Internet is a wonderful gift for for mankind but only occasionally we find great resources .
Hats off to Dr .Pybus from Australia for his efforts
A must read for all cardiologists rather everyone involved with echocardiography
Click on the Image to reach the site
Posted in echocardiography, Great websites in cardiology | Tagged best cardiology website, doppler echocardiography, echocardiography, tee, transesophageal echo | Leave a Comment »
Thrombolytic therapy was a mini revolution when it was introduced two decades ago .It has since evolved , not only in the molecular structure but also in it’s usage pattern.
The first generation streptokinase is continued to be used even today . While the latest generation thrombolytic agent TNKTPA(Tenekteplase) is threatening to push the old warrior out of CCU.
(Of course the American Physician & Pharma community never gave the due respect to streptokinase !)
The two common indications for thrombolytic therapy are
Uncommon indications
From the beginning , there has been a controversy about the thrombolytic dosage and the speed with which it is to be administered .Let us recall , streptokinase was initially used in various regimes ( 5-30lakh units between a 10 -3hr infusion ) Later ,we arrived at a consensus at 15L units in 1 hr infusion . TPA also experienced the same . Which settled for front loaded regimen(35 + 65mg) . The confusion reappeared when we developed bolus thrombolytic agents( TNKTPA) .
In STEMI thrombus formation is often a one time process while thrombolysis is a continuous process. In pulmonary embolism both thrombus formation and lysis is often continuous process .
The success of thrombolysis depends on the sustained drug concentration , the pressure at which the drug interacts the thrombus.
Many times it is prudent to administer intensive heparin after thrombolysis to prevent recurrent thrombosis. Further , most of the pulmonary embolisms will require long term anticoagulants.
How to maximize the success of thrombolytic agents ?
It makes sense , to administer these thrombolytic agents over a prolonged period of time so that the lytic process gets wider recruitment of the natural lytic mechanisms.
When a drug is infused continuously , the drug reach the thrombus in a pulsatile manner , which facilitates thrombus dessication (Like drip irrigation ) . A long acting drug even with a high concentration may not be very effective , since the drug is required to produce a mechanical effect here . (Unlike say a long acting antibiotics !)
TPA in Pulmonary embolism
The inadequacies of 2 hour infusion of TPA is glaring in acute pulmonary embolism .We believe a 48-72 hour streptokinase infusion has a definte edge over a short and brief TPA infusion.
Issues need answer
It is yet , not understood why we can’ t infuse TPA as a long term infusion like streptokinase .
Advantage of bolus TNK TPA in pre-hospital phase of STEMI
The argument in favor of bolus dose thrombolytic agent is the ease of administration .
The other the major advantage claimed is , a 10 second TNK TPA in STEMI can substantially reduce the time window and facilitate early completion of thrombolysis .
Counter point
But , the later concept is hard to prove . . .
In fact , there are no controlled studies available for assessing the efficacy of TNK-TPA vs Streptokinase with reference to various time windows. We presume so many things. An incomplete early thrombolysis may not be better than a more successful but slightly delayed TIMI3 flow .
As scientists, when we try to answer these question we ask for data . Are we getting it any way ? Are the existing data reflect fact ? We wonder, will we may never get an hourly angiographic data base about the IRA patency in TPA bolus vs streptokinase infusion .
It is most unfortunate, with many of the critical questions still to be answered , the cardiology community believes , they have reached the summit of knowledge about thrombolytic therapy . Current perception is , the research on existing thrombolytic drugs is deemed to have been complete .
In this hyped era of interventional coronary care , it is a remote possibility to have any further comparative studies on thrombolytic agents .
The greatest threat faced by us today is the destiny of modern medicine is often decided in few corporate board rooms and hence research questions rarely emanate from bed side !
In this scenario, where we are not likely to generate genuine clinical data , the only way to move forward is to go by our experience – ” Genuine experience to be precise . . .”
Final message
Ease of administration should never be the criteria in choosing a thrombolytic agent . It can severely compromise the quality of thrombolysis ! especially in pulmonary embolism and to a certain extent in STEMI. Success rarely comes with ease . . .
Many believe , the choice between streptokinase & TPA goes much beyond it’s academic reasons. TNK TPA (Tenektepalse) has come in a big way to replace streptokinase even in developing countries. Ofcourse it is backed by a huge study ! (ASSENT) .
The cost effectiveness and worthiness of TPA over streptokinase was never proved comprehensively.
Note of caution :
The observation made above is based on personal opinion in about 20 patients . Readers are argued to do their own analysis on this issue and come to a conclusion .
Posted in Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, cardiology- coronary care | Tagged alteplase, pharmacokinetics, stemi, streptokinase, streptokinase vs tenektepalce, streptokinase vs tnktpa, tenektepalce vs streptokinase, tenekteplace, thrombolysis, thrombolytic therapy, tnk tpa, tpa vs streptokinase | 1 Comment »
Coronary artery anomalies are relatively common . It can be either in it’s origin, course , or termination etc.
There are two major sub groups.
The second category which we encounter in cath labs frequently does not have major implications . RCA and LCA arising away from it’s respective sinuses ,Separate origin for LCX, or conus, RCA from left sinus or a high take off of RCA are the common anomalies.
While coronary anomalies are commonly associated in complex congenital heart disease (TOF, DORV, TGV, etc )
Isolated complex anomalies of coronary arteries are extremely rare
This happens , when one coronary artery arises from pulmonary artery instead of aorta and it becomes a fascinating disease !
The ALCAPAs and ARCAPAs
When the LCA originates from PA it becomes a rare cause of left to right shunt .it is referred to anomalous origin of LCA from PA (ALCAPA) .
The ALCAPA is many times common than the “ARCAPA”
We report a case of ARCAPA (Anomalous orgin of RCA from PA )
The unique features of ARCAPA could be
Image and video of the ARCAPA will be uploaded shortly
Reference
1 http://asianannals.ctsnetjournals.org
Posted in Cardiology - Clinical, cardiology congenital heart disese | Tagged arcapa | 2 Comments »
The bundle of his divides into two
Middle fascicle * Many dispute it’s presence . One may wonder , how can anatomy be under dispute ? If you cut a heart you should be able to clear the dispute . But medicine is not that simple . . . What you do not see may be more important than what we see.
The anterior fascicular block (LAFB) is one of the common conduction disorder. It ‘s significance : Can be a benign or a dangerous entity depending upon the clinical situation .The problem with LAFB is , it is diagnosed primarily by the axis shift it inflicts on the QRS complex.
In a strict sense, it is not a ideal way .There is a tendency to label all significant left axis (> -60*) deviations as LAFB. This practice has made diagnosing LAFB very common in elderly, hypertensives, etc. In these situations it may not mean anything , except to suggest a delay in conduction in left anterior fascicle.
If we filter out all these benign axis shift ECGs , the true organic pathological LAFB may not be that common .
Organic , LAFB occurs in the following situations.
Even in degenerative , ischemic conduction defects LAFB is far more common than LPFB why ?
The traditional explanations are
** Which experiences the peak LV pressure at > 100mhg and a dp/dt up to 2000mmhg (While, the posterior fasicle is located away in the inflow portion of LV , which is exposed to low pressure – at best 10mmhg filling pressure )
Posted in Cardiology - Clinical, cardiology -ECG, Tutorial in clinical cardiology | Tagged av block, bi fascicualr block, bundle of his, fascicular blocks, hemiblocks, lafb, lafb vs lpfb, left anterior fascicular block, lpfb, rosenbaums block, why lafb is more common | Leave a Comment »
Human body is now approached by many of the physicians as collection of multiple organs . This is the price we pay for modernity in medical science. The era of great physicians in general medicine has gone . Now, a super specialist of one organ is rarely concerned about what is happening to the patient’s other organ , it is considered foreign to him ! While , this is the dominant thinking pattern of modern-day specialist
Let us travel intime and go to the year 1954 . . .
Three physicians from Michigan ,USA published one of greatest observation in clinical sciences , namely the ECG changes in various forms of stroke .
Now , a shrewd physician , will suspect a subarachnoid hemorrhage (SAH) by looking at the ECG when the clinical situation demands . But , what we need is every one should develop that skill . We have seen errors happening even in big institutions (or is it because it is big ?) when an elderly person comes with deep T inversions with or without altered sensorium being rushed into CCUs & cath labs instead of neurology units.
We need to teach our junior colleagues . . . That , ECGs of patients with acute neurological syndromes (ANS) can mimic as acute coronary syndromes (ACS) ( especially in elderly ) .
The following ECG changes * are observed during stroke
The ECG changes tend to occur very early after CNS injury.May last up to 1 week. They are not useful to identify the type of stroke. But , deep T wave inversions strongly suggest SAH rather than ICH or thrombotic stroke.
What is the mechanism of these ECG changes ?
It is a clear proof that heart and brain are interconnected by neural network. All the noted changes occur during myocardial repolarisation . (ie ST segment ) The current thinking is (Ofcourse , it is same as our thinking in 1950s !) it is mediated by adreneergic surge initiated by CNS insult transmitted to myocardium by the sympathetic system.
Why should SAH produce more ECG changes than others ?
It is possible the net adrenegic drive from the brainstem and spinal cord will be greater in SAH as it spreads the entire CNS through the cerbro spinal fluid. While localised ICH and infarct is likely to generate less adrenergic impulse.
Reference
Read the link to circulation 1964 .With courtesey to circualtionaha.com
http://circ.ahajournals.org/cgi/reprint/9/5/719.pdf
This came 50 years ago , we still quote their work and no one has improved their work .
Final message
If only we make the clinical bed side teaching as a regualr habit , we do justice to our great physicians of the past , who enriched our life with their clinical skills and passion for knowledge sharing .
Posted in Cardiology - Clinical, cardiology -ECG, cardiology -Therapeutics, Cardiology -unresolved questions | Tagged acs, acute coronary syndrome, cardiologists, cva, deep t wave inversion, ECG, intra cerebral hemorrhage, mimicers of stemi, neurologist, non ischemic st depression, non specific st segemnt, qt interval, stroke, sub arachnoid hemorrhage, t inversion, u wave | Leave a Comment »
Imaging coroanry artery is generally in the domain of interventional cardiologists. MDCT has helped us to change that.
The humble echocardiography can identify the origin* of coronary arteries in most persons. The resolution power of modern day echocardiography is 2mm and the left main ostium is >3.5mm in 99% of population . If some body says one can’t visualise the coronary artery by echo , it can only reflect their ignorance or lack of patience to get an optimal image. Of course technological limitations are there.
* To be emphasised again , only the origin can be identified.
Can we identify ostial leftmain or proximal left main disease by echocardiography ?
It should be possible in few .
Can we place a doppler sample volume within the left main and measure coronary flow velocity ?
When obsterticians are able to assess the uterine artery flow in a bulky uterus , it should be possible to do the same in a coronary artery . Motion artifacts is the issue in the heart. Micro sample voulme (<1mm) are expected in the future that will make a non invasive coronary flow assesment a distinct possibility.
Posted in Cardiology - Clinical, cardiology -Therapeutics, echocardiography, Tutorial in clinical cardiology | Tagged aortic cusps, coroanry ostium, coroanry sinus, coronary, coronary artery, coronary artery origin, echocardiography, lcc, left main coroanry artery, left main disease, lmd, ncc, non coronary cusp, rcc, right coroanry cusp, short axis in echocardiography | 1 Comment »
Hypotension is one of the dreaded complication of acute STEMI.
A new mechanism for persistent hypotension is increasingly recognised.
This is due to the
1.Loss of LVOT dynamic activity.
2.Excessive dynamism of LVOT.
LVOT contractile and ejectile falure
Even though LV outflow tract contain less contractile myocytes , it has an important mechanical job to do. We know , it’s primary job is that of a conduit but it also has to eject the blood into aorta with sufficient force. In fact, it is thought much of the acceleration of blood velocity occur in LVOT . So, LVOT plays a key role in maintaining the cardiac index. An excessively dynamic LVOT will impede the forward blood flow as in HCOM. Similarly less dynamic contraction of LVOT results in low velocity propulsion , that interferes with proper delivery of blood from LV cavity into the aorta .
These factors get amplified in acute MI , as it is a compromised situation with fluctuating HR and contractility. So a properly functioning LVOT conduit is absolutely mandatory.
STEMI due to a proximal LAD obstruction located can involve the septal .If the first septal branch happens to be a major one, there will be definite impact on the LVOT function.
Excessive dynamism , LVOT desynchrony LVOT collapse .
LVOT has a medial border formed by IVS , an anterior surface and a posterior surface .The lateral border is relatively boundary less , except it is guarded by the anterior mitral leaflet.
But one should recall , the AML comes towards the LVOT only in diastole . When it comes in systole it becomes a pathological event called SAM (Systolic anterior motion )
The LVOT wall desynchrony can occur in both anterior and posterior MI.In a mulivessel CAD this can happen when there is disproportionate inferior to anterior wall motion defect.
Management.
http://circ.ahajournals.org/cgi/reprint/116/5/e110.pdf
Haley et all Mayoclinciproceedings 1999
Posted in Cardiology - Clinical, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions | Tagged dynamic lvot obstruction, hcm, hocm, hypotension in stemi, lvot collapse, lvot stemi, refractory hypotension, RVMI, sam | Leave a Comment »
Here is the Link
Just sample an article : A great review about cardiac arrhythmias in congenital heart diseases , Must read by all cardiologists http://www.ipej.org/0906/khairy.htm
Posted in cardiology journals | Tagged cardaic pacing, cardiac arrhythmias in children, carto, ddr, drsvenkatesan, ECG, electrophysiology, endosense, ep study, heart rhythm society, IJEP, india, pace, pediatric cardaic arrhythmias, pediatric cardiology, vvi | Leave a Comment »
Now we have a dedicated journal for cardiovascular CT scan .
Does it surprise you ? For me . . . It is !
Link to the current journal page . Get updated !
Posted in Cardiology - Clinical | Tagged 64 slice ct, cardiology, cardiology journals, ct coroanry calcium, ct scan, drsvenkatesan, mdct | Leave a Comment »
There are millions of articles in cardiology . Some simply occupy valuable spaces without any purpose . Some give us knowledge . Some enlighten us. While few are so vital , it is almost a crime if we do not read such articles and apply it in day to day practice .
This an article written by Henri Justino that has a immense importance for the patients as well as the physicians .
Do not think the article which came in pediatric radiology is not applicable in adults !
Posted in Cardiology - Clinical, Cardiology -Interventional -PCI | Tagged 64 slice ct, alara, angiocardiography, cardiac catheterisation, cath lab, drsvenkatesan, hazards of ct scan, mdct scan, physician safety, radiation badge, radiation dose, radiation hazard, radiation safety | Leave a Comment »
Dr.S.Venkatesan MD 
