P-Wave Terminal Force V1 Is Associated with Left Ventricular Diastolic Function in Patients with No Significant Perfusion Abnormality: Assessment by Myocardial Perfusion Single-Photon Emission Computed Tomography

P-wave terminal force in lead V1 (PTFV1) is a marker of increased left atrial (LA) overload. Whether PTFV1 is associated with left ventricular (LV) diastolic function remains undetermined. We tested the hypothesis that PTFV1 is associated with LV diastolic parameters derived from gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with no significant perfusion abnormalities.The study population included 158 patients with preserved ejection fraction and no significant perfusion abnormalities. The amplitude and duration of the P-wave negative phase in lead V1 were measured using an electrocardiogram, and PTFV1 was calculated. The peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained as LV diastolic parameters using gated SPECT.PTFV1 showed a weak correlation with the LA volume index (r = 0.31; P < 0.001). Significant associations were observed between PTFV1 and PFR (r = −0.27; P < 0.001) and 1/3 MFR (r = −0.26; P = 0.001). A multivariate linear regression analysis showed that age (β = −0.26; P < 0.001), LV end-diastolic volume index (β = −0.27; P = 0.001), and PTFV1 (β = −0.15; P = 0.036) were significant factors associated with PFR. Moreover, male gender (β = −0.16; P = 0.041), LV mass index (β = −0.17; P = 0.046), and PTFV1 (β = −0.17; P = 0.022) were significant factors associated with the 1/3 MFR.PTFV1 is associated with LV diastolic function, as derived from gated SPECT in patients with no significant perfusion abnormalities.