<unk><unk>  A<unk> , or<unk>  atrial<unk> , are<unk>  seen occasionally in the jugular vein of humans with certain cardiac arrhythmias. When the atria and ventricles happen to contract simultaneously, the right atrium contracts against a closed tricuspid valve, resulting in back pressure into the venous system that can be seen in the jugular venous pulse as a high-amplitude<unk> <unk> . It is associated with heart block, in particular third-degree (complete) heart block. It is also seen in pulmonary hypertension.<unk>  may also be seen in ventricular tachycardia due to the inherent AV dissociation of the arrhythmia. This<unk> will cause pulsation in the neck and abdomen, headache, cough, and jaw pain.
Cannon A waves
Empty delta sign
T wave alternans
Golden S sign
Mayer waves
Apex beat
High frequency QRS
J wave