Posted in cardiac surgery, Cardiology - Clinical, Cardiology -Interventional -PCI, tagged annals of thoracic surgery, cabg, dor procedure, STICH Hypothesis, STICH TRIAL, ventricualr reconstruction surgery, ventricualr reduction surgery on March 31, 2009| Leave a Comment »
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 .
Posted in Uncategorized, tagged cabg, coronary collateral, coronary collateral circulation, courage, cto, LAD, lad 100%, lad stump, oat, pci, pda, rca to lad, toal lad on March 29, 2009| Leave a Comment »
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
Posted in Cardiology -Interventional -PCI, Uncategorized, tagged cardaic tamponadew, collagen embolism for perforation coronary, coroanry perforation, coronary guidewire, dissection, ellis classification of coronary perforation, epicardail perforation, europcr, false lumen, freed, gruentzig, home made ptfe stent covered, jacc, manual of interventional cardiology, pci, pericardium covered stent, pseudo science, ptca, ptfe coated stent, scai, stent sandwich for coronary perforation, tctmd, tissue palne on March 28, 2009| Leave a Comment »
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.
How is this possible ? (Type 1 Ellis has zero mortality Read below)
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 .
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.
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 ?
How do you classify coronary perforations ?
How do you manage coronary perforation?
Simple guide wire induced perforations are less trouble some unless we have crossed it with balloon without realising the fact the wire has entered the pericardial space. So, caution is required and always watch for guide wire tip movement which is often funny looking wihtin false lumens or very freely moving within pericardial space. Anticipate the complication especially so when you do CTOs and venous graft PCI. Keep one cath lab tamponade crash bin in ready mode before embarking upon a complex PCI
2018 update
This is nearly 10 years old article. Now, we have gained much experience and hardware utilisation have rapidly expanded. While expertise has minimised this complication , more PCIs in complex lesion subset tend to keep the incidence static , if not higher.(Its around .5% )
Tips to use balloon occlusion during perforation
Perforations which are active and flowing should be immediately occluded with a balloon either at the site of leak or just proximal to it. Doing a proximal occlusion is easier in emergency , as often times its technically difficult to reach the site of leak especially in CTOs where the leaky site is not defined clearly or forward looking (Local balloon inflation across the leaky site is not feasible )
How long to occlude , Intermittent /complete, proximal ? or at the site of perforation ? These queries are answered in Ref 4
Reference
4.A very good review comes from Royal Hospital, Muscat, Sultanate of Oman
iFAQs in coronary perforations
1.Does the plane of the coronary artery (Sub epicardial within the fat layers) determine the likely hood of tamponade ?
While myocardial tissue can resist flow we are not sure about sub-epicardial fat on the pericardial aspect.
2.How common is Intra-cavitory perforation ?
Perforations into chamber is invariably associated with septal branches (PCI to septal branch itself is less common )
Posted in cardiac surgery, Cardiology - Clinical, tagged cabg, coronary subcalvian dtal, lima, reversal of lima flow, subcalvian stenosis on March 27, 2009| Leave a Comment »
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
Posted in cardiology -congenital heart disease, tagged 100% oxygen, asd, bi directional shunt, biochemical diagnosi of pulmonary hypertension, eisenmengersyndrome, heath edwards, nitric oxide, pd, pht, reversibility of pulmonary hypertension, right to left shunt, severe pulmonary hypertenison, tolazoline, vsd on March 27, 2009| Leave a Comment »
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.
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
Posted in Uncategorized, tagged left main artery on March 26, 2009| Leave a Comment »
Left main coronary artery disease is a major form of CAD .
A 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
Posted in cardiology -Therapeutics, cardiology-ethics, Cardiology-Land mark studies, Uncategorized, tagged beta blockers in cardiac failure, carvidilol, cibis, comet, copernicus, f.waagstein, metoprolol, observational study, practolol, randomised control trials, statistics on March 26, 2009| Leave a Comment »
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
Posted in cardiac drugs, Cardiology - Clinical, cardiology -Therapeutics, tagged adrenergic receptors, cardaic pharmocology, cardiac failure, catecholamine, dobutamine, dopamine, dopaminergic receptors, inotrpic agents, ischemic lvf, lvedp and dobutamine, nor epinephrine, pcwp and dopamine, renal dopamine dose on March 25, 2009| 6 Comments »
Dopamine and dobutamine are the most commonly used inotropic agents in clinical cardiology.
The following table represents a simple comparison of the two drugs.
Posted in cardiac surgery, Cardiology - Clinical, Cardiology -Interventional -PCI, Tutorial in clinical cardiology, tagged aortic band, aortic disscetion, aortic septum, cob webs in aorta, dissecting aneurysm of aorta, entry point in aorta, exit point in aorta, falp curvature, false lumen, false lumen of aorta, mri of aorta, stents for aortic aneurysm, tendrils, trans esophageal echocardiography, true lumen, true lumen of aorta, type a debaky, vinculum on March 24, 2009| 4 Comments »
This helps the interventional cardiologist to plan the specific therapeutic procedure .
One may wonder , why is that difficult to identify the true aortic lumen by echo, after all , the LV empties the blood into true aortic lumen ! Yes , in aortic root dissections identifying the true from false lumen is rarely an issue.
The issue becomes important and complicated as the propagation of dissection goes in a random and erratic way into the ascending aorta and arch and downwards.The situation could further get complicated by the fact there could be multiple communication between the two lumens .Some of these communication are hemodyanically patent others form a simple anatomical continuity.The size and the configuration of true and false lumen are not uniform it is highly variable.In the aortic root the size of the true lumen is usually large and when it reach the descending aorta as in type3 the whole thing could be reversed.
The enigma of these lumonomics , is that some of the native branches of aorta , would either be, subtended by false or true lumen. This is a real tricky issue for the surgeons . If a aortic vessel branch (Say bronchial artery . . .) is perfused successfully by the hemodynamically active false lumen should we meddle that at all ?
What are the types of false lumen ?
Usually single septae divide the aorta into two , one false lumen and true lumen.There can be other types.
Triple lumen aorta :This is usually seen in the aortic root following dissection .Usually there is two false lumen and and one true lumen in the centre
Double barreled aorta: A circumferential aortic dissection with a central true lumen surrounded by a circumferential false lumen mimicking a double barrel on within the other.
but more often multiple exit points can occur. Some points can have both two and fro flow as it may act as both as entry or exit points
Large thrombus can occur within false lumen.The presence of which , sometimes an advantage as
it limits further progression of false lumen (An organised thrombus is sort of natural stent graft !)
many of these patients do well with medical management.
C J Sanderso Thorax 1981;36:194-199;
Yes , but it is rare as the velocity is more .But it can occur in following situations.
Cob web are the residual ribbons of dissected internal elastic lamina of aorta .
They are variably called as aortic bands, strands , septae, flaps etc.
The classic false lumen is crescent shaped. True lumen is either round or oval(Gibbous moon)
Tunction between false and true lumen has some characteristic feature.It mimics the letter Y. The mainstem of Y correspond to main( Normal full thickness)aortic wall of the true lumen.The oblique lines represent the outer wall of the false lumen and the septae dividing true (Fig 3)
Surgeons often leave the false lumen insitu , especially beyond the arch in type A dissection.
If false lumen is large >70% of aorta , secondary dissections may occur in the long term.
Even though MR angiogram and CT scans are shown to be good imaging tools in the evaluation of dissection of aortamany practical issues creep in doing MR or CT angiogram.Many of these patients are too ill and will be on multiple arterial and venous lines Doing an MRI is too dificult a task .Further these imaging modalities require a another arterial access .Requires contrast injection and CT has in addition , radiation hazard.
TEE is a simple investigation can be done even in unstable patients in the bedside .Further also help us us evaluate the aortic valve function and associated complications of dissection. TEE will be very useful peroperative also in assessing the repair.
*But MRI and CT can give a long axis , saggital cuts of aortic dissection depicting the entry and exit points in a single image
Posted in Cardiology -Interventional -PCI, cardiology -Therapeutics, tagged 2b 3a antagonists, acs, coronary dead space, coronary thrombosis, distal protection, drug eluting stent, expoert catheter, freed, ivus, pci, pci and thrombus, primary pci, ptca, stent approximation, tct md, thrombus and pci on March 22, 2009| Leave a Comment »
First and foremost is
Avoid the procedure if not really indicated.A lesion which has more thrombus load than a plaque and it is , subcritical and not limiting the flow , PCI may be inappropriate especially if the ACS is stabilised.
Fig 1
Dr.S.Venkatesan MD 