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The following are suggested diagnostic criteria for the items listed in the test section. These are not intended to be comprehensive, and minor variations of these criteria exist in textbooks of electrocardiography. The suggested test answers in this text, however, use the following basic criteria.


  1. A Rhythm Abnormalities

    • A. Supraventricular rhythms and complexes

    • B. AV junctional rhythms and complexes

    • C. Ventricular rhythms and complexes

    • D. Pacemaker function, rhythms, and complexes

  2. AV Conduction Abnormalities

  3. Miscellaneous AV Relationships

  4. P-Wave Abnormalities

  5. Abnormalities of QRS Axis or Voltage

  6. Intraventricular Conduction Abnormalities

  7. Ventricular Hypertrophy (or Enlargement)

  8. Q-Wave Myocardial Infarction

  9. ST-, T-, U-Wave Abnormalities

  10. Technical Problems


  1. Rhythm Abnormalities

    • A. Supraventricular Rhythms and Complexes

      • 1. Sinus rhythm

        A physiologic rhythm initiated in the sinus node and characterized by a heart rate of 60 to 100 bpm. The configuration of the P wave is upright in leads I, II, and aVF and inverted in lead aVR.

      • 2. Sinus arrhythmia

        Sinus rhythm in which the PP interval varies by 0.16 s or more.

      • 3. Sinus bradycardia

        Sinus rhythm with a heart rate less than 60 bpm.

        Note: For clinical purposes, many cardiologists consider sinus bradycardia to be less than 50 bpm.

    • 4. Sinus tachycardia

      Sinus rhythm with a heart rate greater than 100 bpm.

    • 5. Wandering atrial pacemaker within the sinus node

      Sinus rhythm with minor variations in P-wave morphology remaining upright in leads I and II and inverted in aVR. The PR interval is variable but remains 0.12 s or greater.

    • 6. Wandering atrial pacemaker to the AV junction

      Sinus rhythm with progressive alteration in P-wave configuration, eventually becoming inverted (retrograde). The PR interval of the AV junctional focus characteristically becomes less than 0.12 s.

    • 7. Sinus arrest or pause

      A failure of the SA node to initiate an impulse, which results in absence of P waves and QRS complexes. The pause is not a multiple of the intrinsic PP interval.

    • 8. Sinoatrial exit block

      An abnormality of transmission of the sinus impulse, which results in a delay or failure of production of a P wave. Only second-degree SA block can be identified on the surface electrocardiogram. It may manifest in two patterns, type I and type II.

      • □  Type I second-degree SA block is characterized by progressive shortening of the PP interval prior to an absent P wave.

      • □  Type II is characterized by a pause in the PP cycle that is an exact multiple of the intrinsic sinus rate.

        Note: In some individuals with underlying sinus arrhythmia, the duration of the longest pause may be slightly less than an exact multiple of the sinus rate.

    • 9. Ectopic atrial rhythm

      A rhythm initiated by an atrial pacemaker other than the sinus node. It is characterized by a rate less than 100 bpm with a P-wave morphology different from that of the sinus node. The PR interval is within normal ...

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