Resting heart rate, electrocardiographic markers of atrial cardiopathy, and all-cause mortality

Elevated resting heart rate (HR) and atrial cardiopathy are each linked to higher mortality risk, yet their interrelationship and joint prognostic value remain unclear.

We analyzed 7326 adults (mean age 59.0 ± 13 years) without cardiovascular disease from the Third National Health and Nutrition Examination Survey with available electrocardiograms. Atrial cardiopathy was defined by electrocardiogram as abnormal P-wave axis or deep terminal P-wave negativity in V1. Multivariable logistic regression assessed cross-sectional associations between HR categories and atrial cardiopathy. Cox proportional hazard models evaluated independent and joint associations of HR categories and atrial cardiopathy with all-cause mortality.

Atrial cardiopathy was present in 1833 participants (25.0%). After adjustment, sinus tachycardia ((≥100 bpm) was associated with higher odds of atrial cardiopathy (OR 1.76, 95% CI 1.06-2.92), whereas sinus bradycardia (≤50 bpm) was associated with lower odds (OR 0.61, 95% CI 0.43-0.84). Each 10-bpm HR increase corresponded to 25% higher odds of atrial cardiopathy. Over a median 13.8-year follow-up, 2415 deaths (33.0%) occurred. Sinus tachycardia (HR 3.58, 95% CI 2.61-4.91) and atrial cardiopathy (HR 1.27, 95% CI 1.16-1.39) were independently associated with mortality. Individuals with both conditions had the highest risk (HR 4.11, 95% CI 2.63-6.41). Associations varied by age and race.

Elevated resting HR is associated with higher odds of atrial cardiopathy, and their coexistence confers markedly increased mortality risk. Integrating resting HR into atrial cardiopathy metrics may enable granular population-level risk profiling.