Archive for September, 2010

Mankind’s  elusive pursuit of happiness  has an  interesting relationship with human physiology.The recent research  from  Princeton  university has confirmed a concept about the relation between  happiness and the economic well being .It was strange it exactly mimicked a famous physiological concept involving hemoglobin and oxygen.

Two simple questions were asked

  1. Can money bring happiness to life ?
  2. Is there a linear relationship  between money  and happiness ?

The answer to the first question is  “yes” it can.

The answer to second  looks complicated but , it is actually simple !

The relationship between money and happiness is  linear initially  , till it  hits the flat  section of  the curve  at 75000$ /year . (In India it may at 12,0000 lakhs/year)

Like hemoglobin , which   gets saturated  with oxygen  at  Pa o2 of  90  %  ,

Beyond  a particular point , however much you increase  your salary , the  mind can not be enriched with further happiness !  , as all the happiness receptors  get  saturated !

Link to Princeton university paper

Another  curious phenomenon is ,  the more time you spent  in pursuit of happiness less likely you get it  !

(The following  illustration  is from the original Princeton paper which i got from  NDTV  website )


Hemoglobin Oxygen dissociation curve

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Cardiology is probably the most rapidly growing field  in medicine. Radiology is closely following .When both combine together there is  bound to be  plenty of action ! That’s what is happening with this journal .

Knowledge is power , do not bother if you do not have such  a machine in your work place.Just know what is happening in the world of cardiac imaging.


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  • Endothelium is the largest vascular organ in the body .
  • It is constantly being serviced by both the circulating blood  from the luminal side as well as from the abluminal plane.

  • The discovery of nitric oxide and endothelin  was a breakthrough .
  • They are under neural, mechanical and endocrine control .
  • Negative emotions like anger and depression has a high correlation with hypertension and cardiac event
  • Positive emotions like laughter and happiness is expected to have good vascular tone

This fascinating  study from Japan and USA (Texas)  published  in American journal of cardiology , discusses how a comedy movie possibly releases nitric oxide profusely from our endothelium

Link placed with the courtesy of AJC


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The world of  medical science is  moving in a alarming speed.In any field , speed is always dangerous ! That’s why we have speed breakers , traffic police , speed cameras , etc etc . The medical world  is flooded with new devices, drugs , procedures . Though the mankind is benefited with many of them , a equal number could do the opposite.

How to identify which is causing benefit and which doing harm ?

It is a horrible fact , this is the most difficult exercise  for the  medical academia   . . . Still worse , harm will masquerade as benefit ! Further ,  beneficial concepts are  often buried alive if  it lacks  glamor  or  commercial value (Eg: The Digoxins,)

Lay public (as well as )  the physicians   are fed with half-baked ( Often quarter baked !) medical information .Many  of the medical journals,  guidelines , sponsored  seminars  ,  some times  even text books do a clandestine  campaign  . Even after a completion of major trial,  real truths rarely  come out . Funnily ,  they call them aptly , as blinded study ! Who is blinding whom is a different issue .

So ,  in  this  new millennium , thousands of innovations are on the pipeline. These pipes are often  infested with trivial , duplicate or even  harmful  concepts waiting for a grand release into human domain.

Take the story of coronary stents

In 1977 , Gruntzig mastered the  opening  of  the obstructed coronary  arteries with a simple balloon without any add ons . That patient is still alive  without  angina  . In the next 30 years we have ridiculed (Rather , we were compelled  to ridicule it ! * Read the related article  Is  there a role for  plain balloon angioplasty ?

Technology made  it  possible to introduce a  gamut of intra coronary  devices .We used (?abused ) all sort of anticancer drugs within the tender human coronary arteries .In 2002 , we claimed to  have climbed the summit and conquered  the restenosis with DES. And in 2010 , every one knows  what is happening to DES .

The malaise is  deep rooted  in every specialty . Next  came the  Stem cell fiasco ? and more  recently huge  conflicts of interest exposed  in the  vaccines  against H1NI

Final message

Who is going to regulate the menace ?  Hmm . . . . then  . . . Who will regulate the regulators ?

Is there a way out for our patients ?  or  they  have to suffer with it  along with the disease . The later is  more realistic option !

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In 1960 , exactly 50 years ago , a group of doctors from Jhon Hopkins published their observation in 20 cases. It went on to become , one of the most remarkable discovery  in the history of cardiology .

They taught us how to use  a pair of hand  ,  as an  artificial  heart and save lives

They are . . .

  1. Dr Kouwenhoven*
  2. Dr  James R. Jude, and
  3. Dr G. Guy Knickerbocker .

* He was not a medical doctor but an electrical engineer at Hopkins but he worked in the medical school as well .

They meticulously documented , each patient’s case history ,  whom they were able to successfully revive , (It was in the same  period , the  AC/DC shock was also invented  in the  Hopkins ) .One of  the  highlights of their paper was ,  with each chest compression  they were  able to elevate the carotid pressure  up to 90mmhg and was recorded in a pressure tracing .

We have to thank the  JAMA (Journal  of American medial   association )  for  making this  original  article   available  free in their website .

Must read for every cardiologist


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We owe a lot  , to  our ancestors for making our  journey   smooth  and purposeful   in  our  pursuit ,   of   healing the   mankind  . It is because of their  meticulous  clinical acumen , passion  , dedication ,sacrifice we are enjoying  the fruits  of success .

Though there are thousands of them , one life that always fascinates  me is that of Harvey Cushing. His fame went  to dizzy heights  after his publication of  biography of William Osler .

A book every medical  professional must read and cherish especially the elite cardiologists !

I wonder  ,what  Harvey Cushing  ,  if alive would make  a difference  in the current  world of medical  science contaminated with commerce ,  hyped up technology ,  and  the near extinct bed side clinical skills.

Links to life of Harvey Cushing http://www.med.yale.edu/library/historical/cushing/peter.html

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We now understand , heart rate reduction  could be the single most important factor  in the management of heart failure .Beta blockers have proved this time and again.We know heart rate has a linear relationship between survival .

SHIFT trial has  proven  that  Ivabradine  has a major role in the management  of chronic heart failure therapy .It is an If current blocker .  No hemodynamic  side effects was noted.

How does Ivabradine act ?

It acts on the phase 4 diastolic depolarisation in SA node by slow I f  currents.

SHIFT trial Link to lancet

SHIFT study official website

In this trial , the usage of  optimal Beta blockers  was  only in 25 %  . Patients  who received   complete beta blockade did show much benefit with Ivabradine . Further, the usage of  digoxin was only around 20% .This does not represent  the realistic  population of  cardiac  failure in many  countries  .In India , almost 70-80 % receive  it . Digoxin , the wonder drug does have an important vago mimetic action, to  reduce the heart rate .

Another  contentious issue   in SHIFT study  is , the Class 4 patients constituted <2% of the study population .It is ironical , these are the patients , one would  like to try a new rate control drugs like Ivabradine  , because we  are worried about beta blockers in this population  .A great opportunity was  lost as Ivabradine could have  been tried in this population.

We need a study  like this .

  • One to one comparison   of  beta blocker  and   Ivabradine  in cardiac failure  . Such a study will ever happen ? My guess is , it is  next to impossible !
  • Efficacy of  Ivabradine in patients with class 4  failure  , where beta blockers were contraindicated  or could not be administered.

Final message

Ivabradine , a new generation  negative chronotropic agent  is a great concept drug. But , the worthiness of this drug  is questionable , when we have  proven , well tolerated  drugs namely , the beta blockers to reduce the heart rate.. However , if the beta blockers are poorly tolerated  Ivabradine may be tried.Last , but not the least, never under-estimate the greatness of digoxin in heart failure.It is the only drug that has a positive  inotropic  properties coupled with  negative chronotropic action . Both benefits patients in CHF  . It can do wonders than any other drugs .(DIG trial was the most misunderstood by cardiologists!)

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For the lay public   the term complete heart block (CHB) often convey a sinister message . When  encountered in   pregnancy,  it is   frightening    for the  physicians as well .  One need not  say  . . .the anxiety to the Obstetrician !

Congenital complete heart block is the usual etiology. Though there are other important causes of CHB in general population , it is very rare to  get an  ischemic or  degenerative heart  blocks  in the reproductive age group.

There are  many  ways it can present .

How does it present ?

  • Symptomatic CHB detected  first time during ante natal screening
  • Asymptomatic CHB detected incidentally during ante natal screen
  • CHB first time recognised during active  labor. Either symptomatic /Asymptomatic
  • A more familiar  situation  is  CHB  diagnosed in child hood . Women in question can undergo an  elective marriage and a managed  pregnancy.

* The success of modern medicine  lies in the  mantra  of  “early  diagnosis ” .Ironically , early detection  of CHB in  pregnancy adds  considerable anxiety  to mother , family  and the treating physician  . So ignorance  can be a  bliss here ,  as 99/100 with CHB  would not require any intervention during pregnancy  .But , in this hyped up scientific world  one  needs  lot  of courage to  simply watch a pregnant mother with a heart rate of 45  !   .You are tempted to do something . We have seen CHB presenting  in labor room as emergency and delivering successfully  by vaginalis .

Where is the pathology in congenital complete heart block ?

It is  usually due to anatomical discontinuity between AV node and the bundle of his. The most fortunate thing  here is ,  these patients  develop a junctional escape rhythm at around 40-45/mt .This is enough for most basal activities. Further this junctional rhythm can increase   up to 100 in many, or  even up to 120 at times of stress.(Accelerated junctional  rhythm )* .An ECG which shows a narrow qrs  complex is nearly  100 %  specific  for a stable junctional escape rhythm.

What is the hemodynamic stress of pregnancy ? Will a heart rate of 50 /mt enough , to support the labor or cesarean section ?

Nature  is a wonderful equalizer. What the pregnant mother requires is a good cardiac output to nourish the baby as well as herself. A heart rate of 50 is often able to sustain and support the entire pregnancy with ease.

How it is done  ?  . . . is  it not simply  amazing ?

In pregnancy there is less of  systemic vascular resistance due to various reasons (Low impedance  placental circulation, reduced sensitivity to Angiotensin 2  ) . The heart can always increase it’s out put by increasing  the heart rate or stroke volume.  In  patients with CHB , as the  rate can not be increased much , the heart  accepts  the  alternate option quite easily without  any protest  . The low SVR also facilitates  increase in stroke volume. This  is the reason pregnancy  is  often well tolerted  even with the heart rate < 50 /mt.

But , at the time of delivery increase in heart rate may be important in some.We do not know , who will require this HR support .This makes it mandatory to have a  temporary pacer standby.

What are the ominous signs and symptoms of CHB in pregnancy ?

Having discussed a lot about the benign nature of congenital CHB ,  one need to realise it is also a potentially dangerous heart rhythm . Syncope, symptomatic hypotension  (BP<90) and some times  signs of PIH ,  all possibly indicate a pacemaker support .

Can we do an exercise test  to  assess  the chronotropic competence in pregnancy ?

Tread mill test is generally not done  in pregnancy. It is a good option ,  to test the adequacy of heart rate increase during activity . If the heart rate increases up to 100 -120 it is a good response .

What about holter ?

A less predictive , but more acceptable investigation is the 24 hour holter monitoring  that gives a rough idea about lowest and highest heart rate. If there is a  long pause > 5 sec ,  she will be a technical candidate for permanent pacing !  once you have documented this ,  we will be sued if not paced however asymptomatic the patient is ! So beware of this investigation !

Atropine stress test ?

This again is a simple test , that will measure the chronotropic reserve. A concern for fetal tachycardia is genuine !

Pre-conceptional  counseling

A patient with congenital complete heart block should never be adviced against pregnancy.

“Pace and become pregnant ” strategy is also not warranted.This is based more on the perceived  scientific approach the and  litigation  fear  than reality !

Only issue is we have to make sure ,  the women in question has  adequate hemodynamic reserve. This  can be easily accomplished  by asking some basic questions about exercise capacity .Or , she can be put on a  tread mill (or atropine stress test). If the heart rate increases up to 100/mt  there is absolutely , no need to put  permanent pacemaker.

Peculiar  issues in   pregnant  women with permanent pacemaker

The paradox of modern medicine  felt at it’s  best here !

We think ,  we are  implanting   a  pacemaker in CHB of  to provide good hemodynamic support  during the stress of labor. But a  fixed rate VVI pacemaker will not do this job . The real reason  to put a pacemaker is to avoid a dangerous bradycardia during the labor .

Hence ,   patients  with CHB carry equal  concern (if not more !)   during labor as the pacemaker fires at a  fixed  rate of 70/mt and  the native rhythm is often suppressed due to long-term pacing . Hence their heart rate often fail to increase   beyond the pacemaker rate of  70  . Paradoxically , patients with untreated  CHB (with their native rate ) , can increase their  heart  rate often up to 100-120  at times  of stress .This is possible because  their AV node is still under the control of autonomic system , while artificial  pacemakers* are not !

*Some of the current pacemakers have overcome this problem with rate adaptive pacing .

Mode of delivery ?

  • Natural , expected
  • Induction  of labor
  • Elective cesarean
  • Emergency Cesarean

Can complete heart block per se , become an  indication for cesarean section ?

No. It is always an obstetrical indication .It  is better to avoid GA / Regional anesthesia  in cardiac disease. The stress of  second stage of labor is always less than   that of   surgery provided it is not unduly prolonged .

Assisted /accelerated vaginal delivery is the  best option .However , one should be ready for any intervention. Some obstetricians  feel  that, elective cesarean section  could  be less stressful than  labor( which could be prolonged for some unpredictable reasons  ) while a ,  Cesarean section  can not  be a  prolonged one  !

Cardiologist’s role in the labor room

The role of cardiologist is to provide support to the obstetrical and anesthetic team   prevent   extreme bradycardia. Inserting a temporary pacemaker with back up pacing of 50/mt is preferred.Trans-jugular approach is ideal .In difficult cases fluroscopy guided temporary pacing in cath lab is advised.

Role of temporary trans cutaneous pacing  as stand by ?

This method of pacing with two sticky electrodes in the chest wall  with external pacing .It is proven , efficient useful modality of pacing in coronary care units  .However this can be a substitute for  only few hours of support . May have patient discomfort .In places from expertise for temporary  pacing is not immediately available  this can be used .However presence of such a machine increase the comfort level of physicians.

Is there a rate adaptive temporary pacing available ?

Currently available temporary pacemakers  are not rate adaptive , and hence we have to pace  roughly at  about 90 or 100 give  allowance  for labor related demand  (We would not know, how much  the mother is compensating with increasing with  stroke volume ) in this case pacing rapidly may  reduce the net cardiac output as the mother’s heart is  used to operate  at different  point in the  frank staling curve right  through the 10 months


Anesthetic issues in complete heart block  during cesarean section

Anesthetists have a concern here.(Genuine one of course)  A cardiologist  with a standby temporary pacemaker is  to be arranged. Cardiologist  will decide whether to have sheath or sheath plus lead  in standby mode .

Many anesthetic drugs have an adverse effect on heart rate. Drugs to be avoided are  Fentanyl ,suxamethonium, neostigmine  Induction with propofol has risk of worsening bradycardia . Controlled epidural anesthesia is preferred .This ensures slow onset anesthesia and limits hemodynamic instability.Bupivacaine is known to cause depression of heart rate .(Even with epidural route )

Miscellaneous questions

A often debated  query among obstetricians : Should I refer a CHB patient  to a cardiologist or electro-physiologist ?

There  is no  academic answer  to this question.Logic demands conservative (without compromising patient/baby  safety ) management .Electrophysiologists are rarely conservative

Radiologically how safe it  is ( for the fetus ) to undergo permanent  pacemaker implantation ?

For implanting a permanent pacemaker, about   15 minutes of  fluro time is required which could be significant .So it should be used in  exceptional situations only.

What is the effect of maternal  complete heart block on the fetal hemodynamics?

Nil or almost nil (Surprise ! surprise)



Issues during  weaning of pacing  in postpartum

Post partum period can be troublesome in few as fresh  blood volume  injected from contracting uterus.If temporary pacing has been done , it is usually possible to wean by 48 hours. Permanent pacing  is rarely required


Final message

  1. Congenital complete heart block* during pregnancy is  a well tolerated rhythm.
  2. The panic  this   entity creates is  largely unwarranted. This conclusion is derived from decades of observation by eminent clinical cardiologists.
  3. The heart  rate reserve can be estimated by a  minimal exercise test .(Atropine test with caution )
  4. Insertion of either permanent  pacemaker is not necessary* in most .
  5. If there is symptomatic hypotension /syncope during any time during pregnancy  pacemaker becomes mandatory .
  6. During labor /or cesarean section  insertion of temporary pacemaker  “may be” needed. Hence a cardiologist stand by with a temporary pacemaker  is advised to tackle any  emergency(Which is anyway  highly unlikely  !)


* This rule is applicable only in  isolated congenital CHB.  Ischemic CHB  or CHB  with associated LTGV,AV canal defects etc  need special attention.




Journal articles

The famous paper which first described safe outcome four patients with CHB in preganancy without pacemaker




anesthetic issues in pregnancy and CHB


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The classical statistics says  Congenital heart disease occurs .8/1000 in general population. Survival into adult hood is  an entirely different story  .In the last half a century  , cardiac surgeons ably  assisted by anestheteists (Most dedicated ,Hats off !) , interventional cardiologists (With some conflicts !)    have lifted up the survival curve of all sort of  congenital  heart disease.

We have now complete  cure for  many   of the  dreaded diseases of the past .Currently ,most cases of TOF, VSD, ASD , Co-arctation of aorta,  bulk of the TGVs , DORVs are correctible.Only patients with severe forms of hypoplastiv LV, pulmonary atresias and complex outflow defects are facing death in infancy.

However ,  these patients often require prolonged follow up and may require  staged surgeries,  especially who undergo univentricualr  repair for complex cyanotic diseases .Some require   fine tuning of the  anatomical conduits  etc as dictated by the growth of child. Few may develop complications in adult hood .

 This may be due to

  •   Added hemodynamic stress 
  •   Infection of the  biological or synthetic material used .
  •   Few will show progression of the native disease .

 The timing of release of this guideline could not be more appropriate . In this hi -tech pediatric cardiology  era , we are  talking about cardiac transplantation for complex CHD , where surgery is not possible or has unacceptable mortality .

ESC  has updated the version in 2010.  Let us enjoy this 43 page treasure , gifted to cardiac physicians, surgeons and the fellows !

Link placed  here  with the  due courtesy  of  ESC

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Dronedarone is a drug which was developed to replace the very effective  , (but side effect prone ) antiarrhythmic drug Amiodarone.

After years of study ,  Dronedarone has been  approved for use in some* of  our  patients with atrial  fibrillation

* Who are they ?

That is the only thing  , we are  unclear about Dronedarone  ! ! !

The recent studies on Dronedarone DIONYSOS have  clearly  proven it , to be  a  less effective  agent in controlling  AF  , but has a  advantage of fewer adverse effects.

Hence ,  for preventing the potential  side effects  of Amiodarone , let our patients  take an inefficient drug ! This is  how we are inclined  to think ! But the medical industry can not be blamed altogether  , after years of research they develop  a molecule and they would like to  have at least a small pie in the atrial fibrillation market place !

It again proves the centuries old adage,  that all drugs are poisons .If a drug lacks side effects it ceases to have the desired effect also . If you want a drug with zero side effect  a sugar coated placebo  is the best choice !

Is there  really a  role for Dronedarone ?

  • Yes , may be in patients  who have recurrent AF in spite  of stabilising  the underlying conditions that perpetuate AF( Hypertension, CAD, COPD etc)
  • When Amiodarone is contraindicated or withdrawn due to side effects
  • Remember ,  Digoxin, Beta blockers, or even calcium blockers  , can have an  important role in the  chronic management  of AF. But they are unpopular  for many reasons other than academics!

Final message

Dronedarone is power-less antiarrhythmic  drug  ( “Less- powerful ” could be a more  polite  and decent  word !) that has a specific role in the management of AF when  efficient rate or rhythm  control is  deemed unnecessary !

Why don’t  we have study  with  one to one comparison of Digoxin ,Beta blocker and Dronedarone  in the chronic management of   atrial fibrillation !

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