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Diastolic time - frequency relation in the stress echo lab: filling timing and flow at different heart rates.

Bombardini T, Gemignani V, Bianchini E, Venneri L, Petersen C, Pasanisi E, Pratali L, Alonso-Rodriguez D, Pianelli M, Faita F, Giannoni M, Arpesella G, Picano E - Cardiovasc Ultrasound (2008)

Bottom Line: Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.Diastolic time decreased during stress more markedly than systolic time.Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Echocardiography, Institute of Clinical Physiology, National Council of Research, Pisa, Italy. tbombardini@yahoo.it

ABSTRACT

Unlabelled: A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration.

Aims: 1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress.

Methods: We enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients).The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal. Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.

Results: Diastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 +/- 0.12) than in patients (0.86 +/- 0.10, p < 0.05 vs. controls). Diastolic filling rate increased from 101 +/- 36 (rest) to 219 +/- 92 ml/m2* s-1 at peak stress (p < 0.5 vs. rest).

Conclusion: Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate.Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.

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Related in: MedlinePlus

Operator-independent cardiologic systole and diastole quantification. The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. A stable, reproducible, and consistent first heart sound and second heart sound signal was obtained in all patients and utilized as time markers to continuously assess cardiologic systole and diastole during exercise, dipyridamole and pacing stress echo.
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Figure 2: Operator-independent cardiologic systole and diastole quantification. The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. A stable, reproducible, and consistent first heart sound and second heart sound signal was obtained in all patients and utilized as time markers to continuously assess cardiologic systole and diastole during exercise, dipyridamole and pacing stress echo.

Mentions: The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case (Figure 2) which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress [15]. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. The accelerometer simply records naturally generated heart vibrations, which audible components in the isovolumic (preejection) contraction period give rise to the first heart sound; while in the isovolumic relaxation period give rise to the second heart sound. Non myocardial noising vibrations (skeletal muscles, body movements, breathing) were eliminated by frequency filtering. Apart the first and the second heart sound amplitude (related to the isovolumic contraction force and to the isovolumic relaxation force) this recording system can be utilized to quantify both cardiological systole and diastole duration.


Diastolic time - frequency relation in the stress echo lab: filling timing and flow at different heart rates.

Bombardini T, Gemignani V, Bianchini E, Venneri L, Petersen C, Pasanisi E, Pratali L, Alonso-Rodriguez D, Pianelli M, Faita F, Giannoni M, Arpesella G, Picano E - Cardiovasc Ultrasound (2008)

Operator-independent cardiologic systole and diastole quantification. The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. A stable, reproducible, and consistent first heart sound and second heart sound signal was obtained in all patients and utilized as time markers to continuously assess cardiologic systole and diastole during exercise, dipyridamole and pacing stress echo.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2365937&req=5

Figure 2: Operator-independent cardiologic systole and diastole quantification. The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. A stable, reproducible, and consistent first heart sound and second heart sound signal was obtained in all patients and utilized as time markers to continuously assess cardiologic systole and diastole during exercise, dipyridamole and pacing stress echo.
Mentions: The transcutaneous force sensor is based on a linear accelerometer from STMicroelectronics (LIS3). The device includes in one single package a MEMS sensor that measures a capacitance variation in response to movement or inclination and a factory trimmed interface chip that converts the capacitance variations into analog signal proportional to the motion. The device has a full scale of ± 2·g (g = 9.8 m/s2) with a resolution of 0.0005·g. We housed the device in a small case (Figure 2) which was positioned in the mid-sternal precordial region and was fastened by a solid gel ECG electrode. The acceleration signal was converted to digital and recorded by a laptop PC, together with an ECG signal. The system is also provided with a user interface that shows both the acceleration and the ECG signals while the acquisition is in progress [15]. The data were analyzed by using software developed in Matlab (The MathWorks, Inc). An analog peak-to-peak detector synchronized with the standards ECG scans the first 150 ms following the R wave to record first heart sound force vibrations and the 100 ms following the T wave to record second heart sound force vibrations. The accelerometer simply records naturally generated heart vibrations, which audible components in the isovolumic (preejection) contraction period give rise to the first heart sound; while in the isovolumic relaxation period give rise to the second heart sound. Non myocardial noising vibrations (skeletal muscles, body movements, breathing) were eliminated by frequency filtering. Apart the first and the second heart sound amplitude (related to the isovolumic contraction force and to the isovolumic relaxation force) this recording system can be utilized to quantify both cardiological systole and diastole duration.

Bottom Line: Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.Diastolic time decreased during stress more markedly than systolic time.Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Echocardiography, Institute of Clinical Physiology, National Council of Research, Pisa, Italy. tbombardini@yahoo.it

ABSTRACT

Unlabelled: A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration.

Aims: 1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress.

Methods: We enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients).The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal. Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.

Results: Diastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 +/- 0.12) than in patients (0.86 +/- 0.10, p < 0.05 vs. controls). Diastolic filling rate increased from 101 +/- 36 (rest) to 219 +/- 92 ml/m2* s-1 at peak stress (p < 0.5 vs. rest).

Conclusion: Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate.Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.

Show MeSH
Related in: MedlinePlus