Length-dependent regulation of left ventricular function in coronary surgery patients
| Autor: | A C Moulijn, Thierry C. Gillebert, S. De Hert, P. W. Ten Broecke |
|---|---|
| Přispěvatelé: | Other departments |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Male
medicine.medical_specialty Heart disease Systole Hemodynamics Ventricular Function Left law.invention Phenylephrine law Internal medicine medicine Cardiopulmonary bypass Humans Derivation Coronary Artery Bypass Aged Leg business.industry Stroke volume Middle Aged medicine.disease Pathophysiology Anesthesiology and Pain Medicine Blood pressure Anesthesia Cardiology Female business medicine.drug |
| Zdroj: | Anesthesiology, 91(2), 379-387. Lippincott Williams and Wilkins Anesthesiology |
| ISSN: | 0003-3022 |
| DOI: | 10.1097/00000542-199908000-00011 |
| Popis: | Background Load-dependent impairment of left ventricular (LV) function was observed after leg elevation in a subgroup of coronary surgery patients. The present study investigated underlying mechanisms by comparing hemodynamic effects of an increase in LV systolic pressures with leg elevation to effects of a similar increase in systolic pressures with phenylephrine. Methods The study was performed in patients undergoing elective coronary surgery prior to cardiopulmonary bypass. High-fidelity LV pressure tracings (n = 25) and conductance LV volume data (n = 10) were obtained consecutively during leg elevation and after phenylephrine administration (5 microg/kg). Results Leg elevation resulted in a homogeneous increase in end-diastolic volume. The change in stroke volume (SV), stroke work (SW) and dP/dtmax was variable, with an increase in some patients but no change or a decrease in other patients. For a matched increase in systolic pressures, phenylephrine increased SW and dP/dtmax in all patients with no change in SV. Load dependence of relaxation (slope R of the tau-end-systolic pressure relation) was inversely related for changes in SV, SW, and dP/dtmax with leg elevation but not with phenylephrine. Conclusions The different effects of leg elevation and phenylephrine suggest that the observed decrease in SV, SW, and dP/dtmax with leg elevation in some patients could not be attributed to an impaired contractile response to increased systolic LV pressures. Instead, load-dependent impairment of LV function after leg elevation appeared related to a deficient length-dependent regulation of myocardial function. |
| Databáze: | OpenAIRE |
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