Left Ventricular Ejection Fraction Correlation With Stroke Volume as Estimated by Doppler Echocardiography in
Hazem Lashin1, Olusegun Olusanya2, Andrew Smith1
1Adult Critical Care Unit, Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom; William Harvey Research Institute, Barts, and the London school of medicine and dentistry, Queen Mary University of London, Charterhouse square, London, United Kingdom.
Insights
In intensive care unit (ICU) patients with cardiogenic shock (CS), left ventricular ejection fraction (LVEF) shows a weak correlation with stroke volume (SV) and SV index (SVI) measured by Doppler echocardiography. Visual LVEF estimation slightly outperformed Simpson's method for predicting SV/SVI.
Area of Science:
- Cardiology
- Intensive Care Medicine
- Echocardiography
Background:
- Echocardiography is crucial for cardiac assessment in intensive care unit (ICU) patients with cardiogenic shock (CS).
- Left ventricular ejection fraction (LVEF) is a standard measure of left ventricular (LV) systolic function.
- The correlation between LVEF and stroke volume (SV)/SV index (SVI) in CS patients with reduced LVEF requires further investigation.
Purpose of the Study:
- To investigate the correlation between LVEF and Doppler-estimated SV/SVI in ICU patients experiencing CS.
- To compare the predictive value of visually estimated LVEF versus Simpson's method for SV/SVI in this patient cohort.
Main Methods:
- Retrospective analysis of 100 patients admitted to an ICU with ST-elevation myocardial infarction (STEMI) and CS (LVEF <40%).
- Collected clinical and echocardiographic data, including LVEF (visual estimate and Simpson's method).
- Correlated LVEF measurements with SV and SVI derived from Doppler echocardiography.
Main Results:
- A weak but statistically significant correlation was found between LVEF and Doppler-estimated SV/SVI (r=0.44-0.47).
- Visually estimated LVEF showed a slightly stronger correlation with Doppler SV/SVI (r=0.48-0.49) compared to LVEF calculated by Simpson's method (r=0.36-0.37).
- The study included 100 patients (mean age 62.6 years, 78% male) with a median LVEF of 29%.
Conclusions:
- A weak correlation exists between LVEF and Doppler-derived SV/SVI in ICU patients with STEMI-induced CS and reduced LVEF.
- Visual estimation of LVEF may offer a slightly better correlation with Doppler SV compared to the modified Simpson's method in this specific clinical context.
- These findings highlight potential limitations in using LVEF alone to assess cardiac output in critically ill patients with CS.
Objectives:
Echocardiography is the main tool for cardiac assessment and helps to guide management in patients admitted to the intensive care unit (ICU) with cardiogenic shock (CS). Left ventricular ejection fraction (LVEF) is a commonly used echocardiographic surrogate for left ventricular (LV) systolic function. In this hypothesis-generating study, the authors investigated the correlation between LVEF and stroke volume (SV)/SV index (SVI) estimated by Doppler echocardiography in patients admitted to the ICU with CS and reduced LVEF.
Design And Setting:
This retrospective analysis was performed in a single tertiary cardiac center in London, United Kingdom.
Participants:
Patients admitted to the ICU over a 34-month period with ST elevation myocardial infarction (STEMI) complicated by CS and LVEF <40%.
Interventions:
Clinical and echocardiographic data were collected. LVEF (total, by visual estimate and by modified Simpson's method) was correlated with SV and SVI estimated by Doppler echocardiography.
Measurements And Main Results:
One-hundred patients were included. The mean age was 62.6 ± 12.7 years and 78% were male patients. The median LVEF was 29% (20-35) and the mean SV and SVI by Doppler echocardiography were 47 mL ± 16 and 25 mL ± 9, respectively. Analysis revealed a weak yet statistically significant correlation among LVEF and Doppler SV and SVI (r = 0.44, confidence interval [CI] 0.26-0.60, p < 0.0001, r = 0.47, CI 0.28-0.62, p < 0.001, respectively). Visually estimated LVEF (n = 74) correlated weakly with Doppler SV and SVI yet better compared to LVEF by Simpson's method (n = 25) (r = 0.48, CI 0.27-0.65, p < 0.0001 and r = 0.49, CI 0.28-0.66, p < 0.0001, respectively, v r = 0.36, CI 0.05-0.67, p = 0.08 and r = 0.37, CI -0.04-0.67, p 0.07, respectively).
Conclusions:
There is a weak correlation between LVEF and SV or SVI estimated by Doppler echocardiography in patients admitted to the ICU with STEMI complicated by CS and reduced LVEF. Visually estimated LVEF correlated slightly better with Doppler SV compared to modified Simpson's LVEF.
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