Premium
Cardio‐respiratory Coupling is Negligible in a Rodent Septic‐Model
Author(s) -
Hsieh Yee Hsee,
Jacono Frank J,
Dick Thomas E
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1148.5
Subject(s) - respiratory rate , respiratory system , medicine , heart rate , heart rate variability , ventilation (architecture) , cardiorespiratory fitness , cardiology , morning , blood pressure , anesthesia , respiratory failure , mechanical engineering , engineering
Cardio‐respiratory failure is a frequent complication of sepsis and is associated with the loss of heart rate variability (HRV) but the effects on ventilatory pattern variability (VPV) and cardio‐respiratory coupling are undetermined. We hypothesize that cardio‐respiratory failure may be associated with a loss of cardio‐respiratory coupling in terms of power spectral analysis of heart rate (HR) and cardio‐ventilatory coupling (CVC). To test this hypothesis, adult male Sprague Dawley (Harlan) rats (n=4) were implanted with an indwelling blood pressure transducer (DSI). Both ventilatory pattern (plethysmography) and blood pressure were recorded for 2h in the morning and 2h in the afternoon for 4d. The septic model was induced by injecting animals with a single bolus of lipopolysaccharide (LPS) (24 mg/kg, intraperitoneal injection) every morning for 3d. After 3 injections, both respiratory and heart rate doubled while the coefficient of variation (CV) did not change. Furthermore, the high frequency component of HRV disappeared. Entropy‐based measures of CVC reveal a decrease in coupling strength after LPS treatment. We concluded that although CV, a measure of HRV, did not decrease in the septic model, cardio‐respiratory coupling was markedly diminished. The loss of coupling may result in gas‐exchange inefficiency which may contribute to cardio‐respiratory failure. Supported by T32 HL007913 and HL087377