Significance of End-Tidal Pco2 Response to Exercise and Its Relation to Functional Capacity in Patients With Chronic Heart Failure

Quimiossensibilidade durante exercício na insuficiência cardíaca: respostas ventilatórias, cronotrópicas e neurohormonais

“…The Ventilation/VCO 2 slope elevation that we observed is probably related to the primary modification in respiratory pattern in both groups (hyperventilation) and less to PCO 2 or estimated dead space increasing as previously described during room air test maximum exercise in HF patients [20][21][22][23][24][25][26] . We didn't find studies that used 6minWT concomitant to hypoxia, but despite the lack of comparison, we could suppose that the walked distance reduction observed may be related to great hyperventilation that would lead to thoracic muscle fatigue, and hypoxia of tissues.…”

“…The resting heart rate increment similarly observed in both groups confirms that hypoxia is a great chronotropic stimulus, and that peripheral chemoreceptors if stimulated can modulate resting HF group heart rate despite b-blockers [3][4][5]15,20,21 . However, the greater chronotropic response is indicative of higher exercise sensibility of peripheral chemoreceptors in HF group during exercise.…”

Comparative Hemodynamic Evaluation of the LUCAS® Device and Manual Chest Compression in Patients with Out-of-Hospital Cardiac Arrest

“…According to current knowledge, automated systems for external cardiac massage (Autopulse ® and LUCAS ® for France) provide hemodynamic bene its thanks to the quality of the massage and ensure better cerebral and myocardial perfusion for a longer period of time. Nonetheless, even though the bene its have been demonstrated for physiological data, no human studies have clearly shown that automated systems improve survival, or the neurological prognosis or the proportion of ROSC [31,33]. Prolonged cardiac massage is still the only indication for the use of these devices.…”

“…This low statistical power could also explain the low correlation coef icient for EtCO2-CO, as well as the absence of signi icance with regard to manual massage. In the literature, studies that evaluated the correlation between CO and EtCO2 reported coef icients close to 0.8 [31]. The second limitation was the technique used to evaluate cardiac output, namely the Doppler method, which is known to be operator-dependent.…”

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

“…In patients with left ventricular dysfunction, the failure of pulmonary blood flow (cardiac output) to increase appropriately during exercise aggravates the V/Q mismatch (high ventilation/perfusion) and the pulmonary dead space, leading to a greater arterialend-tidal PCO 2 difference. This greater difference attributes to the lower PETCO 2 and becomes much greater with the increasing severity of heart failure [4,7,20]. Also during exercise, patients with heart failure have a lower PaCO 2 as compared to healthy subjects because of their lactic acidosis-induced hyperventilation [21].…”