Sinus rhythm Flashcards
1
Q
regular sinus rhythm
A
- 60-100
- rhythm regular
- p waves are normal, upright, and only before each QRS complex
- PR interval- .12-.2 sec
- QRS complex- normal, duration of < .12s
2
Q
causes of dysrhythmias
A
- myocardial ischemia, necrosis, or infarction
- autonomic nervous system imbalance
- distention of the chambers of the heart
- blood gas abnormalities
- electrolyte imbalances
- trauma to the myocardium
- drug effects and drug toxicity
- electrocution
- hypothermia
- CNS damage
- idiopathic events
- normal occurences
3
Q
dysrhythmia
A
- something off with the heart
- not working right
4
Q
arrhythmia
A
-something is absent
5
Q
ectopic foci
A
- other parts of the heart initiates their own pulse
- multiple beats
- ectopic beats
6
Q
reentry
A
- part of the impulse gets out of the electrical tract and then back into it
- causes multiple beats to take place
7
Q
classification by site of origin
A
- originating in the SA node
- originating in the atria
- originating within the AV junction
- sustained in or originating in the AV junction
- originating the in the ventricles
- resulting from disorders of conduction
8
Q
dysrhythmias originating in the SA node: bradycardia
A
- rate less than 60
- everything else is normal
- bradycardia!
- maybe too much parasympathetic
- maybe something wrong with SA node-> slow
- maybe drugs
9
Q
sinus bradycardia
A
- etiology- increase parasympathetic (vagal) tone, intrinsic disease of the SA node, drug effects
- may be a normal finding in health well conditioned persons
- clinical significance- may result in decreased cardiac output, hypotension, angina, or CNS symptoms
- in healthy well conditioned person, may have no significance
- treatment- generally unnecessary unless hypotension or ventricular irritability is present
10
Q
dysrhythmias originating in the SA node: tachycardia
A
- rate is greater than 100
- everything else is normal
11
Q
sinus tachycardia
A
- etiology- results from an increased rate of SA node discharge
- potential causes include exercise, fever, anxiety, hypovolemia, anemia, pump failure, increased sympathetic tone, hypoxia, or hyperthyroidism
- clinical significance- decreased cardiac output for rates > 140
- greater than 140- ventricles arnt filling enough -> stroke volume is too low
- very rapid rates can precipitate ischemia or infarct
- treatment- is directed at the underlying cause
12
Q
dysrhythmias originating in the SA node: sinus dysrhythmia
A
-rhythm is irregular
13
Q
sinus dysrhythmia/arrhythmia
A
- etiology- often a normal finding, sometimes related to the respiratory cycle
- rate gradually increases with inspiration and decreases with expiration
- may be caused by enhances vagal tone
- clinical significance- normal variant
- treatment- typically, none required
14
Q
dysrhythmias originating in the SA node
A
- normal to slow rate
- irregular rhythm
- pause in rate
15
Q
sinus arrest
A
- etiology- occurs when the sinus node fails to discharge
- may result from ischemia of the SA node, digitalis toxicity, excessive vagal tone, or degenerative fibrotic disease
- clinical significance- frequent or prolonged episodes may decrease cardiac output and cause syncope
- prolonged episodes may result in escape rhythms- AV node may fire (back up plans)
- treatment- none if patients is asymptomatic -> treat symptomatic bradycardia (treat just like bradycardia)