A. It is a record of the voltage changes (as measured at the body surface) due

to the depolarisation of the muscle cells of the heart as it beats.

B. The potentials measured by the ECG electrodes are combined in various

ways to give 12 different ECGs.

C. The ECG consists of the electrical events that follow the depolarisation of

ventricles (PQR section), the depolarisation of atria (the S section) and the

repolarisation of the ventricles (the T section).

D. The value of the potential difference called “limb lead II” varies with time

to produce the familiar ECG trace – a graph of voltage vs time.

A. A graph of the variation of voltage produced by the heart against time.

B. The voltage at right arm (RA) plus the voltage at left leg (LL).

C. The electrical events that precede the contraction of the ventricles.

D. The projection of the electric dipole vector of the heart on the line from left

arm (LA) to right arm (RA).

A

Septal

B

Lateral

C

Anterior

D

Inferior

A

Left axis deviation

B

Right axis deviation

A

Left circumflex coronary artery

B

Left anterior descending coronary artery

C

Right coronary artery

D

All of the above

A

A septal myocardial infarction

B

A posterior myocardial infarction

C

An anterior myocardial infarction

D

An inferior myocardial infarction

A

0.04 - 0.12 seconds (1-3 small squares)

B

0.08 - 0.12 seconds (2-3 small squares)

C

0.12 - 0.2 seconds (3-5 small squares)

D

0.04 - 0.08 seconds (1-2 small squares

A

Septal

B

Anterior

C

Lateral

D

Inferior

A

Septal

B

Inferior

C

Lateral

D

Anterior

A

Septal

B

Inferior

C

Lateral

D

Anterior