HRV can act as an indicator of the presence of CSB in CHF patients, and could therefore be used, under outpatient conditions, to identify a CHF patients with a poor prognosis.

Sleep-disordered breathing (SDB) causes fluctuation of the RR interval. However, the details are uncertain. We studied the characteristics of sleep-related heart rate variation (HRV) in congestive heart failure (CHF) patients with SDB. Ambulatory electrocardiograms and data on respiration (oronasal flow, trachea sound, abdominal wall movement, and oxygen saturation) were simultaneously recorded by a multi-channel digital recorder for 13 CHF patients (8 men and 5 women; mean age, 68 +/- 4 years). Heart rate variation occurred as a result of cyclical apnea attacks between 0.005 and 0.03 Hz (apnea band). The proportion of the apnea band (% apnea) increased with the number of apnea episodes, and SDB was highly likely when the % apnea was > or = 80%. Low-flow oxygen administration effectively reduced apnea frequency, and the apnea-related HRV also decreased. We concluded that apnea-related HRV was useful for detecting and following SDB in CHF cases.

Application of radiofrequency current to the septal isthmus, between the tricuspid valve annulus and the eustachian ridge, can shift both the anterior and posterior propagation of flutter around the coronary sinus ostium.

Background:Transmeridian flights commonly cause the physical distress and somnolence known as jet lag. Because the influence of jet lag on autonomic nerve tone (ANTi is unclear, we studied its influence by evaluating heart rate variability before versus after a flight from Tokyo to San Francisco. Methods:We recorded the ambulatory electrocardiograms of 12 healthy young men for 11 days, i.e., 3 days in Tokyo before the flight and 8 days in San Francisco following the flight. Heart rate variability was determined by power spectrum analysis. After calculating high frequency power (0.15–0.4 Hz, HF), low frequency power (0.04–0.15 Hz, LF), and LF/HF, we evaluated autonomic nerve tone using HF and LF/HF as indices of the activity of sympathetic and parasympathetic tone, respectively. In addition, we analyzed the circadian rhythm of autonomic nerve tone by the maximum entropy method. Results:Parasympathetic nerve tone was found to increase during the flight. The time required for the ANT to return to preflight levels differed between the waking and sleeping periods, being 5 and 7 days, respectively. Conclusions: ANT varied for 1 week after an eastward transmeridian flight. A.N.E. 2000;5(1):53–59