Makindo Medical Notes

Related Subjects: |Classical Ventricular Tachycardia |Idiopathic Ventricular Tachycardia |Right Ventricular Outflow Tract Tachycardia |Idiopathic Fascicular Left Ventricular Tachycardia |Left Ventricular Outflow Tract Tachycardia |Ventricular Fibrillation |Resuscitation - Adult Tachycardia Algorithm |Resuscitation - Advanced Life Support |Automatic Implantable Cardioverter Defibrillator (AICD)

Idiopathic ventricular tachycardia in patients with an anatomically normal heart is a distinct entity whose management and prognosis differs from ventricular tachycardia associated with structural heart disease. This is a specialist diagnosis.

About

• A form of Idiopathic ventricular tachycardia (IVT)
• This is most common Idiopathic VT of the left ventricle

Aetiology

• Absence of structural heart disease
• Re-entrant arrhythmia
• Mainly affects males (60-80%)

Forms

• Posterior fascicular ventricular tachycardia
• Anterior fascicular ventricular tachycardia
• Upper septal fascicular ventricular tachycardia

Criteria

• No structural heart disease
• No metabolic/electrolyte abnormalities
• No long QT syndrome can be found

Fascicular VT

Clinical

• Typically presents in young adults males (15 to 40 years)
• Syncope, palpitations often with exercise, infection, exertion. Usually well tolerated

Investigations

• Bloods: normal
• Echocardiogram: normal
• CXR: normal
• 12 lead: ECG QT normal
• Acute ECG: VT with RBBB morphology. Axis can vary depending on subtype. The QRS is usually narrower than other forms of VT at 100-140 ms.

Classical VT is by far the most common cause of wide complex regular tachycardia, and there is no perfectly reliable way to distinguish classic VT with all its dangers from idiopathic VT or SVT with aberrancy on the surface 12-lead ECG. Treat as Classical VT - follow Adult tachycardia algorithm above

Management

• ABC, involve cardiology unless diagnosis and treatment plan known. If unsure follow Adult Tachycardia pathway and treat as classical VT. An echocardiogram is very useful to know that the LV is normal.
• ABC, Under specialist senior cardiology supervision IV Verapamil 10 mg over 3-5 mins. Ensure normal Echo first and good LV function and contractility. Be read to DC convert if needed.
• Patients with moderate symptoms can be treated with oral verapamil (120 mg/day to 480 mg/day) by senior cardiologist.
• Radiofrequency catheter ablation is an appropriate management strategy for patients with severe symptoms or those intolerant or resistant to antiarrhythmic therapy

References

• Idiopathic fascicular left ventricular tachycardia