Sleep apnea and ventricular arrhythmias: Clinical outcome, electrophysiologic characteristics, and follow-up after catheter ablation.

BACKGROUND AND OBJECTIVES: Sleep apnea is highly prevalent in patients with heart disease. However, the association between sleep apnea and ventricular arrhythmias is unclear. The aim of this study was to examine the relationship between sleep apnea and electrophysiologic characteristics and clinical outcome after catheter ablation in patients having ventricular arrhythmias. METHODS AND RESULTS: Forty-four patients with ventricular tachycardia (VT) or premature ventricular complexes (PVCs) without structural heart diseases (57% men; mean age: 55 + or - 15 years) underwent a sleep study. Subjects with an apnea-hypopnea index (AHI) > or = 10/h were considered to have sleep apnea. Electrophysiologic studies were performed on all patients, and 35 patients underwent catheter ablation therapy. Seventeen patients (39%) had sleep apnea with an average AHI of 27 + or - 17/h. Electrophysiologic characteristics of ventricular arrhythmias showed that sites of VT/PVCs origin in the pulmonary artery and the aortic sinus of Valsalva were detected in 27% and 20% patients with sleep apnea, which was a relatively higher rate than that in patients without sleep apnea (8% and 0%, respectively). Successful catheter ablation was achieved in 11 patients (85%) with sleep apnea and 17 (77%) without sleep apnea. During a mean follow-up period of 13.5 + or - 7.3 months after catheter ablation, 5 patients (45%) with sleep apnea and 1 patient (6%) without sleep apnea experienced recurrent VT/PVCs. Comparing the outcome between the two groups, the VT/PVCs recurrence rate was significantly higher in patients with sleep apnea than in those without sleep apnea (p=0.02). CONCLUSIONS: Ventricular arrhythmia patients with sleep apnea have a high recurrence of arrhythmias after successful catheter ablation. Patients with ventricular arrhythmias should be systematically assessed for sleep apnea owing to the potential detrimental effects of sleep apnea in the follow-up period.

[The effectiveness of measurement of nasal resistance in patients with sleep disordered breathing].

Nasal breathing disorder has been associated with the condition and treatment of sleep disordered breathing (SDB). In the current study, we investigated the utility of measurement of nasal resistance in patients with SDB. We examined the relationship between nasal symptoms and nasal resistance in 219 patients, and how the results affected the administration of nasal continuous positive airway pressure (nCPAP) in 34 SDB patients. Total nasal resistance was not significantly different between patients who were divided into two groups: those with nasal symptoms, and those without. The left-right ratio of nasal flow in the group with nasal symptoms was higher than in the group without nasal symptoms (p < 0.01). The mean percentage of nCPAP use was not significantly different between two groups divided by total nasal resistance. The mean percentage of nCPAP use > or = 4 hours was lower in the group in which total nasal resistance was more than 0.25Pa/cm3/sec (p < 0.05). The left-right ratio of nasal flow does not affect nCPAP use. We conclude that measurement of nasal resistance for confirming nasal breathing disorder is effective in patients with SDB, whether a patient complains of nasal symptoms or not.

Association of sleep-disordered breathing and ventricular arrhythmias in patients without heart failure.

The prevalence and characteristics of sleep-disordered breathing (SDB) in patients with ventricular arrhythmias, such as premature ventricular complexes and ventricular tachycardia, are unknown. Therefore, this study was conducted to evaluate the prevalence of SDB in patients with severe ventricular arrhythmias and normal left ventricular (LV) function. Thirty-five patients (63% men, mean age 57.4 +/- 13.8 years) underwent a sleep study. All patients had ventricular tachycardia or frequent premature ventricular complexes (>or=300/hour) and had been referred to the cardiology department for medication, catheter ablation therapy, or the implantation of a cardioverter-defibrillator. Patients with heart failure with LV ejection fractions <50% were excluded; in the remaining patients, the mean LV ejection fraction was 63.9 +/- 8.0%. Twenty-one patients (60%) had SDB with apnea-hypopnea indexes >or=5/hour, and the average apnea-hypopnea index was 22.7 +/- 17.9/hour. Twelve patients (34%) had moderate to severe SDB, with an average apnea-hypopnea index of 33.6 +/- 16.6/hour. Central dominant sleep apnea was evident in 3 patients with SDB. The average age and body mass index were significantly higher in patients with SDB than in those without SDB (age 62.0 +/- 12.8 vs 50.6 +/- 12.7 years, body mass index 26.3 +/- 4.0 vs 21.2 +/- 2.0 kg/m2). In conclusion, this study found a high prevalence of SDB in patients with ventricular arrhythmias and normal LV function.

Unilateral cortical application of interleukin-1beta (IL1beta) induces asymmetry in fos, IL1beta and nerve growth factor immunoreactivity: implications for sleep regulation.

Unilateral injection of interleukin-1 beta (IL1beta) into the somatosensory cortex enhances EEG slow wave activity ipsilaterally during non-rapid eye movement sleep [Yasuda, T., Yoshida, H., Garcia-Garcia, F., Kay, D., Krueger, J.M., 2005. Interleukin-1beta has a role in cerebral cortical state-dependent electroencephalographic slow-wave activity. Sleep 28, 177-184]. We show that a similar unilateral microinjection of IL1beta (10 ng) into layer VI or onto the surface of the primary somatosensory cortex induced increases in the neuronal activity marker, Fos, relative to the contralateral side that received saline or heat-inactivated IL1beta. When IL1beta was microinjected into layer VI, increases in Fos-immunoreactive nuclei were evident in layers II, III and VI of the somatosensory cortex and connected cortical regions, such as the endopiriform, secondary somatosensory, piriform and prefrontal cortex. Asymmetrical increases in Fos were also observed in subcortical regions, such as the reticular thalamus, which receives a main cortical projection, and hypothalamic regions implicated in sleep regulation, such as the ventrolateral preoptic area and dorsal median preoptic nucleus. Fos activation was not observed in many other brain regions. In the reticular thalamus and somatosensory cortex, the number of IL1beta-immunoreactive glial cells increased. Further, the number of NGF-immunoreactive cells in the primary somatosensory cortex and magnocellular preoptic nucleus increased on the IL1beta-injected side. These results are consistent with the hypothesis that sleep is initiated within the cortex after the local activation of specific cytokines and that whole organism sleep is coordinated via cortical connections with the subcortical sites.

[Prediction of the date of Japanese cedar pollen release in Aomori Prefecture].

When we treat patients with pollen allergy, we require correct information about pollen release. The total count of pollen and the date of first pollen release are strongly influenced by local weather conditions, so we wanted to predict local pollen release. Patients have degrees of sensitivity to pollen, with symptoms triggered in some cases by only small amounts. Therefore, we wanted to determine the previous dates of first pollen release (A), the first of two consecutive dates when one (count/cm2) or more grains were released (B), and the first of two consecutive dates when ten (count/cm2) or more grains were released (C). Aomori Prefecture has three different weather zones because it is surrounded by three oceans the Sea of Japan, the Pacific Ocean, and Mutsu Bay. We predicted pollen release in the major cities--Aomori, Hirosaki, and Hachinohe. Using nine years (1996-2004) of temperature data for each city from January 1 through February 1, we recorded the number of days in which the daily highest temperature was higher than each of five set temperatures (0 degree C, 1 degree C, 2 degrees C, 3 degrees C, 4 degrees C) up to the dates of A, B, and C. Multiple recordings were made for each year with the initial date of recording staggered at 10-day intervals. We then calculated the standard deviation and the efficient of variation of total days and totals of temperatures over set temperatures. For Aomori, results indicated that A was predicted as day 19 with temperatures over 4 degrees C after January 21. B was day 23 over 4 degrees C after January 21. C was the day 31 with over 4 degrees C after January 21. For Hirosaki, A was expected to be day 26 having temperatures over 0 degrees C after February 1. B was day 21 over 3 degrees C after February 1. C was day 30 over 3 degrees C after January 21. For Hachinohe, A was day 34 with temperatures over 0 degrees C after February 1. B was day 33 over 1 degree C after January 21. C was day 27 over 4 degrees C after January 21. We examined the day of pollen release in 2005.

State-dependent effects of light-dark cycle on somatosensory and visual cortex EEG in rats.

Somatosensory (SSctx) and visual cortex (Vctx) EEG were evaluated in rats under a 12:12-h light-dark (LD) cycle and under constant light (LL) or constant dark (DD) in each sleep or wake state. Under LD conditions during light period, relative Vctx EEG slow-wave activity (SWA) was higher than that of the SSctx, whereas during dark period, relative Vctx EEG SWA was lower than in the SSctx. These effects were state specific, occurring only during non-rapid eye movement sleep (NREMS). Under LL conditions, the duration of REMS and NREMS during the period that would have been dark if the LD cycle had continued (subjective dark period) was greater than under LD conditions. DD conditions had little effect on the duration of NREMS and REMS. SSctx and Vctx EEG SWA were suppressed by LL during the subjective dark period; however, the degree of Vctx SWA suppression was smaller than that of the SSctx. DD conditions during the subjective light period enhanced SSctx SWA, whereas Vctx SWA was suppressed. Under LL conditions during the subjective dark period, Vctx EEG power was higher than that of the SSctx across a broad frequency range during NREMS, REMS, and wakefulness. During DD, SSctx EEG power during NREMS was higher than that of the Vctx in the delta wave band, whereas SSctx power during REMS and wakefulness was higher than that of the Vctx in frequencies higher than 8 Hz. We concluded that the SSctx and Vctx EEGs are differentially affected by light during subsequent sleep. Results provide support for the notion that regional sleep intensity is dependent on prior regional afferent input.

Unilateral cortical application of tumor necrosis factor alpha induces asymmetry in Fos- and interleukin-1beta-immunoreactive cells within the corticothalamic projection.

A unilateral microinjection of tumor necrosis factor alpha (TNFalpha) (150 ng) onto the primary somatosensory cortex induces state-dependent asymmetries in electroencephalographic (EEG) slow wave activity during non-rapid eye movement sleep in rats [H. Yoshida, Z. Peterfi, F. Garcia-Garcia, R. Kirkpatrick, T. Yasuda, J.M. Krueger, State-specific asymmetries in EEG slow wave activity induced by local application of TNF alpha, Brain Res. 1009 (2004) 129-136]. In the current study, analogous TNFalpha injections were performed to determine Fos- and interleukin-1beta (IL1beta) immunoreactivity (IR). A unilateral microinjection of TNFalpha increased the number of Fos- and IL1beta-IR cells in the primary somatosensory cortex relative to the contralateral side that received heat-inactivated TNFalpha. These asymmetric TNFalpha-induced increases in the number of Fos- and IL1beta-IR cells were evident along the outside surface of the cortex (mainly layers II and III) in a restricted rostral to caudal zone. Asymmetrical increases in the number of Fos-IR cells were also observed in the subcortical region that receives the main cortical projection from the somatosensory cortex, the somatic region of the reticular nucleus of the thalamus (reticular thalamus). The IL1beta-IR cells double-labeled with glial fibrillary acidic protein (GFAP), suggesting that many of the IL1beta-IR cells were astrocytes. The number of the IL1beta-IR cells in the reticular thalamus increased significantly ipsilateral to the TNFalpha injection. Current results indicated that Fos- and IL1beta-IR may be utilized to study the functional neuroanatomy involved in the TNFalpha-mediated state-dependent enhancement of EEG slow wave activity.

[Prediction of Japanese cedar pollen emission in a snowy area--surveillance in Hirosaki City].

Japanese cedar is the most common pollinosis allergen in Japan. Predictions of total pollen counts and the first 2 or more days of the Japanese cedar pollen season are beneficial to patients. We developed predictive methods for those 2 factors in Hirosaki. We conducted an atmospheric Japanese cedar pollen survey from 1996 to 2002 in Hirosaki and compared yearly data with the male flowering index counted in 50 cedar trees in the preceding autumn. The male flowering index correlated highly positively with total cedar pollen counts in regression analysis, indicating its usefulness in predicting total pollen counts. Although the number of days from January 1 to the first day of continuous pollen emission showed no correlation with the cumulative maximum temperature during these days, the number of days from the day of first detection of pollen emission (minimum of 1 particle per sq. cm) to the first day of continuous pollen emission correlated highly with the cumulative maximum temperature and cumulative amount of snowfall on these days, suggesting that it is possible to predict the first day of continuous pollen emission by the cumulated daily maximum temperature after the day of first detection of pollen emission.