Plasma brain natriuretic peptide levels indicating thromboembolism in very elderly patients with non-valvular atrial fibrillation.

BACKGROUND: Assessment of left atrial (LA) function by transesophageal echocardiography is useful for detecting patients with a high risk thromboembolism secondary to atrial fibrillation (AF). A recent study showed that the atrium is the main source of brain natriuretic peptide (BNP) in AF patients without overt heart failure. The purpose of this study was to assess the possible relationship between LA function and plasma BNP levels in very elderly patients with non-valvular AF. METHODS AND RESULTS: Seventy-four consecutive patients with chronic non-valvular AF (aged, 82+/-6 years) underwent transthoracic and transesophageal echocardiography and measurement of plasma BNP. Thirteen AF patients who had a history of cerebral embolism or echocardiographic evidence of thrombus (TE+ group) were compared with 61 AF patients who had no such complications (TE- group). The TE+ group demonstrated a lower LA appendage (LAA) velocity and higher plasma BNP level than the TE- group. Assessment of variables by multiple logistic regression analysis revealed that BNP was a significant predictor of thromboembolism. There was a significant negative correlation between the plasma BNP level and the LAA peak flow velocity. CONCLUSIONS: The present findings would suggest the usefulness of measuring plasma BNP to detect very elderly non-valvular AF patients at high risk for thromboembolism.

Can personality traits predict pathological responses to audiovisual stimulation?

The "Pockemon shock" is the most famous accident in the history of the broadcasting industry in Japan. Based on the experiences of this unfortunate accident from famous animation program "Pocket Monster", this study focused on the psychology and psychosomatics of the patients. A head-mounted display was used as the three-dimensional image presentation device and "Descent", a free software shooting game, was used as the software. Ten healthy adult male volunteers were used in this experiment after obtaining their informed consent. The oxygen metabolic change in the anterior lobe of the brain was measured by near infrared spectroscopy and recorded on an electrocardiogram. The mental scaling tendency of the object was analyzed using the type A behavior pattern and the hostility scaling. The Cook and Medley hostility (HO) scale from the Minnesota multiphasic personality inventory (MMPI) was also used in this experiment. From this scaling methodology, the paranoid scale, cynicism scale, lie scale, social support quality and social support quantity were calculated. All measured time series data were kept in the normal range, and no fatal arrhythmia or epilepsy were observed during experiments. In some cases, the brain oxygen metabolism may completely differ for the objects of Type A and Type B behavior patterns. On the whole, correlation did not become significant in type A scaling and hostility scaling. In a comparison of the percent changes of the HF in HRV with lie scaling, significant negative correlation was observed. The social support quantity was calculated from Cook and Medley, and significant negative correlations were observed with percent changes of LF/HF in HRV. The lie scale and social support quantity are opposite scaling. The sympathetic nervous system and parasympathetic nervous system have an opposite function also. Therefore, our results showed an interesting phenomenon, when considering the relationship between the autonomic function and the pathophysiological reaction to the audiovisual stimulations. As for the photo sensitive epilepsy, it was reported to be only 5-10% for all patients. Therefore, 90% or more of the cause could not be determined in patients who started a morbid response. The results in this study suggest that the autonomic function was connected to the mental tendency of the objects. By examining such directivity, it is expected that subjects, which show morbid reaction to an audiovisual stimulation, can be screened beforehand.

Pupillary and cardiovascular responses to a video movie in senior human subjects.

The effects of watching video movies on autonomic functions were estimated by measuring changes in pupillary and cardiovascular parameters in 10 senior subjects. The subjects looked at a series of video images (with accompanied sounds) taken during the execution of motor vehicles. The images were rear-projected on a large screen for 15 min. Pupil diameter and parameters of the light reflex were measured by an infrared pupillometer before and after the video presentation. Their electrocardiograms (ECG) and blood pressure were measured continuously. Subjects were divided into two groups depending on their values of blood pressure and fasting plasma glucose level. Subjects in Group A had blood pressures of less than 140 mm Hg and a fasting plasma glucose level of less than 7 mmol/dl (normal group). Other subjects were included in Group B (mild hypertension or diabetes mellitus group). While changes in pupillary light reflex after video viewing were minimal in the members of Group A, amplitudes of the pupillary reflex in the members of Group B varied over a significantly wide range. By the spectral analysis of cardiovascular rhythm, %LF and %HF components of blood pressure rhythm were significantly different between the two groups before video viewing. However, the ratios of frequency components before and after video viewing were not significantly different between the two groups. Our findings suggest that pupillary light reflex was less precisely controlled in subjects with mild autonomic dysfunction after prolonged audiovisual stimulation.