Electrocardiographic left atrial abnormalities predict cardiovascular mortality.

Objective: Clinical utilization of electrocardiography for diagnosis of left atrial abnormalities is hampered by variable P-wave morphologies, multiple empiric criteria, and lack of an imaging "gold standard". Our aim was to determine the prevalence of P-wave patterns and demonstrate which components have associations with cardiovascular death (CVD).

Methods: This is a retrospective analysis of 20,827 veterans <56 years of age who underwent electrocardiograms at a Veteran's Affairs Medical Center from 1987 to 1999, followed for a median duration of 17.8 years for CVD. Receiver Operating Characteristic, Kaplan-Meier and Cox Hazard analyses were applied, the latter with adjustment for age, gender and electrocardiography abnormalities.

Results: The mean age was 43.3 ± 8 years, and 888 CVD (4.3%) occurred. A single positive deflection of the P-wave (Pattern 1) was present in 29% for V1 and 81% for V2. A singular negative P-wave (Pattern 2) was present in 4.6% for V1 and 1.6% in V2. A P-wave with an upward component followed by downward component (Pattern 3) was present in 64.5% for V1 and 17.5% for V2. When the downward component in Patterns 2 and/or 3 is at least -100 μV, a significant association is observed with CVD (adjusted hazard ratios [HRs] 2.9-4.1, P < 0.001). Total P-wave duration ≥140 ms was also associated with CVD (adjusted HR 2.2, P < 0.001).

Conclusions: A negative P-wave in V1 or V2 ≤-100 μV, and P-wave with a duration of ≥140 ms, all have independent and significant associations with CVD, with HRs comparable to other electrocardiography abnormalities.