Chapter 4 Test — The 11-Step ECG Method

A 62-year-old woman on a cardiac monitor sets off a "ventricular tachycardia" alarm. She is alert, talking comfortably, and her radial pulse is 90/min and regular. The recording obtained (25 mm/sec, 10 mm/mV) is shown. Leads I and III show chaotic, large-amplitude baseline deflections, while lead II shows narrow, regular QRS complexes throughout.

What is the correct interpretation?

A resident reports "left ventricular hypertrophy by Sokolow-Lyon criteria" on the routine ECG of an asymptomatic 24-year-old athlete. On checking the recording, the calibration pulse at the start of each lead measures 20 mm tall.

What is the correct next step?

On a regular rhythm strip recorded at the standard paper speed of 25 mm/sec, the interval between two consecutive R waves measures exactly four large boxes.

Using the 300 rule, the ventricular rate is:

The figure shows how the 1500 method is used to calculate heart rate from a strip recorded at 25 mm/sec.

Applying the same method to a regular rhythm in which the R-R interval measures 6 small boxes, the heart rate is:

A 76-year-old man has an irregularly irregular pulse. His ECG shows a fibrillatory baseline with no discernible P waves and widely varying R-R intervals. A house officer measures the gap between two adjacent R waves as two large boxes and reports the ventricular rate as 150/min.

What is the correct way to determine the rate in this patient?

Step 3 of the 11-step method requires all five criteria for normal sinus rhythm to be satisfied.

Which of the following correctly states the required P wave polarity?

The PR interval on a routine ECG measures 0.21 seconds. Every P wave is followed by a QRS complex and the PR interval is constant.

What is the correct interpretation?

A short QTc interval (<340 ms) on an ECG should most strongly suggest which of the following?

A mean frontal QRS axis of −30° to −90° indicates:

A 68-year-old man with a previous myocardial infarction presents with a regular tachycardia at 170/min. The QRS complex is negative in lead I and negative in aVF.

What is the axis, and what should it make you think of first?

A 70-year-old man with a previous anterior myocardial infarction arrives in the emergency department with a regular tachycardia at 165/min and a QRS duration of 150 ms. His blood pressure is 82/50 mmHg and his peripheries are cold and clammy.

What is the most appropriate management?

The middle panel of the figure shows the precordial pattern in which the R wave fails to grow in height across V1 to V3.

In a patient with chest pain and Q waves in V1–V4, what does this pattern most importantly suggest?

The figure shows how ST-segment deviation is measured on a tracing recorded at standard calibration (10 mm/mV).

From which point is ST elevation measured, and what does the left panel demonstrate?

A 35-year-old man presents with one hour of crushing chest pain. His ECG shows 2 mm of ST elevation confined to leads V2 and V3, with no reciprocal changes elsewhere.

Applying the ACC/AHA ST-elevation criteria used in this chapter, this degree of elevation:

A 28-year-old man presents with sharp central chest pain that is worse on lying flat. His ECG shows widespread concave ST-segment elevation with PR-segment depression in most leads, sparing aVR, and no reciprocal ST depression in any territory.

These findings favour which diagnosis?

A 54-year-old smoker had severe central chest pain three hours ago, which has now completely resolved. He is currently pain-free and his troponin is normal. His ECG, recorded in the pain-free state, shows the biphasic T-wave morphology illustrated in the figure in leads V2 and V3, with no ST elevation.

What is the most appropriate next step?

Step 11 requires every ECG interpretation to end with a structured report.

Which set correctly lists the five components a professional ECG report must include?