AEROBIC CAPACITY AND FUNCTIONAL CLASSIFIC ATION BY NYHA, CCS AND AMA SCALE IN PATIENTS WITH SEVERE LEFT-VENTRICULAR DYSFUNCTION (LVD)

Classes I/II versus III of the New York Heart Association (NYHA), the Canadian Cardiovascular Society (CCS) and the American Medical Associa tion (AMA) classifications were compared with the Weber classification (V-O2/kg during treadmill walking) in 35 male patients with severe le ft ventricular dysfunction (LVD). Points of measurement were ventilato ry threshold and the end of treadmill ergometry. In addition, it was i nvestigated whether 1. CCS- and AMA classifications because of their s tronger differentiation were more precise in determining a limited phy sical capacity than NYHA classification and 2. there were differentiat ing classification factors. Results: Ventilatory threshold: The mean V -O2/kg of the patients did not differ significantly in al three classi fications in classes I/II versus III (12.8 +/- 2.5 versus 11.1 +/- 2.3 ml/kg/min). End of treadmill ergometry:The mean V-O2/kg only differed significantly within the NYHA classification (classes I/II:16.3 +/- 3 .1 ml/kg/min versus class III:13 +/- 3 ml/kg/min;p < 0.05). The indivi dual values displayed a large scattering. Factors differing in classes I/II and III of all three classifications at the ventilatory threshol d were: ventilatory equivalent O-2 and CO2 as well as endtidal partial pressure for O-2 and CO2. At the end of treadmill ergometry these fac tors showed a separating character only in the AMA classification. Con clusion: It is not possible to determine by way of NYHA-, CCS- and AMA classifications the objective functional impairment analog to the Web er classification. Yet, these classifications are relevant for clinica l assessment.