Arrhythmias Flashcards
Whats is flutter?
When contractions are very rapid, but coordinated; can live
What is fibrillation?
When contraction of myocardial cells occurs at different times
Coordinated pumping is impossible
What is the outlook of Afib? Vfib?
In atria, survivable→ 80% of filling occurs before atrial contraction
In ventricle, fatal
What is going on with a problem in the P-Q area?
A delay of action potential through atrium
What are 4 causes of P-Q problems?
Scar tissue (impedes SA-AV information)
Ischemia (in atria)
Dilated atrium, delays action potential, causing arrhythmia
Compression or necrosis of AV node
What is going on with a problem in the Q-T area?
Delay of action potential through ventricles
What are 2 causes of Q-T problems?
eg MI- Sudden death of a patch of myocardial cells
eg Abnormally large ventricle (delays signal)
What is the cardiac cycle? What are the 2 phases?
Includes all events associated with the flow of blood through the heart during one heartbeat
Systole- Contraction
Diastole- Relaxation
What is systole? What does the heart do? What happens to BP?
Contraction
Chamber contracts and pushes blood into adjacent chamber
Pressure rises during systole
What is diastole? What does the heart do? What happens to BP?
Relaxation
Chamber relaxes and fills with blood
Pressure falls
What is EDV? What does it mean?
End-diastolic volume- Total volume of blood in the ventricle at the end of diastole
120 ml, the maximum amount of blood the heart can hold in this cycle
What is ESV? What does it mean?
End-systolic volume- Total volume of blood in the ventricle at the end of systole
50 ml - Ventricles do not completely empty, there’s some blood left
What is stroke volume?
Volume of blood pumped out of a ventricle during each beat or cardiac cycle- 70 ml
How is stroke volume determined?
EDV-ESV= Stroke Volume 120-50= 70 ml
What is cardiac output?
The volume of blood pumped per minute by each ventricle