Prognostic value of end-tidal CO2 pressure during exercise in patients with left ventricular dysfunction

Abstract

We compared the prognostic power of end-tidal CO 2 pressure (PETCO 2 ) during exercise, an index of arterial CO 2 pressure, with those of established respiratory gas indexes during exercise testing in patients with left ventricular dysfunction. Seventy-eight consecutive patients with a left ventricular ejection fraction (LVEF) B40% were enrolled in the study. All the patients performed a symptom-limited incremental exercise test with respiratory gas measurements. PETCO 2 at peak exercise, peak O 2 uptake ( _ VO 2 ), the ratio of the increase in ventilation to the increase in CO 2 output ( _ VE/ _ VCO 2 slope), and the ratio of the increase in _ VO 2 to the increase in work rate (D _ VO 2 / DWR) were measured. PETCO 2 at peak exercise was significantly correlated with peak _ VO 2 , _ VE/ _ VCO 2 slope and D _ VO 2 /DWR. During a prospective follow-up period of 992 ± 570 days, 14 cardiac deaths occurred. As compared to survivors, non-survivors had a significantly lower LVEF, lower PETCO 2 at peak exercise, lower peak _ VO 2 , lower D _ VO 2 /DWR and a higher _ VE/ _ VCO 2 slope. Among these indexes, only PETCO 2 at peak exercise was found to be an independent predictor for cardiac death. PETCO 2 at peak exercise is useful in predicting poor prognosis in patients with left ventricular systolic dysfunction.

Abnormal End-Tidal PO2 and PCO2 at the Anaerobic Threshold Correlate Well With Impaired Exercise Gas Exchange in Patients With Left Ventricular Dysfunction

“…15 Very recently, it has been shown that low PETCO2 measured during exercise predicts poor outcome in patients with LV dysfunction. 16 These findings strongly suggest that a lower PETCO2 during exercise caused by the V/Q mismatch, and additionally by a reduced PaCO2 such as at peak exercise when the subject hyperventilates in response to the lactic acidosis, is strongly related to insufficient cardiac reserve. In contrast, the clinical significance of PETO2 during exercise has rarely been reported in cardiac patients.…”

Dynamic of end-tidal carbon dioxide pressure during cardiopulmonary exercise testing before and after heart transplantation

“…Кроме того, у 31% испытуемых было зарегистрировано отсутствие прироста данного показателя при КПНТ. Полученные данные соотносятся с результатами других исследований [7,10]. Глубокое угнетение сердечной деятельности у пациентов-кандидатов на ТС обуславливает отсутствие в данной группе адекватного прироста сердечного выброса при выполнении нагрузки, что приводит к снижению эффективности доставки кислорода к работающим мышцам, более раннему наступлению анаэробного порога, и соответственно, повышению нагрузки на респираторное Несмотря на доказанную прогностическую значимость VO 2 peak и VE/VCO 2 slope в стратификации риска не только при сердечно-сосудистых, но и при многих других нозологиях, изучение ассоциаций параметров легочного газообмена, состояния резервных возможностей организма с исходом развития заболеваний и эффективностью лечения остается актуальным [5,15,16].…”

“…PetCO 2 отражает концентрацию углекислого газа в конце выдоха, измерение его неинвазивно и является неотъемлемой частью КПНТ. Немногочисленные исследования показали связь уровня PetCO 2 с тяжестью ХСН [7][8][9]. В одном из исследований даже сообщалось, что PetCO 2 является более сильным предиктором неблагоприятного исхода у пациентов с ХСН, чем VO 2 peak [10].…”

Clinical Usefulness of Response Profiles to Rapidly Incremental Cardiopulmonary Exercise Testing

“…Regardless of the exact mechanism, abnormally low values at the LT have been found useful for the diagnosis of pulmonary vascular diseases in patients with unexplained dyspnea [111]. There is now established evidence that P ET CO 2 at rest [112–114], LT [115], and peak exercise [116] are valuable for prognosis estimation and disease severity assessment in CHF [219, 220]. Low P ET CO 2 values have also been found in PAH (see also later) [97, 111, 117, 118].…”

“…In fact, Yasunobu and co-workers suggested that observation of an unusually low P ET CO 2 at the LT (<30 mmHg or, in particular, <20 mmHg) in a patient with exertional dyspnea of unknown cause without evidence of acute hyperventilation (ie, normal R) should prompt the hypothesis of pulmonary vasculopathy [111]. P ET CO 2 response profile is also informative as failure to increase below the LT or progressive decreases from the start of exercise are associated with worsening clinical and hemodynamic impairment (Figures 9(b) to 9(e)) [111] and are rarely found in CHF [112–116]. Based on (2), it might be expected that if P ET CO 2 changed parallel to P A CO 2 , a hyperbolic relationship between $\mathrm{\hspace{0.17em}\hspace{0.17em}}{\dot{V}}_{\text{E}}/{\dot{V}}_{{\text{CO}}_{\mathrm{normal2}}}$ and P ET CO 2 at the LT would result.…”