Exam 1 Advance EKG Flashcards
What is the benefit of using a 5-lead monitoring system vs a 3-lead set-up?
You can look at more than one lead at a time with a 5-lead system compared to the 3-lead system
Lead I:
Negative Electrode:
Positive Electrode:
Lead I:
Negative Electrode: Right Arm
Positive Electrode (eyeball): Left Arm
When the heart depolarizes, the + electrode senses electrical movement coming toward it. Lead I is therefore an upright tracing.
Lead II:
Negative Electrode:
Positive Electrode:
Lead II:
Negative Electrode: Right Arm
Positive Electrode (eyeball): Left Leg
Lead III:
Negative Electrode:
Positive Electrode:
Lead III:
Negative Electrode: Left Arm
Positive Electrode (eyeball): Left Leg
To connect this lead, the negative electrode is placed near the left shoulder, usually under the outer third of the left clavicle, and the positive electrode is placed to the right of the sternum in the fourth intercostal space. The QRS in negative deflection in this lead.
MCL-1 or Modified V1
If you see asystole on the monitor, how many leads will you need to look at for confirmation?
Confirm asystole in two leads
This is true for any dysrhythmias
Why would you stress the importance of shaving chest hair on males or proper lead placement around a woman’s chest?
Appropriate lead placement is crucial:
Assessing looks for underlying conditions.
Axis determination and hemiblocks.
Accurate infarct locations.
When getting an EKG, what is the recommended positioning for the patient?
In a perfect world, the patient would be supine.
Sitting position may also be used as some patients will not allow you to lay them flat
How many actual electrodes are there in a 12-lead EKG?
10 electrodes
-one for each limb (4)
-6 precordial electrodes
Limb lead go on the ______.
LIMBS (LA, RA, LL, RL)
biceps and wrist are ok, avoid the shoulders
Name the placements for the following leads:
V1:
V2:
V3:
V4:
V5:
V6:
Name the placements for the following leads:
V1: 4th intercostal space, right of the sternum
V2: 4th intercostal space, left of the sternum
V3: between V2 and V4
V4: 5th intercostal space, left of the sternum (mid-clavicular)
V5: 5th intercostal space, left of the sternum (anterior axillary line)
V6: 5th intercostal. space left of the sternum (mid-axillary line)
A normal 12-lead will not get a good view of the _________ side of the heart.
Right side of the heart
The 12 lead is designed to look at the left ventricle
Name all 12 views of the EKG:
Column 1:
Column 2:
Column 3:
Column 4:
Name all 12 leads of the EKG:
Row 1: I, II, III
Row 2: aVR, aVL, aVF (Romeo Loves Fiona)
Row 3: V1, V2, V3
Row 4: V4, V5, V6
What is the J-point?
The J (junction) point is where the QRS complex ends and the ST segment begins.
What does an RSR’ wave indicate?
The R prime wave represents the second time the complex goes above the isoelectric line. It can represent a conduction abnormality/bundle branch block.
What are two reasons why the J-point is important?
- Point of reference for determining bundle branch block.
- Point of reference for measuring the ST-segment elevation.
The first negative deflection after the p-wave is called the ________.
First positive deflection after the p-wave is called the ___________.
Q-wave
R-wave
What is axis?
Axis is how the electricity flows down through the heart, the direction of electricity down the conduction system.
How do you determine the axis?
Look at QRS complexes for ventricular axis.
As electricity flows towards a positive electrode (eyeball) it makes a _________ deflection on the EKG.
Positive Deflection
In a normal axis, describe the deflection in each lead.
Lead I:
Lead II:
Lead III:
What are the degree ranges for a normal axis?
Lead I: Positive
Lead II Positive
Lead III: Positive
0 to 90 degrees (59 degrees per Schmidt)
In a pathological left axis deviation, describe the deflection in each lead.
Lead I:
Lead II:
Lead III:
What are the degree ranges for pathological left axis deviation?
Lead I: Positive
Lead II: Negative
Lead III: Negative
-40 to -90 degrees
In a right-axis deviation, describe the deflection in each lead.
Lead I:
Lead II:
Lead III:
What are the degree ranges for a right-axis deviation?
Lead I: Negative
Lead II: Negative (can also be non-committal or positive)
Lead III: Positive
90 to 180 degrees
In an extreme right axis deviation, describe the deflection in each lead.
Lead I:
Lead II:
Lead III:
V1:
What are the degree ranges for an extreme right-axis deviation?
Lead I: Negative
Lead II: Negative
Lead III: Negative
V1: Positive
-90 to -180 degrees
In a physiological left axis, describe the deflection in each lead.
Lead I:
Lead II:
Lead III:
What are the degree ranges for a normal axis?
Lead I: Positive
Lead II: Positive or non-commital
Lead III: Negative
0 to -40 degrees
What kind of axis is a result of an anterior hemiblock?
Pathological Left Axis Deviation
What kind of axis is a result of a posterior hemiblock?
Right Axis Deviation
What kind of axis will result if the conduction origin is in the ventricles?
Extreme Right Axis Deviation
Hypertrophy of either ventricle can shift the axis _________ the area that is hypertrophied.
toward
Hypertrophy of the left ventricle is most commonly caused by __________. Other less common causes include:
Hypertension
Hypertrophic Cardiomyopahty
Extreme Exercise
Aortic Disease
Hypertrophy of the right ventricle is most commonly caused by ___________. Other less common causes include:
Severe lung disease
Pulmonary embolus
Pulmonary valve disease
What is the difference between a physiological left axis and a pathological left axis?
The physiological left axis is a normal variant (obese, athletic)
The pathological left axis means there is a disease process.
Is a right axis deviation pathological or physiological?
Pathological
Although per Schmidt if you are really skinny, you can have a slight right axis deviation
Name the axis deviation.
Lead I: Negative deflection
Lead II: Positive deflection
Lead III: Positive deflection
Right axis deviation
Name the axis deviation
Lead I: Negative
Lead II: Negative
Lead III: Negative
Extreme right axis deviation
Name the axis deviation.
Lead I: Positive
Lead II: Positive
Lead III: Positive
Normal Axis
Name the axis deviation
Lead I: Positive
Lead II: Non-committal
Lead III: Negative
Physiological Left Axis Deviation
Name the axis deviation
Lead I: Positive
Lead II: Negative
Lead III: Negative
Pathological Left Axis
What is a bundle branch?
A fascicle of electrical conduction system cells designed to carry an impulse to the ventricles.
Reminder: conduction rate for bundle branches are 20-40 bpm
Describe the turn signal method to determine whether it is a right or left BBB.
Which lead do you use:
QRS complex must be at least _____ seconds
Which lead do you use: Use MCL-1 (V1)
QRS complex must be at least 0.12 seconds (3 little boxes)
up= Right BBB
down = Left BBB
A patient with a BBB is at increased risk for what?
What are other problems associated with BBB?
Complete Heart Block (affects the syncytium of the heart)
Decrease perfusion and decrease blood pressure
A bundle branch block represents a ________ times higher mortality rate in the setting of an acute MI.
4 times
MI’s and BBB are bad
Determine what type of BBB for each EKG
What are the three types of bifascicular block?
RBBB + Anterior Hemiblock
RBBB + Posterior Hemiblock
Left Bundle Branch Block (Anterior Hemiblock + Posterior Hemiblock)
What drugs are contraindicated in a bifascicular block?
Lidocaine and Procainamide
Patients with bifascicular block will present with signs and symptoms of _____________________.
What are you worried about?
an acute MI.
A patient going into v-fib/v-tach or complete heart block
(Go ahead and get the pads on the patient, high risk for arrest)
Patients with bifascicular block will most likely have occlusion to which coronary artery?
Left Descending Coronary Artery (The Widow Maker)
What kind of axis deviation can a left bundle branch block present?
A LBBB can present with a normal, right, or left axis deviation depending upon the level at which it is blocked.
Where does your Right Coronary Artery supply blood to?
Inferior wall (LV)
Posterior wall (LV)
Right Ventricle
SA and AV node
Posterior Fascicle of the LBB
What kind of symptoms will be exhibited by a patient with an RCA occlusion or RCA ischemia?
Bradycardia
(SA and AV node not getting enough blood supply)
What will a RCA occlusion look like on a 3-lead EKG?
On a 3-lead EKG, the inferior wall of the LV can be seen so an RCA occlusion there will be an ST elevation depicted.
What is another name for the Left Anterior Descending Coronary Artery?
The Widow Maker
Where does the LAD supply blood to?
Anterior Wall of the LV
Septal Wall
Bundle of His and Bundle Branches
What kind of referred pain can be associated with RCA occlusion?
Acute onset of abdominal pain
Nause and vomiting
Especially in women and diabetic patients
Where does the circumflex supply blood?
Lateral Wall of LV
SA and AV nodes
Posterior Wall of LV
Genesis of an acute MI is from _____________ formation over time.
Atherosclerotic Plaque
Once the plaque ruptures, the lesion will set off a cascade clot forming biochemistry. Clot forming is a dynamic process.
What medication can interrupt the process of clot development?
Aspirin and Heparin
Chest pain on exertion = ___________% occlusion.
70 to 85%
Chest pain at rest = ___________% occlusion.
90%
Chest pain unrelieved by nitro = _________% occlusion
100%
How do you treat an acute MI?
Intervention plan: O2, NTG, pain control,
4 baby aspirins, heparin bolus
Morphine might not be the best agent for pain control due to histamine release which can cause hypotension, and decrease coronary perfusion pressure. Fentanyl may be a better option.
What are the contraindications for thrombolytics given for an acute MI?
Recent major surgeries (within 3 weeks)
Recent intracranial hemorrhage
Recent Ischemic Strokes
Active Bleeding
Significant Head Injuries
Patients with uncontrolled HTN (SBP >180 or DBP>110)
Age 75+
Pregnant Patients
What are the limitations of 12-Lead EKGs?
12 Leads are only 40-60% sensitive and may miss half of AMIs, and OMIs (You only really see the left ventricle).
A quality image is necessary.
Training to read the 12 leads.
EKG evidence is only one piece of the puzzle.
Some non-MI conditions look like MI’s. (aortic tear)
A normal 12 lead does not rule out a MI
What are the benefits of 12-Lead EKGs?
Highly specific (+90% confidence)
If it shows an MI, there probably is an MI
Rapid ID of MI in early stages (consider on-going serial 12 Leads)
What are the 3 phases of infarction?
Ischemia
Injury
Necrosis (Infarction)
What is going on in ischemia?
What will the T-wave look like?
Transient reduction of blood flow to the myocardium.
Symmetrical inverted T waves in 2 or more leads. (Usually V2 to V4)
Inverted T-waves are normal in aVR and MCL-1
What precordial leads look at the septal wall?
What precordial leads look at the anterior wall?
What precordial leads look at the lateral walls?
V1 and V2 (septal)
V3 and V4 (anterior)
V5 and V6 (lateral)
What is going on in injury?
What will the EKG look like?
When ischemia progresses, but still salvageable.
ST-segment elevation of more than 1 or 2 mm related leads.
picture shows ST elevation on all inferior leads
What leads can see the inferior wall?
Lead II
Lead III
aVF
What are causes of ST depression?
Reciprocal changes to other ST elevation
Can indicate subendocardial injury
Ischemia
Drug/Electrolyte problems (digoxin/hypokalemia)
(The EKG shows ST depressions in segments in Lead 1, aVL, V1, V2, V3, and V4)
Patients with infarcted tissue will develop what type of wave on the EKG?
Pathological Q-waves.
Greater than .04 seconds wide (1 little box) or 1/3 depth of r-wave height
Picture shows pathological q-waves in V4-V6
When a pathological Q-wave is seen with an ST-segment elevation, an acute MI is ________.
When a pathological Q-wave is seen without acute changes such as an ST-segment elevation or depression, it is considered ________.
Occurring
An old MI or of undetermined age
Inferior Leads:
Septal Leads:
Anterior Leads:
Lateral Leads:
High Lateral Leads:
Inferior Leads: Lead II, Lead III, aVF
Septal Leads: V1, V2
Anterior Leads: V3, V4
Lateral Leads: V5, V6
High Lateral Leads: Lead I, aVL
Which coronary artery supplies the lateral and high lateral leads?
Circumflex Artery
Lead I, aVL, V5, V6
Which coronary artery supplies all the inferior leads?
Right Coronary Artery
Lead II, Lead III, aVF
Which coronary artery supplies the septal and anterior leads?
Left Anterior Descending Artery
V1, V2, V3, V4
What leads are reciprocal to the inferior leads (Lead II, LeadII, aVF)?
High Lateral Leads
Lead I and aVL
What leads are reciprocal to the anterior leads (V3, V4)?
Inferior Leads
Lead II, Lead III, aVF
What leads are reciprocal to all lateral leads (Lead I, aVL, V5, V6)?
Inferior Leads
Lead II, Lead III, aVF
What leads would be reciprocal to septal leads?
Posterior Leads
If there is an acute MI in the posterior side of the heart. What leads will show ST-elevation?
Where will you see reciprocal changes (ST-depression)
What coronary artery supplies the posterior wall of the heart?
V8 and V9
Septal Leads (V1, V2) and Anterior Leads (V3, V4)
Right Coronary Artery
How do you get a right-sided 12-lead EKG?
Which reversed precordial lead will show an elevated ST segment in an acute MI of the RV?
What coronary artery supplies the right ventricle?
Mirror the precordial leads V1 to V6 to the patient’s right side to get a view of their right ventricle.
V4R
Right Coronary Artery
What is the most common MI?
Inferior wall MI
For inferior wall MI, ______% have posterior and right ventricles involved.
What kind of symptoms will patients experience with inferior wall MI?
50%
Bradycardia and hypotension
Nausea (use antiemetic)
Inferior MIs can have what kind of blocks are associated with them?
1st degree AV Block
2nd degree Type 1 Block (Mobitz 1)
What should be used with caution with inferior MI?
Nitrates (can precipitously drop BP)
If the inferior MI affects the right ventricle, it can compromise preload. May need fluids and titrate nitrate carefully
Which MI has the highest mortality?
Anterior Wall MI
LAD is the widow maker
What can anterior wall MI suddenly develop into?
If you see an anterior wall MI with hemiblocks or BBB what do you need to do?
CHB, VF, or VT (fun)
Get the pads and hold on to your hat.
Anterior wall MI can extend to the _______ and __________.
Septum and lateral walls
What is great for anterior wall MIs. What should be spared?
Nitrates great.
Spare Fluids.
What can be infarction imitators?
Left BBB (The late depolarization makes ST elevation, LBBB will be considered a non-diagnostic ECG)
Left Ventricular Hypertrophy (LVH will have no reciprocal changes)
Pericarditis (ST elevation in all leads, the patient will feel better if they lean forward, not reciprocal ST depression)
Thoracic Aortic Aneurysm (Dangerous if misdiagnosis, heparin, thrombolytic, and NTG can be fatal, does not have reciprocal changes, get a CXR to view a widened mediastinum).
A genetic condition that can cause sudden death. Patients with this syndrome may experience syncope and abnormal EKG in the V1 and V2 leads.
Brugada Syndrome
ST elevation on V1 and V2
What does the slow gradual rise of the QRS complex indicate?
Wolff-Parkinson-White Syndrome
What is concerning you about this rhythm?
Sinus Arrthymia
Patients with hypocalcemia will have what associated changes to the EKG?
Prolonged QTc
Normal QTc range is 0.35 to 0.45
