Abstract
The Pwave in hypertension was studied comparing with that in normal and mitral stenosis.
(1) In various findings of the Pwave, there were significant differences between normal and pathological conditions. Hypertensive cases had inter-mediate changes compared with the other two groups, and these changes were intensified by the elevation in the diastolic blood pressure level.
(2) From the results obtained in these comparison studies, we proposed the 7 electrocardiographic criteria to assess the changes in the Pwave in both hypertensive and mitral stenosis. In hypertensive cases, the incidence of each criterion was increased according to the elevation in the diastolic blood pressure level. Special attention was given to some criteria, namely "relative" left axis deviation of the Pwave, which was characteristic to mitral stenosis and mild hypertension, and the finding that the amplitude of the Pwave in lead V6 was higher than that in V5, which indicated the more definite sign of the left atrial overloading and often seen in mitral stenosis and severe hypertension.
(3) The grade of Pwave change gave us the more distinctive differentia-tion of the Pwave between normal and mitral stenosis. In hypertension, this grade was increased with the elevation in the diastolic blood pressure level, and in severe cases, the grade of Pwave change became similar to that seen in mitral stenosis.
(4) On the bases of the observations in the follow-up cases as well as above-mentioned results, we suggested that the change in the Pwave in hypertension was a reflection of the left atrial overloading possibly resulted from the left ventricular one.
