Contribution of cardiopulmonary indices in the assessment of patients with silent and symptomatic ischemia during exercise testing

Abstract

Cardiopulmonary and radionuclear indices were used to evaluate and compare cardiac function during exercise testing in patients with symptomatic and silent ischemia. The study comprised 58 patients aged 35–74 years, divided into three groups: Group I — 20 patients (controls) with neither ST depression nor chest pain; Group II — 22 patients with ST depression >1 mm and no chest pain; Group III — 16 patients with both ST depression and chest pain. All patients in Groups II and III demonstrated significant coronary artery disease. No antianginal medication was taken at least 24 h before testing. All patients underwent a cardiopulmonary exercise test and a multigated acquisition radionuclear study. The following variables were measured: oxygen consumption (VO 2), CO 2 output (VCO 2), minute ventilation (VE), O 2-pulse, ventilatory anaerobic threshold (VAT), left ventricular ejection fraction (LVEF) at rest (r) and at maximal effort (ex). Probability values were significant for all variables ( P < 0.01−0.0001) except left ventricular ejection fraction-rest ( P not significant between the three groups). No significant differences in extent of coronary artery disease were noted between Groups II and III. These findings suggest that during exercise testing patients with silent ischemia have better overall cardiac function than patients with symptomatic ischemia. Their value for both cardiopulmonary and radionuclear indices are closer to those of the control group than to the symptomatic group, regardless of the severity of the coronary artery disease Summary of results: (mean ± 1 S.D.) Group VO 2-max O 2-Pulse max VAT (%) VAT (ml/min) LVEF-rest Δ LVEF (ex-r) I 25.2 ± 6.3 15.7 ± 3.4 51.2 ± 6.6 1075 ± 289 54.7 ±7 5.4 ± 4.85 II 22.4 ± 2.8 14.5 ± 2 47.0 ± 5.3 854 ± 136 52 ± 10 1.2 ± 6.7 III 16.0 ± 2.5 11.4 ± 2 41.6 ± 7.7 683 ± 105 51 ± 8.5 −5.87 ± 6.3