Lipkin D P, Buller N, Frenneaux M, Ludgate L, Lowe T, Webb S C, Krikler D M
Division of Cardiovascular Diseases, Royal Postgraduate Medical School, Hammersmith Hospital, London.
Br Heart J. 1987 Dec;58(6):613-6. doi: 10.1136/hrt.58.6.613.
Atrial tracking pacemakers may improve exercise capacity and symptoms because they maintain atrioventricular synchrony and preserve the physiological response of heart rate to exercise. A rate responsive pacemaker which reacts to physical activity may be effective in patients with sinus node disease who are unsuitable for VDD pacing. At least three months after implant a double blind randomised short and long term crossover study was performed in ten patients with complete heart block: block was present at rest and during exercise on a modified Bruce protocol. Symptoms were assessed on a visual analogue scale and exercise capacity (maximal oxygen consumption and anaerobic threshold) was measured during rate responsive (peak rate 125/min) and conventional fixed rate (VVI) pacing (70/min). One month after randomisation treadmill exercise was performed. The mode was then changed to the other pacing mode and exercise was repeated three hours later. After another month the process was repeated but in the reverse order. During long term assessment there was subjective improvement in the sensation of breathlessness with rate responsive pacing. During short term assessment maximal oxygen consumption increased and the benefit was maintained during long term rate responsive compared with long term VVI pacing; oxygen consumption at the anaerobic threshold was similarly improved. Activity detecting rate responsive pacing is better than fixed rate ventricular pacing in patients with complete atrioventricular block.
心房跟踪起搏器可能会改善运动能力和症状，因为它们能维持房室同步，并保持心率对运动的生理反应。对体力活动有反应的频率应答起搏器可能对不适合VDD起搏的病态窦房结疾病患者有效。在植入起搏器至少三个月后，对10例完全性心脏传导阻滞患者进行了一项双盲随机短期和长期交叉研究：在休息时以及按照改良布鲁斯方案进行运动时均存在传导阻滞。症状通过视觉模拟量表进行评估，运动能力（最大耗氧量和无氧阈值）在频率应答起搏（峰值频率125次/分钟）和传统固定频率（VVI）起搏（70次/分钟）期间进行测量。随机分组后一个月进行跑步机运动。然后将模式改为另一种起搏模式，并在三小时后重复运动。再过一个月，以相反的顺序重复该过程。在长期评估中，频率应答起搏时呼吸急促的主观感觉有改善。在短期评估中，最大耗氧量增加，与长期VVI起搏相比，长期频率应答起搏时这种益处得以维持；无氧阈值时的耗氧量也有类似改善。在完全性房室传导阻滞患者中，活动感知型频率应答起搏优于固定频率心室起搏。
