Blood pressure and sympathetic nerve tone relation during hemodialysis may reflect cardiovascular dysfunction.

Background: The blood pressure response to the rapid removal of fluid during hemodialysis is complex and the pathophysiological mechanisms underlying intradialytic hypotension are not clear and sometimes these mechanisms render dialysis difficult to continue.

Purpose: We analyzed the changes in blood pressure and sympathetic nerve tone and attempted to clarify whether the dynamic pattern of this relationship reflects cardiovascular dysfunction.

Methods: The dynamic pattern of sympathetic nerve activity throughout dialysis was analyzed by frequency analysis of RR intervals recorded by 24 hours Holter electrocardiography in 64 patients and 3 minutes ECG every 15 minutes during dialysis in 121 stable end-stage renal failure patients who underwent maintenance hemodialysis.

Attempt of quantitative analysis of visual evaluation for (123)I-BMIPP myocardial scintigraphy images.

We developed a new technique to quantitatively analyze visual evaluation single photon emission computed tomography (SPECT). Short axis tomograms and color scales were computer scanned. The scales were divided into 25 parts; numbers of each hue pixel were scored 0-100%.

ST shape classification in ECG by constructing reference ST set.

Abnormal changes in the ST segment of an electrocardiogram (ECG) are very important diagnostic parameters for detecting myocardial ischemia. ST segment analysis requires a long-term ECG recording because of the transient change of the ST segment. Deviations of the ST segment are generally related to myocardial abnormality.

Evaluation of carotid atherosclerosis from the perspective of blood flow reflection.

Detection and prevention of atherosclerosis at an early stage is important for its prevention. The aim of this study was to propose a valid and highly reliable index for the evaluation of carotid atherosclerosis or carotid function. Images of carotid Doppler wave profiles were processed using an image processing software, and the relative fluctuation in blood flow was calculated from the luminance in one cardiac cycle.

Effects of daily physical activity level on the degree of sympathetic tone.

Background: Exercise is recommended for the treatment and prevention of cardiac disorders. Relaxation of the sympathetic nervous system has been considered to be one of the therapeutic mechanisms. However, the means by which the level of daily physical activity affects sympathetic activity remains unclear.