Cardiac Axis and ECG Interpretation

The video tutorial by Tom from Zero to Finals explains the cardiac axis on an ECG. It covers the heart's electrical activity, the concept of axis deviation, and how to calculate it using ECG limb leads. The tutorial provides a practical example to clarify the calculation of left and right axis deviations, emphasizing the importance of understanding the direction of electrical activity in the heart.

What is the starting point of electrical activity in the heart?

• Sinoatrial node

• Bundle of His

• Atrioventricular node

• Purkinje fibers

How is left axis deviation visualized?

• Electrical activity moves downwards

• Electrical activity moves upwards

• Electrical activity shifts to the left

• Electrical activity shifts to the right

Which leads are primarily used to determine the cardiac axis on an ECG?

• Augmented leads

• Limb leads

• Chest leads

• Precordial leads

What is the normal range for the cardiac axis?

• -90 to 30 degrees

• 0 to 180 degrees

• 90 to 180 degrees

• -30 to 90 degrees

What indicates a right axis deviation in lead 1?

• Positive reading

• Negative reading

• Isoelectric reading

• No reading

In a normal ECG, what is the expected reading for lead 2?

• No reading

• Positive

• Isoelectric

• Negative

What does a negative reading in lead 2 indicate?

• Right axis deviation

• Left axis deviation

• Normal axis

• No deviation

Which lead is often used to find the isoelectric point?

• Lead 1

• Lead 2

• AVR

• Lead 3

How do you calculate the exact axis if AVR is isoelectric?

• Add 60 degrees to AVR

• Subtract 60 degrees from AVR

• Subtract 90 degrees from AVR

• Add 90 degrees to AVR

What is the axis if the calculated angle is -60 degrees?

• Indeterminate axis

• Normal axis

• Right axis deviation

• Left axis deviation