Interatrial block: correlation with P-terminal force

UMMS Affiliation

Department of Medicine, Division of Cardiovascular Medicine

Publication Date


Document Type



Double-Blind Method; Electrocardiography; Heart Atria; Heart Block; Humans; Predictive Value of Tests; Sensitivity and Specificity; Stroke Volume


Bioinformatics | Biostatistics | Epidemiology | Health Services Research


BACKGROUND AND HYPOTHESIS: Interatrial block (IAB: P-duration > 100 ms) is poorly recognized in hospital populations. In addition to reduced left atrial function and left atrial enlargement it predicts atrial fibrillation and other arrthymias. P-terminal force (Ptf): +/- biphasic P in lead V(1) > or = area of 1 small square on the electrocardiogram (ECG) grid also indicates left atrial abnormality, particularly left atrial enlargement. These 2 should be related. We determined the intercorrelation.

METHODS AND RESULTS: Two blinded observers evaluated 500 consecutive patients' ECGs for both Ptf and IAB utilizing all 12 leads for IAB and V(1) for Ptf. Measurement differences were resolved in a consensus conference. Among 482 usable ECGs, IAB and Ptf were strongly and significantly correlated (chi(2) = 68.041; P < or = .001).

CONCLUSION: IAB and Ptf are significantly and strongly correlated and one should be expected in the majority of cases when the other is recognized.

DOI of Published Version



Clin Cardiol. 2009 Apr;32(4):181-2. Link to article on publisher's site

Journal/Book/Conference Title

Clinical cardiology

PubMed ID


Related Resources

Link to Article in PubMed