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.

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

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Link to Article in PubMed

Journal/Book/Conference Title

Clinical cardiology