If these concurrent beats number three, they are called triplets and are considered as a brief run of non-sustained
Ventricular tachycardia or NS-VT.
Examples:
Bigeminal premature ventricular contractions = Normal, PVC, Normal, PVC...
Trigeminal premature atrial contractions = Normal, Normal, PAC, Normal, Normal, PAC...
Bigeminal Couplets: Normal, Normal, PVC, PVC, Normal, Normal, PVC, PVC...
NS-VT: Normal, Normal, PVC, PVC, PVC, PVC, Normal, Normal, PVC....