Relationship between abnormal P-wave terminal force in lead V1 and left ventricular diastolic dysfunction in hypertensive patients: the LIFE study.

Background: Abnormal P-wave terminal force in lead V₁ (PTF-V₁) is an ECG marker of increased left atrial (LA) volume, elevated LA filling pressures and/or LA systolic dysfunction. Because left ventricular (LV) diastolic dysfunction is one of the potential mechanisms driving LA remodelling, we hypothesized that PTF-V₁ might be an additional ECG marker of diastolic dysfunction.

Methods: LV diastolic function after 3 years' systematic antihypertensive treatment was examined in relation to baseline PTF-V₁ in 431 hypertensive patients undergoing protocol-driven blood pressure reduction who had baseline and year-3 ECG and echocardiographic data and a preserved LV ejection fraction (EF >45%) at year-3. Abnormal diastolic function was defined by the tenth or 90th percentile values from 405 normotensive, non-obese and non-diabetic adults without overt cardiovascular disease. Abnormal PTF-V_1, defined by the presence of a negative terminal P-wave in lead V1 ≥ 4000 μV·ms, was present in 167 patients (38.7%).

Results: Abnormal PTF-V₁ was associated with worse year-3 mean diastolic first third filling time (0.43 ± 0.08 vs 0.40 ± 0.07 sec, p = 0.039), first half filling time (0.55 ± 0.07 vs 0.53 ± 0.07 sec, p = 0.041), mitral valve A velocity (86 ± 27 vs 76 ± 19 cm/sec, p = 0.009) and mitral valve E/A ratio (0.85 ± 0.22 vs 0.94 ± 0.27, p = 0.007) after adjusting for other potential predictors of diastolic dysfunction including race, and heart rate, systolic blood pressure and severity of ECG LVH by Cornell product criteria at baseline. In parallel multivariate logistic regression analysis, abnormal PTF-V₁ was associated with significantly increased odds of abnormal mitral valve E/A ratio (OR 1.55, 95%CI 1.04-2.32 p = 0.032), and a trend toward higher odds of abnormal half filling time (OR 1.42, 95%CI 0.94-2.15, p = 0.098) at year-3 of follow-up.

Conclusions: Abnormal P-wave terminal force in lead V₁ is associated with worse diastolic function and predicts abnormal LV diastolic behaviour in patients with preserved EF after 3 years of blood pressure reductive therapy.