Clinical Significance of the Presence of Oscillatory Breathing Both at Rest and During Exercise in Cardiac Patients.

Cardiac patients often experience nocturnal and daytime oscillatory breathing (OB). OB noted at rest sometimes becomes unclear or even disappears during exercise. We evaluated the physiological significance of OB by comparing the clinical characteristics of cardiac patients who manifested OB only at rest (group A), only during exercise (group B), and both at rest and during exercise (group C).Among 3,432 cardiac patients who underwent cardiopulmonary exercise testing (CPX), 114, 94, and 65 patients were identified as group A, B, and C, respectively. Left ventricular ejection function was 57 ± 17% in group A, 49 ± 20% in group B, and 41 ± 21% in group C (P < 0.05 for all comparisons among the 3 groups). The level of brain natriuretic peptide (BNP) was significantly higher in group C than in groups A and B. The peak VO2 was lower and the VE-VCO2 slope was higher in groups B and C than in group A.The present findings suggest that cardiac function is more impaired in cardiac patients who manifest OB both at rest and during exercise than in cardiac patients who manifest OB only at rest or only during exercise.

Clinical significance of the overshoot phenomena of respiratory gas indices during recovery from maximal exercise testing.

BACKGROUND: Overshoot phenomena of the gas exchange ratio (R:VCO2/VO2), ventilatory equivalent for O2 (VE/VO2), and end-tidal O2 pressure (PETO2) are commonly observed during recovery from maximal cardiopulmonary exercise testing (CPX). We investigated the clinical significance of the overshoots of these indices by comparing their magnitudes between healthy subjects and cardiac patients with left ventricular dysfunction. METHODS: In total, 121 subjects (73 healthy subjects and 48 cardiac patients with left ventricular ejection fraction<40%) who underwent CPX and achieved peak R≥1.10 were enrolled. We evaluated and calculated the presence and magnitude of the overshoot phenomena of R, VE/VO2, and PETO2. RESULTS: The overshoot phenomena of R, VE/VO2, and PETO2 were observed in all the subjects. The magnitudes of the R (21.4±12.4% vs. 29.3±10.0%, p<0.001), VE/VO2 (45.5±23.5% vs. 77.5±28.5%, p<0.001), and PETO2 (5.3±3.4% vs. 10.1±4.2%, p<0.001) overshoots were significantly lower in cardiac patients than in healthy subjects. In cardiac patients, the magnitude of the PETO2 overshoot showed significant positive correlations with the peak O2 uptake (VO2) (r=0.52, p<0.001), anaerobic threshold (r=0.43, p=0.003), and ratio of the increase in VO2 to the increase in the work rate (r=0.41, p=0.005), and a negative correlation with the slope of the increase in ventilation versus the increase in CO2 output (r=-0.50, p<0.001). The magnitudes of the R and VE/VO2 overshoots showed the same patterns of significant correlation with the CPX indices. CONCLUSIONS: We concluded that the overshoots of R, VE/VO2, and PETO2 during recovery from maximal exercise reflect the natural cardiopulmonary adaptation after exercise and are more prominent in subjects with better cardiopulmonary function.

Clinical significance of a spiral phenomenon in the plot of CO2 output versus O2 uptake during exercise in cardiac patients.

A spiral phenomenon is sometimes noted in the plots of CO2 output (VCO2) against O2 uptake (VO2) measured during cardiopulmonary exercise testing (CPX) in patients with heart failure with oscillatory breathing. However, few data are available that elucidate the clinical significance of this phenomenon. Our group studied the prevalence of this phenomenon and its relation to cardiac and cardiopulmonary function. Of 2,263 cardiac patients who underwent CPX, 126 patients with a clear pattern of oscillatory breathing were identified. Cardiopulmonary indexes were compared between patients who showed the spiral phenomenon (n = 49) and those who did not (n = 77). The amplitudes of VO2 and VCO2 oscillations were greater and the phase difference between VO2 and VCO2 oscillations was longer in the patients with the spiral phenomenon than in those without it. Patients with the spiral phenomenon also had a lower left ventricular ejection fraction (43.4 ± 21.4% vs 57.1 ± 16.8%, p <0.001) and a higher level of brain natriuretic peptide (637.2 ± 698.3 vs 228.3 ± 351.4 pg/ml, p = 0.002). The peak VO2 was lower (14.5 ± 5.6 vs 18.1 ± 6.3, p = 0.002), the slope of the increase in ventilation versus VCO2 was higher (39.8 ± 9.5 vs 33.6 ± 6.8, p <0.001), and end-tidal PCO2 both at rest and at peak exercise was lower in the patients with the spiral phenomenon than in those without it. In conclusion, the spiral phenomenon in the VCO2-versus-VO2 plot arising from the phase difference between VCO2 and VO2 oscillations reflects more advanced cardiopulmonary dysfunction in cardiac patients with oscillatory breathing.

Mastitis is associated with IL-6 levels and milk fat globule size in breast milk.

BACKGROUND: From animal studies, it is known that mastitic inflammation of the mammary lobes can produce proinflammatory cytokines and can damage the milk fat globule (MFG). OBJECTIVE: To investigate, in women, whether MFG and interleukin (IL)-6 differences are observed between mastitic milk (MM) and healthy milk (HM) of a mother. METHODS: MM was obtained from the specific nipple pore leading to the mastitic lobe of 17 women; HM was obtained from the other breast. Milk sampling occurred at days 0 (pre-treatment), 1, and 2 (post-treatment). MFG size and IL-6 were measured by laser light scattering and enzyme-linked immunosorbent assay, respectively. We analyzed MFG and IL-6 differences between HM and MM, whether any differences occurred over time with treatment, and whether differences were observed between mothers with systemic symptoms (fever/malaise, Group A) or without systemic symptoms (Group B). RESULTS: On day 0, MM had higher MFG size (P < .01) and IL-6 levels (P < .001) than HM. This difference significantly decreased over time with treatment for both MFG size (P < .01) and IL-6 (P < .05). On day 0, Group A mothers had significantly larger MFG size (P < .01) and IL-6 (P < .001) than Group B. CONCLUSIONS: MM contains larger MFG and higher IL-6 levels than milk from the healthy breast. This difference is larger if accompanied by systemic symptoms of mastitis (fever/malaise). These changes decreased over time with treatment. Therefore, early initiation of appropriate treatment may be useful in limiting the processes that contribute to alterations in MFG size and IL-6.