Sheps D S, Herbst M C, Hinderliter A L, Adams K F, Ekelund L G, O'Neil J J, Goldstein G M, Bromberg P A, Dalton J L, Ballenger M N
University of North Carolina, Chapel Hill.
Ann Intern Med. 1990 Sep 1;113(5):343-51. doi: 10.7326/0003-4819-113-5-343.
To assess the effects of exposure to 4% and 6% carboxyhemoglobin on ventricular arrhythmias in patients with coronary artery disease.
Randomized, double-blind, crossover design.
Exercise laboratory with an environmentally controlled exposure.
Forty-one nonsmokers with documented coronary artery disease.
On day 1, a training session with no exposure, the baseline carboxyhemoglobin level was measured, and a supine bicycle exercise test was done. On days 2 to 4, patients were exposed to room air, 100 ppm carbon monoxide (target, 4% carboxyhemoglobin) or 200 ppm carbon monoxide (target, 6% carboxyhemoglobin), and they then did supine bicycle exercise with radionuclide ventriculography. Ambulatory electrocardiogram recordings were made during the 4 consecutive days to determine the frequency of ventricular premature depolarization (VPD) at various intervals.
The frequency of single VPD/h was significantly greater on the 6% carboxyhemoglobin day than on the room air day during the exercise period (167.72 +/- 37.99 for 6% carboxyhemoglobin compared with 127.32 +/- 28.22 for room air, P = 0.03). During exercise, the frequency of multiple VPD/h was greater on the 6% carboxyhemoglobin day compared with room air (9.59 +/- 3.70 on the 6% carboxyhemoglobin compared with 3.18 +/- 1.67 on room air, P = 0.02). Patients who developed increased single VPD during exercise on the 6% carboxyhemoglobin day were significantly older than those who had no increased arrhythmia, whereas patients who developed complex arrhythmias were also older and, in addition, exercised longer and had a higher peak workload during exercise.
The number and complexity of ventricular arrhythmias increases significantly during exercise after carbon monoxide exposure producing 6% carboxyhemoglobin compared with room air but not after exposure producing 4% carboxyhemoglobin.
评估接触4%和6%碳氧血红蛋白对冠心病患者室性心律失常的影响。
随机、双盲、交叉设计。
在环境可控的运动实验室进行。
41名有冠心病记录的非吸烟者。
第1天，进行无暴露的训练课程，测量基线碳氧血红蛋白水平，并进行仰卧位自行车运动试验。在第2至4天，患者分别暴露于室内空气、100 ppm一氧化碳（目标为4%碳氧血红蛋白）或200 ppm一氧化碳（目标为6%碳氧血红蛋白）环境中，然后进行带有放射性核素心室造影的仰卧位自行车运动。在连续4天内进行动态心电图记录，以确定不同间期室性早搏（VPD）的频率。
运动期间，6%碳氧血红蛋白日的每小时单发性VPD频率显著高于室内空气日（6%碳氧血红蛋白时为167.72±37.99，室内空气时为127.32±28.22，P = 0.03）。运动时，6%碳氧血红蛋白日的每小时多发性VPD频率高于室内空气日（6%碳氧血红蛋白时为9.59±3.70，室内空气时为3.18±1.67，P = 0.02）。在6%碳氧血红蛋白日运动期间单发性VPD增加的患者比未出现心律失常增加的患者年龄显著更大，而出现复杂性心律失常的患者年龄也更大，此外，运动时间更长，运动时的峰值工作量更高。
与室内空气相比，一氧化碳暴露产生6%碳氧血红蛋白后运动期间室性心律失常的数量和复杂性显著增加，但产生4%碳氧血红蛋白暴露后未出现这种情况。
