Cardiac Cycle and Sounds - Karius Flashcards
Electrical event vs mechanical event for heart contraction
The electrical event happens first Quality of electrical event doesn’t effect quality of mechanical event
EKG x and y axis
X : time Y : voltage
P wave is initiated by the
SA node
Conduction velocity in the AV node
Is slow causing pause = PR interval (end of P, start of R)
AV node transmits AP by purkinje fibers where in what order
Septum Apex Back up lateral walls of each V
Which direction does the heart contract of V
Towards the septum
Q wave R wave S wave
First - wave + wave Second - wave
What happens from S to T
Phase 2 (plateau phase) CA+ influx
When is heart relaxed
End of T wave
The 1st cell to depolarize in the myocytes
Is the last to repolarize
The last of the myocytes to depolarize
Is the first to repolarize
Mechanical event of heart ventricle from Q—> end of T-wave
SYSTOLE of ventricle Contracted
When is Ventricular Diastole
Relaxed From end of T-wave to beginning of QRS
When is arterial 1. Systole 2. Diastole
- Beginning of P- wave to QRS 2. QRS to strat of next P-wave
Atrial P increases when (long steady)
End of QRS to start of next P wave As it fills with blood
Ventricular Pressure increases a lot when and what effects height of this spike
QRS to end of T wave The Systemic BP determines height
Aortic P is how much at its peak
Just slight hair above the ventricular P during its peak = causes the decrease in V contraction and ejection of blood
Diastolic P on Aorta and in V
V = 0mmHg Aorta = higher like can be around 80mmHg
How much blood does the V have at end of Diastole
Around 100-120mL
How much blood does the V have at end of Systole
Ejects 50%-60% of Ventricle Maybe around 80mL
When is diastole short of long
SHORT = fast HR LONG = slow HR
Jugular P is how
Only slight hair above the Artrial P lines Decreases a little when during Ventricular repolarization or (decrease in P)
Jugular P comes from
The Jugular V going into the Atria
Reason Aortic P has
This is when the Aortic Valve closes and stays at a steady P inside Aorta before blood starts flowing down = end of ventricular ejection + systole = the V Pressure decreases a little earlier
Reason AV node has delay
Allows the atrium to contract and eject all blood to the ventricle Before ventricle contracts