Tue28September1204PM 6

A 54-year-old ex-professional rugby player comes to the rapid access ambulatory clinic for review.

He has been admitted twice to the Emergency department with episodes of collapse whilst out running during the past two months. Each time he reported an episode of very rapid palpitations. On the first occasion he did not actually lose consciousness. On the second occasion he thinks he did, and awoke to find a passer-by standing over him. The passer-by reported feeling a thready pulse with a very rapid rate.

There is no significant past medical history. Examination in the clinic reveals a BP of 110/70 mmHg, pulse is 62 and regular. There are no murmurs and there are no signs of cardiac failure.

Investigations reveal:

Hb 140 g/L (135-180)

WCC 7.0 ×109/L (4.5-10)

PLT 202 ×109/L (150-450)

Na 137 mmol/L (135-145)

K 4.0 mmol/L (3.5-5.5)

Cr 100 µmol/L (70-110)

12 lead ECG shows no significant abnormalities. CXR is normal.

Which of the following is the most likely diagnosis underlying his collapses?

(Please select 1 option)

Exercise-induced ventricular tachycardia This is the correct answer

Paroxysmal atrial fibrillation

Congenital long QT syndrome

Hypertrophic obstructive cardiomyopathy (HOCM) Incorrect answer selected

Brugada syndrome

Explanation

Transient exercise-induced VT is occasionally seen as a cause of collapse in fit sportsmen with a structurally normal heart. The normal examination in clinic, normal heart size, and lack of reported abnormalities on the resting ECG further supports this as the underlying diagnosis.

In the first instance the priority is to assess systolic function and to rule out significant coronary artery disease. In the presence of normal systolic function and no underlying CAD, the condition is associated with a benign outlook. Beta blockade is considered as the first line intervention.

Brugada syndrome is associated with characteristic ST changes and therefore cannot be the underlying cause of the palpitations seen here. QT prolongation would also have been identified on one of the many resting ECGs taken over the past few months.

HOCM is associated with LVH.

Paroxysmal AF is a more likely cause of presyncope rather than the collapse seen here.

Answer Statistics

1

63%

2

13%

3

2%

4

19%

5

6%

Times answered: 262