scholarly journals Non-Contrast Myocardial Perfusion in Rest and Exercise Stress Using Systolic Flow-Sensitive Alternating Inversion Recovery

Author(s):  
Markus Henningsson ◽  
Carl-Johan Carlhäll ◽  
Tino Ebbers ◽  
Johan Kihlberg

Abstract Objective: To evaluate systolic flow-sensitive alternating inversion recovery (FAIR) during rest and exercise stress using 2RR (two cardiac cycles) or 1RR intervals between inversion pulse and imaging. Materials and Methods: 1RR and 2RR FAIR was implemented on a 3T scanner. Ten healthy subjects were scanned during rest and stress. Stress was performed using an in-bore ergometer. Heart rate, mean myocardial blood flow (MBF) and temporal signal-to-noise ratio (TSNR) were compared using paired t-tests. Results: Mean heart rate during stress was higher than rest for 1RR FAIR (85.8±13.7bpm vs 63.3±11.1bpm; p<0.01) and 2RR FAIR (83.8±14.2bpm vs 63.1±10.6bpm; p<0.01). Mean stress MBF was higher than rest for 1RR FAIR (2.97±0.76ml/g/min vs 1.43±0.6 ml/g/min; p<0.01) and 2RR FAIR (2.8±0.96 ml/g/min vs 1.22±0.59 ml/g/min; p<0.01). Resting mean MBF was higher for 1RR FAIR than 2RR FAIR (p<0.05), but not during stress. TSNR was lower for stress compared to rest for 1RR FAIR (4.52±2.54 vs 10.12±3.69; p<0.01) and 2RR FAIR (7.36±3.78 vs 12.41±5.12; p<0.01). 2RR FAIR TSNR was higher than 1RR FAIR for rest (p<0.05) and stress (p<0.001). Discussion: We have demonstrated feasibility of systolic FAIR in rest and exercise stress. 2RR delay systolic FAIR enables non-contrast perfusion assessment during stress with relatively high TSNR.

Author(s):  
Markus Henningsson ◽  
Carl-Johan Carlhäll ◽  
Tino Ebbers ◽  
Johan Kihlberg

Abstract Objective To evaluate systolic flow-sensitive alternating inversion recovery (FAIR) during rest and exercise stress using 2RR (two cardiac cycles) or 1RR intervals between inversion pulse and imaging. Materials and methods 1RR and 2RR FAIR was implemented on a 3T scanner. Ten healthy subjects were scanned during rest and stress. Stress was performed using an in-bore ergometer. Heart rate, mean myocardial blood flow (MBF) and temporal signal-to-noise ratio (TSNR) were compared using paired t tests. Results Mean heart rate during stress was higher than rest for 1RR FAIR (85.8 ± 13.7 bpm vs 63.3 ± 11.1 bpm; p < 0.01) and 2RR FAIR (83.8 ± 14.2 bpm vs 63.1 ± 10.6 bpm; p < 0.01). Mean stress MBF was higher than rest for 1RR FAIR (2.97 ± 0.76 ml/g/min vs 1.43 ± 0.6 ml/g/min; p < 0.01) and 2RR FAIR (2.8 ± 0.96 ml/g/min vs 1.22 ± 0.59 ml/g/min; p < 0.01). Resting mean MBF was higher for 1RR FAIR than 2RR FAIR (p < 0.05), but not during stress. TSNR was lower for stress compared to rest for 1RR FAIR (4.52 ± 2.54 vs 10.12 ± 3.69; p < 0.01) and 2RR FAIR (7.36 ± 3.78 vs 12.41 ± 5.12; p < 0.01). 2RR FAIR TSNR was higher than 1RR FAIR for rest (p < 0.05) and stress (p < 0.001). Discussion We have demonstrated feasibility of systolic FAIR in rest and exercise stress. 2RR delay systolic FAIR enables non-contrast perfusion assessment during stress with relatively high TSNR.


Heart ◽  
2015 ◽  
Vol 101 (Suppl 4) ◽  
pp. A25.2-A26
Author(s):  
Alexander Sharp ◽  
Afzal Sohaib ◽  
Keith Willson ◽  
Jamil Mayet ◽  
Alun Hughes ◽  
...  

2021 ◽  
Author(s):  
Peter Kirk ◽  
Sarah Garfinkel ◽  
Oliver Joe Robinson

Heart rate and its variability have enabled insight into a myriad of psychophysiological phenomena. There is now an influx of research attempting using these metrics within both laboratory settings (typically derived through electrocardiography or pulse oximetry) and ecologically-rich contexts (via wearable photoplethysmography, i.e. smartwatches). However, these signals can be prone to artifacts and a low signal to noise ratio, which traditionally are detected and removed through visual inspection. Here, we developed an open-source Python package, RapidHRV, dedicated to the preprocessing, analysis, and visualization of time-domain heart rate and heart rate variability. Each of these modules can be executed with one line of code and includes automated cleaning. In simulated data, RapidHRV demonstrated excellent recovery of heart rate across most levels of noise (&gt;= 10dB) and moderate-to-excellent recovery of heart rate variability even at relatively low signal to noise ratios (&gt;=20dB) and sampling rates (&gt;=20Hz). Validation in real datasets shows good-to-excellent recovery of heart rate and heart rate variability in electrocardiography and pulse oximetry recordings. Validation in real photoplethysmography demonstrated RapidHRV estimations were sensitive to heart rate and its variability under low motion conditions, but estimates were less stable under higher movement settings.


2020 ◽  
Vol 12 (1) ◽  
pp. 31-35
Author(s):  
Budi Sugandi ◽  
Muhammad Haikal Satria ◽  
Hamdani Arif ◽  
Nelmiawati Nelmiawati ◽  
Indra Hardian Mulyadi

Elektrokardiograf (ECG) yang bersifat wearable dan nirkabel telah banyak digunakan untuk monitoring jangka panjang karena alasan praktis. Selain Signal to Noise Ratio (SNR) yang tinggi, salah satu manfaat ECG dalam bentuk patch adalah fleksibilitasnya bagi pengguna dalam menempatkan elektroda. Sebagian besar ECG patch nirkabel komersial yang ada di pasaran hanya dapat menampilkan Heart Rate Variability (HRV) saja, tanpa kemampuan untuk menyediakan atau merekam gelombang EKG. Beberapa produk komersial menggunakan dua elektroda saja: Right Arm (RA) dan Left Arm (LA), tanpa elektroda tambahan yang disebut Right Arm Drive (RLD). Selain itu, menyediakan lebih dari satu opsi teknologi nirkabel untuk ECG patch merupakan keuntungan tambahan. Pada penelitian ini, kami membuat ECG patch nirkabel berbiaya rendah yang memiliki kemampuan untuk menyediakan bentuk gelombang EKG (Lead I) dan menghitung HRV secara otomatis. Selain RA dan LA, alat ini menggunakan elektroda RLD untuk meningkatkan Common Mode Rejection Ratio (CMRR). Untuk pemrosesan data, kami menggunakan ESP32, mikrokontroler 32-bit berdaya rendah yang dilengkapi dengan Bluetooth Classic (BT), Bluetooth Low Energy (BLE), dan Wifi dalam modul yang ringkas. Hasil tes menunjukkan bahwa ECG patch yang dibuat menghasilkan perhitungan HRV yang lebih akurat serta waktu transisi 2,7 kali lebih cepat dibandingkan dengan produk komersial yang kami jadikan referensi.


Entropy ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 114 ◽  
Author(s):  
Martín Calderón-Juárez ◽  
Gertrudis Hortensia González-Gómez ◽  
Juan C. Echeverría ◽  
Héctor Pérez-Grovas ◽  
Claudia Lerma

Linear heart rate variability (HRV) indices are dependent on the mean heart rate, which has been demonstrated in different models (from sinoatrial cells to humans). The association between nonlinear HRV indices, including those provided by recurrence plot quantitative analysis (RQA), and the mean heart rate (or the mean cardiac period, also called meanNN) has been scarcely studied. For this purpose, we analyzed RQA indices of five minute-long HRV time series obtained in the supine position and during active standing from 30 healthy subjects and 29 end-stage renal disease (ESRD) patients (before and after hemodialysis). In the supine position, ESRD patients showed shorter meanNN (i.e., faster heart rate) and decreased variability compared to healthy subjects. The healthy subjects responded to active standing by shortening the meanNN and decreasing HRV indices to reach similar values of ESRD patients. Bivariate correlations between all RQA indices and meanNN were significant in healthy subjects and ESRD after hemodialysis and for most RQA indices in ESRD patients before hemodialysis. Multiple linear regression analyses showed that RQA indices were also dependent on the position and the ESRD condition. Then, future studies should consider the association among RQA indices, meanNN, and these other factors for a correct interpretation of HRV.


EP Europace ◽  
2016 ◽  
Vol 18 (suppl_1) ◽  
pp. i134-i134
Author(s):  
Alexander Sharp ◽  
Afzal Sohaib ◽  
Keith Willson ◽  
Jamil Mayet ◽  
Alun Hughes ◽  
...  

2021 ◽  
Author(s):  
Lin He ◽  
Kazi Shafiul Alam ◽  
Jiachen Ma ◽  
Eric Burkholder ◽  
William Cheng Chung Chu ◽  
...  

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