CCT CCT - Certified Cardiographic Technician 12-Lead ECG Interpretation and Cardiac Conditions Questions and Answers 2 — Questions and Answers
Question 1: True posterior MI is best confirmed on a 12-lead ECG by which finding in the standard leads?
- ST elevation in V1-V4
- Tall broad R waves and ST depression in V1-V2 (mirror of posterior STEMI) (Correct answer)
- Q waves in II, III, aVF
- Inverted P waves in V1
Correct answer: Tall broad R waves and ST depression in V1-V2 (mirror of posterior STEMI)
Posterior MI appears as a mirror image in V1-V2: tall, broad R waves (posterior Q equivalents) and ST depression (reciprocal of posterior ST elevation), confirmed with posterior leads V7-V9.
Question 2: A patient's 12-lead ECG shows a short PR interval (<120 ms), delta wave, and wide QRS. This triad defines:
- Left bundle branch block
- Wolff-Parkinson-White (WPW) syndrome pre-excitation pattern (Correct answer)
- Hyperkalemia
- First-degree AV block
Correct answer: Wolff-Parkinson-White (WPW) syndrome pre-excitation pattern
The WPW pre-excitation pattern consists of a short PR interval (accessory pathway bypasses AV node), a delta wave (initial slow ventricular activation via the pathway), and a widened QRS.
Question 3: Which lead is considered the best single-lead view for detecting atrial activity and identifying P-wave morphology?
- V1 (Correct answer)
- aVR
- I
- V5
Correct answer: V1
Lead V1 sits directly over the right atrium and provides the clearest biphasic P wave, making it ideal for identifying atrial activity, flutter waves, and P-wave morphology.
Question 4: On a 12-lead ECG, a Brugada pattern is most commonly seen in which lead grouping?
- Inferior leads II, III, aVF
- Right precordial leads V1-V2 (Correct answer)
- Lateral leads I, aVL, V5-V6
- All 12 leads simultaneously
Correct answer: Right precordial leads V1-V2
Brugada pattern (coved-type ST elevation with RBBB morphology) is characteristically seen in the right precordial leads V1 and V2, reflecting right ventricular outflow tract abnormality.
Question 5: Left axis deviation (LAD) on a 12-lead ECG is defined as the QRS axis falling between:
- -30° and -90° (Correct answer)
- 0° and +90°
- +90° and +180°
- -90° and -180°
Correct answer: -30° and -90°
Left axis deviation is defined as a QRS axis more negative than -30°, with the range of -30° to -90° representing pathological LAD on a standard 12-lead ECG.
Question 6: Which finding on a 12-lead ECG is most specific for an acute anterior STEMI caused by proximal LAD occlusion?
- ST elevation in V1-V4 with new LBBB pattern
- ST elevation in V1-V4 with reciprocal depression in II, III, aVF (Correct answer)
- Delta waves in V1-V3
- Peaked T waves only in V2
Correct answer: ST elevation in V1-V4 with reciprocal depression in II, III, aVF
Anterior STEMI from proximal LAD occlusion causes ST elevation in V1-V4 with reciprocal inferior ST depression in II, III, and aVF, indicating a large ischemic territory.
CCT CCT - Certified Cardiographic Technician 12-Lead ECG Interpretation and Cardiac Conditions Questions and Answers 2
True posterior MI is best confirmed on a 12-lead ECG by which finding in the standard leads?