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Archive for the ‘Cardiology research topics’ Category

Bedside wisdom

We have been  using unfractioned Heparin for long , and its  is better than any other anticoagulants  in ACS . . . 

Our observation shows that Streptokinase has distinct advanatge over Tenektepelase as it works longer duration  . . .

My experience  says Diuretic and beta blockers  are still good as first line therapy for Hypertension  . . .

Mind you , there are infinite  number of such wisdom in every sub specialty of medical field.

However , the typical response from any  modern scientific intellect would be . . .

Stop it . . . Its old  stuff folk  , What does the current data say ?

medical-data-ethics-futility

Common uttering  in scientific forums,

Is there data backing up your  treatment modality ?

Is there sufficient data ?

Come’on , grow up , don’t talk about experience in a scientific forum . . . come out with data man !

No one seem to care the quality of the data . Every one bothers  about the quality of the Author and Journal instead  .  if its X Y Z its ok If its A B C no its not acceptable data.

Probably , Data is most misused word in medical science.

In scientific world,  “unpublished sense” goes straightway to  dustbin ,while we have so many avenues for the  published nonsense to  be celebrated (Still, bulk of guidelines in cardiology is backed up by Level C evidence which means experience  of experts !)

By the way what do we mean by data ?

Its organised collection of genuine scientific information , that’s post processed ,  follow it up with sound inference and faithful questioning and debate that should ultimately end up as  “clinical  application” in patient domain for consumption.(No prizes for guessing , whats happening in real world !)

OMG, give us back that elusive Common sense . . . which  I  think we  lost some time  at the turn of this millennium  !

Wrong or useless data : Who will recall ?

Once applied to patient , these data is  to be scrutinized and monitored . If we find a study conclusion  and reality does not match , we  need to stall the data from adversely  exploding .Every stake holder should have the power to do it. There have been instances a treatment modality got banished in one country is legally permitted in other country knowing fully well the futility.

Final message 

Modern scientific Data* is not God sent. Its  created , synthesised and disseminated in various mind factories. All you require is , backing up with some pioneering journal publication with huge impact factor.It’s not really blasphemy to question things which doesn’t make sense .Unfortunately , wrong data can be tackled only with further data .(There is no other means I guess !)

When does “good common sense”  become hard data and evidence ?

Its the act of publication , so  please guys whenever you  find some contamination  in so-called scientific data  please post here.  To begin with I am registering a new Journal  “Commonsense journal in cardiology”

*Please note, data is not a bad word as this write-up  seem to suggest.Naturally occurring , epidemiological and  observational data about diseases are the foundations for medical science .The issue become murky when few motivated humans play brutal  games at the sensitive  interface between science and truth.

It should be acknowledged , there is a distinct risk  of  this fight against falsehood end up in blocking  true progress  of science . Still , Homo sapiens  are (believed to be !)  intelligent enough to differentiate good from bad , that’s the reason God gave us the sixth sense !

Link to Lown Institute (Started by Cardiologist and Nobel peace prize  Laurate Dr Lown who strives hard to pursue this goal)

Further reading :  Scientific Reversals in cardiology 

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We know Nitroglycerine(NTG) as a most powerful epicardial coronary dilator  . We use it for instant relief during episodes of coronary arterial spasm in cath lab.

What will happen if we administer NTG over a stented segment ?

Does it dilate it with same vigor ? What will be the consequence  ?

A perfect setting for stent migration isn’t ?

Let us bust the myth around  NTG . NTG  rarely  show  visible coronary dilating effect except in the setting of coronary spasm .

NTG and coronary vasodilatation

Does a LAD with 3 mm diameter become 3.1 or 3.2  and so on with NTG ?

No .It won’t .It is my belief. It is well known , NTG’s action varies significantly in normal and diseased endothelium . Again , there is an irony .It seems , it can act only in normal endothelium , but  we need require it’s therapeutic action only in pathological segments.Further any stented segment would contain   clusters of  both normal and abnormal endothelium .

One more inference is that, stented segment exerts constant pressure on intima making any  pharmacological vasodilatation irrelevant .

Importance of  radial strength of a stent

This issue of vaso-dilator induced  stent migration may not arise in self expanding wall stent with high radial force.But we do not know how long these metals will carry this metallic property .Balloon delivered  stents ( currently used 99% of times ) do not have permanent radial strength .

Final message

I am yet to comprehend what nitrates are expected to do (and what it really does ?)  in a patient post PCI ? (By the way  . . . why we need to prescribe Nitrates it in the first place ? but  In real world most continue to take this for many reasons .)

We need to analyse the micro-vasomotion at the stent -coronary intimal interface.The dynamism in this  narrow space  can be critical  , and may make the difference between life and death !

After thought .

In the hind sight,  this post appears quixotic  for myself . But some one , some where , may generate a great idea  out of it , that will help our patients.

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Medical research   often ventures into a directionless and meaningless  exercise with or without intention .The reason is simple , unlike  other fields,  scientists enjoy  the ultimate freedom of expression.

How to find genuine treasures from this chaos ?

We need people like Valentine Fuster ,

valentine fuster global cardiology what is the future

Here is link to the article in   circulation 2011  which I consider a must read for all cardiologists !

global  cardiovascular health valentine fuster circulation 2011

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world congress cardiology dubai  3  2012

Abstracts  published in Circulation 2012

http://circ.ahajournals.org/content/125/19/e741.full.pdf+html?sid=94b7a220-982f-4cfe-9792-8c7087dc046d

Paper 1

Echocardiographic IVC diameter: a simple, bedside guide to monitor fluid therapy in right ventricular infarction

Sangareddi Venkatesan1,*, G Gnanavelu1, M.S Ravi1, V.E Dhandapani1, G Karthikeyan1,D Muthukumar1
, Madras medical college, Chennai, India
Introduction:

Right ventricular infarction (RVMI) is one of the unique subsets of acute coronary syndrome. In RVMI augmentation of RV preload with fluids is considered vital. The seemingly paradox of raising the already raised RVEDP and RAP is often a risky hemodynamic adventure .There is no simple guide to monitor fluid therapy in RVMI.

Objectives:

In this context, we reasoned, a simple estimation of IVC diameter and it’s respiratory variation would give an accurate reflection of volume in the right heart chambers Methods: 12 patients with established RVMI by clinical, ECG criteria were the subjects of the study. 6 had associated posterior MI, 3 had lateral ST elevation. Patients were treated as per STEMI protocol .10 were eligible for thrombolysis.The mean blood pressure on admission was 106(70 -120mmhg)
During thrombolyis the blood pressure fell by 5–10mmhg .All patients were administered IV normal saline to augment the blood pressure. 1000ml were given over 1 hour and if the BP was  not raising another 1000 ml was infused in the next 1 hours . Results: Bedside echocardiography  was done on admission and was repeated during and/or after fluid infusion. The  baseline IVC, RA, RV were dilated in 9/12 patients. The mean RV dimension was 2.8cm (2.4 –3.6) RA -3.9 cm(3.6–4.5) The mean IVC diameter was 2.1cm (1.4 –2.6). On completion  of 1000ml fluid infusion, the mean IVC diameter was 2.5(2.3–3.0) .In terms of absolute size,  IVC increased by 3–5mmin diameter at the end of fluid infusion. It amounted to 20–30%  increase of diameter. There was minor increase in RA and RV dimension also. When there
was  30% increase of IVC diameter, JVP became non pulsatile and four patients showed  signs of lung congestion. There was a new reversal of E:A ratio in the mitral inflow in 2 patients  who had lateral ECG changes .There was no significant increase in RV dp/dt following fluid administration. The TR jet derived peak RV pressure did not show significant difference with  reference to fluid therapy. The mean LVEF was 44%(38–62%).

Conclusion:

Simple bedside estimation of IVC dimension by 2D echocardiography, can provide a fairly accurate estimate of  volume status of right heart chambers .Careful monitoring of IVC size help us, in the fluid  management of RVMI. One rule of thumb is an increase of IVC diameter by 30% from its basal  value could be a cut of point for termination of fluid infusion.

world congress cardiology dubai  5  2012 world congress cardiology dubai 2012

Paper 2

Circulation. 2012 125 e741e925  venkatesan  sangareddi madras medical college

Echocardiographic evaluation of papillary muscle function in ischemic mitral regurgitation
Muralidharan Azhakesan1, Venkatesan Sangareddi1, Jai Shankar1, Rudrappa Arunagiri1, Kalyanaraman Kannan1,* and Prof R. Alagesan,Prof P. Arunachalam, Prof V.E. Dhandapani, Prof M.S. Ravi.
1Cardiology, Madras Medical College, Chennai, India
Introduction:

Ischemic MR has been attributed to dysfunction of papillary muscle .The  experimental and clinical data emphasize the importance of changes in the geometry of the LV.
Objectives:

To assess the mechanisms of ischemic mitral regurgitation in patients with old  myocardial infarction Methods: The study cohort comprises 30 consecutive patients with old  myocardial infarction and Mitral regurgitation. Group 1 has old inferior wall myocardial  infarction and Group 2 has old anterior wall myocardial infarction. Patients with increased left
ventricular sphericity belong to Group Ia and with normal left ventricular sphericity belongs to  Group Ib.Echocardiographic evaluation of all patients was done using Philips iE33 machine.
Results:

The incidence of moderate to severe mitral regurgitation is high in group Ia and II  compared to Ib(50%and 40%vs. 20% p0.01). The average left ventricular sphericity is high in group Ia compared to group Ib & groupII (66%VS 49.1%&58.2) .Mitral annular area is  increased in patients with moderate to severe mitral regurgitation than patients with mild mitral
regurgitation (46.8mm vs. 41.2mm, p0.01). The incidence of MR in patients with increased  LV sphericity to normal LV is 50% vs. 20% p0.01. In all groups of patients, the leaflet  tethering distance with moderate to severe MR compared to mild MR is 24.09 mm Vs. 17.84 mm [P0.01]. The papillary muscle systolic peak velocity does not have consistent
correlation with ischemic mitral regurgitation in all groups. In group Ia papillary muscle systolic  peak velocity has linear correlation between mild and moderate to severe ischemic mitral regurgitation(5.98m/s vs 7.9 m/s.p0.05)

Conclusion:

1. Mitral leaflet tethering distance is consistently directly proportional to severity of Ischemic mitral regurgitation. 2. Papillary muscle  dysfunction is not an independent determinant of ischemic MR in all cases.

References:
Burch GE, De Pasquale NP, Phillips JH. The syndrome of papillary muscle dysfunction. Am Heart J 1968;75:399–415.
Kaul S, Spotnitz WD, Glasheen WP, Touchstone DA. Mechanism of ischemic mitral regurgitation. An experimental evaluation. Circulation 1991;84:2167– 80.
Matsuzaki M, Yonezawa F, Toma Y, et al. Experimental mitral regurgitation in ischemiainduced papillary muscle dysfunction. J Cardiol 1988;18 Suppl:121– 6. Kono T, Sabbah HN, Rosman H, et al. Mechanism of functional mitral regurgitation during acute myocardial ischemia. J Am Coll Cardiol 1992; 19:1101–5.

world congress cardiology dubai 2  2012

Cardiac failure following VVI pacemaker, a myth or reality: an echocardiographic study and an indian perspective
Arun Ranganathan1,* Venkatesan Sangareddi, Gnanavelu G, Dhandapani V.E., Ravi M.S. 1Cardiology,

Madras Medical College,Chennai,Tamil Nadu,India, Chennai, India
Introduction:

Permanent pacemakers has revolutionized the management of symptomatic bradyarrhythmias. In India, about 10000 pacemakers are implanted every year. There is a huge  cost variation between modern day pacemakers and conventional pacemakers. The apparent  advantages of newer generation pacemakers over conventional pacemakers are not  clear.There has been some concern about development of cardiac failure with VVI pacemaker1. We have already reported the incidence of cardiac failure with VVI pacemaker from our registry  which was surprisingly negligible. In this context, we studied bi-atrial and left ventricular function in patients following VVI pacing.

Objectives:

To Assess Biatrial And Left Ventricular Function In Vvi Pacemaker Implanted Patients. Methods: 31 patients were randomly selected from a group of 526 VVI pacemaker implanted patients of duration more than 6 months with
mean 50 40 months.The shortest duration was 6 months and longest was 185 months. Of the 31 patients,17 were males and 14 were females. The indications for VVI Pacemakers were complete heart block (22 patients) and sick sinus syndrome(9 patients). Patients who sustained MI, valvular heart diseases, cardiomyopathies and who had RWMA were excluded from the study. 31 persons of similar age and sex distribution without pacemaker were included in the
study as controls. All selected patients including controls underwent ECHO, ECG.

Results:

In VVI  group there was no significant reduction in EF and LA volume index,but mitral E/E’& RA volume index were reduced significantly. Paradoxical septal motion(PSM) did not influence any parameter.
Conclusion:

Contrary to the popular belief, VVI pacemaker was not associated with worsening LV function and left atrial dimension in our study. But there was a marginal deterioration in LV diastolic functional parameter.There was no significant impact on the quality of life indices, and no adverse outcome observed.We believe VVI pacemaker would continue to be safe and effective for our population.The usage of dual chamber pacemaker may be selectively used and need not be recommended routinely.
Reference:
1. Nathan AW, Davies DW. Is VVI pacing outmoded? Br Heart J 1992; 67: 285–8.

world congress cardiology dubai  4  2012

Changing angiographic CAD profile in young STEMI population
Venkatesan S. Sangareddi1, Pattanam S. Chakkaravarthi1, Srikumar Swaminathan1,* 1Department of Cardiology,

Madras Medical College, Chennai, India
Introduction:

Previous data on young patients with acute myocardial infarction have indicated  higher rates of normal CAG. Incidence of normal CAG in young STEMI is reported to be between 40–50%. There was a suggestion of decline in normal CAG in young STEMI .In this context, this study was planned.

Objectives:

The present study was conducted at madras medical college, Department of Cardiology, Chennai to assess the incidence of CAD in young diabetic post myocardial infarction patients in the urban and suburban populations of Chennai.
Methods: Angiographic data of 80 consecutive young patients with MI were studied Patients  who were nondiabetic,more than 40 years old and not thrombolysed were excluded.

Results:

out of 80 patients 74 were males and 6were females.25% of patients had normal LV function and75% had mild LV dysfunction. All are having DM and 30% are having HT and 40% are smokers In our study 20%of patients with inferior wall MI and 80%had anterior wall MI. CAG was performed on a mean average of 4 weeks after the index myocardial infarction and optimal medical treatment. Of the 80 patients 75%(60) had coronary artery disease and the remaining
25 %( 20) had normal coronaries .Of the 60 patients with CAD, 52(65%) patients had single vessel disease, 4(5%) had double vessel disease and 4(5%) had triple vessel disease.LAD lesion was present in 46patients and RCA lesions found in 16 patients. This made us to think why there is a higher incidence of CAD in these group of patient’s .Physical inactivity has become rampant due to high degree of automation. Diabetes added to this physical inactivity accelerates atherosclerotic process. So these patients might have had CAD already and myocardial infarction might have occurred as an acute insult .More lesions were found in atherosclerotic prone LAD than RCA.

Conclusion:

According to our observation, it seems, CAD in young is taking a different avatar compared to what we have witnessed few decades ago. The incidence of normal coronary arteries following a STEMI is distinctly reduced. While most
have critical SVD, significant subset do have extensive mutivessel disease. We suggest this changing angiographic profile need to recognized and looked for in different geographical locations of our country. It would have major management implication.
Reference:
1. Changes in CAG in young MI patients-Branco LM, Patriciol, Port Cardio 2001 Oct;10(10)
749–55.

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A pulse wave is generated  with each heart beat  when  the potential energy is converted into kinetic energy.

  • For the pulse wave  to travel from the heart to periphery  Aortic integrity is vital.
  • The pulse wave travels through the walls of arterial tree  , in the process the wall itself is set into oscillations .
  • Whether the  moving blood imparts the  pulse  on the walls or the walls itself  vibrate  independently is not clear .

The following   M -Mode  echocardiogram  of  aorta from young man   stunningly  documents  the  morphology  of  central aortic  pulse  wave . Note how closely it resembles the  Intra- aortic  pressure curve recorded with a catheter.

The anterior aortic wall motion was sliced from the above motion image  to create a non invasive recording of aortic   pulse wave

This simple observation was made in  a crowded  echo lab our hospital. Cardiology fellows can explore  further  ,  the link between aortic pulse transduction (From mechano -hemodynamics)

Further studies are warranted regarding the  rate of raise (Slope)  of aortic  wall motion  , and the quantum of motion ,its correlation with central aortic pressure etc. This would unravel the the mechanisms  of Isolated systolic  hypertension  , where a stiff aorta amplifies  the systolic pressure due to loss of elasticity .

Read also

Rail roading of  Aorta in Severe  LV dysfunction

Wind Kessel effect

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