Ventricular Tachycardia (VT)

Pathology:                    

Broad complex tachycardias areVT until proven otherwise.

Non-sustained VT is defined as 3 continuousventricular ectopics for <30seconds

Aetiology:                    

Most cases due to damage tothe myocardium and structural heart disease e.g. MI                              Othercauses of VT include:

                                                        Inheritedchannelopathies e.g. Brugada syndrome,

                                                      Arrhythmogenic Right Ventricular Cardiomyopathy(ARVC)

                                                      LongQT syndrome

Symptoms:                  

Pre-syncope, syncope, SOB,chest pain, palpitations

Signs:                              

Hypotension,tachypnoea, pallor, raised JVP, Cannon ‘a’ waves

Investigations:          

‍ECG:Monomorphic VT – Regular, Broad complex, AV dissociation, concordance

across chestleads, capture or fusion beats

                                        Echo:To assess for structural abnormality

                                        Diagnosticcoronary angiography +/- PCI

                                        CardiacMRI: Useful when the cause is unclear

Treatment:                  

Acute: Pulseless VT is a cardiac arrestand should be treated with ALS guidelines

   Chronic: Amiodarone, beta-blockers or mexiletine

   ICD implantation

Complications:          

Death, syncope injuries, medicationside effects, inappropriate ICD shocks

Prognosis:                    

Prognosis without treatmentis poor.

Treatment with ICD improves prognosisbut mortality rate still increased

Figure 1.6 Monomorphic VT Note broad complexes.Extreme left axis deviation Concordance   across chest leads No clear P waves