
If only we had applied our mind to this article published in 1988 we will never ever have the need to split our hairs for decades.(That too without success !)
In pursuit of knowledge , are we often chasing an imaginary issue ?
The cardinal principle of medicine says
“Diagnosis should precede treatment whenever possible ”
But there need to be a correction in the above statement . Time , effort , cost involved in arriving at a diagnosis should be meaningful .( Needless to say . . . it should a correct diagnosis too ) And if the power of statistics far exceeds the frivolous scientific data , street sense can be applied liberally even though current generation may call it un scientific .
The issue here is not being scientific or unscientific , but whether you are right or wrong . The article which is quoted here has a great insight about the philosophy of VT diagnosis.
The message form this article goes something like this . . .
In the diagnosis of wide qrs tachycardia , If we apply the so called scientific principles the chances for missing a real VT is extraordinarily high , while if you blindly apply common sense and logic you are going to be 90% right .
What a powerful statement this ! even though it appears absurd , it is absolutely true !
A young physician should realize the importance of this . Scientific decoding of arrhythmia may be an academic pursuit but in a given patient at bedside diagnosing by experience and common logic are far more productive and accurate. Miss diagnosis of VT was not common prior to 1980s . It has become a recent phenomenon .
Probably too much of electrophysiology haS made a simple diagnostic pathway a complex one. When we relied only on commonsense the errors were less . I have often observed fellows making mistakes quite frequently while nurses were too confident to call a wide qrs tachycardia as VT .
Final message
Medical decision making is an art , in fact it is a “fine art ” We keep saying this for centuries , still medicine as a science easily overtakes medicine as an art. Here comes the problem . Some times (or is it many times ! ) too much of inquisitiveness in the name of science make practice of medicine complicated and the victims are often the patients !
Let us simplify medicine . . . let us accept an occasional bad outcome . . . for not being 100 % scientific ! After all , a million mistakes happen every day in the pure scientific pathway .
Reference
http://www.amjmed.com/article/0002-9343(88)90008-3/abstract
Also read Knowledge disease
Dr.S.Venkatesan MD 