Efficiency of quantitative longitudinal peak systolic strain values using automated function imaging on transthoracic echocardiogram for evaluating left ventricular wall motion: new diagnostic criteria and agreement with naked eye evaluation by experienced cardiologist

PURPOSE

To evaluate the efficiency of automated function imaging (AFI) on transthoracic echocardiogram (TTE) for detecting left ventricular (LV) wall motion (LVWM) abnormalities, we compared longitudinal peak systolic strain (LPSS) measurements using AFI with naked eye TTE evaluations by experienced cardiologists and non-experienced residents.

MATERIALS AND METHODS

A total of 352 segments of LV myocardium from 22 consecutive subjects with LVWM abnormalities based on American Heart Association classifications (11 male, mean age 58 ± 14 years) on previous TTE (Vivid-7, GE) were evaluated. LPSS was measured using stored AFI data. Naked eye evaluation of LVWM was performed by 2 experienced cardiologists and 2 non-experienced residents.

RESULTS

AFI successfully tracked 342 (97%) of all segments (mean LPSS -14.8 ± 8.1%). A significant strong negative correlation was observed between LV ejection fraction using method of disks and global LPSS (R=-0.8974). Temporary AFI criteria of LPSS were normal <-12; hypokinesis -12-2; and akinesis >2. Of 342 segments, 239, 87, and 16 segments were diagnosed as normal, hypokinesis, and akinesis, respectively. Level of agreement and kappa coefficients between qualitative evaluation of LVWM by AFI temporary criteria and qualitative evaluation of LVWM by experienced cardiologist 2 (0.784 and 0.479, respectively) were inferior to those comparing experienced cardiologists (0.845 and 0.595) but superior comparing experienced cardiologist with non-experienced resident (0.696 and 0.323), and between the 2 non-experienced-residents (0.682 and 0.347).

CONCLUSION

Qualitative evaluation of LVWM using temporary AFI criteria had a 97% success rate and agreed well with findings of an experienced cardiologist. AFI can be a useful tool for training residents.

Subclinical left ventricular systolic dysfunction detected in obstructive sleep apnea with automated function imaging and its association with nocturnal hypoxia

BACKGROUND

Early detection of left ventricular (LV) dysfunction is crucial in obstructive sleep apnea (OSA) due to its close relationship with cardiovascular diseases. Global longitudinal strain (GLS) derived from automated function imaging (AFI) can precisely assess global longitudinal function. The aim of this study was to determine if LV GLS was reduced in patients with OSA and a normal LV ejection fraction (LVEF) and to assess any associated determinants.

METHODS

Polysomnography (PSG) and echocardiography were done in consecutive patients with suspected OSA and normal LVEF in this prospective study. Patients were divided into two groups according to apnea-hypopnea index (AHI) (Group 1, normal or mild OSA: AHI < 15/h; Group 2, moderate-to-severe OSA: AHI ≥ 15/h). Clinical, PSG, and echocardiographic parameters were compared between the two groups and the associated factors were investigated.

RESULTS

Of 425 consecutive patients, 244 were analyzed after exclusions. Patients in Group 2 had significantly worse GLS than those in Group 1 (p < 0.001). The prevalence of GLS reduction (defined as < - 19.7%) was 25% and 76%, respectively (χ² = 34.19, p < 0.001). Nocturnal lowest pulse oxygen saturation (SpO₂), AHI, body mass index (BMI), and gender were associated with GLS reduction (all p < 0.05). Further multivariate analysis showed that the lowest SpO₂ (OR: 2.15), gender (OR: 2.45), and BMI (OR: 2.66) remained independent (all p < 0.05), and the lowest SpO₂ was the most powerful determinant (χ² = 33.0, p < 0.001) in forward regression analysis. The intra- and inter-operator variability for AFI and coefficient of repeatability was low even in those with relatively poor images.

CONCLUSIONS

In patients with normal LVEF, more severe OSA was associated with a worse GLS. The major determinants were lowest nocturnal SpO₂, gender, and obesity, but not AHI. GLS can be rapidly and reliably assessed using AFI.

Reliability and feasibility of automated function imaging for quantification in patients with left ventricular dilation: comparison with cardiac magnetic resonance

Automated function imaging (AFI, GE Healthcare) is a novel promising algorithm of speckle-tracking echocardiography that combines two-dimensional strain and AI technology. It shortens the analysis time, saves the cost associated with streamlining of image acquisition, rapid analysis, and reporting, and has greater accuracy and reproducibility of measurements. This study aimed to evaluate the reliability and feasibility of AFI for the quantification of left ventricular (LV) volumes and function in patients with LV dilation by comparison with CMR. We retrospectively studied 50 patients with LV dilation on echocardiography whom both underwent CMR and coronary angiography within three days. LV volumes, ejection fraction (EF), and global longitudinal strain (GLS) were measured from 3 long-axis cine-views via the AFI technique in two modes: without editing (auto-AFI) and with partial border editing (semi-auto-AFI). The LV volumes and EF were also measured with 2D Simpson's biplane method, and CMR, as the standard method, was used for comparison. The AFI method still had significantly underestimated the LV volumes compared with CMR (P<0.01), but there were no significant differences between the AFI method and the conventional Simpson's biplane method. There were no significant differences in EF between CMR and the AFI method with good correlations (auto-AFI: r = 0.81, semi-auto-AFI: r = 0.86). The auto-AFI method provided the most rapid analysis and excellent reproducibility, while the semi-auto-AFI method further improved measurement accuracy. However, there were no significant differences in LV volumes and EF between these two AFI methods. The accuracy of AFI seems to be more affected by the image quality than the left ventricular morphology.  AFI enables accurate, efficient, and rapid evaluation of LV volumes and EF in patients with dilated LV, with good reproducibility and correlations with CMR.

Left ventricular function assessment in Kawasaki disease by two-dimensional global longitudinal systolic strain with automated function imaging

BACKGROUND

Kawasaki disease is an acute febrile vasculitis of childhood mainly affecting children under 4 years of age. In the acute stage of the disease, heart function decreases and gradually returns to normal after treatment. However, subendocardial involvement may persist, which cannot be assessed by M-mode echocardiography. Strain echocardiography is a recently developed technique to assess subendocardial involvement of myocardial deformation. We aimed to study the stratified strain of left ventricular function in a Kawasaki patient at least 6 months after the acute stage of the disease with special conditions for entering the study using two-dimensional speckle-tracking imaging. Between September 2020 and October 2022, 27 healthy children and 27 children with a history of Kawasaki disease more than 6 months ago were evaluated using two-dimensional global longitudinal peak systolic strain with automated function imaging technology.

RESULTS

The mean age of patients was 5.6 years. With M-mode echocardiography, ejection fraction of each group was in the normal range. Mean (± standard deviation) global longitudinal peak strain in four-chamber view of girls with Kawasaki disease was - 23.74 ± 2.77, and that in boys with Kawasaki disease was - 20.93 ± 2.06 (P value = 0.008). GLPS (global longitudinal peak strain) was compared as an overall average and as in a separate segment, which showed significant difference in two comparisons. In our study, a decrease in the function of some cardiac segments is reported. Global longitudinal peak strain in four-chamber view was significantly lower in boys. Comparing different segments, a difference in global left ventricular long-axis strain was found between the two groups. On the other hand, there was a major difference between the two groups in the basal inferolateral, basal anterolateral, and mid-inferolateral, which receives blood from Left Circumflex artery.

CONCLUSION

Using stain echocardiography to detect continued subendocardial involvement in asymptomatic children with a history of Kawasaki disease for a better understanding of the condition, effective management and follow-up is recommended.