This study clearly demonstrates that ME is a powerful clinical predictor for cardiac death in patients with mild to moderate heart failure and with sinus rhythm. Whether these conclusions apply to patients with more severe heart failure requires further investigations.

The degree of ventriculoarterial coupling is far from optimal and the cardiovascular performance is severely depressed mechanically and energetically in patients with idiopathic dilated cardiomyopathy. Although inotropic agents improve the coupling, they have a minimal effect on mechanical efficiency.

The long-term natural course of obstructive sleep apnea syndrome (OSAS) is studied in order to determine whether severity of nocturnal oxygen desaturation associated with apnea/hypopnea, body mass index (BMI), and hypertension influence survival in young (<40 years), middle-aged (40-64 years), and aged (265 years) using a questionnaire survey. One hundred and forty-eight patients with OSAS aged 17-78 years (136 men, 12 women, mean 52.0k12.3 years), who were diagnosed by standard polysomnography (PSG) between 1983 and 1993, participated in the study. The survey revealed 15 deaths and 101 survivors; 32 subjects could not be located. The survival rate was 71.4% (95% confidence interval: 55.6-87.2%). The survival rate in patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (87.6%). In the young group, only one death (a 19-year-old woman) occurred unexpectedly during sleep. The patient showed an apnea/ hypopnea index (AHI) of 33 per h and the length of time that the nocturnal oxygen saturation (SaO') fell below 90% (time of SaO? < 90%) of 205 min. The survival rate in middle-aged patients with OSAS was significantly lower than that in the age and sex-adjusted control Japanese population (79.2 vs 91.0%), but this pattern was not seen among the aged. Time of SaO? <90% was significantly longer in the middle-aged patients than in the aged patients, but AH1 did not differ between the two groups. Moreover, it was significantly correlated with AH1 in middle-aged patients, but not in the aged patients. The survival rate was significantly lower in patients with hypertension than in the patients without such complications in the middle-aged group (57.9 us 90.4%). Cox proportional-hazard regression model including age, hypertension, BMI, AHI, lowest SaO?, and time of SaO? <90% showed that hypertension was only significantly associated with lower survival rate in total group and middle-aged patients, but not in the young or aged patients. The prognosis in patients with OSAS may differ among the generations. The prognosis in the middle-aged population may depend on the role of OSAS on the complications of hypertension or severity of oxygen desaturation, but not on AH1 only.

Exercise-induced enhancement of the relaxation-frequency relation was inhibited in all HCM patients, regardless of the degree of LV hypertrophy. The patients without exercise-induced enhancement of the force-frequency relation had more severe LV hypertrophy than the patients with the enhancement, indicating that the adrenergic control of the force-frequency relation may, at least in part, depend on the severity of LV hypertrophy or the stage of HCM.

These results indicate that beta-adrenergic stimulation and phosphodiesterase inhibitors have different effects on early diastolic filling through different mechanisms in patients with congestive heart failure.