Dysrhythmias Flashcards
Main Concern of Dysrhythmias
- Ineffective Tissue Perfusion
Dysrhythmias
- Any disturbance or irregularity in the electrical system of the heart
Electrophysiologic Properties
-Automaticity
- Ability of the pacemaker cells to initiate an electrical impulse
Electrophysiologic Properties
-Excitability
- Ability to respond to electrical impulse
Electrophysiologic Properties
-Conductivity
- Ability to transmit impulse from cell to cell
Electrophysiologic Properties
-Contractility
- Ability of muscle fibers to shorten in response to impulse
P Wave
- Atrial depolarization
QRS Wave
- Ventricle Depolarization
2. Atrial re-polarization
T Wave
- Ventricle Re-polarization
Refractory Periods
-Absolute Refractory Period
- Cell is unresponsive to another stimulus
Refractory Periods
-Relative Refractory Period
- A stimulus could initiate an action potential and cause a dysrhythmia
- Located at the last half of the T wave
QT Interval
- Ventricular Cycle
Normal PR Interval
- .12 to .20
- Time the impulse travels to AV node and bundle branches
Normal QRS Complex
- .06 to .10 seconds ( above .13 is considered above)
- Ventricular depolarization
- Q wave - first negative deflection
- R Wave - first positive deflection
- S Wave - First negative after R wave
ST Segment
-What to look for?
- If ST is Elevated, it indicates myocardial ischemia
Normal QT Interval
- 0.32 to 0.44
- Beginning of QRS to end of T wave
U Wave
- Usually NOT SEEN
2. May be seen with HYPOKALEMIA
Sick Sinus Syndrome
- Problems with impulse formation, transmission, & Conduction
Sinus Bradycardia
-Occurs in response to?
- Carotid sinus massage
- Hypothermia
- Increased vagal tone
- Parasympathomimetic drugs
- Hypothyroidism
- Obstructive jaundice
Sinus Bradycardia
-Clinical Significance
- Dependent on Symptoms
- Hypotension
- Pale, cool skin
- Weakness
- Angina
- Dizziness or syncope
- Confusion or disorientation // SOB
Sinus Bradycardia
-Treatment
- Atropine
2. Pacemaker may be required
Sinus Tachycardia
-Clinical Associations
- Associated w/ physiologic stressors
- Exercise
- Pain
- Hypovolemia
- MI, HF, Fever
Sinus Tachycardia
-Clinical Significance
- Dizziness & hypotension
2. Increased Myocardial oxygen consumption may lead to angina
Sinus Tachycardia
-Treatment
- Beta-adrenergic blockers to reduce HR and myocardial oxygen consumption
- Antipyretics to treat fever
- Analgesics for pain