Dr.S.Venkatesan MD

In this mean world ,most truths  exist without evidence  . . . and often  falsehoods  masquerade as truths with  overwhelming evidence !

Human  biology   has  always  been a mystery  and can express  in dramatic  ways  . While  ,  many  disorders   combine to play havoc on the body ,  few tend to  protect  each other. HT and DM can join a deadly coalition to attack the heart .Smoking  causes  extensive peripheral vascular disease ,  still  thrombo angitis of coronary arteries ( due to smoking ) is  virtually unknown. Tuberculosis does not  have the  courage to attack  the heart  valves  ,  while  it  can inflict serious injuries  all over the body . Similarly , systemic hypertension and  Rheumatic heart disease  does not  combine  well . So , it can be assumed  some unique  and hidden   protective factors  are at play  among different pathological entities and their target organs.

A  brief  account  of how COPD could be related to  CAD !  (* Mostly Imaginary !)

We know ,  COPD ,   stresses  the right  ventricle by pressure overload and in extreme situation  affects  the  LV function because of  hypoxia. It rarely impacts the coronary artery disease  . This has been  our  consistent  observation. While COPD patients often land up with LV dysfunction , investigations reveal  they are  more of a dilated cardiomyopathy and their coronary arteries are entirely normal. Diffuse atherosclerotic CAD is a rarity in  patients with  history of  bronchial asthma. Coronary micro circulation  is also observed  to be largely  intact in most people with  COPD .

We  haven’t got a call   from our pulmonology  wards  in  many decades ,  for  a true   emergency  coronary consult . Mind you ours is a  200 year old  Institution , with 3000 beds  , largest east of Suez canal !

It’ s very rare for bronchial asthma  patients  to die of  a cardiac event. Thousands of   elderly patients   throng our ER with acute severe asthma every winter  , still  extremely rare  to  precipitate an acute coronary event !

We are yet to see  critical  triple vessel disease in a patients with documented  bronchial asthma and COPD .  Even  non-critical CAD is far less  frequent  in  COPD   vis a vis  general population .  It is indeed a strange  observation  , considering both entities are rampant in the community  .

What could be  mechanism  for the perceived disconnect between COPD and CAD ?

Is it a myth ? Does it happen in all geographical zones ?  If  hypoxia is the sine qua non  of COPD  ,  one would rather  expect a close association  with CAD  , isn’t ?

One  suggestion  that  keeps  erupting  from my cortex   . It is  the  wide swinging intra thoracic pressures in COPD or  asthmatic individuals  . . .   somehow responsible . These wide swings  of pressure  are  transmitted to aortic  root . They  transform into  good coronary perfusion pressure  ,   keep the vessels  clean by pressure vacuuming effect .

We have  asked our epidemiological unit to  analyse the  25  year data from our coronary care unit  to decode the mystery .

Counterpoint

Meanwhile,  a  diagonally opposite  question was asked in UK  and found a partial proof as well . Our experience do not agree with this study  conclusions .

What is your take on the issue ?

http://ije.oxfordjournals.org/content/33/4/743.full.pdf+html

Introspection

How can a opinion (rather an Imaginary essay !) based on personal observation   projected as a  scientific fact ? We need to observe , analyse and publish the data . This is what the scientific world expects us to do . Unfortunately , the journey form observation into publication has been kept  purposefully difficult . In my opinion bulk of  the international peer reviewed  medical journals with high impact factor can  convert any  junk  data  into a  scientifically palatable  recipe  !