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Archive for March, 2009

CABG is the most common cardiovascular surgery  done world wide .

When the ventricle is dilated it is a common practice to do a ventricular  reduction surgery.

It was a logical to expect benefit when we correct the adverse remodelling of heart  that aoccur following an MI.

The STICH trial compared  plain CABG with ventricular  reconstruction and reduction .

Unfortunately , in medicine , the logics often fail  as this study  found no  mortality advantage .

Click here to read the land mark article from NEJM

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Coronary collateral circulation is the most poorly understood, and often neglected concept among the cardiology community.There is a general perception , in obstructive CAD ,  coronary collaterals are an inferior modality of  back up blood supply than artificial collateral (Also called CABG ) ! One of the reasons,  it is   been ridiculed by many  mainstream cardiologists is   because  , it comes by nature , and also free of cost !

The often quoted statement* ,collateral blood flow can not sustain blood flow during exercise ,  is not based on solid scientific data. In the real world , there are thousands of patients actively pursuing life with chronic total occlusion and good collaterals.

It is surprising , there is no  physiologically valid ,  controlled study available to compare CABG with natural collaterals

*When repeatedly told , a  statement becomes a fact !

It can be assumed (Unscientifically ofcourse ! )   the  remarkable  success  of medical therapy  in COURAGE  and the OAT * study  can be attributable to the naturally occurring coronary collateral circulation.

* Summary of COURAGE & OAT : A   block  in the coronary artery  need not be opened  to prolong human survival !

You draw your own conclusions from the  following case study

A 40 year old women , with stable angina and good physical activity

Her angiogram shows.

coronary-collateral-2

RCA injection

coronary-collateral

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Coronary artery  perforation is a dreaded complication of PCI. Perforations are the Interventional cardiologists ultimate worry   as they need to  manipulate their  hardware for  long periods in many complex lesions.  Especially  it is a  real threat in chronic total occlusions.

Still , an important fact is ,  many of the coronary perforations are not life threatening ?

How is this possible ?

As the guide wire injures and perforates the cor0nary vessel,  it results in  small puffs of dye extravasating  into peri coronary space .

The coronary artery , which is located   within the  atrioventricular groove  (LAD), or AV groove (LCX, RCA) have  two distinct anatomical relationship with reference to epicardium and pericardial space.

50 % 0f circumference of the coronary artery is  hugged  by the myocardium  another 50% or so is related directly to the pericardial aspect.

Guide wires hitting on the myocardial aspects face a stiff resistance than the pericardial aspect. So , generally the risk of perforating pericardial aspect is more than myocardial aspect

Even if , the coronary artery is punctured on myocardial aspect , no great danger occur as there is no potential space for the blood to drain and further,  the  elastic nature of myocardial muscle plane effectively seals the leak. At the most , mild myocardial staining is noted .

coronary-perforation-2

While ,  perforations  into  the pericardial space  , often threaten with a tamponade. The fact that pericardial space has negative pressure and  the mean  coronary arterial pressure around 40mmhg ,  it is  , all the more likely blood is sucked into the pericardial  space. Of course , very minute  perforations  even into the pericardial space ,  could  be self limited and  benign.

coronary-perforation

What is unrecognised coronary perforation?

Many times , the guidewire goes in a false track in the tissue plane.This is  nothing,  but perforation without hemodynamic implication. Most often , these are the instances of guide wire entering the epicardium.They mimic , false lumen entry , dissections, etc. There are occasion , where false lumen of the  coronary artery were  stented.

What are the  factors which increase risk of perforation ?

perforation-6


How do you classify coronary perforations ?

perforation-3

How do you manage coronary perforation?

Anticipate the complication. Keep one cath lab  tamponade crash  bin  in ready mode before embarking upon a complex PCI

  • Self limited, none required  but requires close observaion for ext 24 hours.
  • Temporary balloon occlusion may be suffice in some cases
  • PTFE covered stents if prolonged leak.
  • Emergency surgery

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  • CAD is the major cardiovascular disease of our population.
  • CABG is the most common cardiac surgery done world over.
  • LIMA to LAD graft is the most common by pass done.

The purpose is to short circuit some of the blood meant for the hand to the heart.

But ,  is it always a helping hand ?

May not be . . . at times  of crises  the  hand  sucks  blood  from the heart .This is called coronary-subclavia steal phenomenon

Is it not dangerous ?

How to anticipate or prevent this complication in patients who are posted for CABG-LIMA graft ?

Click on the link for the reveiw article from Annlas of  thoracic   surgery

lima

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Biochemical diagnosis for PHT and Eisenmenger syndrome

Identifying reversibility of pulmonary arterial  hypertension remains a difficult clinical problem.Heath edwards grading of pulmonary hypertension is based on lung pathology .Grade 4 and 5 constitute severe obstructive vascular pathology including pulmonary vascular necrosis.

Lung biopsy is an invasive procedure and has a  huge risk in patients with elevated pulmonary artery pressure.

Do we have an alternative ?

Does the pulmonary artery  sheds  necrosed  endothelial cells  into the circulation  ?

Yes it seems so , This month’s Nature cardiology  reveals a breakthrough concept

The CEC (Circulating endothelial cells count )  can be used as marker  and  may be considered a non invasive equivalent of lung biopsy

http://www.nature.com/nrcardio/journal/v6/n4/full/nrcardio.2009.18.html

nature1

pht

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Left main coronary artery disease is  a  major form of CAD .

left-main-41A long left main by virtue of  it’s surface area   statistically ,  are  more prone for atherosclerosis as it preferentially affect the proximal vessel.A long and tubular leftmain generally give  the LCX branch at right angles(In the above pateint it is 90*).This makes  interventions in Lcx difficult.

A short leftmain or absent leftmain could be a blessing for the simple reason these people have the unique freedom from developing left main disese the dreaded form of  CAD !

Have a look at this angiogram

left-main-31

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Beta blocker use in cardiac failure has come a full circle from a “contraindication to indication”

You don’t need gimmicks of statistics for science to progress. What you require is meticulous observation.

F .Waagstein of    Sweden just did this  with a  study population of seven  patients .

This land mark study , was least significant statistically , but most significant clinically

Today , as on 2009 , if any one submits a manuscript of a study  to a journal  ,  done with seven patients   he or she   will be called as a  fool  !  BMJ  , in 1975 had a courage in not  doing  so  and thus a break through concept was born.

So young scientists , should not  get bothered about sophisticated statistical method.

Science is not about number gimmicks it is about truth and nothing but truth  ! Truths  may  come out from  single digit study or even a single patient study

beta-blocker

To read & download  this land mark article click here

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