#1
Which of the following ions primarily contributes to the resting membrane potential of cardiac cells?
#2
Which phase of the cardiac action potential represents rapid depolarization due to the opening of voltage-gated sodium channels?
#3
Which ion plays a crucial role in the initiation and propagation of the action potential in cardiac pacemaker cells?
#4
Which phase of the cardiac action potential represents rapid repolarization due to the opening of voltage-gated potassium channels and closing of voltage-gated sodium channels?
#5
Which of the following is a characteristic feature of atrial fibrillation on an electrocardiogram (ECG)?
#6
Which phase of the cardiac action potential is characterized by the plateau phase where calcium influx balances potassium efflux?
#7
Which ion is primarily responsible for the initial depolarization of pacemaker cells in the sinoatrial (SA) node?
#8
During which phase of the cardiac action potential do voltage-gated calcium channels open, leading to the plateau phase?
#9
Which component of the cardiac conduction system is responsible for delaying the impulse transmission from the atria to the ventricles?
#10
During which phase of the cardiac action potential do voltage-gated potassium channels open, leading to repolarization?
#11
Which arrhythmia is characterized by chaotic, irregular electrical activity in the atria resulting in an irregular ventricular response?
#12
Which of the following ECG findings is indicative of a prolonged QT interval and an increased risk of ventricular arrhythmias?
#13
What is the typical heart rate range of a patient experiencing sinus tachycardia?
#14
Which arrhythmia is characterized by a widened QRS complex and irregular ventricular rhythm?
#15
What is the typical heart rate range of a patient experiencing sinus bradycardia?
#16
Which arrhythmia is characterized by a regular atrial rhythm with a sawtooth appearance of the P waves on ECG?
#17
What is the term for a cardiac arrhythmia characterized by rapid, irregular atrial depolarizations with a chaotic baseline pattern on ECG?
#18
Which of the following ECG findings suggests an increased risk of sudden cardiac death due to the presence of a prolonged QT interval?
#19
What is the term for an abnormally fast heart rhythm originating from the ventricles and often associated with hemodynamic compromise?
#20
What is the mechanism of action of class III antiarrhythmic drugs such as amiodarone?
#21
Which of the following ECG findings is indicative of an accessory pathway between the atria and ventricles resulting in a short PR interval and a delta wave?
#22
Which of the following ECG findings is indicative of a complete heart block where the atria and ventricles beat independently?
#23
What is the primary mechanism of action of class I antiarrhythmic drugs such as lidocaine?
#24