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Published on: December 13, 2019
Evaluation of left ventricular systolic function using synchronized analysis of heart sounds and the
Xiu-Chang Li1, Xiao-Hong Liu1, Li-Bo Liu1
1Department of Cardiology, The Second Affiliated Hospital of Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, People's Republic of China.
Insights
A new wearable device analyzing heart sounds and ECGs can identify patients with reduced left ventricular ejection fraction (LVEF). This electromechanical activation time (EMAT) index aids in diagnosing heart failure, especially when NT-proBNP levels are unclear.
Area of Science:
- Cardiology
- Biomedical Engineering
- Diagnostic Technology
Background:
- Heart failure diagnosis often relies on echocardiography.
- A novel wearable device for simultaneous heart sound and ECG recording is introduced for outpatient use.
- This technology aims to improve accessibility and efficiency in diagnosing cardiac conditions.
Purpose of the Study:
- To evaluate the utility of synchronized heart sound and ECG analysis.
- To identify patients with depressed left ventricular ejection fraction (dLVEF) <50%.
- To assess the diagnostic value of electromechanical activation time (EMAT) for dLVEF.
Main Methods:
- One hundred eighty-nine patients with dyspnea or chest discomfort were enrolled.
- Simultaneous recording of heart sound and ECG signals using a wearable device.
- Wavelet analysis was used to compute EMAT, EMAT/RR, S1-S2 time, and S1-S2/RR from the signals.
Main Results:
- Electromechanical activation time (EMAT) was significantly higher in patients with dLVEF (159.82 ± 83 ms) compared to controls (91.58 ± 28 ms).
- A strong negative correlation was found between EMAT and LVEF (r = -0.449; P <.001).
- EMAT ≥104 ms demonstrated high sensitivity (92.1%) and specificity (92%) for diagnosing EF <50%, with similar performance in patients with intermediate NT-proBNP values.
Conclusions:
- The EMAT index derived from synchronized heart sound and ECG signals is a valuable tool for diagnosing reduced ejection fraction (EF <50%).
- This method is particularly beneficial for patients with inconclusive NT-proBNP results.
- The wearable device offers a promising non-invasive approach for heart failure assessment in outpatient settings.
Background:
Heart failure is a major health concern and often requires echocardiography to confirm the diagnosis. We introduce a new method that uses a wearable heart sound and electrocardiogram (ECG) device that can be used in the outpatient setting.
Objective:
The purpose of this study was to determine the value of synchronized analysis of heart sounds and ECG in identifying patients with depressed left ventricular ejection fraction (dLVEF) <50%.
Methods:
One hundred eighty-nine patients (76 with dLVEF; 113 with normal ejection fraction) were enrolled. All were admitted to the hospital because of dyspnea or chest discomfort. N-Terminal pro-B-type natriuretic peptide (NT-proBNP) was measured in all patients. LVEF was determined by echocardiography. Heart sound and ECG signals were simultaneously recorded using the wearable synchronized phonocardiogram and ECG device. Heart sound and ECG signals were automatically analyzed using wavelet analysis and utilized to determine electromechanical activation time (EMAT), EMAT/RR, S1-S2 time, and S1-S2/RR.
Results:
EMAT in the dLVEF group was significantly higher than that in the control group (159.82 ± 83 ms vs 91.58 ± 28 ms). Pearson correlation test showed a negative correlation between EMAT and LVEF (r = -0.449; P <.001). Receiver operating characteristic curve analysis demonstrated that the sensitivity and specificity of EMAT ≥104 ms for the diagnosis of EF <50% were 92.1% and 92%, respectively. Patients with intermediate NT-proBNP values were identified as dLVEF by EMAT ≥104 ms, with sensitivity of 93.5% and specificity of 92.8%.
Conclusion:
The heart sound and ECG signal index EMAT contributes to the diagnosis of EF <50% and is especially helpful in patients with an inconclusive NT-proBNP value.
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