DICOM PS3.3 2019b - Information Object Definitions
A.34.4.4.7 Waveform Annotation Module

The Defined CID for the Concept Name Code Sequence (0040,A043) in the Waveform Annotation Sequence (0040,B020) shall be CID 3335 “ECG Annotations”. This Context Group supports the annotation of suppressed pacemaker spikes in the ECG waveform.

DICOM PS3.3 2019b - Information Object Definitions