The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Paul Erne - One of the best experts on this subject based on the ideXlab platform.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in atrial fibrillation
Cardiology Research and Practice, 2011Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt <1600 mmHg/s. Acoustic Cardiographic parameters included electromechanical activation time (EMAT) and the systolic dysfunction index (SDI). Results. Acoustic Cardiography detected systolic dysfunction with high specificity and moderate sensitivity with similar performance to EF (sensitivity/specificity without afib: EMAT 30/96, SDI 40/90, EF at 35% 30/96; sensitivity/specificity with afib: EMAT 64/82, SDI 59/100, EF at 35% 45/82). Conclusions. Acoustic Cardiography can be used for diagnosis of LV systolic dysfunction in atrial fibrillation.
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Noninvasive Detection of Left-Ventricular Systolic Dysfunction by Acoustic Cardiography in Atrial Fibrillation
Cardiology Research and Practice, 2010Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt
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a comparison of acoustic Cardiography and echoCardiography for optimizing pacemaker settings in cardiac resynchronization therapy
Pacing and Clinical Electrophysiology, 2008Co-Authors: Michel Zuber, Stefan Toggweiler, Lori Quinntate, Lei Brown, Ali Amkieh, Paul ErneAbstract:BACKGROUND: Cardiac resynchronization therapy (CRT) is useful in managing patients with refractory heart failure. To increase efficacy, pacemaker settings are optimized, with Doppler echoCardiography being the preferred method. Recently, acoustic Cardiography, an automated method that records, analyzes, and displays simultaneous ECG and heart sound data, has been developed. In this study, the suitability of acoustic Cardiography as an alternative to Doppler echoCardiography in CRT optimization is evaluated. METHODS: We studied 43 CRT patients undergoing optimization. Using Doppler echoCardiography, we determined the optimal atrioventricular (AV) delay with a transmitral flow assessment. For optimization of the interventricular (VV) delay, we used the left ventricular outflow tract velocity time integral (VTI). For acoustic Cardiography, we used the electromechanical activation time (EMAT, the interval from QRS onset to the S1). Reproducibility of echoCardiography and acoustic Cardiography was determined by programming 10 different delay settings twice in random order. RESULTS: All 43 subjects underwent AV optimization, and 14 had CRT devices allowing VV optimization. While the intraobserver variability of EMAT and Doppler echoCardiography parameter was similar (9.9% vs 8.5%), the reproducibility of EMAT was the highest (r = 0.91) and VTI was the lowest (r = 0.35). The correlation between the optimal AV delays determined by EMAT versus transmitral flow assessment was 0.86 (P > 0.001). The correlation between the optimal VV delays determined by EMAT versus VTI was 0.58 (P > 0.05), perhaps due to the poor reproducibility of the VTI. CONCLUSION: For CRT optimization, acoustic Cardiography provides results similar to echoCardiography but with improved reproducibility and ease of use.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in cardiac failure patients
Journal of Cardiac Failure, 2008Co-Authors: Markus Roos, Michel Zuber, Richard Kobza, Stefan Toggweiler, Rolf Meier, Peiman Jamshidi, Paul ErneAbstract:Abstract Background Despite its shortcomings, ejection fraction (EF) is widely used to detect left ventricular systolic dysfunction (LVSD) as has prolonged QRS duration as indirect evidence of LVSD. However, acoustic Cardiography provides other parameters for detecting LVSD without these limitations. One parameter, the electromechanical activation time (EMAT), is prolonged in LVSD. We compared the abilities of acoustic Cardiography, EF, and QRS duration to detect LVSD. Methods and Results We studied a sample of 108 patients who underwent elective diagnostic cardiac catheterization. The diagnostic findings included left ventricular filling pressures, angiographic EF, and maximum left ventricular dP/dt. We defined LVSD as a maximum left ventricular dP/dt of Conclusions Acoustic Cardiography is a convenient, automated diagnostic method whose performance for detecting LVSD exceeds both angiographic EF and QRS duration alone.
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improved response to cardiac resynchronization therapy through optimization of atrioventricular and interventricular delays using acoustic Cardiography a pilot study
Journal of Cardiac Failure, 2007Co-Authors: Stefan Toggweiler, Michel Zuber, Richard Kobza, Markus Roos, Rolf Meier, Peiman Jamshidi, Paul ErneAbstract:Abstract Background The purpose of this pilot study was to determine the utility of acoustic Cardiography for the optimization of atrioventricular (AV) and interventricular (VV) delays in cardiac resynchronization therapy (CRT). Methods and Results We evaluated 14 patients (86% male, mean age 64 ± 9 years, mean time since implant 15 ± 18 months). Subjects were enrolled >10 weeks after CRT implant. Spiroergometry and 2-dimensional/3-dimensional echoCardiography were used to assess cardiac performance for “out-of-the-box” settings (baseline settings: AV 120 ms, VV 0 ms) versus optimal settings (determined by acoustic Cardiography). Cardiac performance measurements were performed 6 weeks after settings were modified. Optimal AV/VV settings were determined based on the lowest electromechanical activation time (EMAT, the time from the onset of QRS to the mitral valve component of the first heart sound). Statistical analysis was performed using a paired 2-tailed Student's t -test. In comparison to “out-of-the-box” settings, AV/VV delay optimization with acoustic Cardiography improved cardiac performance as indicated by significant changes in work capacity, maximum oxygen uptake, oxygen pulse, ejection fraction, end-systolic volume, and velocity-time integral in left ventricular outflow tract. Conclusions AV and VV optimization by acoustic Cardiography produces significant improvements in objective clinical and hemodynamic parameters in comparison to typical “out-of-the-box” settings.
Richard Kobza - One of the best experts on this subject based on the ideXlab platform.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in atrial fibrillation
Cardiology Research and Practice, 2011Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt <1600 mmHg/s. Acoustic Cardiographic parameters included electromechanical activation time (EMAT) and the systolic dysfunction index (SDI). Results. Acoustic Cardiography detected systolic dysfunction with high specificity and moderate sensitivity with similar performance to EF (sensitivity/specificity without afib: EMAT 30/96, SDI 40/90, EF at 35% 30/96; sensitivity/specificity with afib: EMAT 64/82, SDI 59/100, EF at 35% 45/82). Conclusions. Acoustic Cardiography can be used for diagnosis of LV systolic dysfunction in atrial fibrillation.
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Noninvasive Detection of Left-Ventricular Systolic Dysfunction by Acoustic Cardiography in Atrial Fibrillation
Cardiology Research and Practice, 2010Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in cardiac failure patients
Journal of Cardiac Failure, 2008Co-Authors: Markus Roos, Michel Zuber, Richard Kobza, Stefan Toggweiler, Rolf Meier, Peiman Jamshidi, Paul ErneAbstract:Abstract Background Despite its shortcomings, ejection fraction (EF) is widely used to detect left ventricular systolic dysfunction (LVSD) as has prolonged QRS duration as indirect evidence of LVSD. However, acoustic Cardiography provides other parameters for detecting LVSD without these limitations. One parameter, the electromechanical activation time (EMAT), is prolonged in LVSD. We compared the abilities of acoustic Cardiography, EF, and QRS duration to detect LVSD. Methods and Results We studied a sample of 108 patients who underwent elective diagnostic cardiac catheterization. The diagnostic findings included left ventricular filling pressures, angiographic EF, and maximum left ventricular dP/dt. We defined LVSD as a maximum left ventricular dP/dt of Conclusions Acoustic Cardiography is a convenient, automated diagnostic method whose performance for detecting LVSD exceeds both angiographic EF and QRS duration alone.
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improved response to cardiac resynchronization therapy through optimization of atrioventricular and interventricular delays using acoustic Cardiography a pilot study
Journal of Cardiac Failure, 2007Co-Authors: Stefan Toggweiler, Michel Zuber, Richard Kobza, Markus Roos, Rolf Meier, Peiman Jamshidi, Paul ErneAbstract:Abstract Background The purpose of this pilot study was to determine the utility of acoustic Cardiography for the optimization of atrioventricular (AV) and interventricular (VV) delays in cardiac resynchronization therapy (CRT). Methods and Results We evaluated 14 patients (86% male, mean age 64 ± 9 years, mean time since implant 15 ± 18 months). Subjects were enrolled >10 weeks after CRT implant. Spiroergometry and 2-dimensional/3-dimensional echoCardiography were used to assess cardiac performance for “out-of-the-box” settings (baseline settings: AV 120 ms, VV 0 ms) versus optimal settings (determined by acoustic Cardiography). Cardiac performance measurements were performed 6 weeks after settings were modified. Optimal AV/VV settings were determined based on the lowest electromechanical activation time (EMAT, the time from the onset of QRS to the mitral valve component of the first heart sound). Statistical analysis was performed using a paired 2-tailed Student's t -test. In comparison to “out-of-the-box” settings, AV/VV delay optimization with acoustic Cardiography improved cardiac performance as indicated by significant changes in work capacity, maximum oxygen uptake, oxygen pulse, ejection fraction, end-systolic volume, and velocity-time integral in left ventricular outflow tract. Conclusions AV and VV optimization by acoustic Cardiography produces significant improvements in objective clinical and hemodynamic parameters in comparison to typical “out-of-the-box” settings.
Michel Zuber - One of the best experts on this subject based on the ideXlab platform.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in atrial fibrillation
Cardiology Research and Practice, 2011Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt <1600 mmHg/s. Acoustic Cardiographic parameters included electromechanical activation time (EMAT) and the systolic dysfunction index (SDI). Results. Acoustic Cardiography detected systolic dysfunction with high specificity and moderate sensitivity with similar performance to EF (sensitivity/specificity without afib: EMAT 30/96, SDI 40/90, EF at 35% 30/96; sensitivity/specificity with afib: EMAT 64/82, SDI 59/100, EF at 35% 45/82). Conclusions. Acoustic Cardiography can be used for diagnosis of LV systolic dysfunction in atrial fibrillation.
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Noninvasive Detection of Left-Ventricular Systolic Dysfunction by Acoustic Cardiography in Atrial Fibrillation
Cardiology Research and Practice, 2010Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt
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Diagnosis and characterization of left ventricular hypertrophy by computerized acoustic Cardiography, brain natriuretic peptide, and electroCardiography
Journal of Electrocardiology, 2008Co-Authors: R. Kevin Rogers, Michel Zuber, Patti Arand, Michael C. Kontos, Sean P. Collins, Andrew D MichaelsAbstract:BACKGROUND: Using echoCardiography as the gold standard to diagnose and classify subtypes of left ventricular hypertrophy (LVH), we compared the diagnostic accuracy of computerized acoustic Cardiography, brain natriuretic peptide (BNP), and the Cornell voltage criteria. METHODS: Three hundred fifty-two patients with suspected heart failure had contemporaneous BNP sampling, 12-lead electroCardiography, computerized acoustic Cardiography, and echoCardiography. Left ventricular hypertrophy was classified as eccentric vs concentric based on echoCardiographic relative wall thickness. Computerized acoustic Cardiography was used to measure acoustic and automated electrical parameters. RESULTS: Of all models, BNP combined with either computerized acoustic Cardiography (c-statistic, 0.78; 95% confidence interval [CI], 0.74-0.78) or Cornell voltage (c-statistic, 0.76; 95% CI, 0.71-0.81) had the best diagnostic performance for LVH detection. For LVH characterization, the computerized acoustic Cardiography model outperformed other models (c-statistic, 0.73; 95% CI, 0.66-0.80). CONCLUSIONS: Brain natriuretic peptide combined with either computerized acoustic Cardiography or Cornell voltage had the highest diagnostic accuracy for the detection of LVH, compared to Cornell voltage, BNP, or computerized acoustic Cardiography alone. Computerized acoustic Cardiography outperformed other models for the characterization of LVH subtypes.
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a comparison of acoustic Cardiography and echoCardiography for optimizing pacemaker settings in cardiac resynchronization therapy
Pacing and Clinical Electrophysiology, 2008Co-Authors: Michel Zuber, Stefan Toggweiler, Lori Quinntate, Lei Brown, Ali Amkieh, Paul ErneAbstract:BACKGROUND: Cardiac resynchronization therapy (CRT) is useful in managing patients with refractory heart failure. To increase efficacy, pacemaker settings are optimized, with Doppler echoCardiography being the preferred method. Recently, acoustic Cardiography, an automated method that records, analyzes, and displays simultaneous ECG and heart sound data, has been developed. In this study, the suitability of acoustic Cardiography as an alternative to Doppler echoCardiography in CRT optimization is evaluated. METHODS: We studied 43 CRT patients undergoing optimization. Using Doppler echoCardiography, we determined the optimal atrioventricular (AV) delay with a transmitral flow assessment. For optimization of the interventricular (VV) delay, we used the left ventricular outflow tract velocity time integral (VTI). For acoustic Cardiography, we used the electromechanical activation time (EMAT, the interval from QRS onset to the S1). Reproducibility of echoCardiography and acoustic Cardiography was determined by programming 10 different delay settings twice in random order. RESULTS: All 43 subjects underwent AV optimization, and 14 had CRT devices allowing VV optimization. While the intraobserver variability of EMAT and Doppler echoCardiography parameter was similar (9.9% vs 8.5%), the reproducibility of EMAT was the highest (r = 0.91) and VTI was the lowest (r = 0.35). The correlation between the optimal AV delays determined by EMAT versus transmitral flow assessment was 0.86 (P > 0.001). The correlation between the optimal VV delays determined by EMAT versus VTI was 0.58 (P > 0.05), perhaps due to the poor reproducibility of the VTI. CONCLUSION: For CRT optimization, acoustic Cardiography provides results similar to echoCardiography but with improved reproducibility and ease of use.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in cardiac failure patients
Journal of Cardiac Failure, 2008Co-Authors: Markus Roos, Michel Zuber, Richard Kobza, Stefan Toggweiler, Rolf Meier, Peiman Jamshidi, Paul ErneAbstract:Abstract Background Despite its shortcomings, ejection fraction (EF) is widely used to detect left ventricular systolic dysfunction (LVSD) as has prolonged QRS duration as indirect evidence of LVSD. However, acoustic Cardiography provides other parameters for detecting LVSD without these limitations. One parameter, the electromechanical activation time (EMAT), is prolonged in LVSD. We compared the abilities of acoustic Cardiography, EF, and QRS duration to detect LVSD. Methods and Results We studied a sample of 108 patients who underwent elective diagnostic cardiac catheterization. The diagnostic findings included left ventricular filling pressures, angiographic EF, and maximum left ventricular dP/dt. We defined LVSD as a maximum left ventricular dP/dt of Conclusions Acoustic Cardiography is a convenient, automated diagnostic method whose performance for detecting LVSD exceeds both angiographic EF and QRS duration alone.
Roger Dillier - One of the best experts on this subject based on the ideXlab platform.
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noninvasive detection of left ventricular systolic dysfunction by acoustic Cardiography in atrial fibrillation
Cardiology Research and Practice, 2011Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt <1600 mmHg/s. Acoustic Cardiographic parameters included electromechanical activation time (EMAT) and the systolic dysfunction index (SDI). Results. Acoustic Cardiography detected systolic dysfunction with high specificity and moderate sensitivity with similar performance to EF (sensitivity/specificity without afib: EMAT 30/96, SDI 40/90, EF at 35% 30/96; sensitivity/specificity with afib: EMAT 64/82, SDI 59/100, EF at 35% 45/82). Conclusions. Acoustic Cardiography can be used for diagnosis of LV systolic dysfunction in atrial fibrillation.
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Noninvasive Detection of Left-Ventricular Systolic Dysfunction by Acoustic Cardiography in Atrial Fibrillation
Cardiology Research and Practice, 2010Co-Authors: Roger Dillier, Michel Zuber, Richard Kobza, Susanne Erne, Patricia Arand, Paul ErneAbstract:Objectives. Assessment of left ventricular (LV) systolic function in patients with atrial fibrillation can be difficult. Acoustic Cardiography provides several parameters for quantifying LV systolic function. We evaluated the ability of acoustic Cardiography to detect LV systolic dysfunction in patients with and without atrial fibrillation. Design. We studied 194 patients who underwent acoustic Cardiography and cardiac catheterization including measurement of angiographic ejection fraction (EF) and maximum LV dP/dt. LV systolic dysfunction was defined as LV maximum dP/dt
Gary G. Berntson - One of the best experts on this subject based on the ideXlab platform.
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New ambulatory impedance Cardiograph validated against the Minnesota Impedance Cardiograph
Psychophysiology, 2001Co-Authors: Paul A. Nakonezny, John M Ernst, Daniel A Litvack, David L Lozano, Gary G. Berntson, Ray B. Kowalewski, Louise C. Hawkley, John J. Sollers, Paul N. Kizakevich, John T CacioppoAbstract:The validity and reliability of a new ambulatory impedance Cardiograph (AZCG) was tested against the Minnesota Impedance Cardiograph (ZCG) during rest, orthostasis, and mental stress. Impedance Cardiography allows noninvasive assessment of stroke volume, cardiac output, and systolic time intervals. A reliable ambulatory device would allow studies outside the lab. The devices were compared at two sites in healthy subjects. In both studies, the AZCG tracked changes across conditions closely with the ZCG (all Period x Device interactions were nonsignificant). Pearson rs, were .65 to .93, random intraclass correlation coefficients ranged from .80 to .98, indicating high degrees of shared measurement variance, and Cronbach's alpha indicated very good internal reliabilities (.91 to .99). Relative to the ZCG, the new AZCG appears to provide valid and reliable estimates of cardiac function at rest and during behavioral challenges in the lab.
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impedance pneumography noise as signal in impedance Cardiography
Psychophysiology, 1999Co-Authors: John M Ernst, Daniel A Litvack, David L Lozano, John T Cacioppo, Gary G. BerntsonAbstract:Thoracic impedance is modulated by events within the respiratory cycle, which represents a source of “noise” in impedance Cardiography. Respiration itself, however, is a physiological rhythm of interest to psychophysiologists. We report here methods and validation for deriving impedance pneumographic measures of respiration from impedance Cardiography signals, based on standard tetrapolar band electrodes. We recorded the change in impedance ~DZ!, the first derivative of the change in impedance ~dZ0dt!, output from a strain-gauge respirometer, and criterion spirometry from eight healthy adults during rest, paced breathing, abdominal breathing, thoracic breathing, and a mental arithmetic task. Transfer function analyses revealed that a DZd signal ~derived by integration of the dZ0dt signal! provided the best estimate of the criterion spirometric measure for all parameters ~coherence, phase, and gain!, accounting for almost 90% of the variance in respiratory waveform morphology. The results document the potential utility of impedance pneumography, as derived from standard impedance Cardiography signals. Descriptors: Impedance pneumography, Respiration, Respirometry, Tetrapolar electrodes