Yonsei Med J.  2022 Sep;63(9):817-824. 10.3349/ymj.2022.63.9.817.

Associations between Subclinical Myocardial Dysfunction and Premature Fusion of Early and Late Diastolic Filling with Uncertain Cause

• Kim K
• Seo J
• Cho I
• Choi EY
• Hong GR
• Ha JW
• Rim SJ
• Shim CY

• KMID: 2532716
• DOI: http://doi.org/10.3349/ymj.2022.63.9.817

Abstract

Purpose
The fusion of early (E) and late diastolic filling (A) on mitral inflow Doppler, even in the absence of tachycardia, is often found during assessment of left ventricular (LV) diastolic function. We evaluated the echocardiographic characteristics and clinical implications of premature E-A fusion of uncertain cause in the absence of tachycardia.
Materials and Methods
We identified 1014 subjects who showed E-A fusion and normal LV ejection fraction (LVEF) between January 2019 and June 2021 at two tertiary hospitals. Among these, 105 (10.4%) subjects showed premature E-A fusion 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 fusion.
Results
The premature E-A fusion 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 current guidelines. The group showed prolonged isovolumic relaxation time (107.2±25.3 msec 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 fusion occurred at lower heart rate, the |LV GLS| was also lower (p for trend=0.002).
Conclusion
Premature E-A fusion 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.

Keyword

Heart failure; left ventricular dysfunction; diastole; doppler echocardiography