Enlargement of both left and right atria may cause recognizable changes in the electrocardiogram (ECG).
Changes in the ECG associated with bi-atrial enlargement:
(1) high-peaked P wave with an increased duration, especially in II, III and/or aVF (vertically oriented leads)
(2) large biphasic P wave in V1
where:
• The increased duration of the P wave is related to changes in the initial and terminal aspects of the P wave.
