Our objective was to determine the adequate pacing rate during exercise in ventricular pacing by measuring exercise capacity, cardiac output, and sinus node activity. Eighteen patients with complete AV block and an implanted pacemaker underwent cardiopulmonary exercise tests under three randomized pacing rates: fixed rate pacing (VVI) at 60 beats/min and ventricular rate-responsive pacing (VVIR) programmed to attain a heart rate of about 110 beats/min or 130 beats/min (VVIR 110 and VVIR 130, respectively) at the end of exercise. Compared with VVI and VVIR 130, VVIR 110 was associated with an increased peak oxygen uptake (VVIR 110: 20.3 +/- 4.5 VVI: 16.9 +/- 3.1; P < 0.01; and VVIR 130: 19.0 +/- 4.1 mL/min per kg, respectively; P < 0.05 and a higher oxygen uptake at anaerobic threshold (15.3 +/- 2.7, 12.7 +/- 1.9; P < 0.01, and 14.6 +/- 2.6 mL/min per kg; P < 0.05). The atrial rate during exercise expressed as a percentage of the expected maximal heart rate was lower in VVIR 110 than in VVI or VVIR 130 (VVIR 110: 75.9% +/- 14.6% vs VVI: 90.6% +/- 12.8%; P < 0.01; VVIR 110 vs 130: 89.1% +/- 23.1% P < 0.05). There was no significant in cardiac output at peak exercise between VVIR 110 and VVIR 130. We conclude that a pacing rate for submaximal exercise of 110 beats/min may be preferable to that of 130 beats/min in respect to exercise capacity and sympathetic nerve activity.

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A 29-year-old man with von Recklinghausen's disease suddenly developed severe epigastric pain and was admitted to hospital. Physical examination revealed elevated blood pressure (200/130 mmHg) and tachycardia (162 bpm). Initially, he was suspected to have appendicitis, and appendectomy was performed immediately; however, appendicitis was not demonstrable pathologically. Retroperitoneal hematoma was found incidentally during the operation. Further clinical and laboratory examination demonstrated a markedincrease in the urinary excretion ofcatecholamines. Therewasno evidence of pheochromocytoma on computedtomographyor magneticresonance imaging; however, these imaging studies simply showed a hematoma at the right adrenal gland. Transient hypertension and tachycardia, resembling pheochromocytoma,was caused by adrenal hemorrhage. (Internal Medicine 36: 289-292, 1997)

Objectives:In order to examine the first night effect in suspected Obstructive Sleep Apnea Syndrome (OSAS) patients, we performed night Polysomnography (PSG), the long-term actigraphic recording and the self-reported sleep questionnaire. Methods: Nine patients with mild OSAS and four patients with severe OSAS participated in the study. Sleep evaluation was assessed by PSG, 5 days actigraphic recording including PSG night, and the St Mary' s Hospital Sleep Questionnaire. Objective and subjective sleep quality was compared between two groups. Results: There were no significant difference between groups in PSG, actigraphic recording of PSG night, and the perceived quality of sleep. However, the patients with severe OSAS showed poor sleep quality in the long-term actigraphic recording. Conclusions: Our results suggested that long-term recording using actigraphy is useful for sleep evaluation of OSAS patients, and that subjective sleep evaluation may be difficult to adequately assess sleep quality in patients with severe OSAS.

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