Premium
Effects of Body Position and Exercise on Evoked Response Signal for Automatic Threshold Activation
Author(s) -
SCHUCHERT ANDREAS,
VENTURA RODOLFO,
MEINERTZ THOMAS
Publication year - 1999
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1999.tb00351.x
Subject(s) - supine position , medicine , cycle ergometer , cardiology , body position , anesthesia , heart rate , physical medicine and rehabilitation , blood pressure
The Autocapture function controls and optimizes the output of the ventricular pulse amplitude automatically. For this reason an automatic test has to be performed during follow‐up to measure the evoked response signal and lead polarization for the calculation of the appropriate evoked response sensitivity setting. The aim of the study was to assess whether body position and exercise influence the evoked response and polarization. Both parameters were determined in the supine and upright position and subsequently during supine and upright symptom‐limited ergometry. The study included 14 patients with the VVIR pacemaker Regency SR+ who bad received the ventricular pacing leads Membrane E 1450 T (n = 8), CapSure Z 5034 (n = 4), or SX 60 (n = 2). The evoked response signal was 7.4 ± 3.3 mV during supine and increased to 9.7 ± 5.6 mV (+ 35%) during upright position (P < 0.05). The exercise tests were terminated at 105 ± 36 W (supine) and 110 ± 34 W (upright). There was a gradual insignificant decrease of the evoked response during each exercise test with a mean decrease of ‐ 1.1 ± 0.9 mV(‐ 15%; supine) and ‐ 1.6 ± 2.1 mV (‐ 16%; upright). The evoked response increased within 5 minutes during recovery to the initial values. Polarization remained unchanged during both tests. The pacemaker did not recommend activating autocapture in four patients who all had received high‐ohmic pacing leads. In conclusions, the measurement of the evoked response in supine position seems to represent the worst case. Physical activities did not effect autocapture function in patients with the recommended lead, but the pacemaker did not always recommend Autocapture activation in some patients with high‐ohmic pacing leads.