VPC couplet – ECG strip
Monitor screenshot showing ventricular premature complexes in a couplet form (VPC couplet), with no preceding sinus beat in between. The two VPCs (second and third complexes) are seen as wide monophasic QRS complexes with inverted T waves. they occur in quick succession with a cycle length of 400 milliseconds which would correspond to a ventricular rate of 150 per minute should more VPCs occur in sequence to form a ventricular tachycardia. A compensatory pause is seen after the second VPC. The basic sinus cycle length is near 600 milliseconds corresponding to a rate of around 100 per minute. Sweep speed of the monitor is shown as 25 millimeters per seconds and the standardization at 1 millivolt to a centimeter. Sinus beats also show T wave inversion, possibly due to underlying primary T wave change due to ischemia / infarction, which has caused the myocardial irritability in the form of VPC couplet. Though VPC couplets themselves are harmless, they could be a forerunner of ventricular tachycardia, which needs to be anticipated and treated if if occurs.