Why AF is often well tolerated in Hypertrophic cardiomyopathy ?
Up to 25 % of LV filling is done by atrial contraction. Atrial booster function is important in LV outflow lesions. This can be critical in patients who have diastolic deformities of LV. ( an audible or even palpable S4 confirms the atrial kick in these situations ) This is how we were taught for decades right. Still, it may hold good in many left-sided condtions, but in HCM it definitely seems to be not true.
A succinct review of this topic makes a good read.
Incidence if AF in HCM is about 20% (Mostly paroxysmal 70 % , Persistent /Permanent 30 %)
Mechanism of AF IN HCM
Incre...
Source: Dr.S.Venkatesan MD - November 29, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Atrial fibrillation af in hocm affirm study atrial fibrillation in hypertrophic cardiomyopathy current guidelines in hcm hcm hocm mechansim of af in hcm pathophysiologyof hcm Source Type: blogs
ASD device closure: “ Mind the gap ” to avoid SA nodal artery compression.
The branching pattern of the human cardio-vascular tree is as unique as one’s fingerprint. One such hugely variable anatomy is the SA nodal blood supply.
Certain salient features
Variation can be seen in origin, course, and termination.
Now it is estimated to arise from RCA in 70% (Moved up from 55% in old studies )
From LCX (25%)
Dual SA node supply(5%)
Direct from Aorta
It is heartening to find this good anatomical review on this topic.
A) From the Right Coronary Artery; (B) From the Left Circumflex Artery (proximal); (C) From the Left Circumflex Artery (distal); (D) From the Left Coronary Artery; (E) From the Ao...
Source: Dr.S.Venkatesan MD - November 20, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Cardiology research topics cardiology research topics for fellows Uncategorized ASD device closure cardaic lymphatics cardiology reserach topic sa nodal compression during asd device closure Source Type: blogs
Corona second wave might bring some good news !
This article never intends to undermine the importance of preventive measures and vaccine for this worst pandemic in recent human history
(Source: Dr.S.Venkatesan MD)
Source: Dr.S.Venkatesan MD - November 17, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized corona second third wave corona second wave corona vaccine what is the case fatality rate in corona Source Type: blogs
Arrhythmia basics: How often we need to know the mechanism of arrhythmia ?
How many times you have treated cardiac arrhythmia in both emergency & non-emergency situations?
Infinite times.
How many times did you really bother to know the mechanism of a given arrhythmia before ordering medication or shocking?
Hmm,.. let me think. (Except for AVNRT/ AVRT, and few VTs, very rarely I have worried about the mechanism !)
Why is it so? because treatment takes priority and we are able to tame the arrhythmia even without knowing the real mechanism.
The following slide is a gross summary of the cardiac arrhythmia mechanism
Understanding cardiac arrhy...
Source: Dr.S.Venkatesan MD - November 2, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Basic science -Physiology Brugada syndrome cardiac electrophysiology cardiology -Therapeutics Cardiology-Arrhythmias brady dependent vt eads dads early and late after depolarisation enhanced automaticity vs triggerred activity vs reentry Source Type: blogs
Acute Aortic syndrome : Please mind the length of “ Ascending Aorta ” as well.
Aorta probably is the most critical structure in the entire circulatory system. (apart from the heart of course !) It is a 1.5 to 2.5 mm thick tube, with a diameter of 2.5 cm/length of 30 -35 cm from the aortic valve to the iliac bifurcation.(Eric Borsero 2011) It handles about 7500 liters of blood every day. Understanding the Aortic pathology has vastly improved at the molecular level with deep gene sequencing that defines fibrillin phenotypes. Meanwhile, CT , 4D MRI and 3D prototyping have landed us in a new era where we can feel the exact models of a patient’s virtual aAorta for monitoring and treatment purp...
Source: Dr.S.Venkatesan MD - November 1, 2020 Category: Cardiology Authors: dr s venkatesan Tags: aortic aneurysm marfan aortic dissection aorta size new coconcepts in aortic dimension normal aorta size normal aortic root size what is normal length of ascending aorta Source Type: blogs
Acute Aortic syndrome : Please mind the Length of “ Ascending Aorta ” as well !
Aorta probably is the most critical structure in the entire circulatory system. (apart from the heart of course !) It is a 1.5 to 2.5 mm thick tube, with a diameter of 2.5 cm/length of 30 -35 cm from the aortic valve to the iliac bifurcation.(Eric Borsero 2011) It handles about 7500 liters of blood every day. Understanding the Aortic pathology has vastly improved at the molecular level with deep gene sequencing that defines fibrillin phenotypes. Meanwhile, CT , 4D MRI and 3D prototyping have landed us in a new era where we can feel the exact models of a patient’s virtual aAorta for monitoring and treatment purp...
Source: Dr.S.Venkatesan MD - November 1, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized marfan aortic dissection aorta size new coconcepts in aortic dimension normal aorta size normal aortic root size what is normal length of ascending aorta Source Type: blogs
All time best quote on “ Principles of learning and education “
Today is one of the most auspicious days in Indian traditional festive time. Saraswathi pooja, a celebration of the Goddess of knowledge and education. I would like to share one of the all-time great quotes on learning from Thiruvalluvar a sage poet who lived in the southern Indian state of (mine), Tamil Nadu in 4th -5th century BC 2500 years ago.
This Thirukural number 391 in the chapter of education goes on like this. (In the Tamil Language)
In English
Karka, Kasadara, Karpavai , Katrapin,
Nirka , Atharkku Thaga !
It says
Karka : Learn
Kasadara: Here c...
Source: Dr.S.Venkatesan MD - October 26, 2020 Category: Cardiology Authors: dr s venkatesan Tags: bio ethics medical quotes bioethics medical education principles of practice of medicine princniples of learning quotes on education Thirukuraal Source Type: blogs
DAPT blues in ACS : Does Prasugrel really bother to know about the coronary anatomy before it acts ?
It appears,antiplatelet agents are waging a turf war on the CAD battlefield. It is no secret either, the fight often goes beyond academic reasons. Though NSTEMI connotes a true cardiac emergency, it consists of a highly heterogeneous population. A patient with UA can be treated even at home (Low-grade angina with little ECG changes, when it’s due to Increase demand situation). While, in the other extreme of NSTEMI, a patient with a GRACE score >200, in Ischemic LVF, might need an emergency multivessel angioplasty along with Mitra clip ± ECMO support.
Antiplatelet agents along with heparin will re...
Source: Dr.S.Venkatesan MD - October 19, 2020 Category: Cardiology Authors: dr s venkatesan Tags: acute coronary syndrome oral anticoagulants warfarin acitrom prasugrel 2b3a vs prasugrel coronary anatomy in nsteacs dapt mapt NSTEMI guidelines esc acc 2020 prasugrel vs aspirin vs ticagrelor reopro vs prasugrel themis twilight study Source Type: blogs
“ Dialysable LV dysfunction In CKD ” : Myocardial edema clearance plays a role.
In CKD, LVH is a near-constant feature with echo showing thick, bright echoes from IVS. The LV mass increases, partly due to physiological hypertrophy ,also contributed by deposits of uremic middle molecules and fluid collection in the interstitium as myocardial edema.This, is recognised as T 2 weighted MRI signals. Chronic fluid stasis may progress to myocardial fibrosis. (Kidney Blood Press Res 2018;43:134–142 )
Effect of Frusemide on myocardial edema
We know, loop diuretics cause aggressive depletion of ECF volume and to a lesser extent Interstitial fluid. The effect of diuretic on myocardial wate...
Source: Dr.S.Venkatesan MD - October 11, 2020 Category: Cardiology Authors: dr s venkatesan Tags: cardiology research topics for fellows cardiology thesis topics Uncategorized myocardial edema in ckd myocardial edema mri Source Type: blogs
Amiodarone in Ischemic VT : Doesn ’ t work always,.. IRA patency could be the missing link.
Curiously, the management of VT is simple if the patient is unstable. Just, we need to shock. Cardiologists are troubled only with a hemodynamically stable patient with VT. Some of us still think Amiodarone is a universal antidote for any VT. Though It is effective in both ischemic and non -Ischemic VT, the success rate is not uniform.
The mechanism of action of the Initial IV bolus is not a class 3 K + blocking action, instead, it is thought to be its beta-blocking action. If amiodarone fails, we may try Lignocaine, magnesium, Flecainide. .Many times it is the cumulative dose of amiodarone that reverts the VT. In some p...
Source: Dr.S.Venkatesan MD - October 10, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized brugada criteria for vt efficacy of amiodarone localisation of vt magnesiusm for vt research ideas in cardiology research papers in cardiology Source Type: blogs
Newer frontiers in cardiac pacing : Wireless dual-chamber pacing
The field of cardiology is always at the forefront of any technological breakthrough. Cardiac pacing stands tall among all Innovations. While remote monitoring and pacemaker telemetry are well-known concepts. One would have wondered why Intracardiac leads couldn’t communicate with each other wirelessly. Yes, It was just a matter of time, for that to happen.
The leadless pacemaker Micra/Nanostim was Introduced recently but lacked the much needed physiological pacing as they were single chamber based pacing. Though mechanical sensing of atrial activity was possible with Micra TPS software patch (A VDD like...
Source: Dr.S.Venkatesan MD - October 9, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized av micra tps ddd vs dddr pacemaker dual chamber wirless lead less pacemaker micra nanostim paceaker naspe cardiac rhythm society Source Type: blogs
Medical distillery : How to eliminate evidence based falsehoods in medical literature ?
If science is considered as a journey towards truth,.. knowledge, data, and statistics are the key companions in this infinite voyage to the dreamy destination. While hundreds & thousands of scientists do travel in this turbulent road daily, pursuing their mundane work, there are very few researchers worried about the true purpose of their journey, the quality of the road they travel, the dangerous fault lines they create.
It has become a taboo topic to criticize medical science even after realizing the fact that we are compelled to follow and glorify some of the best nonsense.
Dr. Jhon Loannidhis Pr...
Source: Dr.S.Venkatesan MD - October 5, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized audit of medical science bioethics cleansing of medical literature Dr. Jhon Loannidhis ethics in medicine medical science distillery Source Type: blogs
Role of RT-PCR in the diagnosis of Rheumatic fever/RHD
RT-PCR: Real-time polymerase chain reaction, a sophisticated gene sequence-based biochemical test. Thanks to corona, this complex medical investigation has become a household name.
Jones proposed his criteria to diagnose acute rheumatic fever in 1944, we still use it to diagnose with many modifications . Currently, AHA position statement – 2015 by Gewitz et all is being followed. (Circulation 2015)
From Braunwald textbook of cardiology. Apart from this, there is one catch . Even if the child fulfills Jone criteria, there needs to be evidence for preceding streptococcal sore throat, either by culture or antibody. ...
Source: Dr.S.Venkatesan MD - October 1, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized acute rheumatic fever aha rhd 2015 rhuematic fever anti dnase streptococcus group a beta hemolytic streptococci rtpcr mirna rtpcr rhd qpcr in rheumatic fever revised jonec criteria 2015 RHD jones criteria role of rtpcr fro Source Type: blogs
If EF% is a most flawed LV functional parameter,.. why we Insist HF to be classified based on it ?
Heart failure has been classified in many ways, with prevailing levels of our knowledge and ignorance. It is based on a variety of factors like rapidity of onset, etiology, chambers involved, hemodynamics, etc.
Forward vs backward failure
Acute vs chronic failure
RV/LV or Biventicular failure
Systolic vs diastolic heart failure
High output vs low out failure
Ischemic vs non-ischemic failure
Reversible vs Refractory HF
None of them have really helped at the bedside though it helped us understand the condition. Now, in the last decade, we have crash-landed on our favorite obsession to classify HF ie based...
Source: Dr.S.Venkatesan MD - September 25, 2020 Category: Cardiology Authors: dr s venkatesan Tags: Uncategorized ase esc acc csi echo cariteria definition of heart failure diastolic heart failure ejection fraction limitation forward vs backward failure hf with normal GLS HFpEF HFrEF rv vs lv failure systolic vs diastolic heart failu Source Type: blogs
“ Meta physical ” effect of “ Physical exertion ” on coronary plaque
Is sudden, unaccustomed, physical exertion a trigger for plaque rupture and an ACS ?
Yes, it is, but don’t get apprehensive. The underlying risk factors, plaque burden, and its morphology matter much to result in a coronary event.
What is the mechanism?
Plaque morphology, the lipid core, the shoulder region’s eccentricity, the crystallization of cholesterol lay the foundation. The Isometric component of stress surges Intra-coronary pressures and facilitate vascular injury. Endothelial dysfunction leading to erosion and subsequent acute total thrombotic occlusion is a well-known response to stress. C...
Source: Dr.S.Venkatesan MD - September 20, 2020 Category: Cardiology Authors: dr s venkatesan Tags: atherosclerosis vulnerable plaque physical and mental stress and vulnerable plaque physical exertion and plaque fissure Source Type: blogs
