Posted in cardiology -ECG, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, Uncategorized, tagged carto, electrophysiology, epicardail ventricualr tachycardia, heart rhythm, naspe, ventricualr tachycardia on February 15, 2009 |
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Ventricular tachycardia as a group , constitute a major group of cardiac arrhythmias. Most of the VTs are managed by cardioversion followed by medical management. Few require , implantable defibrillator when there is severe LV dysfucntion .(ICD) Localising the origin of VT and subsequent , ablation is the treatment of choice in some of the patients with VT.
Traditionally VT was thought to arise fro the endocardial aspects of myocardium. Now we realise many times VT originate from the epicardial aspects of ventricle.
Epicardial VT : Defintion
Epicardial ventricular tachycardia (VT) is defined as VT in which the critical sites of the reentrant circuit (or the ‘sites of origin’) are located exclusively in the subepicardial tissue, as shown by entrainment manoeuvres or VT that is terminated within 10 s with standard radiofrequency (RF) pulses, or both. E. SOSA,M. SCANAVACCA et all http://www.springerlink.com/content/w608142674154tp5/
How to recognise epicardial origin of VT by surface ECG ?
- Terminal S wave in V2 and q in lead 1 strongly suggest VT of sub epicardial origin.
- Pseudodelta wave
- Intrinsicoid deflection time of 85 ms
- RS complex duration of >120msec
Suggest epicardial origin of the VTs.
Berruezo criteria ,http://circ.ahajournals.org/cgi/content/full/109/15/1842 ( Must read)
What is the clincal significance of epicardial VT ?
Endo cardial ablation not likely to be successful
Trans pericardial approach may be needed.
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Posted in cardiology -Therapeutics, Cardiology -unresolved questions, Cardiology hypertension, general medicine, Infrequently asked questions in cardiology (iFAQs), My presentations, tagged allhat, amlogard, anti hypertensive drugs, hypertension, hypertension clinic, ish, isolated diastolic hypertension, isolated systolic hypertension, jnc, kaplan, mean areterial pressure, sweeny on February 8, 2009 |
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- Hypertension is major determinant of cardiovascular health of our global population
- Millions suffer, hundreds of societies , and as many guidelines , and drugs are still struggling to control the menace.
- An important sub group of HT , (ie IDH ) population has been neglected and never received the scientific interest , which it deserves !
- In our study it occured in 7.2% of all HT patients.
- JNC, the world authority on HT never considered IDH as a separate entity, and as of now there is no specific guidelines.
- And the irony is complete . There is not a major study available to analyse the differential effects of anti hypertensive drugs on systolic and diastolic blood pressure.
If a patient with the BP of 120/96 asks you , “Doctor , will the drug, you have prescribed , selectively lower my diastolic blood pressure ” what will be your answer ?
A clear , I don”t know !
The following paper was presented in the World congress of cardiology Sydney 2002
Isolated Diastolic Hypertension
S.Venkatesan,S.D.Jayaraj.Gnanavelu, Madras Medical College. Madras, India.
Abstract : Systemic hypertension continues to be a major determinant of cardiovascular morbidity. While isolated systolic hypertension(ISH) has been identified as a specific clinical entity, isolated diastolic hypertension(IDH) has not been reported as a separate group. When we analysed our data from our hypertension clinic we found a distinct subgroup of patients who had elevated diastolic blood pressure with normal systolic pressure. We report the clinical profile of these patients. 440 newly registered hypertensive patients between the year 1998-99 formed the study population. All patients with secondary hypertension were excluded.. IDH was defined as diastolic BP more than 90mmhg and systolic BP less than 140mmhg.
IDH was present in 32(7.2%) patients. The male female ratio was 3:1, mean age was 42(Range32-56) The mean diastolic pressure was 96 mm (Range 90-110).The mean systolic pressure was 136mm(Range 128-140). LVH was observed in 4 patients(12.5%). Diastolic dysfunction was detected by echocardiography in 20patients.(62%)
We conclude that isolated diastolic hypertension constitute a significant subset among hypertensive patients and they need further study regarding the pathogenesis, clinical presentation and therapeutic implication.
Link to PPT will be available soon .
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Posted in cardiology -ECG, Cardiology -Interventional -PCI, cardiology -Therapeutics, Cardiology -unresolved questions, cardiology- coronary care, Cardiology-Arrhythmias, Infrequently asked questions in cardiology (iFAQs), My presentations, tagged amiodarone, arvd, cardaic arrhythmias, electro physiology, ep study, heart rhythm, naspe, podrid, rate control, rvot, ventricular tachycardia, wellens, wide qrs tachycardia, zipes on February 8, 2009 |
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Ventricular tachycardia is considered as a dangerous electrical rhythm abnormality .It can immediately degenrate into ventricular fibrillation and result in SCD in many.Ironically, it is also a fact , a patient with VT can present silently without any symptom .Some VTs are slow and recurrent without much affecting The hemodyanmics.
In chronic recurrent, beningn VT (Some may consider it , ” height of absurdity ” to call a VT beningn ! but it is a reality , the term beningn denotes - very remote chance of converting into VF) ” Is there any other therapeutic option other than convertng into sinus rhythm. “( Read related topics)
The following paper was presented in the Annual scientific sessions of Cardiological society of India, Kochi , seven years ago in 2002
VENTRICULAR RATE CONTROL IN VENTRICULAR TACHYCARDIA
S.Venkatesan,,. Madras Medical College. Chennai
Mangement of hemodynamically stable recurrent ventricular tachycardia remains a delicate clinical problem. Reverting to sinus rhythm is considered as the only aim of treating VT.While rate control is accepted as a therapeutic option in atrial fibrillation, it is not so, for ventricular tachycardia.In this context we attempted to analyse the effect of Amiodarone on ventricular rate in stable ventricular tachycardia which fail to convert to sinus rhythm.
The study cohort consisted of 49 patients with stable VT who were admitted in the coronary care unit of Govt. General Hospital between 1998 to 2002.The criteria for inclusion were systolic BP>100mmHg and absence of hypoperfusion of vital organs The mean age was 52 years (range 26-68) with a male female ratio of 4:1. Of the study group 36 patients were either reverted with IV lignocaine , Amiodarone ( 150-300mg bolus ) or DC cardioversion . 13 patients who did not respond to either of these were followed up with Amiodaroneinfusion(1000mg) for 24 hours. The baseline diagnosis were old MI (6)) DCM (3) Arrhythmogenic RV displasia(2). Idiopathic VT was diagnosed in 2 patients.All these patients had VT during most part of the 24 hour follow up.
The pre Amiodarone mean ventricular rate was 152 (124 –196). Post amiadaorne (at 24hrs) mean ventricular rate was 128(88-142). The time taken for 50% heart rate reduction was 6.6h (4-24h). The average systolic blood pressure improved from 100 to 112mmhg . These patients were discharged in stable clinical status with oral Amiodarone and were referred for EP study.
It is concluded that Amiodarone, apart from it’s cardioverting ability , has a distinct ventricular rate controlling effect which can be of therapeutic value in at least certain subset of chronic recurrent VT.
Some of the patients with VT carry a very low risk of VF and SCD .In these patients , the only other major aim is to prevent tachycardiac cardiomyopathy that can be done with drugs which controls the ventricular rate whenever VT occurs !
Corrrecting the primary cause like cardiac failire , revascularisation ,detailed EP study ,tachycardia mapping , followed by RF ablation and ICD implantation is the state of the art approch in the management of VTs.But this small clinical observation was made to impress rate control could also be an option in patients in whom these procedures are contraindicated or not available .
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Ventricular tachycardia (VT) is one of the dangerous form of cardiac arrhythmias.
When it occurs , it may present in many ways
- Cardiac arrest with immediate degeneration into ventricular fibrillation.
- Pulseless VT in a conscious patient but in in shock.
- With pulse, relatively stable , not much fall in blood pressure.
- Incidentally detected.*(Rare)
This , gives us an idea that VT as an electrical abnormality has wide clinical presentations , life threatening at one end and, patient walking into the hospital with minimal palpitation on the other hand !
The management issues
- In patients with hemodynamic instability , decision making is easy as there is only option of DC shock.
- In patients with stable VT, it is natural for the physicians to get tentative or even confused.This is because , dangers of shocking a stable patient has to be weighed against the currently available excellent antiarrhytmic drugs( Amiodarone, Ibutilide etc) .
The major issue here is in ruling out underlying structural heart disease.
Never shock a stable VT, without knowing the myocardial and valvular function.There has been many occasions underlying severe LV dysfunction is missed and they may go for asystole.
VT in the setting of cardiomyopathy, Post MI(Scar mediated) are often refractory even to DC shocks.It is the drugs that will ultimately control the arrhythmia.DC shock is just used to terminate the VT.
VT structurally normal heart , especially arising the outflow tracts of LV or RV behave very differently (Fortunately they are more benign)
- Have less hemodynamic impact as it involves the outflow tract and not over the the pumping zone of LV as in conventional ischemic myocardial VT .
- They respond to calcium blockers verapamil to be precise (As they share properties of SVTs)
- Sensitivity to verapamil by no way convey a meaning of Amiodarone resistance.Out flow tract VTs will also respond to Amiodarone many times.
- Degeneration into VF is rare.
Also read Therapeutic issues in stable ventricular tachycardia
Presented and published in Indian heart journal
Why some ventricular tachycardias are resistant , even to multiple DC shocks ?
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