Influence of left ventricular systolic dysfunction on occurrence of pulsus tardus in patients with aortic stenosis

Although the time difference between peak of left ventricular (LV) and aortic systolic pressures (T_LV-Ao), which is considered to in part reflect pulsus tardus, is reported to be associated with clinical outcome in aortic stenosis (AS), its physiological determinants remain to be elucidated. We hypothesized that not only AS severity but also LV systolic dysfunction could be associated with occurrence of pulsus tardus.

T_LV-Ao was measured by simultaneous LV and aortic pressure tracing in 74 AS patients and prolonged T_LV-Ao was defined as ≥66 ms according to the previous report. Mean transaortic valvular pressure gradient (mPG) and effective orifice area index (EOAI) were estimated by Doppler echocardiography and severe AS was defined as EOAI ≤0.60 cm²/m². Global longitudinal strain (GLS) was measured by using speckle-tracking method.

Although a weak correlation was observed between EOAI and T_LV-Ao, there was substantial population showing discordance between the parameters: severe AS despite normal T_LV-Ao (10 of 47 patients) and moderate AS despite prolonged T_LV-Ao (9 of 17 patients). In severe AS, mPG was significantly higher in patients showing prolonged T_LV-Ao (57±20 vs 36±10 mmHg, p<0.0001) whereas GLS was comparable between the groups (-15.2±3.5% vs -14.8±3.2%). In contrast, in moderate AS, GLS was significantly smaller in patients showing prolonged T_LV-Ao (-12.6±4.7% vs -17.4±3.4%, p=0.0271) while mPG was comparable (34±7 mmHg vs 35±8 mmHg). Multivariable analysis revealed that not only mPG but also GLS was an independent determinant of T_LV-Ao.

The occurrence of pulsus tardus could be associated with not only AS severity but also LV systolic dysfunction in AS patients.