Archive for April, 2023

This is the Incidental ECG of an apparently healthy 50-year-old businessman, recorded while  applying for health insurance

How will you describe this ECG?

Let me magnify it for you 

Why this big fuss about this ECG?

 Such ECGs are so common. Looking at the ST segment, we are supposed to think of significant CAD,, LVH, Aortic stenosis or variants of cardiomyopathy, and sometimes electrolytic shifts. The fact that it is recorded at rest, and the patient is absolutely asymptomatic, it is very unlikely there is ongoing ischemia.It could be a myocardial origin or an unknown repolarisation pattern. But, one thing is clear, we can’t send this guy under the label of non-specific ST/T changes.

The Echo was done it was normal. No WMA,  LVH. The aortic valve was perfect. 

Is CAG indicated here?

Three responses came from three different cardiologists. Everyone agreed, the stress test is not going to be useful, as  baseline  is unstable

  1. Absolutely not Indicated, since he is asymptomatic. I believe the history and Echo. Please follow him up
  2. A definite yes for CAG. (Being a scientific cardiologist, without excluding CAD, I can’t be at peace. Will do at least a CT angiogram)
  3. A third cardiologist said a CT angiogram is waste of time and wanted to do a radial CAG in 10 minutes in his newly opened hi-fi radial lounge.

What happened then?

Don’t know, whether he underwent CAG or not.  But, I can confidently say he will have a normal coronary angiogram.  How can you be so confident?  Confidence doesn’t mean I am correct. Look at the ST segment again. It is not true ischemic depression. It is neither non-sustained nor horizontal or downsloping*, This could be referred to as, primary T inversion with secondary ST segment dragging. Regarding the management,  the first response is ideal,

*Classical slope should begin at J point. Late downsloping has little predictive value as in this ECG.

Is Echo good enough to rule out structural heart disease?

Even after the echo was reported normal, few questioned the quality of the echocardiogram and asked to look specifically for apical wall motion with speckle track and GLS. ( I know, MRI is a must nowadays to rule out structural heart disease as Echo can’t rule out intrinsic myocardial disarray, infiltration, etc)

How is ST dragging different from ST depression?

                                                                Classical horizontal ST depression

Final message

The purpose of posting this ECG is, some ST segments create disproportionate panic than it deserves. The concept of  T waves pulling down the distal part of the ST segment which can be called ST segment dragging is being proposed here.

Some provocation for advanced readers 

Re-exploring the foundations of electro-cardiology is always welcome. Worth diving deep into mysterious terminology non-specific ST/T changes. ST  segment in the ECG  corresponds to the most stressful period since it represents the active part of mechanical contraction. Curiously, it Includes the entire electrical (Repolarisation) & most parts of mechanical relaxation. The true onset of LV myocardial mechanical relaxation we can’t be sure, It happens somewhere in late phase 2. I think it’s so difficult to decode that timing. But, what we can presume is ST segment behavior in its distal half is less specific for both ischemic as well as hemodynamic stress

The electro-mechanical continuity within the ST segment is so intimate, and the demarcation point between them is invisible in many clinical situations.   No surprise, we are largely in the dark about the true influence of the ST segment over T wave morphology and vice versa. (ie distal ST depression pulling down the T wave )  Though chronologically T must follow the S in timing,  it would seem impossible for “T” to go back in time and pull the ST down. (If QRS can precede P in a junctional rhythm, why not T do the same for ST? )  I am not sure whether there is any timing involved in antegrade vs retrograde repolarisation across endo-epicardial repolarisation dissociation.Further, we know very well, myocardial scars cause fragmented depolarisation in QRS. Can anyone guess effect of these scars in repolarisation vectors? (Fragmented ST segment ?)  I think it is worth pursuing this phenomenon. Let the young new age Sodipellares’ look into this.

Though the traditional rule of thumb, makes ST segment shifts more sinister, T-wave changes are largely benign, It is not an easy job to segregate benign from more serious forms of T-wave changes. Isolated new onset T inversion, can be an equally troublesome marker, especially mid-chest leads in the male population. 

It is interesting to note, not every T wave Inversion is empowered to drag the ST segment down. We don’t know why. It is something to do with the curvature of the shoulder zone of phase 2 /3 of the action potential. In this context, ST dragging could be an important concept to explore. 


. An example of isolated T inversion without influencing the ST segment. Try to compare this ECG with the one that is shown to drag the ST segment

Diastolic T wave stress

One more issue, which we are not yet clear is the timing of 2nd sound with reference to the T wave. It is a fact, a significant part of the T-wave will represent early diastolic hemodynamic stress* as well. 






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A non-relishable medical quote

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If some body is struggling with same problem, say for over three decades , there is something seriously wrong with the way we deal with the problem. How do you localise accessory pathway in WPW syndrome from 12 lead ECG ? is one such entity, This question is asked exclusively in cardiology board exams. Now a 2023 paper from EUROPACE claims, it has come out with a simple algorithm bettering all the previous ones. Please check it for yourself.

One thing we can say with conviction is most of these embryological remnant pathways are posteriorly or laterally dragged in peri AV annular region or the para septal region. Very few appear anteriorly, if anterior it is more often placed on the right side.

Why should we take this question easy ?

Try asking any experienced EP specialist* to localise a pathway in given 12 lead ECG . Don’t get surprised by a long silence before they commit, because they know the truth, and how delicate this question might sound on quiet a few occasion, because of various anatomical and physiological reasons.

*Never fail to appreciate their hard long hours in cath lab to spot, analyse and shoot these tracts.(EP stuff is not like angioplasties, which, many can do even in half sleep!)

Final message

Yes, localising WPW can be either a fascinating or frustrating exercise depending on our understanding about the attitudinal cardiac anatomy, variable autonomic tone dependent morphological behaviour of delta waves, PR intervals, QRS axis ,the transition zones etc. Shrewd fellows may go through this 12 lead stress test. ,

For others just try to localise right from left , & then posterior or lateral Forget the anterior ones. This is more than suffice. Unlike drug trials, where statistics are often battered , here the Incident numbers are the key measure of truth. (Even without seeing a ECG you are likely to be correct in 80 % times, if you localise the pathway to posterior, para-septal or left lateral zones. )


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A 62-year-old man who is being scheduled for prostate surgery with no cardiac risk factors or comorbid status came for surgical clearance. I examined him and took an ECG, everything was fine and gave him clearance for surgery.

 I was surprised to spot him the very next day, waiting in the lounge of my office. He said, his anesthetist was not happy with my pre-op-cardiac assessment report, suggested it was incomplete, and sent me back for echocardiography to know the LV ejection fraction.

I wanted to clarify with the patient, what exactly happened when he met his anesthesiologist.

“I am not sure doctor, the moment he saw your report, he called my urologist. I overheard his call, they were discussing the need for an echocardiogram and they were also wondering,  how could a cardiologist give a  surgical clearance without even an echocardiography”.

I wasn’t really surprised by the turn of events and told the patient. 

“I am experienced enough to say, your heart is 100 % normal without an echocardiogram”.

“I understand doctor, but sorry to bother you. Can you please take it for the sake of my anesthetist and urologist, after all, right now I am worried about their peace of mind” 

“You are absolutely right. This is a topsy-turvy world. Investigations are dictated to me in my own field of expertise. Anyway, I am not a fool, to expect a patient’s help to guard my principles of practice. Please check in, let me do the echocardiogram as they wish” 

Thank you so much, Doctor“.

I showed him, the vigorously contracting ventricle and taught the student trainee who was nearby, a simple clinical tip ie, a loud first heart sound on auscultation is good enough to tell you, the EF is beyond 60% in most situations. (A forceful AML movement is a direct auditory marker of EF %)

Final message

It is getting more & more clear,  physicians will face huge hurdles in applying their clinical skills to practice. They may even be unauthorized to do so. It seems, in our misplaced quest for perfection, we have fallen into a scientific trap, that every clinical decision must be authenticated by some objective lab-made obsession. The word clinical acumen could soon become a laughing stock, as AI-powered medical zombies are waiting to join our consultation suits.

(Meanwhile,  the guidelines are very clear. (Read below)  Do echo only in high-risk surgery, if patients’ functional capacity is poor. But, let me confess, at least in our part of the world,  we are happy to violate standard guidelines  without any degree of guilt )


ESC Scientific Document Group, 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery: Developed by the task force for cardiovascular assessment and management of patients undergoing non-cardiac surgery of the European Society of Cardiology (ESC) Endorsed by the European Society of Anaesthesiology and Intensive Care (ESAIC), European Heart Journal, Volume 43, Issue 39, 14 October 2022, Pages 3826–3924https://doi.org/10.1093/eurheartj/ehac270


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