Daytime Cheyne-Stokes Respiration in Ambulatory Patients With Severe Congestive Heart Failure Is Associated With Increased Mortality

Sleep Apnea and Cardiovascular Disease

“…Compared with heart failure patients without CSA/ CSR, heart failure patients with CSA/CSR were more likely to be older (Ͼ60 years of age) and male and to have atrial fibrillation, lower arterial PCO 2 (Յ38 mm Hg), 47 and heightened sensitivity to CO 2 . 36 Oscillatory breathing patterns evident in heart failure patients during wakefulness 341 and exercise 38,342 also may predict both the presence of CSA and poorer prognosis. 39 Thus, in patients with heart failure and Ն1 of these characteristics, a diagnosis of CSA/CSR should be strongly considered, and a careful sleep history should be obtained.…”

Oxygen Uptake Efficiency Plateau Best Predicts Early Death in Heart Failure

“…It is not surprising then that CPET measures such as peak o 2 , AT, peak oxygen pulse, lowest e / co 2 and e -vs-co 2 slope, and OUES are good measures of cardiovascular performance and predictive of survival in patients with HF. [3][4][5][6][7][8][9][10] Another measurement, perhaps even more useful, is the OUEP. Surprisingly, to the best of our knowledge, the measurements of OUEP (or lowest e / o 2 or highest o 2 / e ), either for a fraction of a minute or longer durations, have not been carefully analyzed or reported for prognosis or severity of disease in the past.…”

“…The determination of an OB 1 pattern required all of the following: (1) the amplitude of oscillatory ventilation must exceed 30% of concurrent mean ventilation 3,7,8,31,32 ; (2) three or more consecutive cyclic fl uctuations of ventilation or Ն 60% of entire CPET period 3,7-10,31,32 ; (3) an oscillatory frequency of 40 to 140 (56 Ϯ 5.2) s 3 ; and (4) visible oscillations of similar frequency in three or more of the following variables: oxygen pulse, o 2 , co 2 , e / co 2 , respiratory exchange ratio , or end-tidal pressures for oxygen (O 2 ) and CO 2 . 3 …”

“…[1][2][3] We postulated that management of such patients could be improved by adding more sensitive predictors, further refi ning well-known predictors, or by combining predictors. Currently, in such patients, gas exchange measurements during incremental cardiopulmonary exercise testing (CPET) such as peak oxygen uptake (peak o 2 ) at standard conditions of 0ºC, 760 mm Hg, dry (STPD); anaerobic threshold (AT); peak oxygen pulse; lowest ratio of minute ventilation ( e) at body temperature, ambient atmospheric pressure, saturated with water vapor to minute CO 2 output ( co 2 ) STPD; e -vs-co 2 slope; oscillatory breathing (OB) pattern [3][4][5][6][7][8][9][10] ; and the slope of o 2 to log e (oxygen uptake effi ciency slope [OUES]) [11][12][13][14][15][16][17][18][19][20][21] have been found to be useful in predicting mortality and morbidity and guiding therapy. [3][4][5][6][7][8][9][10] However, the full exercise response pattern of oxygen uptake effi ciency (OUE) ( o 2 / e , mL/L) and specifi cally the measurement of its highest average plateau (OUEP) (mL/L) have not been evaluated.…”

Time-varying signal analysis to detect high-altitude periodic breathing in climbers ascending to extreme altitude

“…Related to differences in the feed-back control system (plant and controller gain, circulation time [20]) the cycle length of periodic breathing is shorter in healthy subjects exposed to hypobaric hypoxia (i.e., in the order of 15-25 s [4]), compared with patients with Cheyne-Stokes respiration due to heart failure (i.e., 25-100 s [6]). Ventilatory control instability causes changes in the cardiac autonomic regulation, which can be evaluated by analysis of heart rate variability (HRV) [35].…”