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Dual LAD is an interesting coronary artery anomaly proposed  originaly  by Spindola in 1983 .He classified it into 4 types. In recent years the  dual LAD has increased from 4 to 6 types.

The essential criteria to diagnose  could be summarised.

  1. Two LADs should be identified.
  2. One would be  large and another small
  3. Both should give a  diagonal  branch .

* Ramus is virtually unknown  if there is dual LAD .

The origin  of second LAD can be from

  • LMCA
  • RCA
  • Direct from Right coronary sinus

Course

  • Can be epicardial
  • Intra -myocardial
  • Or both

Branches

  • Diagonal
  • Septal
  • or Both

Drainage area

  • Highly variable

Implication for intervention

  1. Apart  from  the surprise element , the second LAD   has  little impact on the interventional protocol.
  2. However , it may confer a  ischemic protection  as the critical anterior wall has a twin blood supply.
  3. Whether  they are protected from primary  VT or VF is to be studied  because of better electrical stability
  4. Second LAD may act as an additional collateral channel.

Spindola’s  classification of Dual LAD (Types 1 to 4  was called sometimes A,B,C,D )

classification of dual LAD

Source : Lee et al. BMC Cardiovascular Disorders 2012, 12 :101

Spindola type 1 to 4 classification of dual LAD

An illustration of  first 4 types  of Dual LAD .Note  the type 4 originates from RCA. Image courtesy : Prachi P. Agarwal Ella A. Kazeroon . AJR:191, December 2008

Surgical issues ( This is  excellent data  from India . I convey  my   greetings to one  the authors Dr D.B Baruah,  my friend  from  CMC Vellore !)

dual lad classification Spindola-Franco H, Grose R, Solomon

Reference

Spindola-Franco H, Grose R, Solomon N. Dual left anterior descending coronary artery: angiographic description of important variants and surgical implications. Am Heart J 1983:105;445-55

Dual Left AnteriorDescending CoronaryArterySurgical Revascularization in 4 Patients Tex Heart Inst J 2000;27:292-6

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3509398/pdf/1471-2261-12-101.pdf

Dual LAD  CT  Angiogram : http://www.ajronline.org/doi/pdf/10.2214/AJR.08.1193

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culotte technique for bifurcation senting
Original article
Chevalier B, Glatt B, Royer T, Guyon P. Placement of coronary stents in bifur-

cation lesions by the ‘culotte’ technique.Am J Cardiol 1998;82:943 – 949

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The humble looking strip of ECG  recorded  in millions ,  every day across the globe  has a complex definition.

And this definition  is  the most apt I have found.

An electrocardiogram (ECG) is a curve showing the potential variations against time in the whole body stemming from the heart, which is an electrochemical generator suspended in a conductive medium.

Einthoven(Dutch)  is the the man who invented the ECG  ,  got a Nobel price for not only inventing the string galvanmeter to record ECG,  but also  making us understand   the rules  of the  electrical wave front  that emanates from the heart.( Not to forget the  original concept  of who demonstrated electrical activity from heart by by capillary electrometer.  by Waller.(British). In my opinion waller should have shared the Nobel prize. I am  sure ,even Einthoven would agree to it.

Of course , do not ask  which  comes first  ” Ionic  flow” or  “the current”  that  comes with it !

Credit goes to  the creators of this  wonderful book  on medical physiology and put that free on the net . Three cheers to  them .

The book is from  University of Copenhagen  , Pannum Institute of Medical Physiology.

physiology text book paulev Zubieta sweden

Reference
British physiologist Augustus D. Waller of St Mary’s Medical School, London publishes the first human electrocardiogram. It is recorded with a capilliary electrometer from Thomas Goswell, a technician in the laboratory. Waller AD. A demonstration on man of  electromotive changes accompanying the heart’s beat. J Physiol (London) 1887;8:229-234
Willem Einthoven introduces the term ‘electrocardiogram’ at a meeting of the Dutch Medical Association. (Later he claims that Waller was first to use the term). Einthoven W: Nieuwe methoden voor clinisch onderzoek [New methods for clinical investigation]. Ned T Geneesk 29 II: 263-286, 1893

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Even though multiple mechanisms operate  the major mechanism is due to augmentation and  diversion of blood flow towards sub endocardial region* which is  main area of ischemia in most patients with Angina .
subendocardial-blood-flow
*Beta blockers  does this by smoothing   the  myocardial contractility there by  reducing  trans-myocardial gradient. The coronary arterial perforators which traverse from epicardium to endocardium gets less squeezed and promotes sub endocardial perfusion. 
Link to  a related article from this site

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In L TGV  ventricles are Inverted . Since , coronary  arteries go with  the respective ventricle  , LAD originates from Right sinus , and RCA arises from Left sinus . (Complex anomalies  in origin, course still possible )  LAD supplies   venous ventricle . RCA  supplies systemic ventricle .

The most surprising Irony is that major epicardial  branches run in their respective grooves in the bulk of the patients with L TGV .The LAD runs  in anterior interventricular  groove and LCX in left AV groove etc. (That’s real  power of nature , these epicardial branches home in to their grooves even in the midst of bizarre AV and VA connection !)

Here is the the ultimate reference  article ;  A  study from 255 hearts with C TGV . I wonder ,  we will  never  get a study like this ! 

coronary anatomy in corrected transpostion og great arteries ltga c tgv Ltgv annals of thoracic surgery 1994

Questions to ponder

  1. Is RCA  blood flow adequate to support systemic ventricle ?
  2. If this RCA is a non dominant  one what happens to this ventricular function ?

Implication in surgery

Progressive RV dysfunction is a major determiant of long term outcome . Unless we do an arterial switch  diverting respective ventricular flow  it  is not going to help much in the long term

coronary anatomy in corrected transpostion og great arteries ltga c tgv Ltgv 2
Link to full text article

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Wandering pacemaker is benign  cardiac arrhythmia . The only danger  is , it can create false alarm .This patient was referred   as  AV dissociation

wandering pacemaker

Read a related article  from this site .  ( A restless pacemaker goes for a walk down the  lane )

wandering pacemaker

wandering pacemaker

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In the  2013 American diabetic association(ADA)  annual meet  a paper was presented   which raised  many eye brows ! . The  results were flashed across mainstream media. Published in New England journal of medicine online.

Look Ahead ADA lifes style  NEJM

It may be a  well conducted  trial  but  poorly interpreted  one . It reports one of  the dubious   observations  as a major conclusion  and  confuse the public.

Life style modification is the key to prevent  major diabetic  and cardiac events  . This is well  proved beyond doubt.

Epidemiological evidence  from various  global health  statistics  accumulated over a century will vouch for primary prevention of  diabetic and cardio vascular disease .

Link to Editorial on Look Ahead  : http://www.nejm.org

Why this study wants to make  a mockery of this fact ?  .Fortunately the accompanying  editorial  has  realistically  reported the implications of this study.

Final message

I argue the medical fraternity and patients to ignore this  study . It can be convincingly concluded something is seriously wrong with the outcome analysis  ,  however  modern may be the statistics. Some  groups are obviously worried about the natural and effective control of diabetic by good life style alone . It is a clear case of confusing the public .

There is huge collective evidence  and  common sense  for the  increased physical activity to reduce  cardio vascular risk  (INTERHEART)

Final Message

If life style modification is not going to help  . . . what is the alternative  to our patients ?

Drugs . . . yes  . . . one has to depend on it   . . . this study  seems to suggest .

To me, this is  a dangerous study   . It  plays a spoil sport on a great fact and  belief . This paper  should never have been published in a journal  like  NEJM . Atleast the conclusion  should  have  been re-written !

I guess this study would  promote the  Homo-sapiens  to  be inactive  and  make them diabetic and  consume drugs  perennially !

Reference

http://www.nejm.org/doi/full/10.1056/NEJMoa1212914?query=OF 

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