Persistent atrial standstill is a very rare pathophysiologic condition whose diagnosis is established when both electrical and mechanical silence of the atria are confirmed. To test the hypothesis that secretion of atrial natriuretic peptide is disturbed in patients with persistent atrial standstill, the response of atrial natriuretic peptide secretion and other neurohormonal factors during exercise was investigated in three patients with a rate-responsive ventricular demand (VVI) pacemaker implanted for confirmed persistent atrial standstill. The results were compared with those observed in eight normal subjects and patients with a rate-responsive VVI (Group A) or atrial demand (AAI) (Group B) pacemaker implanted for confirmed sick sinus syndrome. Patients in Group A displayed significant elevation of alpha-human atrial natriuretic peptide secretion both before and during exercise (122.5 +/- 14.8 and 207.5 +/- 8.3 pg/ml, respectively) compared with those in Group B (55 +/- 14.1 and 116.4 +/- 51.5 pg/ml, respectively) and the normal subjects (18.9 +/- 9.8 and 30.8 +/- 19.2 pg/ml, respectively). This indicated development of a nonphysiologic increase in atrial volume or pressure overload, or both, in rate-responsive VVI pacing because of lack of atrioventricular synchrony. However, patients with persistent atrial standstill had undetectable (less than 10 pg/ml) or almost undetectable secretion of atrial natriuretic peptide as well as lower levels of cyclic guanosine monophosphate in the circulation both before and during exercise. Changes in plasma catecholamines during exercise were similar in patients with persistent atrial standstill compared with the other groups. This study indicates that "endocrinologic silence" accompanies electrical and mechanical silence of the atria, which may constitute a third diagnostic clue to persistent atrial standstill.

This study was conducted to determine whether bathing in tepid water is effective in facilitating recovery from fatigue after submaximal exercise. Subjects were six young healthy male university students. Following cycle exercise at 80% aerobic power (VO2 max) for 10 min, recovery was observed during and after 10-min bathing. Three conditions were set; (1) water temperature of 38 degrees C, (2) water temperature of 30 degrees C, and (3) no water in the bath tub (control). Measurements were heart rate, blood pressure, skin temperature, rectal temperature, blood lactase and subjective feelings. There were no significant differences in heart rate and blood pressure between the three conditions at any time. Mean skin temperature and rectal temperature decreased more rapidly after the 30 degrees C bathing than the other two conditions (p < 0.05). Lactate removal was largest for the 30 degrees C bathing, with significant difference between the 30 degrees C bathing condition and the no bathing condition (p < 0.05). Recovery from fatigue was best for the 30 degrees C bathing and worst for the control in terms of subjective feeling. In summary, it was shown that immersion in 30 degrees C water after submaximal exercise resulted in a larger removal of lactate than recovery in air.

No abstract

No abstract

In order to clarify the relationship between thyroid function and left ventricular function in acute myocardial infarction (AMI), 52 patients (63.3 +/- 11.0 years old) admitted to the coronary care unit within 24 hours after the onset were studied. Both FT3 and FT4 levels measured at 48-72 h after the onset (1.66 +/- 0.59 pg/ml, 1.02 +/- 0.37 ng/dl) were significantly lower than those on admission (2.99 +/- 0.76 pg/ml; p < 0.01, 1.14 +/- 0.25 ng/dl; p < 0.05) and controls (3.27 +/- 0.66 pg/ml; p < 0.01, 1.22 +/- 0.23 ng/dl; p < 0.05). The decline of these thyroid hormone levels correlated well with the severity of AMI (Killip's classification), hemodynamic deterioration and liver function (low levels of albumin and cholinesterase). Low thyroid hormone levels were also associated with the elevation of catecholamine and alpha-hANP levels on admission. Low cortisol and impaired renal function were recognized as factors which might prolong the condition of low thyroid hormones. Non-survivors showed significantly lower levels of FT3 and FT4 48 hours after onset, and a lower level of FT4 in aged patients was consistent with a poor prognosis. In conclusion, the measurement of thyroid hormones in AMI is important in evaluating the severity of the condition and waking a prognosis.