- Email: [email protected]
Circadian Variability in Impedance: Homeostasis vs. Heart Failure
S124 Journal of Cardiac Failure Vol. 13 No. 6 Suppl. 2007 171
172
Circadian Variability in Impedance: Homeostasis vs. Heart Failure Yelena Nabutovsky, Mihir Naware, Jeff Siou, Dan Gutfinger, Dorin Panescu; 1St. Jude Medical, Sunnyvale, CA
Improved ER Signal Quality and Capture Discrimination during Early vs. Late LV Pacing Using the Reduced Coupling Capacitor Technology with Biventricular Pacing M. Biffi1, C. Butter2, S. Goetze3, M.J. Brooke4, A. Sathaye4, A. Doelger5, E. Vireca5, J. Sperzel6; 1Ospedale S. Orsola-Malpighi, Bologna, Italy; 2Herzzentrum Brandenburg, Bernau, Germany; 3Deutsches Herzzentrum Berlin, Berlin, Germany; 4 Boston Scientific CRM, St. Paul, MN; 5Boston Scientific, Guidant EMEAC, Diegem, Belgium; 6Kerckhoff-Klinik, Bad Nauheim, Germany
Introduction: Circadian variability (CV) patterns change with onset of heart failure (HF) in many physiological parameters. Device-based impedance (Z) is emerging as a new HF diagnostic. We tested extent and pattern of CV in Z from several vectors before and after HF induction. Methods: Five canines were implanted with Promote RF CRT-D and with left atrial pressure (LAP) sensor, HeartPOD (both St Jude Medical, Inc). Following lead maturation (3-5 weeks), animals were rapid-paced (RP) in RV for 2-4 weeks at increasing rates (180-250 bpm) until congestive HF confirmation. Z was measured every hour along 6 vectors: RVcoil-Case, LVring-Case, RAring-Case, RVring-Case, LVring-RAring, and RVring-LVring. Effects of time of day on Z and of HF status on Z variability were evaluated using ANOVA. Results: Rapid pacing induced HF in all canines as confirmed by increase in LAP (5.9 6 3.1 mmHg to 23.7 6 1.4 mmHg), decrease in EF (65.2 6 12.9% to 40.4 6 6.2%) and increase in LVEDP (52.4 6 9.4 ml to 102 6 23.3 ml) (p ! 0.01 for all) . In all vectors, at homeostatic baseline and HF, Z was lowest between midnight and 3 AM and highest between noon and 3 PM, with CV significantly lower during HF (Fig). Table lists drops in Z from day- to nighttime at baseline and during last 5 days of HF. Conclusion: High variability between daytime and nighttime Z was found, significantly decreasing with onset of HF. Due to animal model limitations, it was not evident whether Z decrease was linked to HF progression or to regularized RP heart rate. Our results warrant further investigation into utilizing changes in CV as an additional HF diagnostic. Circadian Variability in Impedance
Vector RVcoil-Case LVring-RAring RVring-LVring LVring-Case RAring-Case RVring-Case
DZ Baseline (U)
D%Z Baseline (%)
DZ HF (U)
D%Z HF (%)
% Change in DZ from Baseline to HF
5.38 24.3 16.0 15.7 19.8 10.1
9.13 4.02 2.95 4.14 6.15 3.79
1.42 12.8 7.19 9.13 7.79 3.96
2.63 2.40 1.52 2.83 2.60 1.71
73.60* 47.40* 55.04* 41.87* 60.72* 60.60*
Introduction: Automatic Capture Verification (ACV) technology enables advancement in automated and remote patient management. The reliability of evoked response (ER) sensing via reduced output coupling capacitor technology has been clinically proven. This technology was applied to the LV and used in this study to evaluate the effect of interventricular pacing timing or LV Offset (LVO) during biventricular (BiV) pacing for a new ACV algorithm. Methods: Sinus rhythm patients (pts) indicated for CRT-D implantation were enrolled for intraoperative evaluation. An external pacing system was used to conduct unipolar (LVTip to Can) LV step-down threshold tests during BiV pacing at various LVO. During off-line analysis, min LV ER (ERmin) and max pacing artifact (ARTmax), or polarization, amplitudes were assessed to calculate the min signal-to-artifact ratios (SARmin 5 ERmin/ ARTmax) for each threshold test in all pts; SARmin and ERmin were used to evaluate the worst-case signal discrimination. SARminO 2 with ERminO 2mV was defined as a successful signal discrimination. Negative LVO was defined as LV pace preceding the RV pace. Results: Data from 43 pts, aged 63.7 6 11.0 yrs., M/F 33/10 were analyzed. Five different transvenous LV lead types from 3 manufacturers (unipolar/bipolar 14/29) were used with left and right pacemaker pocket locations (41/2). Simultaneous BiV pacing (0ms LVO) resulted in 35/43 (81%) pts with SARminO 2 and ERminO 2mV; -80ms and -40ms LVO showed 41/43 (95%) and 42/43 (97%) pts, respectively. The number of patients with SARminO 2 and ERminO 2mV during the þ40ms LVO test was 36/43 (83%). When compared to simultaneous BiV pacing (8.5 6 6.6 mV), ERmin was statistically (p ! 0.05) larger at -80ms (10.0 6 5.8 mV) and -40ms (10.5 6 5.9 mV) LVO, while þ40ms (7.8 6 5.0 mV) LVO was statistically smaller. Conclusion: The application of the reduced output coupling capacitor technology in the LV is susceptible to changes in interventricular pacing timing during BiV pacing. Negative LVO showed a greater potential for signal discrimination based on the percent of patients with SARminO 2 and ERminO 2mV.
DZ-change in Z from daytime to nighttime in U, D%Z - percent change in Z from daytime to nighttime, *p ! 0.05.
173 Liver Dysfunction after a Left Ventricular Assist Device: A Comparison between Pulsatile and Non-Pulsatile Pumps Gian Carlo Giove1, Luis F. Alberton1, Biswajit Kar1; 1Heart Transplant, Texas Heart Institute, Houston, TX Background: The relationship between the heart and the liver is well established. Hyperbilirubinemia, a common complication associated with left ventricular assist device (LVAD) implantation, appears as a result of liver dysfunction and can turn into a life-threatening problem. Previous studies have related these events to intrahepatic cholestasis and centrilobular liver necrosis. In this study we want to observe if there is any difference between the type of pump used and the presence of liver dysfunction. Method: We retrospectively compared and analyzed 40 non-pulsatile LVAD (Jarvik 2000) and 48 pulsatile LVAD (HeartMate II). These LVADs were implanted between June 1999 and December 2006. Results: Baseline clinical characteristics were similar in the two groups. Hemodynamic parameters were similar in both groups after the implantation of the LVAD. Patients with non-pulsatile pumps had a slightly bigger number of days with the pump (171 days vs. 165 days e p O 0.05). There was an almost 10% increase in the first month mortality in the non-pulsatile LVAD patients (p ! 0.05) when compared to pulsatile pumps. There was also a higher incidence of positive blood culture in non-pulsatile pumps being Staphylococcus aureus the most prevalent pathogen. Patients with Jarvik 2000 reached in average higher values in the liver function tests with a peak value at week two after the implantation. HeartMate II patients had lower values and a peak value around week 1. 10% of the patients had a liver biopsy which showed intrahepatic cholestasis except in one patient which showed a biliary hamartoma. Conclusion: The data shows clearly that there is a relation between the type of pump used and the presence of liver dysfunction, morbidity and mortality. A higher incidence of liver dysfunction could be associated with the bigger amount of positive blood cultures and with the fact that non-pulsatile pumps give a non-physiologic waveform.
Direct Billirubin in LVAD patients
J 2000 HeatMate II p ! 0.05.
Initial
Day 2
Day 4
Week 1
Week 2
Month 1
0.86 0.79
2.55 2.27
4.1 3.9
5.8 5.4
9.29 5.2
4.9 2.44
172
Circadian Variability in Impedance: Homeostasis vs. Heart Failure Yelena Nabutovsky, Mihir Naware, Jeff Siou, Dan Gutfinger, Dorin Panescu; 1St. Jude Medical, Sunnyvale, CA
Improved ER Signal Quality and Capture Discrimination during Early vs. Late LV Pacing Using the Reduced Coupling Capacitor Technology with Biventricular Pacing M. Biffi1, C. Butter2, S. Goetze3, M.J. Brooke4, A. Sathaye4, A. Doelger5, E. Vireca5, J. Sperzel6; 1Ospedale S. Orsola-Malpighi, Bologna, Italy; 2Herzzentrum Brandenburg, Bernau, Germany; 3Deutsches Herzzentrum Berlin, Berlin, Germany; 4 Boston Scientific CRM, St. Paul, MN; 5Boston Scientific, Guidant EMEAC, Diegem, Belgium; 6Kerckhoff-Klinik, Bad Nauheim, Germany
Introduction: Circadian variability (CV) patterns change with onset of heart failure (HF) in many physiological parameters. Device-based impedance (Z) is emerging as a new HF diagnostic. We tested extent and pattern of CV in Z from several vectors before and after HF induction. Methods: Five canines were implanted with Promote RF CRT-D and with left atrial pressure (LAP) sensor, HeartPOD (both St Jude Medical, Inc). Following lead maturation (3-5 weeks), animals were rapid-paced (RP) in RV for 2-4 weeks at increasing rates (180-250 bpm) until congestive HF confirmation. Z was measured every hour along 6 vectors: RVcoil-Case, LVring-Case, RAring-Case, RVring-Case, LVring-RAring, and RVring-LVring. Effects of time of day on Z and of HF status on Z variability were evaluated using ANOVA. Results: Rapid pacing induced HF in all canines as confirmed by increase in LAP (5.9 6 3.1 mmHg to 23.7 6 1.4 mmHg), decrease in EF (65.2 6 12.9% to 40.4 6 6.2%) and increase in LVEDP (52.4 6 9.4 ml to 102 6 23.3 ml) (p ! 0.01 for all) . In all vectors, at homeostatic baseline and HF, Z was lowest between midnight and 3 AM and highest between noon and 3 PM, with CV significantly lower during HF (Fig). Table lists drops in Z from day- to nighttime at baseline and during last 5 days of HF. Conclusion: High variability between daytime and nighttime Z was found, significantly decreasing with onset of HF. Due to animal model limitations, it was not evident whether Z decrease was linked to HF progression or to regularized RP heart rate. Our results warrant further investigation into utilizing changes in CV as an additional HF diagnostic. Circadian Variability in Impedance
Vector RVcoil-Case LVring-RAring RVring-LVring LVring-Case RAring-Case RVring-Case
DZ Baseline (U)
D%Z Baseline (%)
DZ HF (U)
D%Z HF (%)
% Change in DZ from Baseline to HF
5.38 24.3 16.0 15.7 19.8 10.1
9.13 4.02 2.95 4.14 6.15 3.79
1.42 12.8 7.19 9.13 7.79 3.96
2.63 2.40 1.52 2.83 2.60 1.71
73.60* 47.40* 55.04* 41.87* 60.72* 60.60*
Introduction: Automatic Capture Verification (ACV) technology enables advancement in automated and remote patient management. The reliability of evoked response (ER) sensing via reduced output coupling capacitor technology has been clinically proven. This technology was applied to the LV and used in this study to evaluate the effect of interventricular pacing timing or LV Offset (LVO) during biventricular (BiV) pacing for a new ACV algorithm. Methods: Sinus rhythm patients (pts) indicated for CRT-D implantation were enrolled for intraoperative evaluation. An external pacing system was used to conduct unipolar (LVTip to Can) LV step-down threshold tests during BiV pacing at various LVO. During off-line analysis, min LV ER (ERmin) and max pacing artifact (ARTmax), or polarization, amplitudes were assessed to calculate the min signal-to-artifact ratios (SARmin 5 ERmin/ ARTmax) for each threshold test in all pts; SARmin and ERmin were used to evaluate the worst-case signal discrimination. SARminO 2 with ERminO 2mV was defined as a successful signal discrimination. Negative LVO was defined as LV pace preceding the RV pace. Results: Data from 43 pts, aged 63.7 6 11.0 yrs., M/F 33/10 were analyzed. Five different transvenous LV lead types from 3 manufacturers (unipolar/bipolar 14/29) were used with left and right pacemaker pocket locations (41/2). Simultaneous BiV pacing (0ms LVO) resulted in 35/43 (81%) pts with SARminO 2 and ERminO 2mV; -80ms and -40ms LVO showed 41/43 (95%) and 42/43 (97%) pts, respectively. The number of patients with SARminO 2 and ERminO 2mV during the þ40ms LVO test was 36/43 (83%). When compared to simultaneous BiV pacing (8.5 6 6.6 mV), ERmin was statistically (p ! 0.05) larger at -80ms (10.0 6 5.8 mV) and -40ms (10.5 6 5.9 mV) LVO, while þ40ms (7.8 6 5.0 mV) LVO was statistically smaller. Conclusion: The application of the reduced output coupling capacitor technology in the LV is susceptible to changes in interventricular pacing timing during BiV pacing. Negative LVO showed a greater potential for signal discrimination based on the percent of patients with SARminO 2 and ERminO 2mV.
DZ-change in Z from daytime to nighttime in U, D%Z - percent change in Z from daytime to nighttime, *p ! 0.05.
173 Liver Dysfunction after a Left Ventricular Assist Device: A Comparison between Pulsatile and Non-Pulsatile Pumps Gian Carlo Giove1, Luis F. Alberton1, Biswajit Kar1; 1Heart Transplant, Texas Heart Institute, Houston, TX Background: The relationship between the heart and the liver is well established. Hyperbilirubinemia, a common complication associated with left ventricular assist device (LVAD) implantation, appears as a result of liver dysfunction and can turn into a life-threatening problem. Previous studies have related these events to intrahepatic cholestasis and centrilobular liver necrosis. In this study we want to observe if there is any difference between the type of pump used and the presence of liver dysfunction. Method: We retrospectively compared and analyzed 40 non-pulsatile LVAD (Jarvik 2000) and 48 pulsatile LVAD (HeartMate II). These LVADs were implanted between June 1999 and December 2006. Results: Baseline clinical characteristics were similar in the two groups. Hemodynamic parameters were similar in both groups after the implantation of the LVAD. Patients with non-pulsatile pumps had a slightly bigger number of days with the pump (171 days vs. 165 days e p O 0.05). There was an almost 10% increase in the first month mortality in the non-pulsatile LVAD patients (p ! 0.05) when compared to pulsatile pumps. There was also a higher incidence of positive blood culture in non-pulsatile pumps being Staphylococcus aureus the most prevalent pathogen. Patients with Jarvik 2000 reached in average higher values in the liver function tests with a peak value at week two after the implantation. HeartMate II patients had lower values and a peak value around week 1. 10% of the patients had a liver biopsy which showed intrahepatic cholestasis except in one patient which showed a biliary hamartoma. Conclusion: The data shows clearly that there is a relation between the type of pump used and the presence of liver dysfunction, morbidity and mortality. A higher incidence of liver dysfunction could be associated with the bigger amount of positive blood cultures and with the fact that non-pulsatile pumps give a non-physiologic waveform.
Direct Billirubin in LVAD patients
J 2000 HeatMate II p ! 0.05.
Initial
Day 2
Day 4
Week 1
Week 2
Month 1
0.86 0.79
2.55 2.27
4.1 3.9
5.8 5.4
9.29 5.2
4.9 2.44