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IN THE NAME OF GOD

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  1. IN THE NAME OF GOD

  2. Ventricular Tachyarrhythmia DrAmirhosseinAzhari Electrophysiologist

  3. VENTRICULAR TACHYARRHYTHMIAS • VENTRICULAR TACHYCARDIA • VENTRICULAR FIBRILLATION

  4. Underlying Arrhythmia of Sudden Death Primary VF 8% Torsades de Pointes 13% VT 62% Bradycardia 17% Adapted from Bayés de Luna A. Am Heart J. 1989;117:151-159.

  5. DEFINITION • Occurrence of a series of three or more consecutive abnormaly shaped premature ventricular complexes, • WHOSE DURATION EXCEEDS 120 ms, • With the ST-T vector pointing opposite the major QRS deflection

  6. Symptoms occurring during VT depend on • The ventricular rate, • Duration of tachycardia, • Presence and extent of the underlying heart disease and peripheral vascular disease.

  7. VT can occur in several forms: • Short, asymptomatic, Nonsustainedepisodes; • Sustained, • Hemodynamicallystable events, generally occurring at slower rates or in otherwise normal hearts; • Unstable runs, often degenerating into VF

  8. VENTRICULAR TACHYCARDIA VT NONSUSTAINED SUSTAINED

  9. NONSUSTAINED VT Three or more consecutive ventricular premature depolarizations, up to a maximum duration of 30seconds before spontaeous termination

  10. Importance of NSVT • Most tachyarrhythmias come to our attention because of the symptoms they produce • In contrast,most instances of NSVTdo not cause symptoms • Rather it derives its importance from the prognostic significance it carries in some patient populations

  11. SUSTAINED VT MONOMORPHIC UNIFORM POLYMORPHIC MULTIFORM ,PLEOMORPHIC

  12. SUSTAINED VT IN PATIENTS WITH ORGANIC HEART DISEASE IN PATIENTS WITH NORMAL HEARTS

  13. VT in normal hearts • 1-Idiopathic VT • 2-long Q-T syndrome • 3-Brugada syndrome • 4-Catecholaminergic polymorphic VT • 5-Short Q-T syndrome

  14. IDIOPATHIC VT PROPRANOLOL -SENSITIVE VT AUTOMATICITY ADENOSINE -SENSITIVE VT TRIGGEREDACTIVITY VERAPAMIL -SENSITIVE VT INTRAFASCICULAR REENTRY

  15. IDIOPATHIC VT

  16. ADENOSINE-SENSITIVE VT CLINICAL CHARACTERISTICS • THE MOST COMMON FORM OF IDIOPATHIC VT(75-90%) • ORIGINATES FROM RIGHT VENTRICULAR OUTFLOW TRACT

  17. RVOT VT USUALLY EXHIBITS ONE OF TWO PHENOTYPES • NONSUSTAINED REPETITIVE MONOMORPHIC VT(RMVT) • PAROXYSMAL EXERCISE INDUCED SUSTAINED VT

  18. THERE IS A CONSIDERABLE OVERLAP BETWEEN THESE TWO PHENOTYPES OF ADENOSINE-SENSITIVE RVOT VT

  19. RF ABLATION

  20. Long QT • Acquired • Congenital

  21. The acquired form has a long-QT interval caused by various drugs, such as • Quinidine, procainamide, sotalol, amiodarone, disopyramide, phenothiazines, tricyclic antidepressants, erythromycin, pentamidine, antimalarials, cisapride, and probucols

  22. Electrolyte abnormalities, such as • Hypokalemia and hypomagnesemia; • The effects of a liquid protein diet and starvation; • Central nervous system lesions; significant bradyarrhythmias.

  23. GENETIC BASIS OF LONG QT SYNDROME

  24. CLINICAL MANIFESTATIONS • The principal symptoms are syncope and SCD,from TDP • Most often,TDP is self-terminating and cause a syncopal episode from which the patient quickly recovers • Cardiac arrest occurs if the TDP is more persistent,and SCD results if the rhythm does not return to normal spontaneously

  25. QT Duration • A widely accepted method for correcting QT interval for rate is Bazett’s formula • Lead II is generally the best single lead for measuring QT interval. • Traditionally, QTc >440 msec were considered prolonged; however, values up to 460 msec may still be normal among females • Affected gene carriers can have a QTc of 410 msec or less and no normal person has a QTc of 470 or more (men) or 480 or more (women)

  26. ECG MANIFESTATIONS • A QTC of 0.47 sec in men and 0.48 sec in women is 100% sensitive for LQTS • A QTC less than 0.40 sec in menand 0.42 sec in women is 100% specific for excluding LQTS

  27. Treatment • Intravenous magnesium is the initial treatment of choice for torsades de pointes from an acquired cause, followed by temporary ventricular or atrial pacing. • In all patients with torsades de pointes, administration of class IA, possibly some class IC, and class III antiarrhythmic agents ( amiodarone, dofetilide, sotalol) can increase the abnormal QT interval and worsen the arrhythmia.

  28. For patients who have idiopathic long-QT syndrome but • Not syncope, • Complex ventricular arrhythmias, • Afamily history of sudden cardiac death, • QTc no longer than 500 milliseconds • No therapy or treatment with a beta blocker is generally recommended

  29. In patients with : • Syncope caused by ventricular arrhythmias or aborted sudden death, • An ICD is warranted

  30. Brugada Syndrome • Brugada syndrome is a distinct form of idiopathic VF in which patients have right bundle branch block and ST-segment elevation in the anterior precordial leads, without evidence of structural heart disease • Mutations in genes responsible for the sodium channel (SCN5A) and calcium channel have been identified in many families with Brugada syndrome

  31. BrugadaSyndrome

  32. Brugada Syndrome

  33. Currently, no pharmacologic treatment reliably prevents VF in these patients. ICDs are the only effective treatment to prevent sudden death

  34. Ischemic Cardiomyopathy • Patients with previous myocardial infarction are at risk for development of VT. In the setting of a remote myocardial infarction, the mechanism of VT is reentry, involving the infarct scar and in particular the border zone or other areas of the scar with deranged conduction. As a result, the VT in this setting is typically monomorphic

  35. VT based on reentry

  36. 1 sec VT

  37. In general, ICDs are indicated to prevent sudden cardiac death from VT in this group of patients, especially in those with depressed LV function

  38. VT IN DCM • BUNDLE BRANCH REENTRY MAY BE SEEN IN THIS POPULATION AND CAN BE TREATED BY ABLATING THE RBB

  39. VT IN HCM RISK FACTORS FOR SCD IN HCM • CARDIAC ARREST(VF) • SUSTAINED VT • SYNCOPE PARTICULARLY IF RECURRENT AND EXERTIONAL • FAMILIAL SUDDEN HCM- RELATED DEATH IN FIRST DEGREE RELATIVES • NSVT ON HOLTER FREQUENT,REPETITIVE AND PROLONGED • ABNORMAL BP RESPONSE IN EXERCISE >20 mm HG • EXTREME LV HYPERTROPHY >30 mm

  40. Acute Management of Sustained Ventricular Tachycardia • VT that does not cause hemodynamic decompensation can be treated medically to achieve acute termination by the intravenous administration of amiodarone, lidocaine, or procainamide, followed by an infusion of the successful drug

  41. In general, amiodarone • loading dose of 15 mg/min is given during a 10-minute period. • This dose is followed by an infusion of 1 mg/min for 6 hours and then • a maintenance dose of 0.5 mg/min for the remaining 18 hours and for the next several days, as necessary

  42. If the arrhythmia does not respond to medical therapy • Hypotension,Shock • Angina, • Congestive heart failure • Symptoms of cerebral hypoperfusion should be treated promptly with DC cardioversion.

  43. Very low energies can terminate VT, beginning with a synchronized shock of 10 to 50 J.

  44. The goal of long-term therapy is to prevent sudden cardiac death and recurrence of symptomatic VT. • Asymptomatic nonsustained ventricular arrhythmias in low-risk populations (preserved LV function) often need not be treated. • In patients with symptomatic nonsustained tachycardia, beta blockers are frequently effective in preventing recurrences.

  45. In patients refractory to beta blockers, class IC agents, sotalol, or amiodarone can be effective. • However, class IC agents should be avoided in patients with structural heart disease, especially those with coronary artery disease because of the increased mortality associated with these drugs caused by proarrhythmia.

  46. Sotalolshould be used cautiously because of its potential for prolonging the QT interval and producing torsades de pointes. • Patients with nonsustained VT after myocardial infarction and poor LV function are at significant risk for sudden death