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Few web sites provide   free  cardiology  service.  This one from cardiomath beats  all  ! It makes the job easier for all those cardiologists who spend  lots of time in echo lab . It provides  simple  online tool  for all common calculations in clinical echocardiography

Here is  the link to the website of cardiomath

With  due  Courtesy   to

Author: Dr. Chi-Ming Chow  Developer: Edward Brawer  Illustrator: Ellen Ho
Sponsored by  Canadian society of echocardiography

Nothing in this world is black and white. In fact,  most events are in between . The irony is , our brain  always wants to view  things in two distinct entities !

  • Success or failure
  • Beautiful or ugly
  • Good or bad
  • Win or lose,
  • Rich and poor etc . . . etc

So it is no  surprise !  cardiologists  also travel in the same boat !

They classified  the events after thrombolysis   into two dogmatic categories . Successful  thrombolysis or failed thrombolysis   . . .  as if no other event  can occur in between .

Traditionally 50% regression of ST segment is called successful .   What  about 30%  and 40 % ST regression ?

Further , there is an important caveat  in the timing,  as we  traditionally assess ,  90 minutes of thrombolysis .

Consider the following  situation  :

  1. Thrombolysis  is failed at 90 minutes, but  succeeds  at 120/180  minutes ?
  2. Is 50 % ST regression at 180 minutes is as bad  or as good as 25 % regression at 90 minutes ?
  3. How to label a patient who  is extremely comfortable in spite of ECG criteria of failed thrombolysis ?(Surprisingly this situation is fairly common !)

So, without finding answers to some critical questions , we have defined the success  of thrombolysis with  half baked data .

This is exactly , is the reason we  are unable to do a  valid  study on failed thrombolysis, rescue PCI etc .  We know the results of rescue PCI  ,  always  been  contradictory to the general logic !

It is estimated a substantial number of  STEMI patients following   thrombolysis   fall into a category of partially successful thrombolysis implying partial restoration of blood flow and salvage. The correct definition for  successful thrombolysis and reperfusion should be at the myocardial mass level , and  not at the level of coronary artery.The ECG  is the best available indicator.

Implication for having a  poor definition  of  failed thrombolysis

It is not a rare sight to wheel  in , a patient to a cath lab  with label of failed thrombolysis dangling in his neck  who is clinically  stable  (Has a less than required 50%  ST regression , but a definite, favorable trend with a 30 % ST regression  at 90 minutes  )

How many cardiologists will be willing to abort a CAG/PCI  , as a repeat ECG just  before puncturing  in the  cath lab reveals    successful  thrombolysis ? (little  delayed though !)

If only we have better methods to risk stratify patients following thrombolysis , we can avoid

  • Huge costs incurred
  • Expected and unexpected hazards of doing an emergency  intervention in an adequately salvaged STEMI
  • Hundreds of cardiology man hours can be saved  for better purposes .

Final message

Classifying thrombolyis into  success  or  failure  is a  skewed  way of looking  at this important  issue .

It is an irony ,  cardiologists often  triage LV dysfunction , valve disease , cardiac failure  etc  into 4  grades (  minimal  , mild , moderate or severe  ) . It is  still a mystery ,  why thrombolysis  is never graded  like that ,  and it is always considered as  all or none phenomenon !

There is a substantial number of patients  with partially successful ( or shall we call partially failed !) thrombolyis  .This group must be given adequate attention or inattention  . There  is a urgent need for a through review of how we look at  the post thrombolysis status  . It is better to use the newer imaging modalities like PET/MRI more  liberally to identify  exact sub group  of failed thrombolysis who will benefit form revascularisation .

Is it not ,  boring to  see  normal coronary arteries every day  ! There need to be surprises  in cath lab to make our time lively  and keep our brain alert .  Have a look at this angiogram in  RAO caudal view.One of our junior cardiology fellows thought it was  a split left main artery .

How can an artery split . . .of course the image indeed looks like that !

It was indeed an absent left main.  Also called as separate origin of LAD and RCA.

Note : There can be three  types of absent  left main.

  • LAD and LCX from same ostia on the left coronary sinus*
  • LAD and LCX separate  ostia but both from same sinus**
  • LAD from left coronary sinus, LCX from right sided sinus (Probably the  common type )

* Some books mention about a left main of 0 -5mm .

** Very difficult to delineate and is rare

Zero  mm  left main is nothing but  single  ostial origin of both LAD and LCX. A very short left main , say 1 0r 2 mm will practically mimic an absent left main.

Here is the  the dynamic angio image. It is  surprising how a catheter in left sinus is able to visualise the LCX from right sinus so well !

Note the separate origin of LAD and LCX.The LCX was originating near the right sinus.It is intriguing to note even though they originate in different sinuses , the main stem of LAD and LCX wants to maintain a close parallel relation.

 

 

Advantages of having  absent left main .

  • It requires no great brains  ,  to predict  the above patient is  immune  to  develop  Left main  or true bifurcation disease
  • Sudden death is  presumed to be less common in this population.

Implications for interventional cardiologists

Guiding catheter selection and positioning could be difficult.

Manuals are not only for doctors . There are few heart  maintenance manuals for patients as well.

This one from Philadelphia ,  is worth reading and of-course  following  thereafter  !

 

Some books can be as effective as CABG or PCI .

This  one is definitely in that league  . . .

God has created  and arranged every organ in an order  with a purpose .  The unique  relationship  of the food tube and  the heart which run silently , posterior  to the heart has evoked much interest for the cardiologists.

Whenever LA is enlarged it pushes the Esophagus back .We also know  the vintage clinical entities   of cardiac  dysphagia that occurred with rheumatic mitral stenosis.

Since the  lower end of  esophagus just hugs  the left atrium , this anatomical concept was successfully exploited   for imaging heart in TEE.Now cardiac  anesthetists routinely use the esophagus as an imaging port during complex mitral valve surgeries.

How  esophagus can be utilized to resuscitate the heart at times of emergency ?

Note , the esophagus does a friendly hug as it crosses the heart posteriorly .It is a perfect anatomical sense , to Image and pace the heart from within the esophagus !

 

In a  cardiac  arrest  situation , when we need to   rapidly   access to heart  , we have  multiple  options  .Each has some  advantage and few draw backs.

  • Trans-venous pacing   is the standard method,   but even for experts  it needs   few minutes to reach the heart for pacing
  • Trans cutaneous pacing (Zoll)  is  a viable option , but  not widely  popular for some  unknown  reason (Patient discomfort ? High threshold ?)
  • Emergency trans-thoracic  needle pacing option is  a primitive method still can save a life or two on it’s day !

It was in 1980 ,  a dramatic  concept was conceived  . Why not    use the  esophagus as an access   for pacing  the  heart

after all ,  it  reaches as close as possible to the heart !

How to convert  a  Ryles tube into a  a  trans – esophageal  pacing lead ?

There was a certain article on this topic , which I read , when I was cardiology resident. It answers the following. Distance form mouth ,  Discomfort of  the lead ,   Pacing threshold ,  Esophageal burns .

I am unable locate that article. Will  post  it  once I get it.

Limitations of trans-esophageal pacing*

  • The most important limitation is it can pace only the atria with high degree of success.
  • Ventricular pacing is not that successful for the simple reason esophagus is anatomically insulated by the atrial chambers.
  • Tran gastric positioning  may reach  the basal aspects of Left ventricle , but the threshold needed  is too high that will invariably cause  discomfort.This can be used in a dying patient  when there is no  other option .

* Primarily  useful in acute SA nodal defects, sinus arrest or any other atrial electrical failure. Infra- nodal complete heart block trans esophageal pacing may not be effective .

Other potential uses  of trans-esophageal  leads

Over drive pacing

Overdrive entrainment of tachycardias ,  including resistant ventricular tachycardia is possible.

Trans esophageal ECG recording .

This can magnify p waves during supra ventricular tachycardias and aid in decoding narrow qrs tachycardias

Safety  Issues and Caution

Good earthing is necessary .Burns can occur.

Final message

Every cardiac physician is  expected to possess  the expertise to rapidly pace a heart  by trans jugular /subclavian access at times of  emergency .

Further , any modern CCU will have a defibrillator equipped with trans-cutaneous pacer as well. (The  disposable pads are too costly and is a deterrent in many hospitals  !).

This article  explores other possible way to pace the heart in dire emergency situations.

It has one more purpose !  It rekindles   the acumen , motivation  and hard work   of  our  cardiac  ancestors  (Which many of us are pathetically lacking !)

http://circ.ahajournals.org/cgi/reprint/65/2/336

Role of trans-esophageal lead during EP study  atrial fibrillation

http://cardiovascres.oxfordjournals.org/content/38/1/69.full

In pacemaker science ,  any pacemaker that maintains AV synchrony is often referred to as physiological pacemaker. This is  of course , a  wrong reasoning .None of the pacemakers available today can be claimed to  be completely physiological .All  pacemakers  which paces the right ventricle  induces IVS dysynchrony (Including  the modern DDD)

Single chamber physiological pacing

AAI

Paradoxically ,  the most primitive of pacemakers AAI can be the near perfect physiological  pacemaker . The simple explanation  is ,  In AAI mode , expect for the origin of pacemaker impulse the entire depolarisation and repolarisation  is through the normally existing physiological conducting system .(AV node, HIS, Purkinje etc)

(It not only has atrio ventricular synchrony but also  has ventriculo ventricular and intra ventricular synchrony )

So, technically AAIR  is most physiological pacemaker possible .But  the practical utility of such a pacemaker is limited.It can be used  only in  isolated sinus node dysfunction with intact AV conduction . (The problem is the AV nodal conduction can develop later )  To over come this DDDR pacemaker can be programmed to AAIR as a default mode.

VVIR

This rate adaptive pacemaker  ,  to a  certain extent  can be termed physiological as the heart rate can improve with exercise . (Still it is unphysiological as it  paces the RV )

VVD

This is based on the concept ,  for pacing to be physiological , it  requires  atria  to be  at least sensed not necessarily paced.This mode which has a floating sensor attached to the lead as it crosses the atria.This facilitates atrial sensed ventricular pacing .But many believe  the atrial sensing is not consistent in VDD mode.Currently this mode is not popular.There is scope for improving the atrial sensor technology .

Dual chamber physiological pacing

DDD, DDRR

Both  these are the prototype dual chamber physiological pacing modes.

Bi-Ventricular or triple chamber pacing  ( one atria two ventricle)   are our  elusive answers for attaining perfect physiological pacing . it need to be realized, we simply ,  can not mimic the natural cardiac  conduction system.It is  estimated to be more than 10 miles long specialized fibers .

Final message

In our quest for physiological pacemaker we often forget the fact  , AAI is the most physiological pacemaker mode  available .(It even has  VV synchrony !  )

We should use it liberally whenever possible .Of course ,we cannot use it in complete heart block .Still 50 % the  permanent pacemaker  we implant is for sinus node dysfunction. Many of them could be candidates for AAI mode .If current generation cardiac physicians feel out dated to insert a AAI pacemaker, at the least they should program the DDDR into AAI mode with a mode switching to ventricular pacing modes whenever required.

In spite of all  advantages ,  why atrial based pacemakers are not gaining popularity ?

  • Ignorance
  • Lack of expertise
  • Technical difficulty of fixing atrial  lead
  • Perceived fear of lead dis-lodgement.
  • The fact remains  the  ventricular based pacing  is always safe  in case of sudden AV block due to any reason .

Prosthetic valve implantation has revolutionized the management of  valvular heart disease . The original concept valve  was a ball in a cage valve  , still considered as a  fascinating discovery.  It was conceived by the young Dr Starr and made by Engineer Edwards  .This was followed   by long hours of arguments,  debates and  experiments that ran into many months . The  silent corridors of  Oregon hospital Portland USA remain the only witness  to their hard work and motivation.  At last,  it happened , the first human valve was implanted in the year 1960. Since then . . . for nearly  50 years these valves  have done a seminal  job for the mankind.

With the advent of  disc valve and bi-leaflet valve in the  later decades of 20th century , we had to say a reluctant good-bye to this valve.

There is a  lingering question among many of the current generation cardiologists and surgeons why this valve became extinct ?

Starr and Edwards with their child !

We in India , are witnessing these old warrior inside the heart functioning for more than 30 years.From my institute of Madras medical college  which probably has inserted more Starr Edwards valve than any other  during the 1970s and 80s by Prof . Sadasivan , Solomon victor , and Vasudevan and others .

It is still a mystery why this valve lost its popularity and ultimately died a premature death.The modern hemodynamic  men  working from a theoretical labs thought  this valve was  hemodynamically  inferior. These Inferior valves worked  like a  power horse  inside the hearts  the poor Indian laborers  for over 30 years.

A Starr Edwards valve rocking inside the heart in mitral position

The cage which gives  a radial support* mimic  sub valvular apparatus, which none of the other valves can provide.

* Mitral  apparatus has 5 major  components. Annulus, leaflets, chordae, pap muscle, LV free wall.None of the artificial valves has all these components.  Though , we would love to have all of them technically it is simply not possible.  The metal cage of Starr Edwards  valve partially satisfies this  , as  it acts as a virtual sub valvular apparatus.Even though the cage has no contact with LV free wall, the mechano hydrolic  transduction of  LV forces to the annulus  is possible .

Further , the good hemodyanmics of this valve indicate , the cage ensures co axial blood  flow  across the mitral inflow throughout diastole. .Unlike the bi-leaflet valve ,  where the direction of  blood flow is determined by the quantum of leaflet excursion  in every beat . In bileaflet valves  each leaflet has independent determinants of valve  motion . In Starr Edwards valve the ball is the leaflet . In contrast to bi-leaflet valve , the contact area  of the  ball and the blood in Starr Edwards  is a smooth affair  and  ball makes sure  the LV forces are equally transmitted to it’s surface .

The superiority of bi-leaflet valves and disc valves  (Over ball and cage ) were  never proven convincingly in a randomized fashion . The other factor which pulled down this valve’s popularity was the supposedly high profile nature of this valve. LVOT tend to get narrowed in few undersized hearts.  This  can not be an  excuse , as no consistent  efforts were made to miniaturize this valve which is  distinctly possible.

Sudden deaths from  Starr Edwards valve  .

  • Almost unheard in our population.
  • The major reason  for the long durability of this valve is due to the  lack of  any metallic moving points .
  • Absence of hinge  in this  valve  confers  a huge mechanical  advantage with  no stress points.
  • A globe / or a ball  has  the universal hemodynamic advantage. This shape makes it difficult for thrombotic focus to stick and grow.

Final message

Science is considered as sacred as our religion Patients believe in us. We believe in science. A  good  durable valve  was  dumped from this world  for no good reason. If commerce is the  the main issue ( as many still believe it to be ! )  history will never  forgive those people who were  behind the murder of this innocent device.

Cardiologists and Cardio thoracic surgeons are equally culpable  for the pre- mature exit of this valve from human domain.  Why didn’t they protest ?  We  can get some solace  ,  if  only we can impress upon  the current valve manufacturers  to  give a fresh lease of life to this valve .

http://www.heartlungcirc.org/article/S1443-9506%2810%2900076-4/abstract

It is   surprising  to find  many   similarities between  our heart and the car .Both essentially carry out  mechanical function.  One carries the  life , while the  other beats ,  breaths life !

  • The car is the status symbol  of modern life  , while the heart is a life by itself .
  • The car has a 4 stroke engine  , while the heart has only two strokes – systole and diastole !
  • The car pumps petrol  , the heart does it with blood.
  • The car can afford to take rest at night in your garage   but  , your heart doesn’t.
  • Car  can be replaced  by a fresh one every 5 -10 years your heart can’t be.
  • In India  , it is  mandatory   for  the cars  to be  insured for  about  10 Lakh  rupees , while  the   poor hearts of our country men  are not even insured for a  single pie  !
  • A dent in your  new  Toyota  can give us   sleep less nights for many days .  A bruised and battered heart with tobacco and cholesterol is rarely  bothered about .

When the silent  screams of the heart  are not respected and heard ,   there is no other option left  for  it ,  to register its protest  , except with  a  heart attack   .This  can either be a  SOS call  or  a  call from  Heaven !

Final  message

Remember ,  the   heart breathes  your life ,  your car  doesn’t .Heart is   million times glorious than your car.

It is foolish to compare  the heart with a car . But let us  at least  learn to respect it  . . . like  our car.

Heart service station

  • Authorized heart service centers are few . Insist on genuine spare parts. Good  service engineers are becoming a rare breed.
  • Remember  both defective spare parts   and  dysfunctional service  engineers  can ruin your heart.
  • Do not allow your heart to  be explored and dismantled for flimsy reasons.
  • Never hand over your heart to strangers.
  • Do not-self indulge in 64 slices  of  fancy   shooting  of  your heart . Resist the temptation.
  • Finally do not ever go for unscheduled  free heart  service camps . That is the beginning of  trouble for your heart.

Some hearts  may  servicing alright , but realise , you are the master of the  service station .

If only you respect it , it  rarely requires to be sent to a  garage (cath lab )


Simple life style, adequate activity,   nutritious diet,  peaceful   sleep,  good work ethics ,respect to  fellow citizens  ,good-bye to  anger , helping the poor, a joyous family life , and finally  . . . less  visits to your physician  !  These  make  a  perfect , sure shot  recipe  for  living   100  glorious years !

Why is it .  .  .  so difficult ,  to  acquire  healthy   habits  and   good  behavior  in life ?

How to over come it ?

Answer :

No body can answer this question . . .Except yourself  !


We know,  electrical deaths constitute the bulk of sudden cardiac deaths in MI.  Mechanical deaths due to pump failure, muscle rupture , valve leak , also cause significant deaths   .(Surprisingly many of the mechanical deaths   may also   fulfill  the sudden death criteria !)

Free wall rupture is  invariably a fatal event. Papillary  muscle trunk  rupture  leads to severe LVF and unless intervened sure to result in fatality.

The ones who tear their interventricular septum  are some what blessed ! Here ,  the rupture does not result in instant death as there is  no loss of blood ,   instead , there is an  volume over load of right ventricle  followed by the  left ventricle  after a  few beats. Hypotension is the  rule. Even though this is a major complication there is something about  VSR which makes it unique.

Sudden giving way of IVS has  a decompressing effect on the ailing left ventricle.This many times  bring a  temporary relief to LV and if the patient survives the first few hour he is likely to stabilise  further . In fact , sudden deaths within 24hours after the onset of VSR is an exception.This defect always gives the cardiologists and surgeon some time to plan the management. We need to use this time judiciously.

The natural history is delicate . Five themes are possible

  1. Very unstable Instant death( Fortunately a  rare theme )
  2. Unstable – Deteriorating further
  3. Unstable to Stable * fit for discharge even without surgery
  4. Stable from the onset and  continue to be stable* .
  5. Stable to Unstable (Probably the most common theme )

* Pleasant themes occasionally witnessed !)

Here is 55 year old women came with extensive anterior MI with lower septal rupture.(She belonged to type 3 of the above scheme)

)

Note the septal rupture is visible even in 2D Echo

 

Color flow showing significant shunting from LV to RV.This shunt depends upon the LV contractile function, LVEDP and ofcourse the RV pressure

 

If there is severe RV dysfunction or bi ventricular dysfunction flow across the defect is inconspicuous.Brisk left to right shunting may be an indirect marker for good LV systolic function and absence of significant pulmonary hypertension.Both imply a better outcome.

The main determinant  of survival is the  underlying LV dysfunction and associated co morbidity(Renal function ) and complications .

Infero -posterior ruptures tend to be complex and  may have multiple irregular tracks  that makes it difficult to repair.

Investigations

Echo cardiogram is the mainstay .Serial echos should be done to assess the mechanical function and the progress of VSR.Hemodynamic monitoring may be done without injuring the patient .

Medical management

  • Often supportive , but  effective . Dobutamine infusion can maintain a life for few days.
  • Paradoxically , LV dysfunction and elevated LVEDP restricts volume overloading of VSD.
  • Associated MR, Arrhythmias  need to be taken care of .

Surgeons role

  • Very Vital.
  • Experience counts.(Individual as well as  Institutional )

Timing of surgery

Continues to be a controversy . Surgeons love to operate in a stable patient. But they need to realise , surgery is often needed to stabilise  many  patients. . The issue of tissue friability  is blown out of proportion in the literature .When a  life is  is at danger we can not worry about  friable tissues !

The rule of thumb could be

  • Operate as early as possible in unstable patient.
  • Post pone surgery in stable patient as late as possible ( Late here means . . .elective non emergent surgery )

Surgical options

  • Simple VSR closure without  knowing coronary anatomy
  • Simple VSR closure after knowing coronary anatomy
  • VSR closure with CABG ( total revascularization)
  • VSR closure with partial revascularization

In our experience  each of the above , has a role in a given patient depending upon the logistic , financial , social and even  the available expertise. (A good surgeon in bad Institution !)

Is coronary angiogram mandatory  before attempting to close VSR ?

Logically yes. If it is not available  just do not bother .  But, many times , when issue is saving lives , we can not afford to be too scientific , many lives have been saved by not following  such strict  protocols .A simple emergency  thoracotomy and closure of rupture site (Without even touching the LAD ) can be a distinct  and viable option in  a selected few .

Role of cardiologists

Contrary to the popular belief the role of cardiologists is minimal , except  to prepare  the patient and hand over to the surgeon.

Interventional approach to close  a VSR  is currently  be termed as an  adventurous option ! The VSRs  can assume unpredictable shapes  and the  tears can be multiple  in  different planes. The devices , catheters and  other hard ware are not specifically made to tackle these  issues  .An acquired VSR  should never be compared with congenital VSD.