Dynamic variations of P-wave duration in a patient with acute decompensated congestive heart failure.

Interatrial block is an abnormally delayed atrial activation, characterized at ECG by prolonged P-wave duration (more than 110 ms), irrespective of morphology. We report the case of a patient with acute decompensated severe congestive heart failure, that at hospital admission showed a prolonged P-wave, which reverted after diuretic therapy. The dynamic change of the atrial P-wave correlates with clinical evolution and serum level modification of B-type natriuretic peptide.