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This write up was triggered after encountering a patient who instructed his cardiologist to remove an incidentaly found block in Right coronary artery. 

Oftentimes, It is a funny & futile world out there in modern medicine. Revealing the complete truths or accepting ignorance in critical decisions to their patients, make the Doctors feel that, their academic modesty and reputation are at stake. 

Still, many patients expect (and think) the doctors to be 100 % transparent and want to understand the nuances of disease better than the doctors themselves. The current fad of online & offline health education for patients is not an accident of technology. Though some benefits exist, I feel, It is an intentionally promoted, maliciously motivated patient empowering movement, trying to disarm the true professionals.

Dear colleagues, always realize, never allow the default ignorance to become patients’ knowledge and ask them to take decisions on behalf of you. (I know, this is diagonally opposite to current principles of the practice of medicine) Fortunately, this issue doesn’t arise in most public hospitals in our country.

This paper was written 30 years ago with great foresight.

 

So, act with tact. You can’t hide behind the patient’s preferences in deciding the treatment choice. It can be “as unethical as” any activity that goes against the interest of the patients under which we are taking our oath. I don’t, recall anywhere in the Hippocratic oath, that we pledge to listen to the patient’s choice of treatment. (Rather, we assure to work in their interest always)

Final message 

Let us sharpen our own skills first. We shall think about how to distill and consume the muddy knowledge emanating from the current mess of premature research spilling all over academia. Don’t try to educate too much to your patients. There is nothing called academic empathy because leaving it to our patients will ultimately end up equivalent to medical negligence.

Forget about the patient-guided treatment menu card. Think about this, if ordering a trendy new medical investigation purely on a patient’s demand is declared as medical negligence, How many doctors on this planet will be left non-negligent.(Stop. then what is a master health check-up? Who is the master ?) 

(Hope this write-up is taken from a proper perspective. No intent to create a chasm between patients and doctors relationship )

Reference 

Drane JF, Coulehan JL. The concept of futility. Patients do not have a right to demand medically useless treatment. Counterpoint. Health Prog. 1993 Dec;74(10):28-32.

Postamble & Counterpoint

It all sounds good on paper. The consequence of not listening to our patients, especially if they land up with complications, will look awkward, is it not?  So, I always go by patients’ desires.

Patients tend to believe in fancy investigations and machines and not me, what to do?

No, it is wrong. You can’t justify it. Regarding your concern and impact on our reputation, nothing can be done. The medical judiciary desperately needs some reforms, understand the reality to protect us  I always tell my patients they have to accept me as a whole. (Do you enter the Aeroplane’s cabin and check the pilot’s mental and physical acumen every time you board a flight. It is trust,.. complete trust, that drives our life right !)

It is true, that medical professionals must be always under a continuous quality* control regimen.  The consequences of consulting less shrewd medical personnel, their errors in judgment, the stress of work, patients need to accept* just like a side effect of a drug or a natural history of a disease.

*, Unlike the engineering field, defining & controlling quality in medical therapeutics is a mystery exercise with multiple agendas!

CPR with BLS and ACLS is time tested method of cardiopulmonary resuscitation. The automatic external defibrillator(AED) was a real breakthrough. Still, complete recovery eveN in “in-hospital cardiac arrest”  is at best 10-15 % . (Brindley PG, CMAJ. 2002. )Here is a technology in-progress story, now I understand FDA has approved this device for emergency resuscitation in cardiac arrest.

The principle is simple. In the early minutes following cardiac arrest, it is the survival of the myocardium and brain that matters. So, occluding Aorta transiently and continuing CPR infuses more life into the brain and heart, and the possibility of revival they say is significantly increased.

Mind you, this is not for the layperson or public but can become a game-changer for the ER crew and in ambulances or even in the cath lab. Emergency insertion of ECMO is never easy and a Neurescue balloon may come in handy in the meantime.

 

The attraction is the simplicity of the device, just inserted through the femoral artery. Don’t know how successful we would be, in centering the collapsed femoral artery though. The balloon actually doesn’t really impede the lower limb flow.It senses and relaxes as and when necessary. 

Final message

The concept behind neurescue looks like a bedside emergency partial IABP-like (IABO-Intra aortic balloon occluder rather) but appears promising. What I understood grossly is, that potential extremity Ischemia is acceptable if it’s going to save a life! Also realize, it is not a magic device that brings back life in every cardiac arrest. It gives us more time to act so that we can do other measures to bring back circulation. 

Reference

Medical science has evolved over 2000 years and moved far away, from the spiritual cure times at the temple of health at Kos islands to the Imaginations of Davicini. We are now in an era, where we can, not-only take stunning live photographs of individual organs but also go inside, assisted by  X RAYs, Ultrasound, CT  MRI, and Optical fiber. Now, a new kid is entering ie Holography. (We may expect haptics very soon).

 

How about a cardiologist operating with a virtual  3D beating heart hanging in front of him?

Yes, it is possible in a scientific fiction movie . No. it’s real. True view, an innovative medical Imaging company from Israel doesn’t think it is a fiction story. The immediate clinical use comes  in electrophysiology labs

Senti-AR command EP system is cleared for clinical use. 

 

Final message

Breaking new frontiers in medicine is becoming the norm, especially in digital imaging. No doubt, we have entered a  new medical world. However, we should be able to realize, that all the excitement is justified, if and only it makes a positive impact on humankind. Even as we are deeply immersed in medical technology, let us remind ourselves, how a tiny virus is teaching all of us, some hard lessons in basic principles and practice of medicine.

Reference

Jennifer N. Avari Silva, Michael K.Southworth, Walter M.Blume, et al. First-In-Human Use of a Mixed Reality Display During Cardiac Ablation Procedures. JACC: Clinical Electrophysiology. Volume 6, Issue 8, August 2020, Pages 1023-1025. https://doi.org/10.1016/j.jacep.2020.04.036.

Bifurcation PCI is a modern-day Cardiologist’s fascinating professional adventure within coronary arteries. Of course, one of their Intentions is to do good for the patient. Bifurcation lesions (BFL) are a special subset of lesions, that looks challenging, more because of the potential biological aftermath following the delicate construction of a grade separator at a critical site. Mind you, it’s done within a live flowing artery and subsequently needs lifelong maintenance.

Strategies for BFL

  1. Strictly committed* single stent strategy (Irrespective of what may come, LCX or LAD  pinching let me take care . Don’t worry strategy *May sound dangerous, but still, it doesn’t make other strategies less ominous) 
  2. Provisional single stent strategy with elective cross-over for truly poor result /cosmetic/peer satisfaction  purpose
  3. Provisional single stent with bail-out cross-over. Often happen as an emergency  (Not all techniques are amenable for this)
  4. Elective planned two stents (Still, flexible  to revert to single stent if the situation allows)
  5. Elective, strictly committed, prefixed  two-stent strategy  (No going back strategy/ Not really a professional PCI )
  6. Always remember, SYNTAX or no SYNTAX CABG is the safe & best bet for many severely symptomatic patients, with complex as well as non-complex BFL lesions esp in diabetic patients.

Wait, there are two more.

7. Please note, there is one benign strategy, that is always available, but hiding deep in the interventional cardiologist’s sub(non)conscious minds. It is a zero radiation, zero contrast, and almost zero cost strategy. Yes, It is “No stent strategy’ also called exclusive medical management, currently referred to as OMT/GDMT. In our analysis of symptom- lesions significance at least 30% of BFL are eligible for exclusive medical management.(FFR & IFRs ? Less we say about it, is better!) 

8. One more option for those patients (&cardiologists) who wants to travel the middle path is POBA or a Glorified POBA ie DEB  (Ref  Corballis NH,. PLoS One. 2021)

Whatever the treatment, bifurcation PCI  cannot be taken lightly. One exclusive club is debating this topic in Europe every year (EBC) for the past 10 years. Currently, Double kiss and crush (DK crush) is considered superior to others. Mini crush and Culotte are good alternatives in specific circumstances (Definition 2, NORDIC, BBC 2)

Something about DK crush (Shao-Liang Chen Nanjing, China first modified mini crush to DK crush)

Best video resource for DK crush 

 

In DK crush every step appears to be double. Apart from the double stent, it is a double wire cross, double crush, double kiss, and double POT (or even more). All must happen in a specific sequence. One may add double Imaging (Pre and Post PCI IVUS or OCT) to the list.  Finally and funnily not to miss the realistic possibility of double complications over the provisional strategy.

I am not sure which of the 10 steps in DK crush is most important. When we go through the physics of  BFL intervention it appears, that proper crushing and kissing may be the key to success. Though kissing is an integral part of any two stent strategies, in DK crush it happens in a unique interface between balloons /balloons with a stent and finally between two stents. In fact 

The physics of bifurcation kissing includes balloon hugging diameter, area, and pressure. Added to that is the intervening metal layer.

Can’t take the kissing in a casual manner. The Morino & Mitsuda model tells us more about the physics of kissing. In BFL interventions, kissing can happen with various layers that include one layer of the balloon with a crushed and non-crushed stent, carina. While we are mastering the techniques, we must realize, Kissing is aimed at stabilizing the carinal basement, still, there is a distinct possibility, that what may appear as innocuous kissing may undo all the good work we have done in previous steps. I guess, no harm in missing the final kissing if everything is ok in OCT.

Dr. Anonio Colombo’s take on kissing 

 

Final message

So, we have both simple and complex modalities for BFL. Evidence and experience reveal that 90 -95 % of patients with BFL would be eligible for the easy path. In one sense, we are indeed wasting our energy and resources in tackling this negligible CAD burden located at the summit of the global CAD pyramid with a gigantic base. However, we can feel scientifically happy, that we have gained considerable expertise in tackling complex lesions with multiple stent strategies in recent times. Still, we are far away from a true vision, of what really might follow such a niche & expertise-intensive procedure.

Let us hope, that modern metallurgy in combination with physics & hydrology would ultimately beat Biology.

Reference 

1.Dr Colomo article (For personal use only)

2..Morino Y, Yamamoto H, Mitsudo K, . Functional formula to determine adequate balloon diameter of simultaneous kissing balloon technique for treatment of bifurcated coronary lesions: clinical validation by volumetric intravascular ultrasound analysis. Circ J. 2008 Jun;72(6):886-92. doi: 10.1253/circj.72.886. PMID: 18503211.

Postamble

Does evidence create expertise?

Looking at the whole issue of complex PCI philosophically, no technique may really be superior based on accrued evidence. In fact, when expertise becomes the key determinant, the evidence goes to the background. It is really surprising we are too much dependent on hasty and often biased evidence to ratify our expertise, technique, or hardware. I know, one of my colleagues can cross any lesion with one or 2 wires.

To insist, that a particular technique must be followed may not be academically correct always. It is similar to telling a coach driver in advance when to apply a brake or accelerator when he is negotiating multiple hairpin bends in hilly terrain on a rainy day, based on clinical trials done with different drivers on different routes. Ultimately, the outcome is decided by the expertise of the driver, the condition of the vehicle, the road, and not least, the destiny of the passenger.

Murmurs are audible noises from within the Heart or vascular tree when blood flow loses its laminar flow and becomes turbulent. There are many factors responsible for it (Recall Reynold’s number ).It is obvious, that when there is hyperdynamic circulation, even in physiology one may hear a murmur. Pregnancy is a classical example and Innocent (still murmur) in children is another one.

Duroziez murmur: A brief history 

In this post let us dwell on something about a classical murmur that occurs in the peripheral circulation away from the action-packed organ heart. It was originally described by French physician  Dr Duroziez  two centuries ago. (In his own words it was called a double crural murmur ). This happened shortly after Lennec’s new era of auscultation began. When everyone was concentrating on the heart Dr. Duroziez was curiously auscultating the legs and found this crural murmur. For this out-of-the-box thinking, he is still being remembered.

In significant aortic regurgitation, we know a substantial amount of blood regurgitates back into LV. This backflow though happens in the chest and into the LV,  it is reflected all over the vascular tree. It so happens, the entire aortic forward flow for a moment slows in end-systole or even reverses at the end-systole and early diastole when the Aortic valve leaks. Almost all peripheral signs of AR are due to this. It is critical to remember, that these signs are heavily modified by arterial distensibility, associates obstruction, LV  contractility, and peripheral vascular resistance.

Is there real reflux of blood back towards the heart* ? 

Duroziez’s murmur remained controversial both for its mechanism and intriguing questions about, whether the blood really travels back in early diastole in the limbs or is just an acoustic illusion from a  pressure wave. The debate was so intense it demanded a curious animal study. The femoral artery of Dogs with induced AR was injected with contrast and retrograde blood reflux was documented up to the iliac artery and Aorta.(NEJM 1965 Ref 1) 

* While retrograde reflux of blood in the femoral artery is real, which manifests as EDM, we must understand antegrade diastolic flow murmurs or even continuous murmurs are common in hyperdynamic circulation over narrowed peripheral arteries and veins (venous hum)

**For Advanced readers: Some of the issues are not clear. Whether Duroziez murmur is truly decrescendo (Like its EDM counterpart in the Aortic area) or Is it mixed with antegrade diastolic flow murmur over the femoral artery due to hyperdynamic circulation.

Echocardiographic correlates of Duroziex murmur 

Now, we are able to document bizarre hemodynamics that happens the entire length of the vascular tree that is responsible for this murmur.(A related post 😦 In AR the run-off is central or periphery ?_)

Image courtesy: medmastery https://www.youtube.com/watch?v=eVhEXCO13ys 

 

 

Phoncardiography with ECG correlation, help us to  time the murmur exactly and also demonstrates reversal of flow in femoral artery  by color flow doppler.

Importance of Duroziez’s murmur & A research proposal 

Though it’s of historical interest, it is still discussed in exams. It may be amusing for the busy clinical cardiologist to auscultate over the legs, when they may be contemplating a  TAVI for leaky Aortic valve  (Arias EA,  Interv Cardiol. 2019). But, for students, it is a different story. If anyone wants to beat the acumen and curiosity of Duroziez, they may assess the length of this murmur and correlate it with descending aortic flow reversal, aortic ERO, and regurgitant fraction. The fate of Duroziez’s murmur after Aortic valve replacement may also be studied.

Final message 

Duroziex murmur is not just a vintage cardiac auscultatory sign meant for exam halls. Looking deep into it, we may get more insights into the behavior of the peripheral circulatory system in normal physiology as well as in patients with AR.  

Reference

1.Duroziez PL. Du double souffle intermittent crural, comme signe de l’insuffisance aortique. Arch Gen Méd 1861; 17: 417–443,588–605.

2. N Engl J Med 1965; 272:1207-1210

3.Jama.1933.Blumgart and Ernstene

 

Some physics: Why is blood under pressure? 

In perfect vascular climatic conditions, the human circulatory system is comparable to a smooth flowing river irrigating 100 trillion cells, traversing many kilometers of the capillary network, to the far away tissue bed. One major difference in the river analogy is, that in human biology, the entire blood has to return back to the heart in about 30 seconds. (The fact that the venous system does this in style with near-zero pressure head is the greatest wonder in circulatory physiology)

The force per unit area, that drives the blood is the blood pressure. It is expressed in kilo pascals. (16/10 Kpa one Kpa is 7.5 mmHg. It has two components streaming pressure as well the lateral pressure. What we measure by conventional BP apparatus is the lateral pressure on the vessel, which is what we are worried about most times. But, the forward driving head is equally important because the branch points bear the brunt of this pressure head. Sudden surges and spikes attack the grade separators more. This is one of the reasons, the arterial branch points are more prone to atherosclerosis. Though we believe onward pressure head does all the damage, it is also worth knowing the velocity of blood flow can also be defining factor in vascular Injury. The flow velocity is surprisingly low in physiological conditions, about 4-6km/h something similar to our walking speed. 

What is normal blood pressure?

We don’t know. The search is going on. But, what is important is the net lifetime BP harming effect on blood vessels. Of course, BP is not a mono player, it interacts with other risk factors like lipids, diabetes, and smoking, along with genetic susceptibility, and epigenetic vulnerability, making cardiovascular events perfectly polygenic.  

How do we define and grade systemic HT?

A dozen different societies keep defining this (ACC/AHA. ESC, ISH, British, whatever be the normal,  one set of numbers is permanently etched in our mind ie 120/80 as the cut-off. 

A more philosophical definition would be, that high BP is defined as the BP at which our blood vessels feel the stress and strain and begin to wear out. We may never ever know that in a given patient. Now, we are adding more twists to this already confusing normality data. Namely nocturnal BP.

Why 24 hr /Nocturnal BP important?

If the average human lived for 75 years, he or she will be spending  25 years in sleep. What does our circulatory system do in those 25 years? We don’t know. We believe if the brain sleeps the vascular tree takes rest as well. How can it be?  The reticular activating system should go off mode, still the vasomotor centers should be vigilant enough to keep vital organ perfusion. Ironically, sleep can be stressful for some. During recumbent posture the fluid compartment redistributes and ECF expands especially in patients with renal and cardiac compromise. (Recall the mechanism of PND) .Add on to this, the ever-fluctuating sympathetic tone with REM/NREM sleep phases. One of the offshoots of widespread use of ambulatory BP monitoring is (ABPM)is the new term nocturnal hypertension. 

Defintion of nocturnal HT

The definition of nocturnal hypertension is, night-time BP ≥120/70 mm Hg (Now it is more stringently defined as >110/65 mm Hg by the 2017ACC/AHA guidelines. I am not sure, but I think this is applicable to anyone with or without HT irrespective of treatment.

Two more entities exist to confuse us. Just don’t bother. (Fellows can’t escape from this though). A Clinic and morning home BP of <130/80 mm Hg is defined either as masked nocturnal hypertension or masked uncontrolled nocturnal hypertension if they are already on drugs.

Night time BP patterns

Normally we expect 10 -20% dip in BP is expected.

The following are four nocturnal BP patterns defined:

  1. Dipper: 10-20 %;
  2. Extreme dipper, more than 20%;  
  3. Non-dipper: less than 10%, 
  4. Riser: 0%.or + side  (I think, this is the same as the reverse dipper )

 

An Important resource from HOPE Asia net work on ABPM Kazuomi Kario Journal of clinical hypertension.https://doi.org/10.1111/jch.13652 While everything looks ok, that blue line amuses us the most. These guys are also called reverse dippers.

Nocturnal dipping: Is it systolic, diastolic, both or mean?

Most studies documented as systolic dippers. Dipping is expected to Impact both systolic and diastolic BP similarly. But, we know it need not be. systolic BP is more volume-dependent, while diastolic BP is resistance is related. I think the concept of diastolic vs systolic non-dipper is yet to be evaluated.

How to measure? How many readings? 

  • Ambulatory BP monitoring equipment is the key. Few companies have defined and have patented software (Omran HEM series is the leader, Micro life is another one )
  • The night-time BP is calculated as the average of night-time BPs (from going to bed to arising) measured by ABPM The number of night-times BP measurements required may be ≥6.
  • The methodology is getting standardized. Errors in measurement are considerable. Posture, temperature, and inflation triggered awakening all matters. 
  • Substantial technology is still evolving. Remote wireless monitoring is possible (Apple and Google are keenly watching the global BP market potential !)

Management issues

Though there are 4 subsets in nocturnal BP patterns,  currently, Identifying non-dippers is the key target that will help diagnose more resistant HT. 

How to convert non-dippers into dippers?

  • Night-time dose of antihypertensive drugs to be encouraged.
  • Salt restriction in the evening diet 

How to prevent excessive dipper (>20%)

The reverse of the above advice is true in this subset. 

Isolated nocturnal  hypertension

I think it is an overzealous concept in sleep medicine. Let us wait and observe. Stojanovic, M., Deljanin-Ilic, M., Ilic, S. et al. Isolated nocturnal hypertension: an unsolved problem—when to start treatment and how low should we go?. J Hum Hypertens 34, 739–740 (2020).

Is there a J curve phenomenon  among dippers ?

We cant generalize,  pro-dipping forces are good & non-dipping forces are bad. Should we consider labeling excessive dippers as nocturnal hypotension? Considering the fact both non-dippers and excessive dippers carry more CVD risk. Like any other biological variables with dynamic safety margins, we are clueless about what is ideal dipping .(A nocturnal J curve)

Clinical trials on nocturnal hypertension 

  • JHOP study Kario K, Hoshide S, J Clin Hypertens 2015 from Japan is a very popular one on this topic.
  • While this elegantly done Finish study  (J.Hypertension 2004 ) stressed the importance of home BP monitoring. 

What is new in nocturnal HT management?

Melatonin, administered as circadian hormone therapy is expected to play a useful role as a night watchman in BP control (Frank et al Hypertension 2004)

Final message

Nocturnal hypertension is trying to emerge as a new cardiovascular risk factor. Understanding this condition and intervening seems to be important, considering the well-known fact, that cardiovascular events are clustered in the early morning hours.

Still, routine ABPM to know the status of nighttime BP in all hypertensive individuals is not warranted. However, people who had an event or who have secondary hypertension may need to do so. The simple truth is if you have a peaceful day and a perfect sleep, your BP is bound to dip naturally. So, the message to all those active and energetic men and women who are carrying a tag of hypertension need not worry about this dipping and non-dipping stuff. Instead, maintain a healthy lifestyle. There is a thin line separating awareness and anxiety.

Reference 

1.Yano, Y., Kario, K. Nocturnal blood pressure and cardiovascular disease: a review of recent advances. Hypertens Res 35, 695–701 (2012). https://doi.org/10.1038/hr.2012.26

2,Cuspidi, C, Sala, C, Tadic, M, et al. Clinical and prognostic significance of a reverse dipping pattern on ambulatory monitoring: An updated review. J Clin Hypertens. 2017; 19: 713– 721. https://doi.org/10.1111/jch.13023

I am unable to answer this question confidently even after spending 25 years in the specialty of cardiology. I thought, the answer was yes. Reality is definitely different. Such is the complexity in the biology of the fluid and circulatory systems. The heart’s function doesn’t seem to end with just pumping 6 liters of blood every minute, ultimately, it has to handle a huge load of water as well with delicate coordination with the kidney. (ANP,& RASS feedback). It is fascinating to note, that the heart transforms into a powerful endocrine organ as and when it is necessary.

Read further, with a caution: (There is no specific physiological /molecular answer attempted)

About 28 of the 42 liters of fluid in the body are inside the 100 trillion cells and are collectively called the intracellular fluid. Thus, the intracellular fluid constitutes about 40 percent of the total body weight in an “average” person. Still, cells are somehow protected from the edema creating hemodynamic force until the very late stages. Fortunately, the Interstitium is the place all excess fluid stagnates. This is a great biological adoption. The simplest explanation is (Na /K+pump never sleeps  ) Bi-directional osmotic forces keep the cell dry even in adverse cellular milieu. Can’t imagine the implications, if every cell begins to swell in early heart failure. Still, it does happen to some degree I guess. We never quantified this.( Andrew Boyle,et al  Myocellular and Interstitial Edema and Circulating Volume Expansion as a Cause of Morbidity and Mortality in Heart Failure)

 

What happens to massive Intra cellular compartment size in HF? If renal perfusion is compromised (As one would expect in any significant heart failure) How does it affect this fluid distribution over that of heart failure? If the lymphatics’ final destination is the right heart how does this interfere with interstitial space clearance?

Practical implications

Though local factors operate, edema* in heart failure is a reflection of a more serious systemic plumbing issue. Even, subclinical fluid collection can interfere with cell function and contribute to unexplained fatigue which is an early sign of heart failure. No doubt, NYHA  gave much importance to this non-specific symptom in heart failure. Further, Individual organ functions may react in a different fashion with respect to water logging.Hepatic, portal splanchnic congestion directly affect GI function and intermediate energy metabolism.

.(*HF with zero edema so-called dry CHF  is a bigger mystery, is discussed elsewhere on this site)

When does the cardiac failure become a disorder of sodium & water metabolism 

Though the heart is a mechanistic pump when it fails it soon becomes a neuro-metabolic-endocrine problem. We are not clear whether heart failure retains sodium and water equally?  In renal failure-free water, accumulation is less than sodium. What happens in cardio-renal syndrome. These have practical implications as both hyponatremia and hypernatremia can be a feature with water content modulating it.(Now the term dysnatermia is more often used)

If RASS is activated net gain in sodium is expected. It doesn’t really happen. (Even with secondary hyperaldosteronism  sodium knows how to escape from the kidney). Vasopressin antagonist was considered a new innovation for hyponatremia associated with HF. To know the current role of V2 receptor antagonists Tolvapan, read here. 

Can we get rid of this excess water by any other means 

We do have powerful diuretics. It can unload the heart rapidly but can be harmful due to intracellular dehydration and electrolyte imbalance. When I asked an experienced Nephrology colleague  “Does excessive diuretics deplete ICF or ECF space? and how to quantify? , he was honest enough to accept, that it is primarily guesswork in a given patient and clinical assessment is supreme.

It is understood now, that there is a role for ultrafiltration of pure water in refractory hydrophilia. Bart B.A  (RAPID-CHF) trial. J Am Coll Cardiol. 2005; 462043-2046

Imaging subclinical edema in heart failure 

How to catch Heart failure early before clinical edema ? NT pro-BNP is a good option (>400pg/l) but physiologists armed with new generation imaging are working on how and where the fluid is accumulating in early heart failure. Nailfold video capillaroscopy (NVC) and confocal laser scanning microscopy (CLSM).  Wish, these modalities are really useful and do not end up as fancy tools and hike up the heart failure treatment costs. 

 

 
Future of Cardiac Hydraulics management.
1. Afterload reduction, 2. Preload optimization, and 3.Inotropics. We have been playing with these three famous principles in heart failure treatment for quite some time. We must admit, nothing really worked to our expectations. “Total body water management” is a new hope. It will revolve around a mechanical fluid management system as this overview from circulation tantalizingly discuss. DRI2P2S  (Circulation heart failure 2020)

Final message 

Edema in HF is primarily extracellular and interstitial until the end stage. Fortunately, the ionic and osmotic forces along with capillary hemodynamic forces keep the excess fluid within a safer interstitial compartment. However, we must realize each organ swells in a different manner depending upon cell membrane responsiveness to neural and humoral factors. The mechanism and content of edema fluids are different in heart vs kidney failure. It is also true, that every cardiac failure patient has a renal component and vice versa.

That’s it. I know it was a superficial attempt to understand water distribution in HF. Someone needs to break the complete truth about H2O metabolism in cardiac failure.

Postamble & a Non-academic trail

 Should we really bother to know where does fluid accumulate in HF ?  In a pragmatic sense the answer is “No” Let it accumulate anywhere, just push inj. Lasix, or if refractory add Metolazone and Torsemide, (I need to rush to the cath lab for the next angioplasty for that angina-free RCA stenosis, you know !)

Reference

This 37-page landmark review about fluid dynamics will help you find many queries raised here. (Tough read though)

 
 
 

 

 
 
 

William Heberden first introduced the term angina to the medical community in 1772. His descriptions became immortal. Still, no one would ever know what was the angina-related artery, Heberden was alluding to.

Now, some jobless cardiologist is asking this question after 200 years. How is angina from the LAD system differ from the RCA  system? or let me put it another way, How does angina of anterior circulation (LAD) differ from posterior circulation (RCA/LCX)? Though there is distinct hemodynamic profiling of RCAvs LAD ACS, surprisingly, cardiology literature does not answer the chest pain aspect of it. One rare study, done  4 decades ago throws some light

Here is a curious little study, with a simple & crisp conclusion.

chest pain and IRA localisation angina LAD angian RCA

It concludes, that LAD angina rarely radiates to JAW or epigastrium. While RCA angina relay radiates to the left shoulder.

So, why does this happen?

What I could guess is the ubiquitous vagal fibers that travel in the posterior aspect of the heart, and carries pain signal directly up to the jaw whenever these areas become ischemia. LAD is less likely to irritate the vagus. Of course, there can be a definite overlap.

OMG, give me some time to keep in touch with  basic science 

Now, fellows of cardiology, please take a  pause from your regular aggressive cardiac cath lab workouts and get a break at least once in a while. How does the ischemia of myocardial tissue generate pain? Why it is severe in some, trivial in others, and even dead silent in some, 

The chest pain genesis is initiated by sensory electrical neural action potential, that captures the epicardial neural plexus first, switching over from somatic to the visceral pathway and trespassing the para ganglionic plexus and traveling further to the spinal cord. Where it may collide with other incoming sensory signals ascends in specific myelinated and non-myelinated neural cables, reaching the brainstem, interacting with local nuclei, and finally reflecting on subcortical and cortical pain matching centers.  We haven’t yet located the exact center for anginal pain. (Perithalmic and amygdala could be closer to real centers) 

So, it is a really complex sensory world yet to be understood fully. Mind you, I haven’t touched upon the neurophysics of referred pain, linked or clandestine angina.

  • What is the effect of cardiac denervation, autonomic neuropathy, or on the perception of chest pain(Does a quadriplegic feel angina ? or post-transplant heart immune to angina ? (Gallego Page JC,Rev Esp Cardiol. 2001) 
  • Is it biochemical or neural, can substance P in blood cause pain hitting the amygdala? 
  • Will hypoglycemia and anemia cause angina due to lack of glucose and oxygen?
  • Finally, how is Infarct pain is different from ischemic pain (Ischemic)

Where do get the answer to these questions?

This paper from Dr. Robert Formean(Ref 2) university of Oklahoma is just the best source I think, to explore and understand the topic. (Reading time 60 minutes: Let me tell you, it is worth more than a time spent on an insignificant angioplasty of painless PDA lesions)

Final message 

So, what have you learned from this post? Does this question about angina matter at all? Surely not. in this space-age cardiac care where we are right inside the coronary even before we listen to the patient’s complaint properly. We are always at liberty to do what we want( or love) to do. But, the urge to understand the foundations of clinical science is the last remaining hope, that will keep the specialty of cardiology enchanting. 

Reference
 
 
A comprehensive reference for the genesis and signal processing  of chest pain 
 
 

This graph is a rare treasure in CAD therapeutics (fished out from a huge, often conflicting chronic CAD literature) that elegantly shows us the complexities involved in the revascularization of ischemic hearts with risks and benefits criss-cross each other. Our job is to identify, that critical point in a given patient’s CAD timeline for optimal management. To make things difficult, this point is a moving target and makes this delicate clinical exercise truly complicated.

It conveys a simple message in strong terms. It says the inflection point is around 10-15%. When the total ischemic areas are beyond this the benefits increase and when it is less there is sure shot harm.

Now comes the tough part. How best we can identify and quantify the true area of ischemia?

There is no such thing called coronary mathematics. Even if we try to make out one, vascular biology will giggle at us. Still, we have no other option but to go for sophisticated imaging modalities. Stress Echo, Nuclear Imaging, Scar imaging, MRI, PET, quantify total ischemic burden, plot it with corresponding coronary anatomical zones for a potential correction.

What this curve does not convey is the complex interplay between Ischemia vs symptoms. Ischemic myocytes have so many invisible tricks to adopt themselves. Should I go after the burden of Ischemia (Often Imaginary) or the burden of symptoms? Despite the lack of benefit in most trials on CTO in hard endpoints, it is yet to rectify the thinking patterns of many elite evidence-based cardiologists.

Final message

However, It will be an unpardonable act of omission if we miss or fail to offer the benefit of opening a critical LAD disease that has troublesome symptoms.

“Publish or perish “

This sound bite is regularly uttered by all academic leads in any university or medical school. I don’t know, why this bothers me. Looking back, many of our mentors & professors never had any great publications. Still, they were extraordinary teachers and wonderful clinicians with great wisdom. They created generations of high-quality doctors who are present all over the globe now. Is scientific publication that important in a doctor’s life? After pondering for quite some time, got a hazy answer to that query in one of my sleepless early morning academic dreams.

Hippocrates was one of the applicants for the post of professor of medicine at Harvard medical school.His application was rejected for a dismally low H index. The reluctant father of medicine tried to impress the authorities, by telling them that his experience was vast and used to teach medicine 2000 years ago, well before their country USA was discovered. The father of medicine almost begged to reconsider their decision.The miffed Harvard academic office ridiculed the old man and insisted nothing will work, except a minimum H index of  50 or atleast 10 papers as first author in a peer reviewed high Impact  factor journal. A dejected Hippocrates returned to Kos islands and asked his new generation fellows, what is this H index and Impact  factor stuff ? His students were worried about their guru’s ignorance. They some how convinced the greatest ever medical teacher to urgently subscribe for a platinum membership of a premium medical authourship services located in the Boston suburb and fixed a 30 day deadline for his first manuscript.

(What is this H index ?)  Why is it so popular?)    Ref : J. E. Hirsch  An index to quantify an individual’s scientific research output

Off to Kos Islands 

Now, let us travel back in time,2000 years ago to this picturesque nation, Kos islands in the Aegean sea,. This is where Hippocrates taught lessons under his favorite tree. No teaching apps, No 4k audiovisuals, The humble noise from within his lips became great wisdom thoughts. All that students had were set of ears to hear him. Hippocrates became the celebrated father of medicine for two reasons. He was the first to dispute the then-prevailing thoughts about human health and disease. He first proposed for every illness there is a hidden reason ie the beginning scientific basis. He insisted and negated the idea that diseases are bestowed upon by evil forces and spirits. The second one is more important. He realized knowledge, skill, and power are a deadly mix for the healing industry if they lack responsibility. He foresaw non-academic factors that will try to challenge the integrity of medical professionals and the health care delivery systems. It is astonishing to note how he could predict this 2000 years ago and wrote the behavior code for medical professionals which has become immortal.

How to grade the quality of medical professionals?

Scientific publication is just one of the indices of quality assessment for medical professionals. Grading them based on a few manufactured rating systems is beginning to look like an academic comical. There are many more visible and invisible, quantifiable and non-quantifiable quality assessment parameters that deserve attention.

Research  & Innovations are indeed the pivotal pillars that take us to newer frontiers of medicine. But, It is explicitly clear now, the prime purpose of research is definitely not aimed at the growth of science. It is more of a survival tool, intertwined with commerce, status symbol, pride, peer pressure, self-esteem, rivalry, or just a filler for CV. 

Final message 

Blanket statements like Publish or perish at any cost could be a dangerous doctrine to adopt in medical education which is essentially about healing and caring (& whenever possible, curing). In one sense, medical teaching is little to do with research. Many of the great professors in our country never published a single paper. Unfortunately, research and teaching have been made to look inseparable. Beware, history has repeatedly taught us medical professionals need not be hyper-intelligent. They need to be just wise, men /women of integrity, enriched with sincerity, righteousness. Proper consumption of knowledge is much more important than the creation of it. Let us hope the future will be at least as perfect as the past. 

Postamble

My  H index stands at 15, I must confess I am confused a lot. Should I bother for more, or be just be happy to reach the H index of our mentor and father of medicine, which is numero Zero, and propagate his work. 

Reference 

Grzegorz Kreiner The Slavery of the h-index—Measuring the Unmeasurable..Front. Hum. Neurosci., 02 November 2016

2.Academic excellence does not always require publication  Ernest L Boyer argued in his 1990 book, Scholarship Reconsidered: Priorities for the professoriate,(BoyerScholarshipReconsidered)

3.Too much academic research is being published https://www.universityworldnews.com/post.php?story=20180905095203579