Critical Level of Cerebral Oxygenation During Exercise in Patients With Left Ventricular Dysfunction Koike Akira Hoshimoto Masayo Tajima Akihiko Nagayama Osamu Yamaguchi Kaori Goda Ayumi Yamashita Takeshi Sagara Koichi Itoh Haruki Aizawa Tadanori 社団法人日本循環器学会 Circulation journal : official journal of the Japanese Circulation Society 13469843 70 11 1457 1461 2006-10-20 Background In a recent study the indexes of cerebral oxygenation decreased during maximal exercise in nearly half of all patients with left ventricular dysfunction. Whether these levels decrease severely enough to influence mental status or level of consciousness was evaluated in the present study. Methods and Results Forty-two patients with idiopathic dilated cardiomyopathy (IDC) and 29 healthy subjects underwent a symptom-limited maximal exercise test. The cerebral oxyhemoglobin (O_2Hb) and tissue oxygenation index (TOI) were continuously monitored using near-infrared spectroscopy. The changes in O_2Hb and TOI were also measured in 7 subjects: 2 who experienced episodes of reduced consciousness caused by sudden decreases in blood pressure during exercise recovery and 5 who exhibited sustained ventricular tachycardia during an electrophysiological study. The change in cerebral O_2Hb during exercise in patients with IDC averaged 0.38±3.39μmol/L, significantly lower than in the normal subjects (4.30±4.47μmol/L, p<0.0001). The cerebral O_2Hb decreased during exercise in 18 of 42 patients with IDC. The change in cerebral TOI in the IDC patients during exercise was significantly less than that in the normal subjects (-2.0±4.7 vs 2.1±5.8%, p=0.002). The mean decreases in cerebral O_2Hb and TOI were -5.34μmol/L and -9.7%, respectively, in the patients with reduced consciousness during exercise recovery, and -2.52μmol/L and -16.5%, respectively, in those with ventricular tachycardia. Conclusion The indexes of cerebral oxygenation may drop severely enough during maximal exercise in some patients with severe IDC that consciousness is affected. 2006-10-20 110004858637 AA11591968 ENG CJP CJPref NII-ELS J-STAGE 3 19 6 Critical Level of Cerebral Oxygenation During Exercise in Patients With Left Ventricular Dysfunction Koike Akira Hoshimoto Masayo Tajima Akihiko Nagayama Osamu Yamaguchi Kaori Goda Ayumi Yamashita Takeshi Sagara Koichi Itoh Haruki Aizawa Tadanori Japanese Circulation Society Circulation journal : official journal of the Japanese Circulation Society Background In a recent study the indexes of cerebral oxygenation decreased during maximal exercise in nearly half of all patients with left ventricular dysfunction. Whether these levels decrease severely enough to influence mental status or level of consciousness was evaluated in the present study. Methods and Results Forty-two patients with idiopathic dilated cardiomyopathy (IDC) and 29 healthy subjects underwent a symptom-limited maximal exercise test. The cerebral oxyhemoglobin (O_2Hb) and tissue oxygenation index (TOI) were continuously monitored using near-infrared spectroscopy. The changes in O_2Hb and TOI were also measured in 7 subjects: 2 who experienced episodes of reduced consciousness caused by sudden decreases in blood pressure during exercise recovery and 5 who exhibited sustained ventricular tachycardia during an electrophysiological study. The change in cerebral O_2Hb during exercise in patients with IDC averaged 0.38±3.39μmol/L, significantly lower than in the normal subjects (4.30±4.47μmol/L, p<0.0001). The cerebral O_2Hb decreased during exercise in 18 of 42 patients with IDC. The change in cerebral TOI in the IDC patients during exercise was significantly less than that in the normal subjects (-2.0±4.7 vs 2.1±5.8%, p=0.002). The mean decreases in cerebral O_2Hb and TOI were -5.34μmol/L and -9.7%, respectively, in the patients with reduced consciousness during exercise recovery, and -2.52μmol/L and -16.5%, respectively, in those with ventricular tachycardia. Conclusion The indexes of cerebral oxygenation may drop severely enough during maximal exercise in some patients with severe IDC that consciousness is affected. Koike Akira The Cardiovascular Institute Hoshimoto Masayo The Cardiovascular Institute School of Health and Sports Science, Juntendo University Tajima Akihiko The Cardiovascular Institute Nagayama Osamu The Cardiovascular Institute Yamaguchi Kaori The Cardiovascular Institute Goda Ayumi The Cardiovascular Institute Department of Cardiovascular Medicine, Tokyo Medical and Dental University Yamashita Takeshi The Cardiovascular Institute Sagara Koichi The Cardiovascular Institute Itoh Haruki Sakakibara Heart Institute Aizawa Tadanori The Cardiovascular Institute