Author(s): Tkacova R, Hall MJ, Liu PP, Fitzgerald FS, Bradley TD
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Abstract In patients with congestive heart failure (CHF), elevated, left ventricular (LV) volume might lead to pulmonary congestion and hypocapnia, which would create a predisposition to the development of Cheyne-Stokes respiration with central sleep apnea (CSR-CSA). In addition, because LV volume affects cardiac output, it should influence the lengths of hyperpneas. We therefore evaluated LV volumes and transcutaneous PCO2 (PtcCO2) during wakefulness and stage 2 sleep in 16 patients with CHF due to nonischemic dilated cardiomyopathy (NIDC). Data were then compared between those with (n = 7) and those without CSR-CSA (n = 9). LV end-diastolic volume (LVEDV) was significantly higher in patients with than those without CSR-CSA (585 +/- 118 versus 312 +/- 41 ml, p < 0.05). Compared with patients without CSR-CSA, those with CSR-CSA had lower mean stage 2 sleep PtcCO2 (36.3 +/- 2.2 versus 41.2 +/- 1.2 mm Hg, p < 0.05) and a lesser change in PtcCO2 from wakefulness to stage 2 sleep (-0.4 +/- 0.3 versus 2.0 +/- 0.4 mm Hg, p < 0.001). Among patients with CSR-CSA, hyperpnea length was inversely related to LVEDV (R = 0.769, p = 0.043) owing to the direct relationship of cardiac output to LVEDV (R = 0.791, p = 0.034). We conclude that CSR-CSA in patients with CHF due to NIDC is associated with increased LV volumes possibly through the direct or indirect influence of LV volume on PaCO2 and cardiac output.
This article was published in Am J Respir Crit Care Med
and referenced in Biochemistry & Analytical Biochemistry