NAPLEX Arrhythmias Questions with Correct Answers (Grade A+)
Question 1: What makes the "lub dub" sounds?
Answer: closing of heart valves
Question 2: S1
Answer: beginning of ventricular systole
Question 3: S2
Answer: end of ventricular systole
Question 4: S3
Answer: third heart sound; murmur common in heart failure
Question 5: What are the symptoms of an arrhythmia?
Answer: can be asymptomatic; others have fluttering, heart skipping a beat, dizziness, SOB, fatigue, chest
pain, syncope
Question 6: How is an arrhythmia diagnosed?
Answer: EKG; sometimes via Holter monitor
Question 7: What is a normal heart rate?
Answer: 60-100 bpm
Question 8: What is the conduction pathway of the heart?
Answer: SA -> AV -> Bundle of His -> right bundle branch -> left bundle branch -> Purkinje fibers
Question 9: What are the causes of an arrhythmia?
Answer: abnormal rate/rhythm of SA node, scar tissue blocking/diverting signal, another pacemaker
Question 10: action potential
Answer: ion movement that provides electricity
Page 1
, Question 11: SA node cells have ___ and initiate their own action potentials.
Answer: automaticity
Question 12: What are the phases of the cardiac action potential?
Answer: phase 0: rapid ventricular depolarization with influx of Na, ventricular contraction; phase 1: early
rapid depolarization, Na channels close; phase 2: influx of Ca, efflux of K (plateau); phase 3: rapid
ventricular repolarization, efflux of K, ventricular relaxation; phase 4: resting membrane potential, atrial
depolarization
Question 13: Phase 0 of cardiac action potential
Answer: rapid ventricular depolarization with influx of Na leading to ventricular contraction
Question 14: Phase 1 of cardiac action potential
Answer: early rapid repolarization, Na channels close
Question 15: Phase 2 of cardiac action potential
Answer: influx of Ca, efflux of K (plateau)
Question 16: Phase 3 of cardiac action potential
Answer: rapid ventricular repolarization, efflux of K leading to ventricular relaxation
Question 17: Phase 4 of cardiac action potential
Answer: resting membrane potential, atrial depolarization
Question 18: What is the most common cause of arrhythmias?
Answer: myocardial ischemia/infarction; also electrolyte imbalances, hyperthyroidism, infection, illicit
drugs, antiarrhythmics, QT prolonging drugs
Question 19: What electrolyte imbalances can lead to cardiac arrhythmias?
Answer: K, Mg, Ca, Na
Question 20: supraventricular arrhythmias
Answer: above the AV node (afib, a flutter, atrial tachycardia)
Page 2
Question 1: What makes the "lub dub" sounds?
Answer: closing of heart valves
Question 2: S1
Answer: beginning of ventricular systole
Question 3: S2
Answer: end of ventricular systole
Question 4: S3
Answer: third heart sound; murmur common in heart failure
Question 5: What are the symptoms of an arrhythmia?
Answer: can be asymptomatic; others have fluttering, heart skipping a beat, dizziness, SOB, fatigue, chest
pain, syncope
Question 6: How is an arrhythmia diagnosed?
Answer: EKG; sometimes via Holter monitor
Question 7: What is a normal heart rate?
Answer: 60-100 bpm
Question 8: What is the conduction pathway of the heart?
Answer: SA -> AV -> Bundle of His -> right bundle branch -> left bundle branch -> Purkinje fibers
Question 9: What are the causes of an arrhythmia?
Answer: abnormal rate/rhythm of SA node, scar tissue blocking/diverting signal, another pacemaker
Question 10: action potential
Answer: ion movement that provides electricity
Page 1
, Question 11: SA node cells have ___ and initiate their own action potentials.
Answer: automaticity
Question 12: What are the phases of the cardiac action potential?
Answer: phase 0: rapid ventricular depolarization with influx of Na, ventricular contraction; phase 1: early
rapid depolarization, Na channels close; phase 2: influx of Ca, efflux of K (plateau); phase 3: rapid
ventricular repolarization, efflux of K, ventricular relaxation; phase 4: resting membrane potential, atrial
depolarization
Question 13: Phase 0 of cardiac action potential
Answer: rapid ventricular depolarization with influx of Na leading to ventricular contraction
Question 14: Phase 1 of cardiac action potential
Answer: early rapid repolarization, Na channels close
Question 15: Phase 2 of cardiac action potential
Answer: influx of Ca, efflux of K (plateau)
Question 16: Phase 3 of cardiac action potential
Answer: rapid ventricular repolarization, efflux of K leading to ventricular relaxation
Question 17: Phase 4 of cardiac action potential
Answer: resting membrane potential, atrial depolarization
Question 18: What is the most common cause of arrhythmias?
Answer: myocardial ischemia/infarction; also electrolyte imbalances, hyperthyroidism, infection, illicit
drugs, antiarrhythmics, QT prolonging drugs
Question 19: What electrolyte imbalances can lead to cardiac arrhythmias?
Answer: K, Mg, Ca, Na
Question 20: supraventricular arrhythmias
Answer: above the AV node (afib, a flutter, atrial tachycardia)
Page 2
