There are 2 parts to this answer.
What do you think this is?
1: left bundle branch block
2: right bundle branch block
3: true posterior wall MI

4: some other interpretation

(This is ventricular pre-excitation (WPW))

Do you think this ECG is helpful in explaining the probable cause of this patient's symptoms?

Yes, see the discussion beginning on next page.

Click here for brief elaboration on answers.
 
59 year old man with a 9 year history of palpitations. Had a recent syncopal episode.
Vent. rate 64 bpm
PR interval 122ms
QSR duration 120ms
QT/QTc 416/429ms
P-R-T axes 49 -2 39