Right Answer (B) During a Stokes-Adams syndrome attack, total A-V block suddenly begins, and the duration of the block may be a few seconds or even several weeks. The new pacemaker of the heart is distal to the point of blockade but is usually deep in the A-V node or the A-V bundle.

Q.101 A man had a myocardial infarction at age 55 years. He is now 63 years old. Use the standard limb lead I tracing on his ECG shown ,

q.101

Right Answer (E) The heart rate can be determined by 60 divided by the R-R interval, which gives a value of 150 beats/min. This patient has tachycardia, which is defined as a heart rate greater than 100 beats/min.

Q.102 A 45-year-old man had the Below ECG recorded at his annual physical.

Right Answer (A) This ECG has characteristics of atrial paroxysmal tachycardia, which means that the tachycardia may come and go at random times. The basic shape of the QRS complex and its magnitude are virtually unchanged from the normal QRS complexes, which eliminates the possibility of ventricular paroxysmal tachycardia. This ECG is not characteristic of atrial flutter because there is only one P wave for each QRS complex.

Q.103 A 60-year-old woman sees her physician for her annual physical examination. The physician ordered an ECG, which is shown above.

Right Answer E : First-, second-, and third-degree heart blocks, as well as atrial paroxysmal tachycardia, all have P waves in the ECG. However, there are usually no evident P waves during atrial fibrillation, and the heart rate is irregular. Therefore, this ECG is characteristic of atrial fibrillation.

Q.104 An 80-year-old man went to his family physician for his annual checkup.

Right Answer(E) This patient’s heart rate is 37 beats/min, which can be determined by dividing 60 by the R-R interval. This is characteristic of some types of A-V block.

Q.105 An 80-year-old man went to his family physician for his annual checkup.

Right Answer (E) This ECG is characteristic of complete A-V block, which is also called third-degree A-V block. The P waves seem to be totally dissociated from the QRS complexes, because sometimes there are three P waves and sometimes two P waves between QRS complexes.
First-degree A-V block causes a lengthened P-R interval, and second-degree A-V block has long P-R intervals with dropped beats. However, this does not seem to be occurring in this ECG, because there is no relationship between the ORS waves and the P waves.