Ventricular tachyarrhythmias
(wide complex tachycardia)

Clinical presentation

Diagnosis

Management

Definition

Epidemiology

Pathphysiology

Cardiac disorder of disrupted conduction
in the ventricular system
causing tachycardia with wide QRS

Rare

Serioous, high mortality

Mechanism
Disrupted conduction in the ventricles,
non-synchronised ventricle contractions

Types

Defect
Pathology in the ventricles

Ventricular ectopics
Common in health and post MI
Ectopic electrical activity arises in ventricles, moving slowly across the ventricular tissue, but conducted along normal healthy conducting pathways once it reaches them
Large irregular wide QRS seen, trace otherwise normal

Ventricular tachycardia (VT)
Scarring of the ventricles and disrupted conduction
No p waves, broad large QRS, regular tachyarhythmia
Sustained: lasts >30s
Non-sustained: lasts <30s

Ventricular fibrillation (VF)
Rapid and irregular ventricular contractions with
no effect on the ventricles, so NO CARDIAC OUTPUT
Rapid loss of pulse and cardiorespiratory arrrest

VT/TdP (Long QT)
Palipitations
SOB
Chest pain
Syncope

VF
Unconcious
Cardiac arrest

Ectopics
Asymptomatic
Extra/heavy/missed beats

Examination

Investigations

History

DH
Meds, allergies

FH
Cardiac disease

PMH
Previous MI, other
cardiac disease, systemic illness

SH
Living arrangements, social support,
occupation, alcohol, smoking, diet, drugs

PC/HPC
Heavy/missed/extra beats,
syncope

Cardio exam
Tachycardic

Bloods
FBC, CRP, U+E, LFT, clotting,
glucose, lipids, troponins, blood cultures

Imaging
CXR
ECHO

Bedside
Obs (tachycardia)
ECG: ectopics (wide bizarre QRS),
VT (wide regular QRS), torsades de pointes (wide, regular QRS of varying amplitude), VF (wide messy QRS)

Initial ABCDE

Definitive

Conservative
Information, advice, support
Identify and treat cause

Immediate

DC cardioversion/defibrillation
Indication: 1L unstable sustained VT, any VF
MOA: deliver shock to resynchronise
heart electrical activity

Chemical cardioversion
Indication: 1L stable sustained VT; freq ectopics
E.g. IV amiodarone or IV lidocaine

Long-term

ICD
Indication: sustained VT/VF
MOA: small device behind rectus abdominus,
connects to heart, recog VT/VF and shocks

B-blockers
Indication: symptomatic ectopics,
non-sustained/sustained VT

Long QT (Torsades de Pointes)
Prolonged ventricular repolarisation
Can be congenital, electrolyte issue, drugs (TCAs etc)
Risk of degrading into VF