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- 1. VENTRICULAR TACHYCARDIADr. Y. Sridhar M.D. Consultant Intensivist Dept. of Critical Care Medicine Apollo Health City, Hyderabad
2. Definition Wide complex rhythm QRS>0.12s Rate > 100 (or120) bpm Origin: from one of the Ventricles i.e., distal tothe bundle of His. Three or more consecutive beats on a ECG. 3. Classification Duration of Episodes Morphology Symptoms 4. 1.Duration of Episodes Three or More beats on an ECG at a rate>100bpm originating from Ventricles Non Sustained VT : If rhythm self-terminatesspontaneously in less than 30seconds Sustained VT : If rhythm lasts > 30seconds(Even if it self-terminates spontaneously after30s) 5. 2.Morphology Monomorphic VT : same configuration beat tobeat. Polymorphic VT : Continually changing QRSmorphology Sinusoidal VT :sinusoidal appearance ofrhythm Accelerated idioventricular rhythm (AIVR) 6. Monomorphic VT Most common cause : circuit through a regionof old MI. Idiopathic VT (less common) No identifiablecause. Right Ventricular outflow tract (RVOT)tachycardia: MC Idiopathic VTLBBB Morphology with inferior axis. 7. Polymorphic VTCauses Active cardiac Ischemia Electrolyte Disturbances Drug Toxicity FamilialTorsade de pointes (twisting of points) Waxing and waning QRS amplitude duringtachycardia associated with prolonged QT interval 8. Sinusoidal VT: seen in severe electrolytedisturbances Hyperkalemia Hypocalcemia Hypomagnesemia AIVR Wide complex ventricular rhythm at a rate of 40-120bpm Usually hemodynamically stable MC cause :reperfusion arrhytmia in first 12hrs after acute MI or during periods of elevated sympathetic tone. Typically preceded by sinus slowing No treatment necessary. Self terminates. 9. Pathophysiology Monomorphic VT : Increased automaticity of a single point ineither left or right ventricle Reentry circuit within the ventricle Polymorphic VT : Abnormalities in ventricular musclerepolarization 10. Etiology Structural Heart Disease : MI, Cardiomyopathies(HCM), Myocarditis Electrolyte Abnormalities : Hypokalemia,Hyperkalemia, Hypocalcemia, Hypomagnesemia Sympathomimetic agents : Ionotropes. Drug toxicity : Digitalis, Methamphetamine,Cocaine Systemic diseases : Sarcoidosis, RA, SLE. Structural Congenital Disorders : Right ventriculardysplasia, TOF 11. EtiologyProlonged QT Interval Acquired : K Channel blocking medication : Quinidine, Erythromycin, Clarithromycin,Haloperidol, Droperidol Type 1A antiarrythmics : sotalol, amiodarone, Congenital : Brugada syndrome Congenital long and short QT syndromes Catecholamingeric polymorphic VT 12. Diagnosis All WCT is VT until proven otherwise AV dissociaton : Dissociation of P wave from QRScomplex. QRS Concordance : Absence of rS or Rs complex inany precordial lead RS > 100ms Capture beats : Supraventricular beat conducts toventricle depolarising ahead of the nexttachycardia beat Fusion beats : Depolarisation simultanously withexcitation from a ventricular focus. 13. BRUGAGADA CRITERIA 14. Ultra simple Brugada Criteria In 2010 Joseph Brugada published simplifiedcriteria Measuring R wave peak time (RWPT) in Lead RWPT > 50ms It measures duration of onset of QRS to firstchange in polarity 15. Differential Diagnosis SVT with aberrant intraventricular conduction Preexcited Tachycardia (associated with ormediated by accessory pathway) BBB Ventricular paced rhythms 16. Symptoms Chest Pain Light headedness Palpitations Syncope Sudden Cardiac Death (SCD) : Ambulatory ECG records at SCD have shown 50- 60% at sustained monomorphic VT as the initial event. 17. TreatmentDepends on Hemodynamics Unstable VT Stable VT 18. ACLS Cardiac Arrest Algorithm. Neumar R W et al. Circulation 2010;122:S729-S767Copyright American Heart Association 19. Stable VT Anti arrhythmic drug (AAD) therapy Implantable Cardioverter-Defibrillator (ICD) Catheter Ablation Therapy (CAT) Antiarrhythmic surgery 20. Tachycardia Algorithm.Neumar R W et al. Circulation 2010;122:S729-S767Copyright American Heart Association 21. AMIODARONE Large volume of distribution & long half life Contraindications Iodine sensitivity Sinus bradycardia Heart block Precautions Incompatible with NS Preferable via CVC Adverse effects Short term : Skin reactions,Brady, hypotension, corneal microdeposits. 22. AMIODARONE Long term : Pulmonary fibrosis, alveolitis, pneumonitis Liver dysfunction..monitor LFT Hypo or Hyperthyroidism (check TFT before starting) Peripheral neuropathy, myopathy, Cerebellar dysfunction. Concomitant Beta and Calcium channelBlockers: Increased risk of bradycardia, AV Block Potentiates effect of Digoxin, Theophylline andWarfarin Reduce dose 23. Implantable cardioverter-defibrillator (ICD) ICD therapy compared with conventional AADassociated with mortality reduction of 23-55%depending on risk group. Current ICD options: Single chamber Dual chamber Biventricular cardiac resynchronization Multilevel shock discharge for VT or VFComplications: Inappropriate shock discharge Defibrillator storm Infections Exacerbation of HF 24. External Defibrillator Automated external Defibrillator Wearable automatic defibrillator Worn under the clothing Delivers shock whenever VF is detected. 25. Procedure targets origin of VT Useful in recurrent VT or VT storm. Catheter is placed into heart chambers throughfemoral vein Radiofrequency energy is applied which producesa small burn of about 4 to 5mm in diameter Currently recommended in early treatment of VTwhen AAD are not preferred or tolerated. 26. Figure 2. Mapping of VT. A 3-dimensional real-time map of the ventricle (created during theprocedure) merged with a computed tomography scan (obtained before the procedure). Tung R et al. Circulation 2010;122:e389-e391Copyright American Heart Association 27. Recurrent VT : Long termManagement Risk of recurrence after successfulresuscitation : 30-40% Management of Intercurrent diseases Implantable Cardioverter Defibrillator Long term therapy on Amiodarone. 28. Antiarrhythmic surgery Surgical resection of arrhythmogenic focus Cardiac Sympathectomy Aneurysm resection 29. Thank you!