P Wave Changes Reflecting Atrial Morphology

¹ Instructor in Medicine, State University of New York, Downstate Medical Center
² Department of Cardiology, Triboro Hospital, Queens Hospital Center; Department of Medicine, State University of New York, Downstate Medical Center

The P wave configuration was studied in the limb leads and in precordial leads V₁ and V₂ in 73 cases of atrial derangement. The cases studied consisted of five cases of pulmonary heart disease, nine cases of pulmonary stenosis, ten cases of interatrial septal defect and 49 cases of mitral valve disease. This total group, presenting predominant right-sided cardiac enlargement, demonstrated high peaked waves in the limb leads (2,8 mm.) with an average duration of 0.191 seconds and a high pressure positive component in leads V₁ and V₂ C=1.94 mm. (heigh of positive component) 1.94 mm. (width of negative component). The depth of the negative component, E, was 0.30 mm. (depth of P wave in precordial lead V₁ or V₂). Hemodynamic and angiographic studies did not correlate with the above P wave changes, which were assumed to reflect right auricular enlargement.

The mitral group showed a mean average of:

[See pdf for the figure]

Component A=0.13 sec. (height and duration of P in standard leads)

Component B=3.06 mm.

Component C=1.9 mm. (height of P wave)

Component D=0.069 sec. (width of negative component)

Component E=2.13 mm. (depth of P wave in precordial lead V₁ or V₂)

Of the 49 cases with mitral valve disease, 35 (69.4 per cent) had corroborative hemodynamic angiographic findings. Thirteen out of 14 (99 per cent) of a sub-group with dominant mitral insufficiency presented positive angiographic and hemodynamic findings of left atrial enlargement. The group with mitral valve disease demonstrated differences of a significant degree in the E (depth of P wave in precordial lead V₁ or V₂) component—an average of 1.83 mm. for the "pure mitral stenosis" group and 2.54 mm. for the mitral insufficiency group. These studies would indicate the plausibility of the inference that a marked E component in leads V₁ and V₂ is consistent with left atrial enlargement and that a value of greater than 0.20 mm. indicates mitral insufficiency.