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