Characteristics and clinical implications of premature summation of early and late diastolic filling in patients without tachycardia

The summation of early (E) and late diastolic filling (A) on mitral inflow Doppler even in the absence of tachycardia is often found during assessments of left ventricular (LV) diastolic function. We evaluated the echocardiographic characteristics and clinical implications of premature E-A summation.

We identified 1,014 subjects who showed E-A summation and normal LV ejection fraction between January 2019 and June 2021 in two tertiary hospitals. Among these, 105 (10.4%) subjects showed premature E-A summation at heart rates less than 100 beats per minute (bpm). The conventional echocardiographic parameters and LV global longitudinal strain (GLS) were compared with 1:1 age, sex, and heart rate matched controls without E-A summation.

The premature E-A summation group had a heart rate of 96.4±3.7 bpm. Only 4 (3.8%) subjects were classified as having LV diastolic dysfunction according to the current guidelines. That group showed prolonged isovolumic relaxation time (107.2±25.3 vs. 61.6±15.6 msec, p<0.001), increased Tei index (0.76±0.19 vs. 0.48±0.10, p<0.001), lower LVEF (63.8±7.0 vs. 67.3±5.6%, p<0.001) and lower absolute LV GLS (|LV GLS|) (17.0±4.2 vs. 19.7±3.3%, p<0.001) than controls. As the E-A summation occurred at lower heart rate, the |LV GLS| was also lower (p for trend=0.002).

The premature E-A summation at heart rates less than 100 bpm is associated with subclinical LV dysfunction. Time-based indices and LV GLS are helpful for evaluating this easily overlooked population.

Type of funding sources: None.