Atrial enlargement and dilation can be caused by tricuspid and bicuspid (mitral) valve disease, hypertensionBlood pressure above acceptable limits – above 90 mm of Hg diastolic and above 140 mm of Hg systolic. 1. Six Second ECG Guidebook (2012), T Barill, p. 167, 197, and ventricular hypertrophyVentricular hypertrophy is reflected in QRS axis deviation towards the hypertrophied ventricle, increased amplitude in the QRS complex, altered R wave progression, and possibly signs of ventricular strain - ST depression and T wave inversion. Note that ST changes can... among other causes. A P waveA wave generated from the depolarization of the atria; the P wave is upright when originating from the SA node. The P wave represents the depolarization of the right and left atria. The P wave begins with the first deviation... can change with atrial enlargement to be taller than 2.5 mm in leads I, II and aVF. Single atrium enalargement can result in a heightened primary or terminal part of the P wave, forming a bifid shape.
1. Six Second ECG GuidebookA Practice Guide to Basic and 12 Lead ECG Interpretation, written by Tracy Barill, 2012 Introduction The ability to correctly interpret an electrocardiogram (ECG), be it a simple six second strip or a 12 lead ECG, is a vital skill... (2012), T Barill, p. 154