Table 2.

Clinical features and ECG characteristics of cardiac ryanodinopathies

	QTca	Exercise-induced ventricular ectopy	Syncope/presyncope prior to sudden cardiac arrest	Bidirectional VT
CPVT	Normal	Common	Common	Yes
Exon 3 deletion syndrome	Normal	Common	Possible	Yes
CRDS	Normal	Infrequent	Possible	No

CPVT, catecholaminergic polymorphic ventricular tachycardia; CRDS, calcium release deficiency syndrome; QTc, corrected QT interval.

^aAt rest and during/post exercise.