Physical activity and atrial phenotype: associations with echocardiography and P-wave indices in a population-based cohort
A Zaghi, A Jujic, M Magnusson, P Platonov, H HannesAbstract
Background
Habitual physical activity (PA) is associated with lower cardiovascular risk, but its relationship to atrial structural and electrical phenotype is not well characterised in the general population. Left atrial remodelling reflects cumulative haemodynamic and diastolic load, while echocardiography and ECG-based P-wave indices (PWIs) provide complementary measures of atrial mechanical and electrical function. Examining both modalities may clarify how objectively measured PA relates to subclinical atrial remodelling in midlife.
Purpose
To investigate associations between accelerometer-measured PA, echocardiographic measures, and PWIs in a Swedish population-based cohort.
Methods
We analysed 1,338 participants (mean age 57.4 years, 54% female) from a Swedish population-based cohort, the Swedish CArdioPulmonary bioImage Study (SCAPIS). PA was assessed using accelerometry (≥4 days) and expressed as log-transformed counts per minute (CPM). Echocardiographic assessments included left atrial volume index (LAVI), left ventricular mass index (LVMI), biplane stroke volume, septal e′ velocity, and E/e′ ratio. PWIs included abnormal frontal P-wave axis (<0° or >75°), prolonged P-wave duration (>120 ms), and abnormal P-wave terminal force in lead V1 (PTF-V1 ≥4000 μV·ms). Associations between PA with continuous echocardiographic measures were evaluated using multivariable linear regression, and PWIs using logistic regression. Fully adjusted models included age, sex, systolic blood pressure, diabetes, smoking, BMI, and accelerometer wear time.
Results
Higher PA was independently associated with higher LVMI (β 6.99, 95% CI 3.91–10.08; p<0.001), higher LAVI (β 3.62, 95% CI 2.25–4.99; p<0.001), and higher stroke volume (β 4.02, 95% CI 1.60–6.45; p=0.001). No associations were observed with septal e′ (β −0.04; p=0.796) or E/e′ (β −0.02; p=0.958) after adjustment. Higher PA was associated with lower odds of abnormal PTF-V1 (OR 0.49, 95% CI 0.27–0.92; p=0.026), i.e. PTF-V1 ≥4000 μV·ms. No associations were found with prolonged P-wave duration (>120 ms) (OR 0.90; p=0.66) or abnormal frontal P-wave axis (OR 0.95; p=0.85).
Conclusions
Higher objectively measured PA was associated with larger atrial and LVMI and higher stroke volume, without evidence of impaired relaxation, elevated filling pressures or electrocardiographic indices of left atrial abnormality. These findings highlight selective associations between habitual PA and subclinical atrial phenotype assessed by echocardiography and ECG.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.