TY - JOUR
T1 - Left ventricular epicardial admittance measurement for detection of acute LV dilation
AU - Porterfield, John E.
AU - Larson, Erik R.
AU - Jenkins, James T.
AU - Escobedo, Daniel
AU - Valvano, Jonathan W.
AU - Pearce, John A.
AU - Feldman, Marc D.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - Porterfield JE, Larson ER, Jenkins JT, Escobedo D, Valvano JW, Pearce JA, Feldman MD. Left ventricular epicardial admittance measurement for detection of acute LV dilation. J Appl Physiol 110: 799-806, 2011. First published December 9, 2010; doi:10.1152/japplphysiol.01047.2010.- There are two implanted heart failure warning systems incorporated into biventricular pacemakers/automatic implantable cardiac defibrillators and tested in clinical trials: right heart pressures, and lung conductance measurements. However, both warning systems postdate measures of the earliest indicator of impending heart failure: left ventricular (LV) volume. There are currently no proposed implanted technologies that can perform LV blood volume measurements in humans. We propose to solve this problem by incorporating an admittance measurement system onto currently deployed biventricular and automatic implantable cardiac defibrillator leads. This study will demonstrate that an admittance measurement system can detect LV blood conductance from the epicardial position, despite the current generating and sensing electrodes being in constant motion with the heart, and with dynamic removal of the myocardial component of the returning voltage signal. Specifically, in 11 pigs, it will be demonstrated that 1) a physiological LV blood conductance signal can be derived; 2) LV dilation in response to dose-response intravenous neosynephrine can be detected by blood conductance in a similar fashion to the standard of endocardial crystals when admittance is used, but not when only traditional conductance is used; 3) the physiological impact of acute left anterior descending coronary artery occlusion and resultant LV dilation can be detected by blood conductance, before the anticipated secondary rise in right ventricular systolic pressure; and 4) a pleural effusion simulated by placing saline outside the pericardium does not serve as a source of artifact for blood conductance measurements.
AB - Porterfield JE, Larson ER, Jenkins JT, Escobedo D, Valvano JW, Pearce JA, Feldman MD. Left ventricular epicardial admittance measurement for detection of acute LV dilation. J Appl Physiol 110: 799-806, 2011. First published December 9, 2010; doi:10.1152/japplphysiol.01047.2010.- There are two implanted heart failure warning systems incorporated into biventricular pacemakers/automatic implantable cardiac defibrillators and tested in clinical trials: right heart pressures, and lung conductance measurements. However, both warning systems postdate measures of the earliest indicator of impending heart failure: left ventricular (LV) volume. There are currently no proposed implanted technologies that can perform LV blood volume measurements in humans. We propose to solve this problem by incorporating an admittance measurement system onto currently deployed biventricular and automatic implantable cardiac defibrillator leads. This study will demonstrate that an admittance measurement system can detect LV blood conductance from the epicardial position, despite the current generating and sensing electrodes being in constant motion with the heart, and with dynamic removal of the myocardial component of the returning voltage signal. Specifically, in 11 pigs, it will be demonstrated that 1) a physiological LV blood conductance signal can be derived; 2) LV dilation in response to dose-response intravenous neosynephrine can be detected by blood conductance in a similar fashion to the standard of endocardial crystals when admittance is used, but not when only traditional conductance is used; 3) the physiological impact of acute left anterior descending coronary artery occlusion and resultant LV dilation can be detected by blood conductance, before the anticipated secondary rise in right ventricular systolic pressure; and 4) a pleural effusion simulated by placing saline outside the pericardium does not serve as a source of artifact for blood conductance measurements.
KW - Bioimpedance
KW - Conductance
KW - Early detection of heart failure
KW - End-diastolic volume
KW - Left ventricular preload
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U2 - 10.1152/japplphysiol.01047.2010
DO - 10.1152/japplphysiol.01047.2010
M3 - Article
C2 - 21148342
AN - SCOPUS:79954622538
VL - 110
SP - 799
EP - 806
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 0161-7567
IS - 3
ER -