71. Which of the following statemen

71. Which of the following statements best describes a patient with premature atrial contraction?
A) Pulse taken from the radial artery immediately following the premature contraction will be
weak
B) Stroke volume immediately following the premature contraction will be increased
C) P wave is never seen
D) Probability of these premature contractions occurring is decreased in people with a large
caffeine intake
E) Causes the QRS interval to be lengthened
Questions 72 and 73
A male patient had a myocardial infarction at age 55. He is now 63 years old. Standard limb lead I is
shown here.
72. What is his heart rate?
A) 40 beats/min
B) 50 beats/min
C) 75 beats/min
D) 100 beats/min
E) 150 beats/min
73. What is his current diagnosis?
A) Sinus tachycardia
B) First-degree heart block
C) Second-degree heart block
D) ST segment depression
E) Third-degree heart block
74. A 55-year-old man has been diagnosed with Stokes-Adams syndrome. Two minutes after the
syndrome starts to cause active blockade of the cardiac impulse, which of the following is the pacemaker
of the heart?
A) Sinus node
B) A-V node
C) Purkinje fibers
D) Cardiac septum
E) Left atrium
75. If the origin of the stimulus that causes atrial paroxysmal tachycardia is near the A-V node, which of
the following statements about the P-wave in standard limb lead I is most accurate?
A) P wave will originate in the sinus node
B) It will be upright
C) It will be inverted
D) P wave will be missing
76. A 45-year-old man had the EKG below recorded at his annual physical. Which of the following is
the likely diagnosis?
A) Atrial paroxysmal tachycardia
B) First-degree A-V block
C) Second-degree A-V block
D) Ventricular paroxysmal tachycardia
E) Atrial flutter
77. A 60-year-old woman sees her physician for her annual physical examination. The physician orders
an EKG, which is shown below. Which of the following is the likely diagnosis?
A) First-degree A-V block
B) Second-degree A-V block
C) Third-degree A-V block
D) Atrial paroxysmal tachycardia
E) Atrial fibrillation
Questions 78 and 79
An 80-year-old man went to his family physician for his annual checkup, and his EKG tracing is shown
here.
78. What is his heart rate?
A) 105
B) 95
C) 85
D) 75
E) 40
79. Which of the following is the likely diagnosis?
A) Left bundle branch block
B) First-degree A-V block
C) Second-degree A-V block
D) Electrical alternans
E) Complete A-V block