Control Of Cardiac Output Flashcards
Afterload
The load the heart must eject blood against (roughly equivalent
to aortic pressure)
Preload
Amount the ventricles are stretched (filled) in diastole – related to the end diastolic volume or central venous pressure
Total Peripheral Resistance
Sometimes referred to as systemic vascular resistance – resistance to blood flow offered by all the systemic vasculature
If TPR falls and CO is unchanged, what would happen to the arterial and venous pressure?
Arterial pressure will fall
Venous pressure will increase
If TPR increases and CO is unchanged, what would happen to the arterial and venous pressure?
Arterial pressure will increase
Venous pressure will fall
If CO increases and TPR is unchanged, what would happen to the arterial and venous pressure?
Arterial pressure will increase
Venous pressure will fall
If CO decreases and TPR is unchanged, what would happen to the arterial and venous pressure?
Arterial pressure will fall
Venous pressure will rise
Cardiac Output equation
Cardiac Output = Stroke Volume + Heart Rate
What are the three shunts in the heart?
Ductus Venosus
Foramen Ovale
Ductus Arteriosus
Pulse pressure
Peak systolic pressure - end diastolic pressure
40mm Hg
Definition of cardiac temponade
Compression of the heart leading to a drop in arterial blood pressure
In a patient with cardiac temponade, why would cardiac output fall?
There is rapid fluid build-up and the outer fibrous layer cannot expand. This puts external pressure on the heart preventing it from filling properly in diastole
What is the name of the procedure that involves aspiration of fluid from the pericardial space?
Pericardiocentesis
In a patient with long standing mitral valve stenosis what would happen to the left atrium?
The left atrium would become dilated. This is because of the increased pressure and volume because it is harder for blood to flow through the stenosed valve.
