Sant'Anna J R, Castro I, Lima L L, Reis A, Kalil R A, Prates P R, Lucchese F A, Halperin C, Pereira E, Rodrigues R
Instituto de Cardiologia do Rio Grande do Sul/Fundação Universitária de Cardiologia, Porto Alegre.
Arq Bras Cardiol. 1995 Jun;64(6):547-52.
To evaluate in the late post-operative period (PO) the chronotropic response to exercise of patients submitted to orthotopic cardiac transplantation (CT) and the implant of a cardiac pacemaker (PM).
A rate response ventricular PM (VVI+R) which uses minute ventilation (MV) as a sensor was implanted in five patients in the early PO of CT due to chronotropic incompetence. The patients were 31 to 64 years old and the indication to implant of PM was low ventricular escape rhythm following atrial taquicardia/bradycardia (one case) or sinus bradycardia (4 cases). The study was performed by means of paired exercise tests using Naughton protocol in order to compare the heart rate in VVI (prefixed heart rate) and VVIR+MV (rate response) mode. The duration of the exercise was compared between the two modes of stimulation.
In VVI mode the heart rate was significantly lower than in VVIR+MV mode for comparable periods of exercise (101 +/- 12 ppm vs 132 +/- 4 ppm; p < 0.05); in VVIR+MV mode the patients had a prolonged time of exercise as compared to VVI mode (15 +/- 7 min vs 12 +/- 7 min; NS).
The MV rate response PM provided patients with satisfactory heart during exercise and may be an adequate option to patients submitted to CT who present chronotropic incompetence.
评估原位心脏移植（CT）及植入心脏起搏器（PM）患者术后晚期对运动的变时性反应。
因变时性功能不全，在5例CT术后早期患者中植入了以分钟通气量（MV）作为传感器的频率应答心室起搏器（VVI+R）。患者年龄在31至64岁之间，植入PM的指征为房性心动过速/心动过缓后出现的低心室逸搏心律（1例）或窦性心动过缓（4例）。采用配对运动试验，使用诺顿方案进行研究，以比较VVI（预设心率）和VVIR+MV（频率应答）模式下的心率。比较两种刺激模式下的运动持续时间。
在可比的运动时间段内，VVI模式下的心率显著低于VVIR+MV模式（101±12次/分钟对132±4次/分钟；p<0.05）；与VVI模式相比，VVIR+MV模式下患者的运动时间延长（15±7分钟对12±7分钟；无显著性差异）。
MV频率应答式PM在运动期间为患者提供了满意的心率，对于存在变时性功能不全的CT患者可能是一个合适的选择。
