Examination of the P wave in lead V1 of the electrocardiogram: its value in routine electrocardiography.

While reporting on the electrocardiograms recorded in this Department during the past four-and-a-half years, interest was aroused by the occasional appearance of a terminal negative component in the P wave in lead V(1). I tried to find out what significance, if any, it had. In the ensuing study a relationship between such a negative component-expressed as a terminal negative force (-ve Ptf V(1) for short)-and the presence of ischaemic heart disease emerged. Such a negative Ptf V(1) is not an in-fallible marker of ischaemic heart disease nor does it necessarily persist in the repeat electrocardiogram of any given patient. It is, however, suggested that attention be routinely paid to the morphology of the P wave in lead V(1) and that when a negative terminal component is present in this wave follow-up study of this feature in serial electrocardiograms may help in the assessment of prognosis in any given patient.