Chest Pain quiz Flashcards
What is the equation for cardiac output
CO = HRxSV
Which side of the heart provides systemic circulation?
Left side
Which side of the heart provides pulmonary circulation?
Right side
What kind of circuit is between the pulmonary and systemic?
Series
What kind of circuit is between all the organs in systemic?
Parallel
What is the equation for Ohm’s law in hemodynamics?
Q = delta P / R
What is pressure difference in hemodynamics?
Delta P = MAP - CVP
What is normal BP (systole/diastole)?
130/80
What are the three main functions of cardiac action potentials?
Pacemaking by SA node, conduction of the impulse, initiating and controlling contraction
What demonstrates fast APs?
Atrial muscle, ventricular muscle, his/purkinje (LEFT SIDE)
What demonstrates slow APs?
Pacemaking (SA node), and slow conduction AV node (RIGHT SIDE)
What are the phases of a fast AP (0-4)?
0: Rapid depolarization activation of inward Na+
1: Initial repolarization (inactivate inward Na+, activate outward K+)
2: Plateau phase mediated by slowly activating inward Ca++
3: Repolarization due to inactivation of Ca currents and activation of several K+ currents
4: Resting membrane pot’l due to inward-rectivying K+ channels
What are the phases of a slow AP (0-4)?
0: slow depolarization due to activation of slowly-activating Ca++ channels
1: absent
2: absent
3: repolarization due to Ca++ channel inactivation and activation of K+ channels
4: slowly depolarizing resting potential
What effect does the parasympathetic NS have on phase 4 depolarization?
The parasympathetic NS releases ACh which reacts with muscarinic ACh recepters, increase in Igirk K currents, reducing the depolarization and HR (negative chronotropic effect)
What effect does the sympathetic NS have on phase 4 depolarization?
Sympathetic NS releases NorEpi and Epi at the heart which interact with B1 adrenergic recepts, increases both If (slow Na channels) and Ica leading to increase in HR and positive chronotropic effect
What is the P-wave?
It is the wave of depolarization from the SA node through the atria
What is the PR segment of an EKG?
It is the section after the P wave where there is no detectible signal as it is depolarizing the AV node
What is the Q-wave?
The depolarization wave along the bundle of his and purkinje fibers
What is the R-wave?
The peak, due to the mass of muscle involved. Wave of depolarization spreads throughout the ventricle, the deflection returns to zero.
What is the S-wave?
The last part of the ventricle to depolarize is near the atrium, a brief negative deflection occurs