Cardiology - QT Prolongation

Question 1

QT interval

Answer 1

represents the time taken for ventricular depolarisation and repolarisation, effectively the period of ventricular systole from ventricular isovolumetric contraction to isovolumetric relaxation

Question 2

The QT interval is (proportional/inversely proportional) to heart rate.

Answer 2

Inversely proportional (QT shortens with tachycardia, and lengthens with bradycardia).

Question 3

With what arrhythmias are prolonged QT segments associated?

Answer 3

Ventricular, specifically Torsades de Points.

Question 4

Congenital short QT syndromes are associated with increased risk of what arrhythmias?

Answer 4

Paroxysmal atrial and ventricular fibrillation —> sudden cardiac death.

Question 5

In what lead(s) should the QT interval be measured?

Answer 5

Lead II or V5-V6.

Question 6

Large U waves (taller than _____) should be included in the measurement of QT segment.

Answer 6

1 mm

Question 7

The corrected QT (QTc) estimates the QT interval and what heart rate?

Answer 7

60 BPM

Question 8

The QTc is used to measure QT over different heart rates to detect the possibility of ______.

Answer 8

Arrhythmias

Question 9

Stopped at QTc formulas

Answer 9

Okay