RNSG 2539 SAC MOBILITY EXAM 2
PERFUSION, CLOTTING, METABOLISM,
& NUTRITION 2026/2027 WITH 152
QUESTIONS AND CORRECT ANSWERS
RATED A+
Also evaluate if PR Intervals are constant or varying across the EKG strip. If they
vary, determine if the variations are a steady lengthening until the point where an
expected QRS does not appear.
PR Interval questions to address:
Does the PR-Interval fall within the norm of 0.12-0.20 seconds?
ECG/EKG strip
P wave=atrial depolarization
QRS wave=ventricular depolarization
T wave=ventricular repolarization
P Wave
The P wave represents atrial depolarization. In a normal EKG, the P-wave
precedes the QRS complex. It looks like a small bump upwards from the baseline.
The amplitude is normally 0.05 to 0.25mV (0.5 to 2.5 small boxes). Normal
duration is 0.06-0.11 seconds (1.5 to 2.75 small boxes). The shape of a P-wave is
usually smooth and rounded.
P-wave questions:
Are they present?
Do they occur regularly?
,Is there one P-wave for each QRS complex?
Are the P-Waves smooth, rounded, and upright?
Do all P-Waves have similar shapes?
The PR Interval indicates AV conduction time.
In this step you should measure the interval from where the P wave begins until
the beginning of the QRS complex. Calipers, marked paper or counting small
boxes methods can be used to determine PR Intervals. Normally this interval is
0.12 to 0.20 seconds (3 to 5 small boxes) in adults, longer in elderly people. This
interval shortens with increased heart rate.
Is the PR-Interval constant across the ECG tracing?
The QRS complex indicates ventricular depolarization. Depolarization triggers
contraction of the ventricles.
Because of the larger tissue mass, the QRS complex is larger than the P wave.
While the prototypical QRS complex consists of three wave components, one or
two of these components may be missing.
In this step, measure the QRS interval from the end of the PR interval to the end
of the S wave. Use calipers, marking paper or by counting small boxes. Normally
this interval is 0.06 to 0.12 seconds (1.5 to 3 boxes).
QRS questions:
Does the QRS interval fall within the range of 0.06-0.12 seconds?
Are the QRS complexes similar in appearance across the ECG tracing?
The T wave indicates the repolarization of the ventricles. It is a slightly
asymmetrical waveform that follows (after a pause), the QRS complex. Take note
of T waves that have a downward (negative) deflection or of T waves with tall,
pointed peaks.
The U-wave is a small upright, rounded bump. When observed, it follows the T-
wave.
The QT interval represents the time of ventricular activity including both
depolarization and repolarization.
,It is measured from the beginning of the QRS complex to the end of the T wave.
Normally, the QT interval is 0.36 to 0.44 seconds (9-11 boxes). The QT interval will
vary with patient gender, age and heart rate. Another guideline is that normal QT
Intervals is less than half of the R-R Interval for heart rates below 100 bpm.
The ST segment represents the early part of ventricular repolarization.
The ST segment is the line that from the end of the QRS complex to beginning of
the T wave. Normally the ST segment is flat relative to the baseline.
Determining Normal vs. Abnormal Atrial and Ventricular Rhythm
For ventricular rhythms, examine the R to R intervals on the EKG strip. Calipers or
paper marks can be used to fix the distance for one R-R interval and then this
distance can be compared to other R-R pairs.
Are they regular, meaning that each heart beat's R-R interval is equal? Small
variations of up to 10% are considered equal. Is the rhythm regularly irregular?
For example is there a pattern, such as increasing R-R durations? Or perhaps
groups of similar intervals as illustrated on the right? Or are R-R intervals
completely irregular?
For atrial rhythm, observe the P-P intervals. Are they regular (minor variations can
be caused by the breath cycle)? If P-P intervals are irregular, is there a pattern?
The simplest method to determine heart rate on an ECG/EKG strip
Count the number of QRS complexes over a 6 second interval. Multiply by 10 to
determine heart rate. This method works well for both regular and irregular
rhythms.
ECG/EKG strip measurements
Atrial Flutter
P Waves are not detectable; sawtooth pattern in-between QRS complexes.
Myocardial Infarction: Pathophysiology
-One or more coronary arteries become occluded.
-Although there are several possible causes, arterial occlusion is usually the result
, of plaque rupture followed by thrombus formation. The thrombus then occludes
a coronary artery, stopping blood flow to the heart and depriving the heart of
oxygen, which causes ischemia that leads to cellular death.
-If coronary occlusion causes ischemia lasting longer than 45 minutes, irreversible
myocardial cell damage and muscle death occur.
-Every MI has a central area of necrosis surrounded by an area of hypoxic injury.
This injured tissue is potentially viable and may be salvaged if circulation us
restored, or it may progress to necrosis.
MI: Risk Factors
-Increased age (40-70)
-Diabetes
-increased serum triglyceride, increased LDL, increased cholesterol, and
decreased HDL
-Excessive intake of saturated fats, carbohydrates, and/or salt
-Hypertension
-Obesity
-Family Hx of CAD
-sedentary lifestyle
-smoking
-stress or type A personality
-use of street drugs such as amphetamines or cocaine
MI: Signs and Symptoms
-Extreme Anxiety
-Chest pain that continues despite rest and medication
-Diaphoresis; cool, clammy skin
-Pulse alterans (arterial pulse waveform showing alternating strong and weak
beats/It is almost always indicative of left ventricular systolic impairment, and
carries a poor prognosis), pulse bisferiens (arterial pulse that has two peaks)
-Restlessness
-Dyspnea
-Tachycardia
-HTN
-Bradycardia and hypotension in inferior MI
PERFUSION, CLOTTING, METABOLISM,
& NUTRITION 2026/2027 WITH 152
QUESTIONS AND CORRECT ANSWERS
RATED A+
Also evaluate if PR Intervals are constant or varying across the EKG strip. If they
vary, determine if the variations are a steady lengthening until the point where an
expected QRS does not appear.
PR Interval questions to address:
Does the PR-Interval fall within the norm of 0.12-0.20 seconds?
ECG/EKG strip
P wave=atrial depolarization
QRS wave=ventricular depolarization
T wave=ventricular repolarization
P Wave
The P wave represents atrial depolarization. In a normal EKG, the P-wave
precedes the QRS complex. It looks like a small bump upwards from the baseline.
The amplitude is normally 0.05 to 0.25mV (0.5 to 2.5 small boxes). Normal
duration is 0.06-0.11 seconds (1.5 to 2.75 small boxes). The shape of a P-wave is
usually smooth and rounded.
P-wave questions:
Are they present?
Do they occur regularly?
,Is there one P-wave for each QRS complex?
Are the P-Waves smooth, rounded, and upright?
Do all P-Waves have similar shapes?
The PR Interval indicates AV conduction time.
In this step you should measure the interval from where the P wave begins until
the beginning of the QRS complex. Calipers, marked paper or counting small
boxes methods can be used to determine PR Intervals. Normally this interval is
0.12 to 0.20 seconds (3 to 5 small boxes) in adults, longer in elderly people. This
interval shortens with increased heart rate.
Is the PR-Interval constant across the ECG tracing?
The QRS complex indicates ventricular depolarization. Depolarization triggers
contraction of the ventricles.
Because of the larger tissue mass, the QRS complex is larger than the P wave.
While the prototypical QRS complex consists of three wave components, one or
two of these components may be missing.
In this step, measure the QRS interval from the end of the PR interval to the end
of the S wave. Use calipers, marking paper or by counting small boxes. Normally
this interval is 0.06 to 0.12 seconds (1.5 to 3 boxes).
QRS questions:
Does the QRS interval fall within the range of 0.06-0.12 seconds?
Are the QRS complexes similar in appearance across the ECG tracing?
The T wave indicates the repolarization of the ventricles. It is a slightly
asymmetrical waveform that follows (after a pause), the QRS complex. Take note
of T waves that have a downward (negative) deflection or of T waves with tall,
pointed peaks.
The U-wave is a small upright, rounded bump. When observed, it follows the T-
wave.
The QT interval represents the time of ventricular activity including both
depolarization and repolarization.
,It is measured from the beginning of the QRS complex to the end of the T wave.
Normally, the QT interval is 0.36 to 0.44 seconds (9-11 boxes). The QT interval will
vary with patient gender, age and heart rate. Another guideline is that normal QT
Intervals is less than half of the R-R Interval for heart rates below 100 bpm.
The ST segment represents the early part of ventricular repolarization.
The ST segment is the line that from the end of the QRS complex to beginning of
the T wave. Normally the ST segment is flat relative to the baseline.
Determining Normal vs. Abnormal Atrial and Ventricular Rhythm
For ventricular rhythms, examine the R to R intervals on the EKG strip. Calipers or
paper marks can be used to fix the distance for one R-R interval and then this
distance can be compared to other R-R pairs.
Are they regular, meaning that each heart beat's R-R interval is equal? Small
variations of up to 10% are considered equal. Is the rhythm regularly irregular?
For example is there a pattern, such as increasing R-R durations? Or perhaps
groups of similar intervals as illustrated on the right? Or are R-R intervals
completely irregular?
For atrial rhythm, observe the P-P intervals. Are they regular (minor variations can
be caused by the breath cycle)? If P-P intervals are irregular, is there a pattern?
The simplest method to determine heart rate on an ECG/EKG strip
Count the number of QRS complexes over a 6 second interval. Multiply by 10 to
determine heart rate. This method works well for both regular and irregular
rhythms.
ECG/EKG strip measurements
Atrial Flutter
P Waves are not detectable; sawtooth pattern in-between QRS complexes.
Myocardial Infarction: Pathophysiology
-One or more coronary arteries become occluded.
-Although there are several possible causes, arterial occlusion is usually the result
, of plaque rupture followed by thrombus formation. The thrombus then occludes
a coronary artery, stopping blood flow to the heart and depriving the heart of
oxygen, which causes ischemia that leads to cellular death.
-If coronary occlusion causes ischemia lasting longer than 45 minutes, irreversible
myocardial cell damage and muscle death occur.
-Every MI has a central area of necrosis surrounded by an area of hypoxic injury.
This injured tissue is potentially viable and may be salvaged if circulation us
restored, or it may progress to necrosis.
MI: Risk Factors
-Increased age (40-70)
-Diabetes
-increased serum triglyceride, increased LDL, increased cholesterol, and
decreased HDL
-Excessive intake of saturated fats, carbohydrates, and/or salt
-Hypertension
-Obesity
-Family Hx of CAD
-sedentary lifestyle
-smoking
-stress or type A personality
-use of street drugs such as amphetamines or cocaine
MI: Signs and Symptoms
-Extreme Anxiety
-Chest pain that continues despite rest and medication
-Diaphoresis; cool, clammy skin
-Pulse alterans (arterial pulse waveform showing alternating strong and weak
beats/It is almost always indicative of left ventricular systolic impairment, and
carries a poor prognosis), pulse bisferiens (arterial pulse that has two peaks)
-Restlessness
-Dyspnea
-Tachycardia
-HTN
-Bradycardia and hypotension in inferior MI
