N	b	Normal beat
L	b	Left bundle branch block beat
R	b	Right bundle branch block beat
B	b	Bundle branch block beat (unspecified)
A	b	Atrial premature beat
a	b	Aberrated atrial premature beat
J	b	Nodal (junctional) premature beat
S	b	Supraventricular premature or ectopic beat (atrial or nodal)
V	b	Premature ventricular contraction
r	b	R-on-T premature ventricular contraction
F	b	Fusion of ventricular and normal beat
e	b	Atrial escape beat
j	b	Nodal (junctional) escape beat
n	b	Supraventricular escape beat (atrial or nodal)
E	b	Ventricular escape beat
/	b	Paced beat
f	b	Fusion of paced and normal beat
Q	b	Unclassifiable 
?	b	Beat not classified during learning
[	n	Start of ventricular flutter/fibrillation
!	n	Ventricular flutter wave
]	n	End of ventricular flutter/fibrillation
x	n	Non-conducted P-wave (blocked APC)
(	n	Waveform onset
)	n	Waveform end
p	n	Peak of P-wave
t	n	Peak of T-wave
u	n	Peak of U-wave
`	n	PQ junction
'	n	J-point
^	n	(Non-captured) pacemaker artifact
|	n	Isolated QRS-like artifact [1]
~	n	Change in signal quality [1]
+	n	Rhythm change [2]
s	n	ST segment change [2]
T	n	T-wave change [2]
*	n	Systole
D	n	Diastole
=	n	Measurement annotation [2]
"	n	Comment annotation [2]
@	n	Link to external data [3]