Module 11 Flashcards
SA Node (60–100 bpm)
The SA Node generates electrical impulses that initiate each heartbeat.
What is the primary pacemaker of the heart?
What is the function of the AV Node?
Delays impulse to allow ventricular filling
This delay is crucial for proper heart function and efficient blood flow.
What does the Bundle of His do?
Conducts impulses from AV node to ventricles
It is part of the electrical conduction system of the heart.
What is the role of Purkinje Fibers?
Distribute impulse for coordinated ventricular contraction
They ensure that the ventricles contract in a synchronized manner.
What does the P wave represent in an ECG?
Atrial depolarization
It indicates the electrical activity associated with atrial contraction.
What does the QRS complex represent?
Ventricular depolarization
This is the most prominent part of the ECG, reflecting the contraction of the ventricles.
What does the ST segment indicate?
Time between ventricular depolarization and repolarization
It is important for assessing myocardial ischemia.
What does the T wave represent in an ECG?
Ventricular repolarization
This reflects the recovery phase of the ventricles.
What is Normal Sinus Rhythm (NSR)?
Heart rate of 60–100 bpm
Indicates a normal heart rhythm originating from the SA Node.
What defines Sinus Bradycardia (SB)?
Heart rate <60 bpm
This can occur in athletes or due to certain medications.
What is Sinus Tachycardia (ST)?
Heart rate >100 bpm
Often caused by stress, fever, or exercise.
What are Premature Atrial Contractions (PACs)?
Early atrial beats often caused by stress or caffeine
These are generally benign but can indicate underlying issues.
What is Paroxysmal Supraventricular Tachycardia (PSVT)?
Sudden burst of rapid atrial contractions
It can cause palpitations and may require treatment.
What is Atrial Flutter characterized by?
Sawtooth ECG pattern, atrial rate 250–350 bpm
It can lead to complications like stroke if untreated.
What is Atrial Fibrillation (A Fib)?
Irregular atrial activity; increased stroke risk
It is the most common type of serious heart arrhythmia.
What defines a Junctional Escape Rhythm?
Originates from AV node; HR 40–60 bpm
This rhythm can occur when the SA Node fails.
What is First-Degree Heart Block?
Prolonged PR interval
It is typically benign and often asymptomatic.
What is Second-Degree Block Type I (Wenckebach)?
Progressively lengthening PR interval, then dropped beat
This pattern can resolve on its own in some cases.
What is Second-Degree Block Type II (Mobitz II)?
Dropped beats without PR lengthening
This type is more serious and can progress to complete heart block.
What characterizes Third-Degree Heart Block?
No atrial impulses reach ventricles; requires pacemaker
This is a critical condition that can lead to severe bradycardia.
What are Premature Ventricular Contractions (PVCs)?
Early, wide QRS ventricular beats
They can be benign but may signify underlying heart disease.
What is Ventricular Tachycardia (V Tach)?
HR >100 bpm, wide QRS; may lead to V Fib
This is a potentially life-threatening condition requiring immediate attention.
What characterizes Ventricular Fibrillation (V Fib)?
Disorganized ventricular activity; life-threatening
It is a critical emergency that requires immediate defibrillation.
What is the duration of an ECG small box?
0.04 seconds
This helps in calculating heart rate and intervals.
