Cardiac Arrhythmias —

Ventricular Tachycardia VT –

Three or more consecutive ventricular ectopic complexes (duration greater than 120 ms) occurring at a rate of 100 to 250 beats per minute.

Cardiac Arrhythmias Ventricular Tachycardia VT

Diagnosis of VT (ventricular tachycardia)

• At least 3 consecutive wide QRS complexes
• Rate at least 100 per minute
• Usually rhythm is regular
• Retrograde P wave seen
• Usually AV dissociation is present
• Associated with severe underlying heart disease
• Concordance of direction of wide QRS in precordial leads (all the QRS in one direction) QRS axis abnormal (-90 to -180°)
• QRS width more than 0.14 second (31/2 small squares)
• Paroxysmal VT initiated by VPC.

Cardiac Arrhythmias Ventricular Tachycardia VT

Causes of VT  Ventricular Tachycardia —

• Although non-sustained VT may occasionally be well-tolerated,
• Non-sustained VT lasts less than 30 sec. Sustained VT lasts more than 30 sec, and is much more likely to produce loss of consciousness or other life-threatening symptoms.
• it often arises in hearts that have suffered ischemic damage or cardiomyopathic degeneration and may be a cause of sudden death.
• IHD
• Cardiomyopathies
• Drug toxicity Idiopathic.
• Metabolic disorders
• Prolonged QT syndrome

Cardiac Arrhythmias Ventricular Tachycardia VT

Clinical features of ventricular tachycardia —

• Cannon a waves
• Underlying heart disease
• Syncope.
• Varying first heart sounds
• Hypotension

Treatment of Ventricular tachycardia —

• The acute treatment of sustained VT is outlined in advanced life support protocols but may include the administration of lidocaine or other antiarrhythmic drugs, cardioversion, or defibrillation.
• Chronic, recurring VT may be treated with sotalol, amiodarone, or implantable cardioverter-defibrillators.
• Asymptomatic, nonsustained VT may not be treated.
• Congenital long QT has to be treated due to risk of sudden death.
• For sustained VT, VT with organic heart disease, hemodynamic compromise, CHF, and CNS hypoperfusion, prompt DC cardioversion is done. .
• If VT is tolerated hemodynamically (blood pressure and perfusion of organs is maintained), drug therapy is given (DC cardioversion not required)
• – Lidocaine
• Disopyramide
• Beta blockers
• Procainamide
• Flecainide