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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

 

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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.

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“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 

 

 

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A path-breaking research is coming up from Jhon Paulson school of engineering, Harvard.

It is all about a tiny lab-made bio-hybrid fish that is mechanically engineered with cardiac stem cells. It can generate enough mechanical force that can transform into a biological organ (or assistance)to the heart. Early lab experiments are exciting. We will soon see a stem cell-enriched bio-fish that will dance to the tunes of the cardiac cycle.

(See the video below) 

Final message

Will it become real? or a just a grandeur thought?

We have just done Xeno heart transplantation and the mechanistic possibility of a fully functional total artificial heart is always there. Now, let us look forward to this bio-hybrid organism*  that will break the ultimate barrier in the biomechanical support for failing hearts.

Reference

*Biohybrid organisms, are devices containing biological components.

KEEL YONG LEE ,SUNG-JIN PARK , DAVID G. MATTHEWS et al  An autonomously swimming biohybrid fish designed with human cardiac biophysics SCIENCE • 10 Feb 2022 • Vol 375Issue 6581 • pp. 639-647 

 

 

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Spanish flu battered our planet in 1918. How did we overcome that? (Did we really do anything ?) About fifty million lives were lost. At that time, we didn’t even know, cells had a fully functional nucleus, forget about the DNA & RNAs. Spanish flu was tackled only with our primitive understanding of microbes, cells, and immunity. Masks and common sense were the weapons.

Now, one century later the next pandemic is In. It is an advanced medical world out there.100 Noble prizes have been won for medicine since then. We do the whole-genome map of not only human cellular DNA but also for the viral particles.

A recent paper on this topic. 

How effective is modern science in controlling the current pandemic ? 

We did wonders saving thousand of life with the help of critical care units. Some precious (elite)lives were saved by ECMO, Even lung transplants saved a few lives. We mastered the art of creating RNA interrupting biologicals. Even as we reap the benefits of stunning discoveries of science, we have equally misbehaved with it and largely undid whatever we should have achieved. We lost more lives due to a lack of simple measures. excess of futile measures, manic dependence on diagnostics.

Where did we collectively lose our sense and decide to chase multiple variants with a full genome mapping on a global scale? Who decided to call the viral variants attractive names and give larger-than-life images to amplify the panic? Even after getting a final vaccine solution, why the World is denied sharing the benefits in an equitable manner. 

There is no meaningful evidence that extensive  RTPCR,  antigen, or antibody testing has impacted this pandemic in a significant way. Testing is meant before the onset of community spread or if there is a specific treatment for the disease. How do we explain countries with maximum testing, maximum vaccine coverage, maximum booster dose had a maximum recurrence and damage?

Final message 

Science is sacred & Godly if only, its creator’s Intentions are pure. The risk-benefit ratio of modern science, (Rather, the way we understand and assimilate it ) in tackling this pandemic is threatening to tilt in an adverse fashion. Definitely, WHO must realize this. Let us go back and read the foundational lessons of clinical epidemiology and pandemic handling. I felt awkward to write this post but truths are rarely sweet.

This article  by Dr. Anand Krishnan, Professor of  community medicine, AIIMS New Delhi, has some enlightening content

https://timesofindia.indiatimes.com/india/whys-pandemic-policymaking-still-short-of-science/articleshow/88650912.cms

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The New England Journal of Medicine (NEJM) the premier journal in medicine originated two centuries ago, in 1811, when  John Collins Warren, a Boston physician, along with James Jackson, submitted a formal prospectus to establish the New England Journal of Medicine and Surgery and Collateral Branches of Science as a medical and philosophical journal. 

Subsequently, the Massachusetts Medical Society (MMS) purchased the Journal for US$1 and, in 1928, renamed it to The New England Journal of Medicine.

NEJM’s New Journey

It is 2022, after 200 years of providing explosive knowledge in medical science, MMS  starts a new journal, fresh and bold. It is called NEJM Evidence. Can you guess, what is the need for such a journal now? I think the most battered word in science in current times is probably “ evidence”.  It has a unique character of appearing most sacred as well as scandalous at the same time.

NEJM has remained the torchbearer of almost all advances in the medical field seen in the last two centuries.  It is heartening to note the newborn is named as NEJM evidence. It has come at a critical juncture. I am sure, everyone will acknowledge that we are at difficult crossroads. Overwhelmed with unregulated scientific discoveries and publications, struggling to deal with self-inflicted knowledge pandemic. In the process, we have lost “not only” the ability to ignore trivial health issues “but also” failed to provide simple, cost-effective care to the real patients who desperately need it.

Let us hope, (& wish,) NEJM’s new prodigy will guide medical science towards a successful, meaningful, and ethically fulfilling journey for mankind. Meanwhile, let us pray for every medical scientist to be blessed with the required strength and courage to steer in the right direction, weeding off both academic and non-academic contaminants.

 

 

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What is in store for the future of cardiology as of 2022?

Here is one of the rare lectures (A grand rounds by Houston Methodist)  by legendary cardiologist Dr. Euegne Braunwald who shares his wisdom, vision, and research and finally his advice for the generation next cardiologist.

 

For those, who are short of time to listen to the father of modern-day cardiology, let me share a preview. The talk is divided into 6 subsets.

  1. Polygenic risk score (PRS)  Dr. Braunwald talks about how genetic risk profiling and risk factor interaction will help us identify susceptible populations. Here, he stresses also the importance of clinical risk assessment.
  2. Primordial prevention of CAD: 
  3. Anti-lipid strategies: He introduces a new concept of  Cumulative LDL score &  CHD threshold.  Dr. Braunwald argues rigorous lipid control should go beyond statins and suggest once a year Injection Inclisiran(Small interfering RNA that prevents PCSK synthesis) will reset the lipids levels by 40% and prolong life by 30 years.
  4. Anti -Inflammatory strategies: He reminds us Atherosclerosis is equally an inflammatory disease and new anti-inflammatory drugs like Canakinumab’s role could be vital.
  5. Artificial Intelligence: Will be the guiding force in the future of preventive cardiology, as well as treatment. He tells us predicting Atrial fibrillation and even LV function from the resting ECG is possible.
  6. Clonal hematopoiesis independent potential (CHIP) is a new risk factor by somatic mutations in leukocytes that accelerate atherosclerosis proven by canonical risk predicting models

    It was a great one hour to spend on a Sunday, under Covid Lockdown.  However, It was a surprise, the biggest Innovation in cardiology in the last century, PCI, and other exotic coronary and noncoronary interventions could not find a place in his one-hour lecture. I think there is a hidden message here. 

He signs off with some important advice for the generation next cardiologist.

Thanks, Methodist for bringing  this to us.

 

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Surprised to find this site, in the 5th slot in the global rankings by feedspot search engine.

Never Imagined, when I started my scribblings way back in 2008 , It will be listed along with American heart asssociation, BMJ and others in top 10.

I need to thank the readers who make this happen.

Thank you all.

(PS :I am not sure on what basis these rankings were done though, still it adds some energy, that keeps this site running)

https://blog.feedspot.com/heart_blogs/

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A new year brings “New hope”

After a hectic two years , let us pray & believe, the good old times will be back in our life.

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     If anyone asks to shortlist the best papers that were, ever published in clinical cardiology, I am sure, this one will reach the top ten. It was 1979, the field of cardiology is just waiting to explode. CAD was managed primarily with drugs and occasional CABGs.  Coronary angiograms were an academic luxury. Both thrombolysis and PCI were unknown. Fortunately, Clinical cardiology was still alive and kicking. Dr. George Diamond and  Dr. James Forrester from  Cedars Sinai, New York worked together to bring this masterpiece. How and when to suspect CAD in the general population? For the first time probability was applied as a diagnostic tool. 

Link to the NEJM Paper

The paper begins by analysing basic clinical symptoms, risk factors, then gradually dwell deep into the population-based likelihood ratio, of CAD with the help of stress ECG, Thallium, and fluoroscopic coronary calcium. It finally ends up with a magical fusion of the  Bayesian theorem into clinical medicine. It essentially taught us how to accrue scattered knowledge, clinical judgment, and diagnostic acumen among physicians in a community and aggregate them to a powerful statistical evidence base.

A popular Inference from the DK model still asked in cardiology boards

It’s more than four decades since this paper was published. There have been some concerns about DF classification in the current era.  It was compared with the new Duke risk and found to be less valuable in the low-risk CAD population.(Wasfy MM, et all AJC 2011)  The concept of pre-test probability deciding the diagnostic value of screening tests is very much valid. We need to recalibrate the DF scale for the current population and new generation screening methods like MDCT etc..(Gibbons et al Jamanetwork 2021 )

Forget the pros and cons, DF study told us the importance of clinical judgment in the decision making process. Now, we are living in a glamorous new world of cardiology. Cath labs have become our 24/7 office suits, always in hot pursuit for instant fix solutions. Still, we often find ourselves desperately blinking at the doors of EBM, for the elusive answers to some critical queries. Why the same intervention seems to work in one large study and totally go wanting in another? (MITRA-FR vs COAPT)

Where are we erring?

The problem is the way evidence is created. It is often made up of data collected from poorly framed questions and methods, which are incompletely collected or wrongly interpreted. I wish, Bayesian theorem derivatives also address the probability of how pure is the pre-test (research) evidence base available in a scientific community. The core of truth in statistical science lies in, how we understand and define the number needed to treat, (NNT) and the number needed to harm (NNH) with any treatment or diagnostic modality.

Final message 

Artificial intelligence and machine learning are projected to be the next big thing in medical science However, the probability of machines prevailing over, human clinical acumen, backed by a sound knowledge base and observation skills appears very minimal. Let us see. Meanwhile, I wish every young cardiologist to go through this paper by D&F to get enlightened.  

Reference

1.Diamond GA, Forrester JS. Analysis of probability as an aid in the clinical diagnosis of coronary-artery disease. N Engl J Med. 1979 Jun 14;300(24):1350-8. doi: 10.1056/NEJM197906143002402

2,Wasfy MM, Brady TJ, Abbara S,  Comparison of the Diamond-Forrester method and Duke Clinical Score to predict obstructive coronary artery disease by computed tomographic angiography. Am J Cardiol. 2012 Apr 1;109(7):998-1004. doi: 10.1016/j.amjcard.2011.11.028. 

3.Gibbons RJ, Miller TD. Declining Accuracy of the Traditional Diamond-Forrester Estimates of Pretest Probability of Coronary Artery DiseaseTime for New MethodsJAMA Intern Med. 2021;181(5):579–580. doi:10.1001/jamainternmed.2021.0171

Further reading 

1.The Duo of D & F didn’t stop with that. They went on to make produce another fabulous paper on the hemodynamic classification of STEMI. Which is discussed elsewhere

Dr. Diamond & Dr . Forrester

 

 

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