[Effect of arterial hypertension on the atrial portion of the electrocardiogram].

Pathologic signs of left atrial load are found very often in arterial hypertension. The diagnostic combinations are very slightly expressed, more often in the orthogonal ECG. Pathologic criteria found most often are: pathologic end-strength of the P wave in lead V1 (in 42% of the patients) and increased amplitude of PX (in 39% of the patients). The pathologic changes of the P wave increase with the development of left ventricular hypertrophy and heart failure. The values of the end-strength of the P wave in lead V1 when they are negative more than - 0.03 mm.s should be considered pathologic in contrast to mitral valvular disease.