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Increasing Pump Speed During Exercise Improves Peak Oxygen Consumption in Heart Failure Patients Supported With Continuous-Flow Left Ventricular Assist Devices - A Double-Blind Randomized Study
Abstracts S13 1( 1) First Implantation in Human of a Wireless Miniaturized Intracardiac Pressure Sensor in a Patient with a HeartMate II™ L. Hubbert , J. Baranowski, B. Delshad, H. Ahn. The Heart Center at the University Hospital, Division of Cardiovascular Medicine, Department of Medicine and Health, Faculty of Health Sciences, Linkoping University, Linkoping, Sweden. Purpose: Patients undergoing implantation of a Heart Mate II™ (HMII) are routinely monitored by fluid- filled catheters traditionally used during thoracic surgery and on intensive care units. The left atrial pressure is of special interest when following the balance between preload to the pump and unloading of the heart. The purpose of this study was to evaluate a new device for long-term wireless monitoring of intracardiac pressure. Methods: A wireless microelectric mechanical pressure sensor (ISSYS Inc. Ypsilanti, MI, USA) was placed in the left atrium (LA) whilst implanting a HMII device. After chest closure intermittent pressure measurements were performed using a special antenna. Results: The pressure sensor delivered detailed pressure curves, seen on the monitor to be similar to the curves obtained with the fluid-filled LA-catheter. The LA-pressure was initially high due to mitral regurgitation, but during the first postoperative week the pressure decreased by 10 mmHg and V-waves became less prominent. Twelve consecutive measurements showed a good correlation between sensor and LA-catheter pressure measurements. A median difference in pressure of 2(1-4) mmHg was detected between these two methods. Conclusion: In a patient receiving a HM II device, an intracardiac wireless sensor delivered detailed pressure curves that correlated well with standard fluid-filled LA-catheter pressure measurements.
capacity is less well documented. It is uncertain whether a fixed CF-LVAD pump speed, which allows for sufficient circulatory support at rest, remains adequate during exercise. The aim of this study was to evaluate the effects of fixed versus incremental pump speed on peak oxygen consumption (peak VO2) during a maximal exercise test. Methods: In 14 CF-LVAD (HeartMate II (HM II)) outpatients exercise testning on an ergometer-bike was performed twice in one day- once with fixed pump speed (test-fix) and once with incremental pump speed (test-inc). Using ”breath-by-breath” technique peak VO2 was measured in both tests. The order of test-fix and test-inc in each patient was determined by randomization, and the patient as well as the physician directing the ergometry were blinded to the sequence. During test-inc pump speed was increased from the baseline value by 400 rpm/2 minutes. Results: Out of 14 patients (aged 23-69) 10 were bridge-to-transplantation and 4 were destination-therapy. 6 patients had ischemic cardiomyopathy and 8 non-ischemic cardiomyopathy. NYHA class varied between I and IIIa with a mean LVEF of 15 ± 9%. Mean support duration was 465 ± 483 days. Mean baseline CF-LVAD pump speed was 9,357 ± 238 rpm and speed was increased by a mean of 1,486 ± 775 rpm during test-inc. No adverse events, such as ventricular suction/arrhythmias, were recorded during the study. Mean peak VO2 was higher in test-inc compared to test-fix (15.4 ± 5.9 versus 14.1 ± 6.3 ml/min/kg; p= 0.012), corresponding to a 9.2% increase. All exercise tests (n= 28) were adequately performed with RER > 1. Mean exercise time did not differ significantly between test-inc and test-fix (474 ± 221 versus 470 ± 219 seconds; p= 0.712) and neither did work load capacity (114 ± 46 versus 111 ± 47 Watt; p= 0.435). Conclusion: Increasing pump speed during exercise augments peak VO2 in patients supported with CF-LVAD. Capability to perform activities of daily life is closely related to VO2, thus making enhancement of oxygen consumption during exercise a desirable aim. An automatic speed-change function in future generation CF-LVADs might improve functional capacity. 1( 3) Interaction of Pulse Perception, Blood Pressure Measurements (By Doppler and Standard Cuff Techniques) and Visual Assessment of Aortic Valve Opening in Continuous Flow LVAD Patients in the Outpatient Setting A. Bhimaraj , R.V. Bellera, D. Martinez, A.M. Cordero-Reyes, B. Elias, B.H. Trachtenberg, G. Ashrith, G. Torre-Amione, M. Loebe, J.D. Estep. Cardiology, Houston Methodist Hospital, Houston, TX.
1( 2) Increasing Pump Speed During Exercise Improves Peak Oxygen Consumption in Heart Failure Patients Supported With ContinuousFlow Left Ventricular Assist Devices - A Double-Blind Randomized Study M.H. Jung ,1 P.B. Hansen,1 K. Sander,1 P.S. Olsen,1 K. Rossing,1 S.D. Russell,2 S. Boesgaard,1 F. Gustafsson.1 1The Heart Center, University Hospital Rigshospitalet, Copenhagen, Denmark; 2Department of Cardiology, Johns Hopkins University Hospital, Baltimore, MD. Purpose: Continuous-flow left ventricular assist device (CF-LVAD) implantation is associated with improved quality of life, but the effect on exercise
Purpose: Accurate BP measurement in CF-LVAD patients is challenging. Opening pressure doppler technique is considered as standard but can erroneously pick up systolic instead of mean pressure in the presence of a pulse. We sought out to assess the interaction of pulse, blood pressure measurements by two techniques and AV valve opening in such patients. Methods: Aortic valve opening utilizing a portable handheld echocardiogram (Vscan) was assessed within a few minutes of the heart failure cardiologist's and LVAD coordinator's assessments of radial pulse. Pearson’s analysis was performed. Results: 73 patient encounters were included for final analysis (Figure). The patients mean age was 56 ± 14 years and 54 (89%) were male. Median days from implant to clinic visit were 455 (40- 1799), average pump speed 9086 ± 377, flow 5.1 ± 0.8, pulsatility index 5.3 ± 0.9 and power 6.2 ± 0.7.Blood pressure by standard automatic cuff was obtainable in 67% of patients with average SBP 106 ± 14 mmHg, DBP 70 ± 11 mmHg and mean BP 82 ±11 mmHg. Average Doppler pressure was 93 ± 11 mmHg. Assessment of AV opening and perception of pulse by MD and RN are shown in figure. There was a weak correlation between AV opening and pump speed (r= -0.335, p= 0.042). When a pulse was perceived, the Doppler BP had only a mild correlation with cuff SBP a(r= 0.377;p= 0.037) but a modest correlation with mean BP measured by standard cuff (r= 0.437 ; p= 0.014. Conclusion: There was concordance in the assessment of pulse between MD and RN irrespective of status of AV opening. Approximately 40% of patients with no AV opening were perceived to have a pulse while ~20% with AV opening did not have a pulse. The correlations between various measured pressures are contrary to current belief. The complex interaction between pulse, AV-opening and blood pressure measurement needs further systematic study to be able to define appropriate measurement techniques and BP goals.
capacity is less well documented. It is uncertain whether a fixed CF-LVAD pump speed, which allows for sufficient circulatory support at rest, remains adequate during exercise. The aim of this study was to evaluate the effects of fixed versus incremental pump speed on peak oxygen consumption (peak VO2) during a maximal exercise test. Methods: In 14 CF-LVAD (HeartMate II (HM II)) outpatients exercise testning on an ergometer-bike was performed twice in one day- once with fixed pump speed (test-fix) and once with incremental pump speed (test-inc). Using ”breath-by-breath” technique peak VO2 was measured in both tests. The order of test-fix and test-inc in each patient was determined by randomization, and the patient as well as the physician directing the ergometry were blinded to the sequence. During test-inc pump speed was increased from the baseline value by 400 rpm/2 minutes. Results: Out of 14 patients (aged 23-69) 10 were bridge-to-transplantation and 4 were destination-therapy. 6 patients had ischemic cardiomyopathy and 8 non-ischemic cardiomyopathy. NYHA class varied between I and IIIa with a mean LVEF of 15 ± 9%. Mean support duration was 465 ± 483 days. Mean baseline CF-LVAD pump speed was 9,357 ± 238 rpm and speed was increased by a mean of 1,486 ± 775 rpm during test-inc. No adverse events, such as ventricular suction/arrhythmias, were recorded during the study. Mean peak VO2 was higher in test-inc compared to test-fix (15.4 ± 5.9 versus 14.1 ± 6.3 ml/min/kg; p= 0.012), corresponding to a 9.2% increase. All exercise tests (n= 28) were adequately performed with RER > 1. Mean exercise time did not differ significantly between test-inc and test-fix (474 ± 221 versus 470 ± 219 seconds; p= 0.712) and neither did work load capacity (114 ± 46 versus 111 ± 47 Watt; p= 0.435). Conclusion: Increasing pump speed during exercise augments peak VO2 in patients supported with CF-LVAD. Capability to perform activities of daily life is closely related to VO2, thus making enhancement of oxygen consumption during exercise a desirable aim. An automatic speed-change function in future generation CF-LVADs might improve functional capacity. 1( 3) Interaction of Pulse Perception, Blood Pressure Measurements (By Doppler and Standard Cuff Techniques) and Visual Assessment of Aortic Valve Opening in Continuous Flow LVAD Patients in the Outpatient Setting A. Bhimaraj , R.V. Bellera, D. Martinez, A.M. Cordero-Reyes, B. Elias, B.H. Trachtenberg, G. Ashrith, G. Torre-Amione, M. Loebe, J.D. Estep. Cardiology, Houston Methodist Hospital, Houston, TX.
1( 2) Increasing Pump Speed During Exercise Improves Peak Oxygen Consumption in Heart Failure Patients Supported With ContinuousFlow Left Ventricular Assist Devices - A Double-Blind Randomized Study M.H. Jung ,1 P.B. Hansen,1 K. Sander,1 P.S. Olsen,1 K. Rossing,1 S.D. Russell,2 S. Boesgaard,1 F. Gustafsson.1 1The Heart Center, University Hospital Rigshospitalet, Copenhagen, Denmark; 2Department of Cardiology, Johns Hopkins University Hospital, Baltimore, MD. Purpose: Continuous-flow left ventricular assist device (CF-LVAD) implantation is associated with improved quality of life, but the effect on exercise
Purpose: Accurate BP measurement in CF-LVAD patients is challenging. Opening pressure doppler technique is considered as standard but can erroneously pick up systolic instead of mean pressure in the presence of a pulse. We sought out to assess the interaction of pulse, blood pressure measurements by two techniques and AV valve opening in such patients. Methods: Aortic valve opening utilizing a portable handheld echocardiogram (Vscan) was assessed within a few minutes of the heart failure cardiologist's and LVAD coordinator's assessments of radial pulse. Pearson’s analysis was performed. Results: 73 patient encounters were included for final analysis (Figure). The patients mean age was 56 ± 14 years and 54 (89%) were male. Median days from implant to clinic visit were 455 (40- 1799), average pump speed 9086 ± 377, flow 5.1 ± 0.8, pulsatility index 5.3 ± 0.9 and power 6.2 ± 0.7.Blood pressure by standard automatic cuff was obtainable in 67% of patients with average SBP 106 ± 14 mmHg, DBP 70 ± 11 mmHg and mean BP 82 ±11 mmHg. Average Doppler pressure was 93 ± 11 mmHg. Assessment of AV opening and perception of pulse by MD and RN are shown in figure. There was a weak correlation between AV opening and pump speed (r= -0.335, p= 0.042). When a pulse was perceived, the Doppler BP had only a mild correlation with cuff SBP a(r= 0.377;p= 0.037) but a modest correlation with mean BP measured by standard cuff (r= 0.437 ; p= 0.014. Conclusion: There was concordance in the assessment of pulse between MD and RN irrespective of status of AV opening. Approximately 40% of patients with no AV opening were perceived to have a pulse while ~20% with AV opening did not have a pulse. The correlations between various measured pressures are contrary to current belief. The complex interaction between pulse, AV-opening and blood pressure measurement needs further systematic study to be able to define appropriate measurement techniques and BP goals.