1060 Review Flashcards
(60 cards)
What is the inherent firing rate of the AV tissues
AV Node (Atrialventricular) 40-60 bpm
What is the inherent firing rate of the SA Node
SA (Sinoatrial)
60-100 bpm
What is the inherent firing rate of the ventricles
20-40 bpm
Where do the coronary arteries originate
The aorta (base of the heart) top of the heart
What coronary artery supplies the majority of circulation to the SA Node
(RCA) Right Coronary supplies 60% SA Node AV Node 90% as well as the Bundle of His, Right Atria and Right Ventricle posterior 1/3 of the septum
What valve prevents regurgitation of blood into the right atrium?
TRI cuspid (RI ght)
During ventricular diastole, which valves are open?
Tricuspid (on the right) aka Mitral valve
Bicuspid (on the left) aka Semilunar valve
During diastole which valves are shut?
semi lunar
List 4 layers of the heart
1) Endocardium = thin innermost layer
2) Myocardium = thick muscular layer
3) Epicardium = thin outer layer
4) Pericardium = the space that surrounds the heart with aprox 25 cc of fluid
What side of the heart is failing if you have pulmonary edema?
Left side (fluid is backing up into the lungs)
What side of the heart is failing if you have edema in the peripery
Right sided heart failure, fluid is backing up into systemic circulation
What coronary artery supplies the AV Node?
RCA Right Coronary Artery 90%
Pitting edema is caused by
right sided heart failure because the fluid is backing up into the rest of the body
What are the properties of the cardiac cell
RACCE (think racy)
Rhymiticity - keeps the beat Automaticity - initiates own impulse Conductivity - conducts impulse to cell Contractility - ability to contract* (*mechanical not seen on EKG) Excitability - ready to accept charge
What is the normal PR interval (time it takes for the impulse to travel from the SA node to Atria to AV node to common bundle)
normally 0.12 to 0.20 seconds
Atrial Repolarization is not visible on an EKG because it gets lost in the QRS
True or False
True
A wide QRS complex means
something is slowing down conduction in the ventricles
How long is the QT interval (the time it takes for the ventricles to depolarize and repolarize)
should be half of previous R to R interval or less than 0.5 seconds
what do the small squares on the EKG paper represent
a small square 1mm x 1mm = 0.04 seconds
What is a pathological Q wave?
Can indicates old/happening MI
>0.04 seconds and 1/3 the height of the QRS complex
How do you measure ST Elevation?
ST elevation is measured one small box from the J point and be > 1mm above the isoelectric line (base line)
And be present in 2 or more anatomically contiguous leads in a 12 lead EKG
How do you measure ST depression
Indicates ischemia
Segment must be >0.5mm below the isoelectric line
What does PQRST & U represent
Atrial and ventricular depolarization and repolarization are represented on the EKG as a series of waves
The PRI is measured from which point to which point?
From the beginning of the P wave to the beginning of the QRS complex