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To define..• Tachyarrythmia- sustained or non sustained forms of tachycardia
arising from myocardial foci or reentrant circuits.
• Tachycardia- rhythm producing ventricular rate >100 bpm
• Supraventricular tachyarrythmia- tachycardia in which the driving circuit or focus arises, at least in part, in tisuues above the level of ventricles.
• PSVT???
Non specific term ; encompass tachycardias with supraventricularQRS, regular R-R interval and no evidence of ventricular preexcitation.
Clinical evaluation in SVT
Symptoms-• Palpitations , Exertional fatigue/dyspnea ,Chest discomfort, Near-syncope (rarely
syncope)
HISTORY : MODE OF ONSET AND TERMINATION
• Triggers
• Abruptness of onset and termination - Common in AVRT and AVNRT
• Frequency of episodes-- Incessant is often AT
• Ability to stop symptoms- Common in AVRT and AVNRT
CASE 1: how to treat??
• ACUTE ATTACK Rest, Reassurance,Sedation
VAGAL Manoeuvre ( Valsalva,CSM, Muller’s, ice water over face)
ADENOSINE- terminates 90% cases
Dose: 6-12 mg rapid intravenous
VERAPAMIL or DILTIAZEM rapid iv (if above manuevers fail)
Beta Blockers
CARDIOVERSION ??
DC shock synchronised, 10-50 Jules, in presence of hemodynamic instability, rarely needed
Can precipitate Vfib in case of Digitalis toxicity
Assess the need
DRUGS – long acting CCBs or long acting Beta Blockers
ABLATION –
• 95% long term cure
• Complete heart block<1%
• Recurrent, symptomatic, sustained AVNRT
• Drugs C/I, intolerant or do not want drugs
• Slow pathway ablation is commonly done, fast pathway preserved.
SECONDARY PROPHYLAXIS
Ventricular Pre excitation
Short PR
Delta Wave
WPW= PR<0.12s + DELTA + RAPID REGULAR TACHYARRYTHMIA
38 year old truck driver undergone a routine ecg for pre op.. CSOM operation
AF with ventricular preexcitation
• ~50% patients with an AP predisposed to AF
• Results from rapid antegrade conduction atria to ventricles over AP
• Rapid ventricular rates– haemodynamiccompromise– may ppt VF
• QRS pattern bizarre and beat to beat variability
Concealed AP s:
~50% of all Aps
No antegrade conduction, only retrograde
Manifest only during tachycardia
Orthodromic AVRT– only
Not at risk of RVR to Afib.
PJRT:
Slow retrograde conduction over AP
Long RP
“incessant” tachycardia
Tachycardia induced LV cardiomyopathy
Accessory pathway mediated
tachycardia- management
• Acute management- Vagal manuevers, ADENOSINE, IV CCB or BB
• Manifest preexcitation and AF—
Hemodynamic compromise- DC CARDIOVERSION
Non life threatening situation-
-----IV procainamide 15mg/kg over 20-30 mins to slow ventricular response.
Ibutilide
CAUTIOUS about using Digoxin or Verapamil
AVRT management cont….
• Chronic Rx- oral BB or CCB( verapamil/ditiazem)
--to prevent recurrences
• AF with RVR or recurrences of SVT on AVN blocking drugs
---- strongly consider CLASS 1A or 1C antiarryhmics( quinidine, flecainide, propafenone)
• ABLATION---- when????
Recurrent symptomatic SVT episodes
Incessant SVT
H.R>200bpm
Managing AVRT..• Accessory pathway ablation: Curative therapy for WPW and concealed accessory
pathways
By pass tract sites-
1. Left laterally, between LA & LV free walls (~50%)2. Posteriorly, between the atrial & ventricular septa
(~30%)3. Right laterally or anteriorly, between RA & RV free
walls (~20%)
Recurrence rate of AVRT post ablation <5-10%
AV Junctional Tachycardia• Enhanced normal automaticity, abnormal
automaticity or triggered activity
• Retrograde atrial conduction±
• P dissociated or intermittent conduction
• Sinus activity dissociated or intermittent captures• Digoxin toxicity may predispose
• Rate- 50-100 bpm---accelerated junctional rhythm
• Treatment- stop digoxin, Fab, BBs, anti arryths
Routine preop ECG of a 60y M ..Atrial Premature complexes
•P occurring before anticipated sinus beat•Different p contour•QRS- RBBB or LBBB may be seen•Sum of pre- and post- APC RR< 2 sinus ppinterval•Increase with age and structural hrt ds•Mostly DONOT NEED INTERVENTION
ATRIAL TACHYCARDIA
Inverted p
•Atrial rate-150-200bpm•Different p wave contour•Long RP, Short PR(RP>PR)•Short frequent bursts withspontaneous termination•May be a/w 2:1 or 3:2 AVblock•Iso electric intervalsbetween p waves•+ve or biphasic p in V1- LA•-ve p in V1 – RA focus
AT significant???• A/w Structural heart disease(CAD±MI, HF etc)
• DIGITALIS toxicity
• Incessant AT- risk of tachycardia induced CMP
• CSM/Adenosine– increases AV block, slowing ventricular rate without termination.
• Management-1. STOP DIGOXIN2. BB/CCB3. If fails– 1A,1C,34. ABLATION
ATRIAL TACH Ablation
• Common ectopic Atrial Tachycardia sites-
1. Crista terminalis2. Valvular annuli3. Pulmonary vein
ostia4. Coronary sinus
ostia• Recurrence rate of
AT post ablation <10%
CASE: A 57y M smoker, COPD for last 10 yrs
MULTIFOCAL ATRIAL TACHYCARDIA(MAT)
Multifocal atrial tchycardiaAtrial rhythm- at least 3 distinct p wave
3 different PR intervalsAtrial rates-100-150 /min
Presence of isoelectric baselineA/w chronic obstructive or restrictive lung ds
Treat underlying diseaseCCB, flecainide, propafenone- some role
Atrial flutter with 2:1 conduction
ATRIAL FLUTTER•Atrial rate- 250-300/min•Ventricular rate~150 bpm
•Regular or Irregular•Saw-toothed flutter waves
•Evidence of continual electrical activity•TYPICAL VS ATYPICAL
•Mechanism – Macroreentry•Structural heart disease, toxic- metabolic substrates
Managing atrial flutter..
ACUTE :: CARDIOVERSION (DCC Vs Pharma)
LONG TERM----
1. Anticoagulation (similar as Afib)
2. Control rate (CCB,Dig,BB)
3. Anti-arrythmics– CAUTIOUS about 1C and 3
4. Identify and treat underlying pathology.
5. ABLATION
Atrial Fibrillation
‘f’ waves
•Affects 2 to 4% of population
•Increases to 5 to 10 % of patients over 80
•Associated with 2-fold increased risk of death
•Risk of thromboembolism is approximately 5% per
year but may be as high as 20% in high risk groups not
anticoagulated
LONG TERM Management--- RATE or RHYTHM ?
• AFFIRM trial- Rhythm vs Rate control strategy in AF patients…….result????NO SURVIVAL ADVANTAGE Rate control- less hospital admission and side
effects
INDIVIDUALISED approach
“Pill in the Pocket” approach
If only rate control,,, strict or lenient?? Outcome was same,, lenient more achievable
ABLATION IN AF..
• Challenging
• All problems cant be solved
• Higher recurrence(vs AVNRT,AVRT)
• Treat with at least 1 rhythm control drug before
• Symptomatic Afib, min. struc heart disease
• Huge LA dilation, persistent>4 yrs– less chance of success
• RFA used for electrical isolation of PV
• C/I– LA thrombus
Maximal sinus tachycardia
• 220- age= Maximal heart rate
i.e. 220-80= 140 bpm
UNLIKELY THIS IS JUST SINUS TACHYCARDIA
SUMMARY
• IDENTIFY SVT at a first glance
• DO NOT waste time over pinpoint diagnosis
• MANAGE emergently
• SEARCH for reversible causes
• RULE out structural heart diseases
• DISCUSS with patients about long term strategy
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