Exercise gas exchange responses in the differentiation of pathologic and physiologic left ventricular hypertrophy

Purpose: The purpose of the present investigation was to examine differences that may exist in maximal and submaximal exercise gas exchange parameters and their use in differentiating pathological and physiological left ventricular hypertrophy, Methods: Exercise gas exchange responses were measured on-line during a maximal ramping cycle-ergometer exercise test in 10 young, male hypertrophic cardiomyopathy (HCM) patients, 11 elite triathletes, and 9 normal controls. Results: The HCM patients exhibited significantly lower (V) over dot O-2max, anaerobic threshold (AT) in both absolute terms (AT(V) over dot O-2max) and as a percentage of (V) over dot O-2max (AT%(V) over dot O-2max), and oxygen-pulse (O-2-pulse) compared with triathletes and normal controls. Elite triathletes exhibited significantly increased (V) over dot O-2max, %(V) over dot O-2max, AT(V) over dot O-2, AT%(V) over dot O-2max, and O-2-pulse compared with controls. The (V) over dot E/(V) over dot CO2 at AT was significantly increased in the HCM patients compared with triathIetes and controls, whereas no difference was observed between triathletes and controls. Conclusions: Maximal and submaximal exercise gas exchange responses may be used as an additional noninvasive tool in the differential diagnosis of physiologic and pathologic left ventricular hypertrophy.