Clinician Underappreciation of Interatrial Block in a General Hospital Population

Abstract

Introduction: Interatrial block (IAB; P wave ≧110 ms), a conduction delay between the right and left atria (LA), is highly prevalent and strongly associated with atrial tachyarrhythmias, LA electromechanical dysfunction as well as a risk of embolism. Nonetheless, clinicians’ underappreciation of its existence and sequelae remains. We appraised this issue in a general hospital population. Methods: From the database of 730 12-lead electrocardiograms (ECGs) of patients aged 17–98 years (mean age 67.80 years; female patients 53.56%) in a tertiary care teaching general hospital, we recorded the computer-generated diagnostic readings of the ECGs and also the official cardiologist and hospitalist ECG interpretations and documentations. For increased sensitivity and specificity, and because the mode P wave duration in IAB is 120 ms, P waves ≧120 ms in any lead were used to diagnose IAB. Results: Six hundred and fifty-three ECGs (89.45%) showed sinus rhythm, and of those, IAB was documented on 309 ECGs (47.32%). LA enlargement was cited 29 times (3.97%), while possible LA enlargement and biatrial enlargement were cited 17 (2.32%) and 6 times (0.82%), respectively. One cardiologist’s ECG interpretation documented IAB (0.32%), but none of the other medical staff diagnosed IAB or abnormal P wave duration. Conclusion: This study demonstrates to extremes how IAB went undiagnosed in a general hospital population. Until more awareness of IAB is cultivated, such ignorance of the existence and sequelae of IAB could continue. Configuring ECG software to include P wave durations in computer-generated ECG readings could be useful in aiding diagnosis.