wiki:cardiovascular:palpitations

Palpitations

• skipped beats • thumping beats • short fluttering • slow pounding AND • normal ECG AND • No FHx AND • no structural disease	• Hx suggests recurrent tachyarrhythmia • palpitations with assoc symptoms AND/OR • abnormal ECG AND/OR • structural heart disease	• palpitations during exercise • palpitations with syncope/near syncope • high risk structural heart disease • FHx of inheritable heart disease/SADS • high degree AV block
'Traffic light system' for risk stratification of palpitations

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

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