Palpitations
| 'Traffic light system' for risk stratification of palpitations | ||
|---|---|---|
|
• skipped beats |
• Hx suggests recurrent tachyarrhythmia |
• palpitations during exercise |
ECG findings | Implication/consideration |
|---|---|
| Pre-excitation/delta wave | WPW – AVRT |
| Left atrial enlargement, frequent PACs, sinus bradycardia | Atrial fibrillation |
| Left ventricular hypertrophy | Atrial fibrillation, ventricular tachycardia |
| Frequent PVCs | Ventricular tachycardia |
| Q waves | Ischaemic heart disease – Atrial fibrillation, ventricular tachycardia |
| Widespread T wave inversion across precordial leads, LVH, Q waves and ST-segment changes | Hypertrophic cardiomyopathy – risk of atrial fibrillation, ventricular tachycardia |
| Long or short QT interval, Brugada pattern, early repolarisation pattern | Genetic arrhythmia syndromes – risk of sudden cardiac death |
| Inverted T waves or Epsilon waves across right precordial leads (V1–V3)* | ARVC – risk of sudden cardiac death |
| *in patients without RBBB ARVC - Arrhythmogenic Right Ventricular Cardiomyopathy |
|
Idiopathic Fascicular VT
LITFL - idiopathic fascic VT
European Soc Cardiol idiopathic fascic VT 2010
- usually in young healthy adults 15-40yo, predominantly male resulting from ventricular ectopic focus
- a re-entrant tachy causing palpitations usually at rest but may be with exercise, stress, other catecholamine triggers etc
- often mis-diagnosed as SVT - look for dissociated P waves and narrow complex 'capture beat'
- good prognosis
- Monomorphic ventricular tachycardia eg. fusion complexes, AV dissociation, capture beats
- 90% of monomorphic VT = result of structural cardiac disease, usually IHD and others etc
- 10% therefore NOT assoc with structural disease & therefore known as idiopathic VT with >75% of these arising in RV and the remainder in the L with most of these in L posterior fascicle
- QRS duration 100 – 140ms — ie. narrower than other forms of VT
- Short RS interval (onset of R to nadir of S wave) of 60-80 ms — the RS interval is usually > 100 ms in other types of VT
- RBBB Pattern
- Axis deviation depending on anatomical site of re-entry circuit (see classification)
- first line treatment = Verapamil
- Classification:
- Posterior fascicular VT (90-95%): RBBB morphology + left axis deviation; arises close to the left posterior fascicle
- Anterior fascicular VT (5-10%): RBBB morphology + right axis deviation; arises close to the left anterior fascicle
- Upper septal fascicular VT (rare): atypical morphology – usually RBBB but may resemble LBBB instead; cases with narrow QRS and normal axis have also been reported. Arises from the region of the upper septum
Management
- characteristically responds to verapamil
- does not respond to adenosine, vagal manoeuvres, lignocaine