I have a client who suffer from Angina and Ischeamic Heart disease. She finds certain aspects of personal care difficult ie washing hair, putting on socks or tights as it makes her dizzy to bend over. She also becomes breathless when walking and needs to stop and if it is cold it brings on Angina.

She claimed DLA Care & Mobility.

They refused ALL. They claim she does not need personal help for long enough each day and that she is not too ill to walk (I paraphrase)
In the first instance should we ask for a written explanation and then ask for the case to be reviewed. If we ask for a review are there any tribunal decisions I can quote to back up the case.

I should add I am new to this role so any pointers would be gratefully received.

By all means ask for their written decision but I suspect that it'll not be very useful to you AT ALL.
Did your client filled in the forms herself? If so it is likely that the right keywords have not been highlighted in the claims form and in the eye of the DM not claimed for the various DLA elements. I would ask for a copy of it (if you have not got one already from the client) and then send a follow on written statement of the difficulties she has on daily basis and the care she needs (not necessarily the care she actually receives) and ask for a review. You can always appeal if the review is not successful. Also see if you can get any supporting letters from your cl's GP etc
Seeing that you are a housing specialist I would recommend you to read Chapter 20 of the Disability Hand Book on claiming DLA, it is very useful.

Write in, asking for a review and for:

1. Copies of all papers that were before the DM at time of decision.
2. Any such review to be held in abeyance until you've had opportunity to look at papers and produce written statement on behalf of client.
3. Write to GP/Consultant asking for medical evidence - bear in mind though that their evidence will relate only to the medical condition - not the manner it affects your cl;ient on a day to day basis.

Look up the medical condition(s) and the prescribed medication in Google searches - get client to keep a daily diary of some sort - talk to partner - their view is often a bit more honest thatn the client when it comes to describing what they really can and can't do without severe discomfort, which is the test.