Cerebral oxygenation during exercise and exercise recovery in patients with idiopathic dilated cardiomyopathy

Effects of Supplemental O2 Inhalation on Cerebral Oxygenation During Exercise in Patients With Left Ventricular Dysfunction

“…Previous reports 3,4,30 and our present findings suggest that patients with heart failure might have cerebral hypoperfusion during daily life. In a recent investigation using proton magnetic resonance spectroscopy to evaluate the cerebral metabolism of heart failure patients, Lee et al 30 discovered abnormalities in patients with advanced heart failure.…”

“…4 We also found that cerebral O2Hb actually decreased during exercise in 43% of patients with dilated cardiomyopathy, indicating cerebral hypoperfusion in these patients. 3 We recently compared the decreased levels of O2Hb and TOI at the forehead during exercise in patients with LV dysfunction with those in subjects who had experienced reduced consciousness because of a sudden drop in blood pressure induced by a parasympathetic reflex or sustained ventricular tachycardia. 22 We found that the decreases in these indexes during exercise in some patients were comparable to those in subjects who experienced reduced consciousness, which suggests that the indexes of cerebral oxygenation may drop to levels low enough to affect the level of consciousness during maximal exercise in patients with severe LV dysfunction.…”

“…3,4 If this is the case, inhalation of high O2 during exercise may be beneficial by raising PaO2 and consequently improving cerebral tissue oxygenation. We tested this hypothesis by selecting patients with LV dysfunction who showed decreased cerebral O2Hb during incremental exercise and evaluating whether this exerciseinduced decrease in cerebral O2Hb was attenuated when the patients inhaled supplemental O2.…”

“…However, this may not be the case in cardiac patients with left ventricular (LV) dysfunction. 3,4 Our group recently studied cerebral oxygenation during exercise in patients with dilated cardiomyopathy 3 using near-infrared spectroscopy (NIRS) to continuously measure the change in cerebral oxyhemoglobin (O2Hb) during exercise. As a result, we found that nearly 50% of the patients exhibited decreases in cerebral O2Hb during exercise, and the rate was even higher among those with lower LV ejection fraction (LVEF).…”

Clinical Significance of Cerebral Oxygenation During Exercise in Patients With Coronary Artery Disease

“…Our group recently studied cerebral oxygenation during exercise using near-infrared spectroscopy (NIRS) in patients with left ventricular dysfunction. 1 We found, as a result, that nearly half of the patients exhibited decreases in the cerebral oxyhemoglobin (O2Hb) during exercise, and that the decrease was more prominent in patients with a lower left ventricular ejection fraction (LVEF). 1 In these patients, cerebral O2Hb, a parameter that initially remained constant at lower work rates during incremental exercise, began to decrease at higher work rates.…”