Posted in Cardiology - Electrophysiology -Pacemaker, Infrequently asked questions in cardiology (iFAQs), Long and Short QT syndromes, tagged how short qt syndrome induce vt, long and short qt syndromes, Mechansim of VT in long and short QT syndrome, short qt syndrome on September 24, 2013| Leave a Comment »
The stretch and strain experienced by the action potential’s left shoulder region is almost similar* in both long and short QT syndromes that trigger a VT.(* Hope this explanation makes some electrical sense !)
*Click over the image for high resolution
Posted in Uncategorized, tagged COPD and CAD, does copd has a protective effect on CAD on August 31, 2013| Leave a Comment »
In this mean world ,most truths exist without evidence . . . and often falsehoods masquerade as truths with overwhelming evidence !
Human biology has always been a mystery and can express in dramatic ways . While , many disorders combine to play havoc on the body , few tend to protect each other. HT and DM can join a deadly coalition to attack the heart .Smoking causes extensive peripheral vascular disease , still thrombo angitis of coronary arteries ( due to smoking ) is virtually unknown. Tuberculosis does not have the courage to attack the heart valves , while it can inflict serious injuries all over the body . Similarly , systemic hypertension and Rheumatic heart disease does not combine well . So , it can be assumed some unique and hidden protective factors are at play among different pathological entities and their target organs.
A brief account of how COPD could be related to CAD ! (* Mostly Imaginary !)
We know , COPD , stresses the right ventricle by pressure overload and in extreme situation affects the LV function because of hypoxia. It rarely impacts the coronary artery disease . This has been our consistent observation. While COPD patients often land up with LV dysfunction , investigations reveal they are more of a dilated cardiomyopathy and their coronary arteries are entirely normal. Diffuse atherosclerotic CAD is a rarity in patients with history of bronchial asthma. Coronary micro circulation is also observed to be largely intact in most people with COPD .
We haven’t got a call from our pulmonology wards in many decades , for a true emergency coronary consult . Mind you ours is a 200 year old Institution , with 3000 beds , largest east of Suez canal !
It’ s very rare for bronchial asthma patients to die of a cardiac event. Thousands of elderly patients throng our ER with acute severe asthma every winter , still extremely rare to precipitate an acute coronary event !
We are yet to see critical triple vessel disease in a patients with documented bronchial asthma and COPD . Even non-critical CAD is far less frequent in COPD vis a vis general population . It is indeed a strange observation , considering both entities are rampant in the community .
What could be mechanism for the perceived disconnect between COPD and CAD ?
Is it a myth ? Does it happen in all geographical zones ? If hypoxia is the sine qua non of COPD , one would rather expect a close association with CAD , isn’t ?
One suggestion that keeps erupting from my cortex . It is the wide swinging intra thoracic pressures in COPD or asthmatic individuals . . . somehow responsible . These wide swings of pressure are transmitted to aortic root . They transform into good coronary perfusion pressure , keep the vessels clean by pressure vacuuming effect .
We have asked our epidemiological unit to analyse the 25 year data from our coronary care unit to decode the mystery .
Counterpoint
Meanwhile, a diagonally opposite question was asked in UK and found a partial proof as well . Our experience do not agree with this study conclusions .
What is your take on the issue ?
http://ije.oxfordjournals.org/content/33/4/743.full.pdf+html
Introspection
How can a opinion (rather an Imaginary essay !) based on personal observation projected as a scientific fact ? We need to observe , analyse and publish the data . This is what the scientific world expects us to do . Unfortunately , the journey form observation into publication has been kept purposefully difficult . In my opinion bulk of the international peer reviewed medical journals with high impact factor can convert any junk data into a scientifically palatable recipe !
Posted in Cardiology -guidelines, Cardiology -Interventional -PCI, medical quotes, Two line sermons in cardiology, Uncategorized, tagged cath lab ethics, ethics in medicine, hippocrates, primum non nocere on August 31, 2013| Leave a Comment »
The doctrine of modern medicine goes something like this . . .
For most medical problems , there would be a solution. Keep trying . . . till you get it !
*But , just make sure that problem on hand deserves a solution in the first place !
Modern medicine continues to remind us every day , the much hyped solutions often end up in new problems and many times worse than the original problem !
Oh ! what a great a quote ! When I was boasting myself . . . My wife reminded me , this is just plagiarized version of a 2000 year old Hippocratic thought !
Primum non nocere . . . first do no harm !
But , Hippocrates’ life was not contaminated with drug eluting stents, I pads, and BMWs
If Hippocrates arrives in cath lab today by BMW which sucks 50000 Rs EMI ,Everolimus coated coronary jewellery will definitely tempt him !
You can’t simply compare lives separated by 2000 years
. . . I told my wife !
Posted in Cardiology - Electrophysiology -Pacemaker, cardiology -ECG, Cardiology -unresolved questions, Cardiology-Land mark studies, Cardiology-Statistics, tagged brugada vs common sense, svt with aberrancy, svt with aberrancy and vt on August 31, 2013| Leave a Comment »
Scientific studies can be fun .In our spare time we often Indulge in rapid fire sessions. We tested 30 wide qrs ECGs from our archives (All proven VTs) and asked our cardiology fellows to apply Brugada criteria . They could correctly diagnose VT in 18* patients.The same ECGs were shown to the staff nurses of coronary care unit . 24 VTs were correctly identified it.They did it by their clinical sense and Instinct. (*12 vs 6 VTs missed)
And now , four clinical data was provided. (Age , sex , Blood pressure , and past H/o MI were given ) The Nurses were able to predict it 28/30 VTs correctly.(97 % accuracy ) and the cardiologists were able to equal the score now. So obviously clinical sense was far superior .
Cardiology fellows were more likely to mistake VT as SVT. This is far more common than SVT mistaken as VT. It is a strange academic irony ,even the junior most nurses never missed a VT !
Summary
Simple sequence of history and clinical presentation is still far more powerful than ECG data in predicting wide qrs arrhythmias . Nurses guess work is far superior than cardiologists in predicting a wide QRS tachycardia as VT.
In fact , the cardiology fellows are preconditioned to get confused whenever they get a wide qrs tachycardia . Why not aberrancy ? In my experience I have seen this question keeps erupting inappropriately .Even shrewd fellows suffer from an oscillatory mind between VT and SVT .This is primarily because , every wide qrs ECG is likely to have at least two criteria that fulfill both VT and SVT.
The implications are genuine and far reaching . While nurses show a patient centric thinking cardiology fellows thought process revolves around ECG . Many modern-day cardiac physicians are disconnected from clinical reality and are obsessed with complex EP concepts and end up with a miserable face in the bed side !
This is not a new revelation in 2013 . Masood Akthar told this three decades ago.
Posted in Cardiology-Statistics, Uncategorized, tagged gimmicks in medical statistics, medical statistics, non inferiority clinical trials, Non inferiority drug trials on August 27, 2013| 1 Comment »
Of late many drugs are entering the market for human consumption backed up by Non -Inferiority trials (NIT ) .Few examples.
“Feb 20, 2013 – … in the New England Journal of Medicine Show Dabigatran Etexilate ... daily was non-inferior to warfarin (p=0.01) in preventing recurrent VTE, …”
What is the logic behind these Non inferiority trials ?
Why it came into vogue ?
Do you agree with the concept of NIT ?
I have taken the privilege of putting my answer in the title. Believers of NIT please excuse me.
Reference
Posted in acute rheumatic fever, Cardiology - Animations, cardiology -ECG, Cardiology-Arrhythmias, Clinical cardiology -JVP, Infrequently asked questions in cardiology (iFAQs), Uncategorized, tagged 1:1 VA association and cannon waves in jvp in avnrt, cannon waves and av association, cannon waves in complete heart block, diagnosisng arrhythmias from neck veins, irregular cannon waves in chb, jugular venous pulse in svt avnrt vt, junctional tachycardia and regular cannon waves, regular cannon waves in avnrt svt, regular vs irregualr cannon waves on August 27, 2013| Leave a Comment »
Cannon waves occur when Atria contracts against a closing tricuspid valve of right ventricle .( There would be a equivalent left atrial cannon which goes into pulmonary vein as well , it is discussed elsewhere !)
Cannon waves happen only when P waves fall within QT interval in ECG as QT represents the electro-mechanical systole of ventricles. (Since P wave represents atrial systole , it is simple to understand when it falls within QT both atria and ventricular contractions collide to produce a cannon wave into the neck or pulmonary veins.)
The following two images of cannon waves taken from the legend Dr Paul woods own tracing .
Regular cannon waves
Occur during SVT with 1:1 VA conduction.*
1 : 1 VA conduction can be considered as absence of AV dissociation (Rather disciplined VA association with every beat ) This is essential to create a hemodynamic milieu for regular cannon waves.
* In AVNRT , VA conduction in strict sense is a misnomer .It is simply a retrograde conduction thorough the AV node .
Irregular cannon waves
Can we get regular cannon in VT ?
Yes , but rare . As explained earlier this can happen only if AV association occur on a retrograde fashion.
Further reading in this site
Posted in rheumatic heart disease, Uncategorized, valvular heart disease, tagged acute rheumatic fever guidelines, best review, inclusion of echo criteria for rheumatic fever, indian criteria for acute rheumatic fever, Indian journal of medical research rhd rheumatic fever, rheumatic fever in india, rheumatic heart disease, tandon and krishnakumar rhd rheumatic fever review article on July 31, 2013| Leave a Comment »
Rheumatic fever and RHD is still a major cause for cardio vascular morbidity and mortality in India .It seems , improving quality of life has little impact on the incidence .(We could realise this as we sit in the cardiology OPD of a 200 year old hospital !) There is no country wide data on the true prevalence . Our understanding of rheumatic heart disease is based on isolated studies on localized populations .
Of late , cardiology resources in our country is diverted towards much glamorous CAD the poor continue to suffer with RHD.
Just Imagine many hospitals indulge in 1000s of PTCA every year but hardly do a hand full of PTMCs.
How our cath lab resources are used across the breadth and length of country needs some introspection (Currently , I believe we have about 750 labs ) .I think there should be a binding legislation in every cath lab .For every 10 PTCAs done at least one PTMC must be done to heal the poor .( Like the Air-craft license .You can’t fly only the lucrative metro sector is given only if IT services less developed areas )
In this scenario , it is a pleasant surprise to find a wonderful review article on RHD from the two pioneers , in lesser known medical journal IJMR .
Especially heartening is the fact , it is a collective effort from two distant regions of India ( Kochi from down south and New Delhi In the north) . While politicians keep the divide , it is a great work of the authors , which would help youngsters who would like to go on a national mission on eradication of RHD. .
Reference
http://www.icmr.nic.in/ijmr/2013/april/centenary%20review%20article.pdf
Posted in Uncategorized, tagged amplatzer asd device, ASD device closure, asd rims, cocoon asd device on July 31, 2013| Leave a Comment »
The following factors are critical determinants of the success of ASD device closure
Posted in cardiology -Therapeutics, Cardiology hypertension, Uncategorized, tagged esc hypertension guidelines, european society of cardiology, how to treat systemic hypertension, hypertension management guidelines european society of cardiology, inappropriate prescription in drugs, jnc guidelines, learning from patients, systemic hypertension on July 31, 2013| Leave a Comment »
The stakes are high for the drug industry .Anti hypertensive drugs are the major source of revenue to them . Any dip in per capita consumption will have direct impact on their health ! ( WHO bothers about public health ? )
The so called scientific guidelines, are generally made balancing patients health vis a vis drug companies health .I have found more often than not it was tilted towards the industry .
* One may wonder why I’m focusing always on non scientific issues more than academics .(I some how feel non scientific factors are going to impact our health more than any other factor in the coming generations )
Now is the beginning of a balance .
Posted in Uncategorized, tagged can technician interpret ecg, ECG, echocardiography, who should do echocardiography ? on July 20, 2013| 1 Comment »
A Cardiologist will never accept the diagnosis , if a technician reports a ECG as normal in a patient with chest pain . . .
While , the same cardiologist gleefully accepts an echocardiogram done by a technician and treats the patient without verifying the veracity of the finding !
Why ?
Some where along the cardiology training , we have been made to believe Interpreting Echo Images does not require serious medical knowledge . . . but we strongly believe ECG cannot be read by technicians however well they are trained .(In-spite of the fact , Echo images are highly dependent on the person who does it , while ECG wave forms are totally independent of the person who record it ! )
ECG, still has a prestigious place in cardiologist’s mind , while Echo is often considered an inferior Investigation. Many of us consider ECG interpretation as a brainy work while Echo image acquisition and interpretation is perceived a dumb job* !
Lastly , probably most importantly , performing Echo is a time intensive process for the present day cardiologist who’s hands are tied with catheters and guide-wires .He has little time for the meanly echo . . . hence ready to compromise on the quality .
* With due respects to all non invasive cardiologists (That includes the author !)
Final message
I would think it is fundamentally inappropriate for technician to report Echocardiogram (Of-course they may record it ) . Unfortunately , for some reason this practice is continued in many parts of world .
Dr.S.Venkatesan MD 