Summary
Summary NURS 493 Med Surg Exam 1 Study Guide
- Institution
- Queens University Of Charlotte
This is a comprehensive and detailed study guide on med surg exam 1 for Nurs 493. ***An Essential Resource for YOU!!
[Show more]
Content preview
Med Surg Exam 1 Electrical Conduction System
o Sinoatrial Node/SA Node
Located in the right atrium
Heart’s main pacemaker, generating impulses 60-100 times per minute
Is normally the “starting point” for electrical activity
SA Node
o 60-100
AV Node
o 40-60
Bundle of His; Bundle Branches
o 40-60
Purkinje Network
o 20-40
ECG Breakdown
o P-Wave
SA node fires, sends the electrical impulse outward to stimulate both atria and manifests
as a P-wave
Represents atrial contraction (depolarizations)
If inverted, impulse does not originate from SA node
o PR interval
Time which impulse travels from the SA node to the atria and downward to the ventricles
Measure from start of P-wave to deflection up or down from baseline (starts of QRS)
Normal PRi is 0.12-0.20 seconds (3-4 boxes)
o QRS Complex
Impulse from the Bundle of His throughout the ventricular muscles
Ventricular contraction (depolarization)
Located after the PRi, measured from the Q-wave to the ends of the S-wave
Measures less than 0.12 seconds (less than 3 small boxes)
Q-wave represents the first downward from the baseline
R-wave represents the first trend upward form the baseline
Buried within QRS is atrial relaxation (repolarization)
o ST Segment
Begins with end of QRS (J point) and ends with the onset of the T-wave
“Elevated” if the segment deviates above the baseline of the PR segment
“Depressed” if the segment deviates below it
o T-Wave
Ventricular Repolarization, meaning no associated activity of the ventricular muscle
Resting phase of the cardiac cycles
May be peaked with high potassium
o QT Segment
Onset of QRS to end of T
Men have shorter than women
T-wave should end before half-way point between 2 QRS complex
Long QT increases chance for sudden death from arrhythmias
Low magnesium can increase the length of the QT
, Summary of ECG Waves
o P-wave
Atrial contraction
o PRi
Time from SA node through atrium to ventricle
o QRS
Ventricular contraction
o T-wave
Ventricular resting
o U-wave
After T, rarely seen
ECG Interpretation
o Step 1: heart rate
o Step 2: heart rhythm
o Step 3: P-wave
o Step 4: PR interval
o Step 5: QRS Complex
Sinus Rhythms
o Normal Sinus Rhythm
Pacemaker site: SA node
Rate: 60-100 bpm
P waves: are upright and all look alike
PR interval: generally constant; 0.12-0.20 sec
R-R interval: usually regular
QRS complexes: usually normal appearing and <0.12 seconds
P to QRS Relationship: one P wave precedes each QRS complex
o Sinus Bradycardia
Same as NSR with ONE exception
Rate: <60 bpm
Symptoms
Dizziness/weakness, diaphoretic, clammy, lethargic, confusion,
hypotension, unresponsive
Treatment
Atropine
o Sinus Tachycardia
Same as NSR with ONE exception
Rate: >100 bpm
In adults, ST is generally limited to a rate of 150-160 bpm
Causes
Anxiety, pain, fever, anemia, meds, compensatory, hypovolemia
Symptoms
SOB, palpitations, diaphoresis, hypotension
Treatment
Vagal maneuver
Beta-blockers
Calcium channel blockers
, o Sinus Arrhythmia
Essentially the same as NSR except:
Rate: 60-100 bpm, may be slightly faster or slower
R-R interval: irregular
Atrial Rhythms
o Atrial Flutter
Heart Rate: ventricular rate normal; atrial rate tachycardia reflected in flutter waves
Rhythm: Saw-tooth or picket fence flutter waves instead of P-waves
Pacemaker Site: Atrial site
P-Waves: No P waves, only flutter (F) waves
PRI: not applicable, no P waves
R-R Interval: usually equal but sometimes variable
QRS Complex: usually narrow
o Atrial Fibrillation
Heart Rate: atrial rate may be very fast, average of 400 bpm; variable (irregular)
ventricular rate
Rhythm: irregular
Pacemaker Site: multiple atrial sites
P-Waves: No P waves; fibrillation waves (Irregular baseline)
P-R Interval: not applicable, no P waves
R-R Interval: unequal
QRS Complex: usually narrow
Types of Atrial Fibrillation
Controlled: A. fib has a ventricular response of less than 100 bpm
Uncontrolled: A. fib has a ventricular response of greater than 100 bpm
Rapid Ventricular Response (RVR): A. fib with a ventricular response above
130 bpm
Symptoms
Palpitations, chest discomfort, irregular pulse, SOB, fatigue, weakness, distended
neck veins, anxiety, syncope, hypotension
Treatment
Slow the ventricular rate, convert the rhythm, anti-coagulate blood
o Metoprolol, Digoxin
o Amiodarone, Diltiazem
o Cardioversion – synchronized
o Anticoagulation
o Supraventricular Tachycardia
Heart Rate: usually 160-240
Rhythm: regular
Pacemaker Site: one ectopic atrial site
P-Waves: present but not appearing as normal P waves
P-R Interval: not applicable
R-R Interval: usually equal
QRS Complex: usually narrow
P to QRS: if P waves visible, one to one relationship
Treatment
o Adenosine; may have pause before rhythm restarts
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
48298 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 15 years now