HEMODYNAMICS Flashcards
what is stroke volume dependent on?
preload, afterload, contractility
what is normal CO and CI?
4-8L/min; 2.5-4.0L/min/m2
what is preload?
volume/pressure in the ventricle at the end of diastole after the AV valves close, just prior to ejection. The RA pressure or CVP reflects the right ventricular preload. PAOP reflects the LV preload;
As preload increases, what happens to SV and CO?
SV and CO increase up to a point. too high preload may lead to heart failure
what is afterload?
pressure (resistance) against which the ventricle must pump to open the valve (pulmonic/aortic); clinically measured by pulmonary vascular resistance (PVR) for the right ventricle or systemic vascular resistance (SVR) for the LV
what happens to SV and CO as afterload increases?
SV and CO decrease
what is contractility?
contractile force of the myofibrils independent of preload and afterload
what happens to SV and CO as contractility increases?
SV and CO increase
what is normal SV and SI?
50-100ml/beat; 25-45ml/beat/m2
what is normal right atrial pressure?
2-6mmHg 3-8cm H20
what is normal pulmonary artery pressure (PAP) and pulmonary artery occlusive pressure (PAOP)?
20/8-30/15mmHg; mean: <20mmHg; 8-12mmHg (although varies depending on LV function)
what is normal systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR)?
800-1200 dynes/s/cm^-5; 50-250 dynes/s/cm^-5
what is normal coronary artery perfusion pressure (CAPP)?
60-80mmHg
what is normal mixed venous oxygen saturation (SvO2), central venous oxygen saturation (ScvO2), and arterial oxygen saturation (SaO2)?
60-75%, >70%, 95-99% on RA
what is normal arterial oxygen content (CaO2), oxygen delivery (DO2), and oxygen consumption (VO2)?
12-16mL/dl; 900-1100mL/min; 250-350mL/min