Diagnostic Characteristics of Combining Phonocardiographic Third Heart Sound and Systolic Time Intervals for the Prediction of Left Ventricular Dysfunction

2007 ◽  
Vol 13 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Mia Shapiro ◽  
Brian Moyers ◽  
Gregory M. Marcus ◽  
Ivor L. Gerber ◽  
Barry H. McKeown ◽  
...  
Keyword(s):  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Heart Sound ◽  
Systolic Time Intervals ◽  
Left Ventricular ◽  
Time Intervals ◽  
Diagnostic Characteristics ◽  
Third Heart Sound ◽  
Systolic Time

P1460Seismocardiographic measurement of systolic time intervals in left ventricular dysfunction: validation with transthoracic echo

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Padmanabhan ◽  
M Bhushan ◽  
R Amba ◽  
P Joseph ◽  
S Sibal ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ischemic Heart Disease ◽  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Systolic Time Intervals ◽  
Left Ventricular ◽  
Wearable Device ◽  
Ischemic Heart ◽  
Time Intervals ◽  
Systolic Time

Abstract Background Systolic time intervals (STI) measured using Transthoracic Echo (TTE) have been shown to be sensitive indicators of contractile performance, but TTE is limited to a hospital setting. Recent advances in technology have enabled the simultaneous measurement of Electrocardiograms (ECG) and Seismocardiograms (SCG) using wearable devices. However, the use SCG to measure STIs has not been validated in a mobile setting, or on pathological subjects. Purpose To test the validity of an automated algorithm for measuring STIs using a wearable device recording ECG and SCG, in subjects with varying degrees of left ventricular dysfunction. Methods 179 Patients with suspected left ventricular dysfunction were assessed using TTE performed by a Cardiologist. Patients were simultaneously fitted with a novel wearable device worn on a chest strap, recording SCG and single-lead ECG data, while the cardiologist measured the pre-ejection period (PEP) and left ventricular ejection time (LVET) with the patient in a supine position. Of these subjects 29 (16.2%) were diagnosed with Dilated cardiomyopathy (DCM), and 109 (60.8%) had Ischemic Heart disease. The SCG and ECG data recorded on the wearable device was then analysed using a peak-detection algorithm, which detected the Q,R,S points on the ECG, and then determined the 4 most prominent peaks in the SCG signal corresponding to each R-peak. Heart rate, patient's age, gender and SCG time intervals were then used in a DecisionTree algorithm to determine the values of PEP and LVET, which were were then compared against those determined by the cardiologist using TTE. Results The correlation coefficient (r2) between PEP calculated using TTE, and the values obtained from the algorithm analyzing SCG data was 0.92 while the mean error was 7.47%. The r2 between the LVET calculated using the TTE and the algorithm was 0.75, while the mean error was 8.53% (p-value<0.001 for all cases). Results All Subjects With IHD Without IHD With DCM Without DCM Number of Subjects 178 109 69 29 149 PEP (r2) 0.92 0.89 0.94 0.88 0.91 PEP (% age error) 7.47 7.50 7.42 6.99 7.56 LVET (r2) 0.75 0.81 0.66 0.55 0.83 LVET (% age error) 8.53 6.69 11.4 20.42 6.16 DCM, Dilate Cardiomyopathy; IHD, Ischemic Heart Disease. ECG + SCG signals for a DCM patient Conclusion The algorithm-derived STIs measured by SCG correlate well with those measured by TTE across most patient groups, including those with Dilated Cardiomyopathy and Ischemic Heart Disease, opening prospects for continuous remote monitoring of STIs in a mobile setting. Acknowledgement/Funding Fourth Frontier Technologies

Value of Systolic Time Intervals in the Diagnosis of Large Patent Ductus Arteriosus in Fluid-Restricted and Mechanically Ventilated Preterm Infants

PEDIATRICS ◽  
1984 ◽  
Vol 74 (6) ◽  
pp. 1069-1074
Author(s):  
François Heitz ◽  
Jean-Claude Fouron ◽  
Nicolaas H. van Doesburg ◽  
Harry Bard ◽  
François Teasdale ◽  
...  
Keyword(s):  
Patent Ductus Arteriosus ◽  
Right Ventricular ◽  
Ductus Arteriosus ◽  
Systolic Time Intervals ◽  
Left Ventricular ◽  
Ejection Time ◽  
Time Intervals ◽  
Systolic Time ◽  
Ventricular Ejection Time ◽  
Patent Ductus

M-mode echocardiographic features suggesting a patent ductus arteriosus are based on two groups of indirect criteria: dilation of the left cardiac cavities and changes of systolic time intervals. The reliability of the first group of criteria has been questioned in fluidlimited, mechanically ventilated preterm infants. The sensitivity of the systolic time intervals in the same circumstances is investigated. Twenty-three patients with a large patent ductus arteriosus were selected. Review of their echocardiograms shows that the sensitivity of the various criteria (expressed as percentage of positivity) was as follows: inversion of the ratio of left ventricular preejection period to right ventricular preejection period, 91.3%; left ventricular preejection period to left ventricular ejection time over right ventricular preejection period to right ventricular ejection time &lt; 1, 83%; left atrium dilation, 74%; shortening of left ventricular preejection period, 70%; dilation of left ventricular internal dimensions in diastole, 65%; increase in left atrium/aorta, 52%; and decrease of left ventricular preejection period to left ventricular ejection time, 48%. Three criteria involving time intervals (left ventricular preejection period to right ventricular preejection period, left ventricular preejection period, and left ventricular preejection period to left ventricular ejection time) had 100% specificity. The lowest specificity was found with criteria involving the left atrium (left atrial to aortic root ratio 75% and left atrium 63%). It is concluded that study of systolic time intervals is a reliable means of detecting preterm infants with hemodynamically significant left-to-right shunt through a patent ductus arteriosus even if the infants are mechanically ventilated and fluid restricted.

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