Left ventricular volume in patients with heart failure and Cheyne-Stokes respiration during sleep.
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.
Tkacova
R
R
Queen Elizabeth Hospital Sleep Research Laboratory, Toronto, Ontario, Canada.
Hall
M J
MJ
Liu
P P
PP
Fitzgerald
F S
FS
Bradley
T D
TD
D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output; D002306:Cardiac Volume; D002639:Cheyne-Stokes Respiration / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012891:Sleep Apnea Syndromes / Q000097:blood / Q000150:complications / Q000503:physiopathology; D012894:Sleep Stages; D013318:Stroke Volume; D016277:Ventricular Function, Left
D002245:Carbon Dioxide; D010100:Oxygen