ECG VII: Ventricular pre-excitation

Question 1

how does ventricular pre-excitation manifest on ECG?

Answer 1

widening / deformation of QRS (delta wave)

short PR

Question 2

what two events can lead to ventricular pre-excitation?

Answer 2

1. abnormal ventricular activation occurs LATE (BBB)

2. ventricular activation occurs EARLY (pre-excitation)

Question 3

what type of wave occurs when ventricular activation occurs early (pre-excitation)? why does this happen?

Answer 3

delta wave

accessory pathway (bundle of kent) that conduct rapidly that does not pass through the AV junction

Question 4

what is the name of the accessory pathway implicated in ventricular pre-excitation?

Answer 4

bundle of kent

Question 5

pre-excitation provides a substrate for what condition?

Answer 5

supraventricular tach

Question 6

how does wolff parkinson white syndrome relate to pre-excitation?

Answer 6

it is pre-excitation PLUS the classic supraventricular arrhythmia

Question 7

wolff parkinson white SYNDROME includes what condition?

Answer 7

arrythmia

Question 8

what are the durations of the PR interval and QRS in ventricular pre-excitation?

Answer 8

PR - less than 0.12 s

QRS - greater than 0.10 s

Question 9

ventricular pre-excitation may mimic what other conditions?

Answer 9

BBB

MI

Question 10

why is the delta wave lost in SVT during ventricular pre-excitation?

Answer 10

conduction is via normal pathway, until the arrhythmia converts