Sinus Rhythm - Intro Flashcards
(32 cards)
What is the origin of Normal Sinus Rhythm?
SA node, the heart’s dominant pacemaker
The SA node initiates the electrical impulses that regulate heartbeats.
What is the heart rate range for Normal Sinus Rhythm?
60 - 100 BPM
BPM stands for beats per minute.
What is the characteristic of the R-R interval in Normal Sinus Rhythm?
Regular R-R interval
The R-R interval measures the time between successive R wave peaks on an ECG.
How many P waves are present for each QRS in Normal Sinus Rhythm?
1 P wave for every QRS
This indicates a direct correlation between atrial and ventricular depolarization.
What is the normal range for the PR Interval (PRI) in Normal Sinus Rhythm?
0.12 sec - 0.20 sec
The PR interval reflects the time taken for electrical impulses to travel from the atria to the ventricles.
What is the QRS Duration range in Normal Sinus Rhythm?
0.06 sec - 0.11 sec
The QRS duration measures the time taken for ventricular depolarization.
What defines Sinus Bradycardia?
Heart Rate below 60 BPM
Sinus Bradycardia can be normal in well-conditioned athletes.
What causes Sinus Bradycardia?
Slowing of SA node impulse formation due to vagal stimulation, drug effects, or circadian rhythm
Vagal stimulation can occur during relaxation or sleep.
What is the heart rate for Sinus Tachycardia?
Greater than 100 BPM
Sinus Tachycardia often occurs in response to increased cardiac output demands.
What causes Sinus Tachycardia?
Increase in SA node impulse formation due to increased cardiac output demands
This can be triggered by factors such as exercise, drug effects, anxiety, hypoxia, and pain.
What is a characteristic of Sinus Arrhythmia?
Rate varies with respiration
Sinus Arrhythmia is often seen in younger individuals and can be a normal variant.
What is the R-R interval characteristic of Sinus Arrhythmia?
Irregular R-R interval
This irregularity is typically related to respiratory cycles.
What is the P:QRS Ratio for all Sinus Rhythms?
1:1
This indicates that each P wave corresponds to one QRS complex.
What is the definition of Sinus Bradycardia?
Heart Rate below 60 BPM
This condition can be physiological or pathological.
What are some causes for increased SA node automaticity with Sinus Tachycardia?
- Fever
- Exercise
- Hypoxia
- Anxiety
These factors stimulate increased heart rate through enhanced SA node activity.
What is the origin of Normal Sinus Rhythm?
SA node, the heart’s dominant pacemaker
The SA node is responsible for initiating the electrical impulses that regulate heartbeats.
What is the normal heart rate range for Normal Sinus Rhythm?
60 - 100 BPM
BPM stands for beats per minute.
What is the characteristic of the R-R interval in Normal Sinus Rhythm?
Regular R-R interval
The R-R interval is the time between successive R waves of the QRS signal on an ECG.
What is the P wave characteristic in Normal Sinus Rhythm?
1 (upright and rounded in Lead II) P wave for every QRS
The P wave represents atrial depolarization.
What is the normal PR Interval (PRI) range for Normal Sinus Rhythm?
0.12 sec - 0.20 sec
The PR interval measures the time from the onset of atrial depolarization to the onset of ventricular depolarization.
What is the QRS Duration range for Normal Sinus Rhythm?
0.06 sec - 0.11 sec
The QRS duration indicates the time taken for ventricular depolarization.
What defines Sinus Bradycardia?
Heart Rate less than 60 BPM
Sinus bradycardia can be normal in well-conditioned athletes.
What causes Sinus Bradycardia?
Slowing of SA node impulse formation due to vagal stimulation, drug effects, or circadian rhythm
Vagal stimulation can occur during rest or sleep.
What are the characteristics of Sinus Bradycardia?
Rate: Less than 60 BPM, Regular R-R interval, 1 sinus P wave for every QRS, PRI: 0.12 sec - 0.20 sec, QRS Duration: 0.06 sec - 0.11 sec
The characteristics are similar to Normal Sinus Rhythm except for the heart rate.
