Transcript Slide 1
An Impedance Sensor (CLS) is Superior to an Accelerometer for Chronotropically Incompetent Patients with Sinus Node Dysfunction: Results of a Pilot Study with a Dual Sensor Pacemaker Behzad B. Pavri, MD, Sarah Russell, RN INTRODUCTION • Patients (pts) with chronotropic incompetence (CI) depend on pacemakers (PM) for rate response • Many sensors do not provide physiologic heart rate (HR) response • The Biotronik Protos PM has 2 independent sensors: • Impedance sensor - DDD-CLS • Accelerometer - DDDR • Closed Loop Stimulation (DDD-CLS) monitors local RV myocardial-blood pool impedance as a surrogate for contractility • CLS establishes baseline impedance curves (at rest) • CLS collects impedance curves with each heart beat, and calculates area deviation from baseline curve • Pacing rate is based on deviation from baseline curve Thomas Jefferson University Hospital, Philadelphia • Accelerometer (DDDR) provides HR increase with detection of oscillation ENDPOINTS • The Ansar System provides a “snapshot” of sympathovagal balance during standard maneuvers 0 = No improvement over baseline 1 = “Modest” improvement 2 = “Significant” improvement 3 = “Tremendous” improvement Quality of Life (QoL) scores: OBJECTIVE AND HYPOTHESIS Holter Data: mean, minimum, and maximum HR • To compare the HR response provided by an accelerometer (DDDR) to Closed Loop Stimulation (DDD-CLS) in pts with chronotropic incompetence Ansar Data: HR and autonomic data during rest isometric handgrip, deep breathing, Valsalva, and postural change (standing) • DDD-CLS provides more physiologic HR behavior compared to DDDR METHODS Inclusion Criteria: • Age > 18 years • CI defined as average HR<55 BPM on 24 hour Holter, AF< 20% Single blind, randomized cross-over trial • Randomized to DDDR or CLS for 4 wks each. Assessed at the end of each 4 wk period. Pts served as their own controls RESULTS • 18 pts enrolled over 28 months, 10 male • Mean age=74.8 (60-86) years • 4/18 rejected due to: • >50% AF in 2 • No CI in 1 (<60% atrial pacing at f/u) • Intercurrent illness and hospitalizations in 1 • 9/14 pts with analyzable data completed study • All pts had normal LV ejection fraction • 6 randomized to DDDR first, 3 to CLS first • CLS 7/9 pts “Significant” or “Tremendous” improvement • DDDR 2/9 pts “Significant” improvement • 7/9 blinded pts opted for CLS sensor QUALITY OF LIFE Score HOLTER HEART RATE (bpm) Baseline DDDCLS DDDR p value (CLS vs. DDDR) 0 1.9 0.8 0.006 Baseline DDDCLS DDDR p valve (BL vs. CLS) Holter Mean HR 56.3 71.9 64.7 0.002 0.004 0.046 Holter Minimum HR 40.3 57.2 57.3 <0.001 <0.001 0.681 Holter Maximum HR 91.6 116.3 106.7 0.002 0.058 0.092 ANSAR HEART RATE (bpm) Resting Isometric Handgrip Deep Breathing Valsalva maneuver Postural Change p value (BL vs. DDDR) p value (CLS vs. DDDR) Baseline DDDCLS DDDR T test p value (CLS vs. DDDR) Wilcoxen test p value (CLS vs. DDDR) 55.8 70.0 60.8 <0.001 0.004 59.4 71.9 62.3 <0.001 0.004 58.0 71.2 60.9 <0.001 0.004 57.1 73.1 61.6 <0.001 0.004 58.1 73.0 64.3 0.015 0.039 Sample 24 Hour HR Trends in same patient CLS DDDR • PM programming identical in both modes except for sensor type CONCLUSIONS • Statistical Methods T-test and Wilcoxen Signed-Ranks test for paired data • DDD-CLS provided superior HR response to standardized autonomic maneuvers as assessed by Ansar testing. • DDD-CLS provided better QoL and was selected as sensor of choice by the majority of blinded patients. • Although Holter-derived minimum and maximum HR were not significantly different between the two sensors, DDD-CLS provided higher mean HR.