The major condition which needs to be differentiated from ARVD is idiopathic ventricular tachycardia arising from the outflow tract. The ventricular tachycardia can be exactly the same, but there is no structural abnormality of the heart, unlike the situation in ARVD where commonly there is dilation of the ventricle. Right ventricular outflow tract tachycardia (RVOT) is more common than ARVD and occurs in young, otherwise healthy people. The treatment is either with medications or with catheter ablation. The chart below compares RVOT to ARVD.

	RVOT Tachycardia	ARVD
Family History of Arrhythmia or Sudden Cardiac Death	No	Frequently Yes
Arrhythmias	PVBs, nonsustained VT or sustained VT at rest or with exercise	Same
Sudden Cardiac Death	Rare	1% per year
Frontal Plane QRS	Positive in leads III and AVF, negative in lead AVL	Inferior or Superior
T-wave Morphology	T wave upright V2-V5	T wave inverted beyond V1
Parietal Block	QRS duration <110 msec in V1, V2 or V3	QRS duration > 110 msec
T-wave Morphology & Parietal Block		84% sensitivity and 100% specificity
Epsilon Wave V1-V3	Absent	Present 30%
Signal Averaged ECG	Normal	Usually Abnormal
Echocardiogram	Normal	Increased RV size and/or wall motion abnormalities
RV Ventriculogram	Usually Normal	Usually Abnormal
MRI	Usually Normal, but data in literature is conflicting	increased signal intensity of RV free wall; wall motion abnormalities with CINE MRI
Response to Therapy	Acute Vagal Maneouvres Adenosine, Beta-blockers Verapamil Chronic Beta-blockers or verapamil +/- class one antiarrhythmic drugs	Sotalol Amiodrone+/- Beta blockers
RF Ablation	Usually Curative	Seldom Curative; may modify substrate to permit AA drugs effective Arrhythmias or different morphology tend to occur