1. Contributions of Respiration and Heartbeat to the Pulmonary Blood Flow in the Fontan Circulation 
Takashi Honda, MD, PhD, Keiichi Itatani, MD, PhD, Manabu Takanashi, MD, Atsushi Kitagawa, MD, Hisashi Ando, MD, Sumito Kimura, MD, PhD, Yayoi Nakahata, MD, PhD, Norihiko Oka, MD, PhD, Kagami Miyaji, MD, PhD, Masahiro Ishii, MD, PhD 
The Annals of Thoracic Surgery 
Volume 102, Issue 5, Pages (November 2016)
DOI: /j.athoracsur
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Fourier analysis for respiratory and heartbeat decomposition. (Upper) Simultaneous pressure and velocity data were obtained in the bilateral pulmonary arteries. (Middle) Using Fourier analysis, we obtained power spectral density of the frequency based on the pressure data. We set the cutoff value at the point that gives the local minimal spectrum value below the heart rate. We subsequently set the low- and high-pass filters at that cutoff value to determine the respiratory and heartbeat spectrums, respectively. (Lower) We performed inverse Fourier transform to obtain respiratory and heartbeat components of pressure and velocity waves. (ECG = electrocardiogram; HR = heart rate; RR = respiratory rate.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Evaluation of wave intensity (WI) analysis. Tube represents a vessel, and blood flows from the left to the right side. Pump represents the flow drive, and the measurement point is also shown. The large and small arrows indicate the directions of the driving force and the blood flow, respectively. Tube deformation represents the expansion or reduction in vessel diameter associated with wave propagation due to compression or expansion waves. A positive WI peak indicated a forward-traveling wave, which arose at a point or points proximal to the measurement point. Whereas, a negative peak indicated a backward-traveling wave, which arose at points distal to the measurement point. Positive dP/dt indicated a compression wave, whereas negative dP/dt indicated an expansion wave.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
In all 10 cases without any respiratory problems, the first backward-traveling expansion and the second backward-traveling compression waves were obtained during one respiratory cycle. Respiratory components of pressure and velocity were displayed under the respiratory wave intensity (WI) curve.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Respiratory wave intensity (WI) in Patients under mechanical ventilation. Two negative peaks were obtained, the first peak of which was a backward-traveling compression wave and the second peak was a backward-traveling expansion wave. This result indicated that pulmonary artery blood flow was pushed back by the lung during the inspiratory phase. Additionally, 2 small positive peaks were also obtained. The first forward-traveling compression wave indicated that the blood retention in the Fontan anastomosis could have worked as a small compression flow drive, whereas the second forward-traveling expansion wave indicated that decreased blood retention in the Fontan anastomosis worked as a small expansion flow drive.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Respiratory wave intensity (WI) in patients with phrenic nerve palsy. (A) Respiratory WI on the nonaffected side showed 2 negative peaks with 2 small positive peaks that might be the result of inefficient venous return. Net WI, which indicates total effect, showed 2 apparently negative peaks. (B) Respiratory WI on the diseased side showed 2 negative peaks whose magnitudes were relatively lower than those on the nonaffected side. Small positive peaks and negative peaks followed. Consequently, net WI showed a disturbed pattern.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

7. Fig 6
Wave intensity (WI) in patients with aortopulmonary shunts. (A) Respiratory WI showed 2 positive peaks in the inspiratory phase. The first peak was a forward-traveling expansion wave, which indicated the possibility that the aortopulmonary shunts were collapsed by the volume increases of the lungs and intrathoracic pressure increase. (B) Cardiac WI showed 2 positive peaks in the systolic phase. The first peak was a forward-traveling compression wave, which indicated that the functional ventricle in front of aortopulmonary shunts worked as a flow drive to compensate the insufficient pulmonary blood flow.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

8. Fig 7
(A) Five patients showed 2 negative peaks in cardiac wave intensity (WI) during the late systolic to early diastolic phase. The first peak was a backward-traveling compression wave; whereas the second peak was a backward-traveling expansion wave. In these 5 patients, pulmonary arterial wedge pressure (PAWP) showed an apparent v-wave, but an a-wave or a c-wave was not detected clearly. (B) In the other 5 cases without aortopulmonary shunts, 4 negative peaks were detected. Two peaks were detected in the late systolic to early diastolic phase, whereas the other 2 peaks were in the systolic phase. The first 2 peaks were backward-traveling compression, and the second 2 peaks were backward-traveling expansion waves. In these 5 patients, PAWP showed significant v and c waves. (ECG = electrocardiogram.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

9. Supplementary Fig 1
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions