QT interval

Question 1

The QT interval measures the time needed for

Answer 1

ventricle de-polarization and re-polarization

Question 2

Length of the QT interval will vary with

Answer 2

heart rate

Question 3

The QT interval extends from the beginning of the ________ to the end of the _______.

Answer 3

QRS

T wave

Question 4

The QT interval lasts ______ seconds.

Answer 4

0.36 to 0.44

Question 5

The QT interval should not be greater than__________.

Answer 5

half of the distance between two R waves (R to R interval).

Question 6

Prolonged QT intervals are caused by:__________.

Answer 6

certain drugs, congenital causes

Question 7

Short QT intervals may result from ______________.

Answer 7

digoxin toxicity or electrolyte disturbances.

Question 8

Prolonged QT interval means the ________period of the cardiac cycle is longer

Answer 8

relative refractory period or vulnerable period

Question 9

Why can a prolonged QT interval be very dangerous??

Answer 9

A prolonged QT interval can cause ventricular tachycardia (usually drug induced). This is Torades de Pointes.