ECG Test – Quiz 3 – Mixed Conditions

A male 25 year-old student at Oxford University is seeing his primary care physician due to palpitations. The palpitations occurs intermittently, but they tend to intensify during stressful periods, such as exam periods. The patient experiences palpitations with sudden onset and occassionally the sensation that the heart skips a beat. Clinical examination reveals nothing suspicious and the patient has not experienced any symptoms during the last week.

What does the ECG show?

Paper speed is 50 mm/s. Heart rate is approximately 65 beats per minute.

A 70 years-old male was admitted to the ER (emergency room) due to chest pain and discomfort in his left arm. These symptoms debuted a few hours earlier. Physical examination did not reveal anything unusual. The ECG shows a heart rate of 69  beats per minute. The PR interval is 180 ms (normal). The QRS duration is 84 ms (normal). The QTc (corrected QT) interval is 437 ms (normal) and the electrical axis is 30 degrees (normal). Note that the ECG paper speed is 50 mm per second and the leads are presented using the Cabrera format, which is the recommended format. As always, you start by viewing lead II, where you note a positive P-wave. Because the heart rate is 69 per minute, and the P-wave is positive in lead II, you conclude that the rhythm is sinus rhythm, which is correct. You also note that the most positive QRS amplitude is noted in lead –aVR, which is consistent with an electrical axis of 30 degrees (lead –aVR is located at 30 degrees in the coordinate system). Finally you also note that the QRS complex is positive in lead I and lead II, which means that the electrical axis is normal. But the question is, why does this patient experience chest pain?

Chest leads

Limb leads

Are there any signs of myocardial infarction? Pay attention to lead III in particular.

The paper speed is 50 mm/s.

Chest leads

Limb leads

Why does this 39-year old male experience palpitations intermittently? Note that paper speed is 50 mm/s (1 large box = 100 ms; 1 small box = 20 ms).

Limb leads

Chest leads

This 75-year old lady has an abnormal ECG. Two days earlier she experienced chest discomfort and shortness of breath. Define the abnormalitites on the ECG.

Paper speed is 50 mm/s.

A 71-year old male is admitted to the emegency room (ER) due to palpitations and chest discomfort. What is the correct diagnosis? Note that the paper speed is 50 mm/s.

Limb leads

Chest leads