Contributions of Respiration and Heartbeat to the Pulmonary Blood Flow in the Fontan Circulation.
BACKGROUND
In the Fontan circulation, driving forces with respiration, heartbeat, and lower limb muscle pump are relevant. However, the mechanics of these forces has not been proven, and their effects on the Fontan circulation remain unclear.


METHODS
We performed catheter examinations and measured pressure and flow velocity simultaneously in the bilateral pulmonary arteries of 12 Fontan patients 1 year after the operation. The pulmonary pressure and flow velocity data were decomposed into respiratory and heartbeat components by discrete Fourier analysis. We then calculated respiratory and cardiac wave intensity (WI) based on the respiratory and heartbeat components of pressure and flow velocity data.


RESULTS
Respiratory WI formed 2 negative peaks, a backward expansion wave during the inspiratory phase, and then a backward compression wave during the expiratory phase. In 2 phrenic nerve palsy cases and 1 case of a patient on a respirator, respiratory WI showed disturbed patterns and a negative pattern, respectively. Cardiac WI showed 2 or 4 negative peaks, the time phase of which matched that of the atrial contractions.


CONCLUSIONS
WI analysis elucidated that inspiration acts as a sucking driving force and increases the pulmonary blood flow in the Fontan circulation. Respiratory complications compromise efficiency in the Fontan circulation. It was also revealed that the pulmonary blood flow was mutually dammed up and sucked in by increases and decreases in atrial pressure.
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Takashi
T
Honda
Department of Cardiovascular Surgery, Cardiovascular Imaging Research Laboratory, Kyoto Prefectural University of Medicine, Kyoto, Japan. Electronic address: keiichiitatani@gmail.com.
Keiichi
K
Itatani
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Manabu
M
Takanashi
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Atsushi
A
Kitagawa
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Hisashi
H
Ando
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Sumito
S
Kimura
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Yayoi
Y
Nakahata
Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
Norihiko
N
Oka
Department of Cardiovascular Surgery, Kitasato University School of Medicine, Kanagawa, Japan.
Kagami
K
Miyaji
Department of Pediatrics, Kitasato University School of Medicine, Kanagawa, Japan.
Masahiro
M
Ishii
D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D006328:Cardiac Catheterization; D002675:Child, Preschool; D018729:Fontan Procedure / Q000009:adverse effects*; D005583:Fourier Analysis; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D009200:Myocardial Contraction / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000209:etiology / Q000503:physiopathology; D010791:Phrenic Nerve / Q000293:injuries / Q000503:physiopathology; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology; D011184:Postoperative Period; D011651:Pulmonary Artery; D011652:Pulmonary Circulation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*