Cools F J C, van Twembeke R R C, Backers J, Verpooten G A
AZ KLINA, Department of Cardiology, Augustijnslei 100, 2930 Brasschaat, Belgium.
Europace. 2003 Apr;5(2):175-83. doi: 10.1053/eupc.2002.0299.
The presence of far field R wave sensing (FFRS) is usually evaluated in patients with dual chamber pacemakers in supine position. To check if this approach is valid, we tested whether FFRS is consistent both in terms of amplitude threshold and timing characteristics in different daily life conditions.
In 42 patients with a DDD pacemaker, the presence, amplitude threshold and timing parameters of FFRS were therefore determined, with patients supine, standing and at peak exercise. Measurements were made of paced and sensed R waves, in unipolar and bipolar sensing configurations (at peak exercise only paced R waves and bipolar sensing). After paced R waves (bipolar sensing) amplitude thresholds/time of FFRS after V pace were 0.32+/-0.18 mV/119-139 ms (supine), 0.32+/-0.16 mV/114-130 ms (upright) and 0.27+/-0.13 mV/121-136 ms (exercise) - with unipolar sensing, this was 0.49+/-0.27 mV/101-150 ms (supine), 0.51+/-0.29 mV/100-144 ms (upright). After sensed R waves (bipolar sensing) amplitude thresholds/time of FFRS after V sense were 0.27+/-0.18 mV/24-42 ms (supine), 0.29+/-0.16 mV/18 to 41 ms (upright) - with unipolar sensing, thresholds were 0.59+/-0.32 mV/3-50 ms (supine), 0.59+/-0.36 mV/2-58 ms (upright).
given the lower FFRS thresholds with bipolar sensing, bipolar sensing is superior in avoiding FFRS compared with unipolar sensing. No differences were found in terms of amplitude thresholds and timing characteristics with patients supine, standing and at peak exercise. Thus, measurements made in the supine position are basically sufficient to predict the presence/absence of FFRS under different conditions.
通常在双腔起搏器患者仰卧位时评估远场R波感知（FFRS）的存在情况。为检验这种方法是否有效，我们测试了在不同日常生活条件下，FFRS在幅度阈值和时间特征方面是否一致。
因此，对42例植入DDD起搏器的患者，分别在仰卧位、站立位和运动峰值时测定FFRS的存在情况、幅度阈值和时间参数。在单极和双极感知配置下（仅在运动峰值时测定起搏R波和双极感知），测量起搏和感知的R波。在双极感知时，V起搏后FFRS的幅度阈值/时间为0.32±0.18 mV/119 - 139 ms（仰卧位）、0.32±0.16 mV/114 - 130 ms（站立位）和0.27±0.13 mV/121 - 136 ms（运动时）；单极感知时，分别为0.49±0.27 mV/101 - 150 ms（仰卧位）、0.51±0.29 mV/100 - 144 ms（站立位）。在双极感知时，V感知后FFRS的幅度阈值/时间为0.27±0.18 mV/24 - 42 ms（仰卧位）、0.29±0.16 mV/18至41 ms（站立位）；单极感知时，阈值分别为0.59±0.32 mV/3 - 50 ms（仰卧位）、0.59±0.36 mV/2 - 58 ms（站立位）。
鉴于双极感知时FFRS阈值较低，与单极感知相比，双极感知在避免FFRS方面更具优势。患者在仰卧位、站立位和运动峰值时，在幅度阈值和时间特征方面未发现差异。因此，在仰卧位进行的测量基本足以预测不同条件下FFRS的存在与否。
