Card Set Information
EKG paramedic cardiac dysrhythmias kmariie
Cardiac Dysrhythmias Class
Where is the heart located?
Middle of the thoracic cavity, attached to the thorax via great vessels
Which heart layer is responsible for contraction and pumping?
Atria vs. Ventricles
: receive blood from the body
: pump blood to lungs and body
Where do the Tricuspid and Mitral (Bicuspid) valves lie?
: between R atrium and R ventricle
: between L atrium and L ventricle
Where do the Semilunar Pulmonary and Aortic valves lie?
: from the R ventricle to the pulmonary artery
: from the L ventricle to the Aorta
What supplies the heart with oxygen?
Cardiac Output Formula is...
CO= SV (stroke volume) x HR (heart rate)
Define CO. What's the normal adult CO?
: amount of blood ejected (pumped) by the ventricles in 1 minute
Normal adult CO= 4-8 LPM
ability to spontaneously initiate an electrical impulse
Major ions in cardiac function
Potassium (K), Sodium, (Na), Calcium (Ca)
Describe the Polarized state of a cell. What does it appears as on an EKG?
Resting state with no electrical activity. The inside of the cell is negative, outside is positive with uneven distribution of ions across the cell membrane.
Describe the Depolarized cell state.
Inside of cell is positive, outside of cell is negative.
Absolute Refractory Period
From the onset of QRS to approximately the peak of T wave. Cells are depolarized and cannot be stimulated.
Relative Refractory Period
"Vulnerable Period" because cells are repolarizing and can be stimulated (if stimulus is strong enough) thus possibly resulting in ventricular chaos.
Downslope of T wave.
EKG provides information about...
conduction disturbances, electrical effects of meds and electrolytes, and ischemic damage and injury.
When depolarization moves toward a positive or toward a negative the waveform deflection appears as...
Toward positive electrode= upward
Toward negative electrode= inverted (downward)
When electrical activity is not detected on an EKG, what appears?
A straight line is recorded, called the "baseline" or "isoelectric" line
In the bipolar leads, which is always positive? negative?
Positive = L leg electrode
Negative = R arm electrode
RA (-) ----> LA (+)
Lead axis II is?
RA (-) -----> LL (+)
Lead axis III is?
LA (-) ----> LL (+)
EKG paper: Small squares?
Small square: 1mm x 1mm, 0.04 sec
EKG paper: Large squares?
Large square: 5mm x 5mm, 0.2 sec
P wave represents...
atrial depolarization and spread of impulse across the L & R atria
End of P wave, beginning of QRS complex. Usually represented by an isoelectric line
PR Interval. What is the normal range?
From the beginning of the P wave to the beginning of QRS Complex. Reflects the impulse travel time from the SA node through the AV node, HB, R & L bundles, and into the Purkinje fibers.
Normal range= 0.12- 0.20
QRS Complex. Normal range?
Represents the depolarization of the ventricles and HR.
Normal range= 0.06- 0.12
a negative deflection following the P wave. Always appears as a negative waveform.
First positive deflection following the P Wave or Q wave (if present). Always appears as a positive waveform.
Negative waveform that follows the R wave.
R & S waves represent?
R & S waves represent the depolarization of the L & R ventricles.
End of the S wave, beginning of the T wave
ST elevation/ depression occurs on EKG if...
above or below by 1mm of the PR segment
ST depression can indicate? ST elevation?
: myocardial ischemia, digoxin, or low K
: myocardial injury, infarction, or pericarditis, or cardiac tamponade.
3 I's of MI (ischemia, injury, infarction)
represents ventricular repolarization
QT Interval. Normal range?
From beginning of Q to the end of the T wave. Represents total ventricular activity.
Normal range= 0.44 or