Alterations in Cardiac Function/Cardiac Anomalies Flashcards
(83 cards)
Role of Clinical Perfusionist
Operates cardiopulmonary bypass apparatus during cardiac surgeries
What is cardiopulmonary bypass + its 2 main components?
Provides a motionless, bloodless field for the surgeon to work on
- an artificial blood pump, which continuously propels blood forward
- an artificial oxygenator and then to the patient’s tissues while the surgeon repairs the anomaly within the heart.
What is a cardioplegia pump?
Used to introduce a high potassium solution directly to the heart to induce and maintain cardiac arrest.
Describe normal blood flow through adult heart
- Periphery
- SVC/IVC
- RA
- Tricuspid
- RV
- Pulmonary
- PA
- Lungs
- PV
- LA
- Mitral
- LV
- Aortic
- Aorta
Systole
when the heart contacts with ejection of blood
Diastole
when the heart relaxes and fills with blood
End Diastolic Volume
volume of blood in the heart after filling
End Systolic Volume
volume of blood left in the heart after contraction
Cardiac Output
The volume of blood ejected from the left ventricle each minute
Equal to HR x SV`
Normal Stroke Volume of Infant
0.032ml
Normal CO for infant
77ml/kg/min
In children CO is almost completely dependent on ________
Until age _____
why?
Heart Rate
5
This is when the heart muscle is fully developed and can better contribute to stroke volume
Tachycardic and Bradycard heart rates can compromise:
Cardiac Output
How does a tachycardic HR compromise cardiac output?
ventricular filling time and end-diastolic volume are lowered, and myocardial oxygen consumption is increased
Therefore, improper filling leading to sub-adequate output and increased workload of ventricle
How does a bradycardic HR compromise CO?
blood is not being perfused in timely manner
When does myocardial perfusion occur?
What are the implications of a tachycardic HR on this?
Diastole
Because there is
1. inadequate output/return in tachycardic HRs and
2. need for myocardial oxygenation increase
cardiac ischemia and ventricular dysfunction can occur
Stroke Volume
Volume of blood ejected per beat
What 3 factors influence stroke volume
Preload Afterload and Contractility
Preload
the amount of blood filling the ventricles during diastole
What effect does increased preload have on stroke volume?
Increase stroke volume to a maximum value, but beyond this stroke volume falls (unable to compensate)
In what conditions is an increased preload seen?
Hypervolemia
Regurgitation of valves
Heart failure
Afterload
is the load that the heart must eject against
What alterations to afterload increase stroke volume?
Reductions in afterload increase stroke volume if other variables remain constant.
In what conditions in an increased afterload seen?
Hypertension
Vasoconstriction