#1
Which of the following represents a normal sinus rhythm on an ECG?
P wave before each QRS complex
ExplanationNormal rhythm characterized by atrial depolarization preceding ventricular depolarization.
#2
What is the typical heart rate range for sinus tachycardia?
100-150 beats per minute
ExplanationElevated heart rate originating from the sinus node, often due to physiological stress or excitement.
#3
Which ECG lead placement is used to assess for right ventricular infarction?
Lead V1
ExplanationProvides a view of the right ventricle, crucial for detecting infarctions.
#4
Which ECG lead is commonly used to detect ST-segment changes indicative of myocardial ischemia?
Lead V4
ExplanationProvides a view of the left ventricle and is commonly used to assess for ischemic changes.
#5
Which ECG lead is commonly used to diagnose posterior wall myocardial infarction?
Lead V4R
ExplanationProvides a view of the right ventricular wall, useful for detecting posterior wall infarctions.
#6
What is the term for a delay in the electrical conduction between the atria and ventricles?
Heart block
ExplanationImpaired transmission of electrical signals from atria to ventricles.
#7
Which ECG finding is characteristic of atrial fibrillation?
Absence of P waves
ExplanationIrregular heart rhythm with chaotic atrial activity and no discernible P waves.
#8
Which ECG lead is commonly used to diagnose myocardial infarction?
Lead V1
ExplanationProvides a view of the septum and right ventricle, useful for detecting infarctions.
#9
What is the term for an abnormally slow heart rate?
Bradycardia
ExplanationHeart rate below normal, often below 60 beats per minute.
#10
What does the PR interval on an ECG represent?
Time taken for atrial depolarization
ExplanationDuration from onset of atrial depolarization to onset of ventricular depolarization.
#11
Which arrhythmia presents with a 'sine wave' pattern on ECG and is considered a medical emergency?
Ventricular fibrillation
ExplanationChaotic, irregular ventricular rhythm leading to rapid cardiac collapse if not treated immediately.
#12
What does the QRS complex represent on an ECG?
Ventricular depolarization
ExplanationDepolarization of the ventricles resulting in ventricular contraction.
#13
Which arrhythmia is characterized by irregularly irregular rhythm and absence of distinct P waves?
Atrial fibrillation
ExplanationIrregular atrial rhythm with absence of distinct P waves.
#14
What is the typical appearance of Torsades de pointes on an ECG?
Prolonged QT interval with twisting of QRS complexes
ExplanationPolymorphic ventricular tachycardia with QT prolongation and twisting of the QRS complexes.
#15
Which arrhythmia is often associated with a 'sawtooth' appearance of the atrial waves?
Atrial flutter
ExplanationRegular atrial rhythm with characteristic 'sawtooth' appearance on ECG.
#16
Which electrolyte imbalance is associated with a prolonged QT interval on ECG?
Hypokalemia
ExplanationLow potassium levels leading to delayed repolarization and QT interval prolongation.
#17
Which ECG finding is characteristic of ventricular tachycardia?
Wide, bizarre QRS complexes
ExplanationRapid, regular heart rhythm originating in the ventricles with widened QRS complexes.
#18
Which ECG finding is characteristic of Wolff-Parkinson-White (WPW) syndrome?
Delta wave
ExplanationPre-excitation syndrome characterized by a slurred upstroke of the QRS complex.
#19
In which condition would you typically find a 'sawtooth' pattern on an ECG?
Atrial flutter
ExplanationRegular atrial rhythm with a characteristic 'sawtooth' appearance.
#20
What does a peaked T wave indicate on an ECG?
Hyperkalemia
ExplanationHigh potassium levels leading to rapid repolarization and peaked T waves.
#21
Which ECG finding is characteristic of complete heart block?
Prolonged PR interval with dropped beats
ExplanationAtrioventricular dissociation with prolonged PR interval and dropped beats.
#22
What is the most common cause of a widened QRS complex on an ECG?
Hyperkalemia
ExplanationHigh potassium levels leading to delayed ventricular depolarization and widened QRS complex.
#23
Which ECG finding suggests an anterior wall myocardial infarction?
ST-segment elevation in leads V1-V4
ExplanationIndicates ischemia or injury to the anterior wall of the left ventricle.
#24
Which electrolyte abnormality is associated with U-wave appearance on an ECG?
Hypokalemia
ExplanationLow potassium levels leading to delayed repolarization of the Purkinje fibers and U-wave appearance.
#25
What ECG finding is typically observed in patients with left bundle branch block?
Widened QRS complex with a slurred S wave in leads I, V5, and V6
ExplanationDelay in conduction through the left bundle branch resulting in widened QRS and slurred S waves in certain leads.