75 year old male with severe dyspnoea

Having never been to a doctor in his life, this gentleman was very hesitant about receiving treatment after his wife brought him into the hospital with severe SOB, getting worse by the day.
O/E he has a VERY loud, split systolic turbulence that masks a possible holosystolic murmur at the apex. He has bilateral crackles and is peripherally cyanotic, using all of his accessory muscles.

This ECG is performed:

Systematically, what does this ECG show?
What could be causing these obvious ECG abnormalities?
Every precordial lead (particularly V1-V4) shows an abnormality or phenomena called...?

50 year old female complaining of frequent AICD shocks

After 4 shocks over an hour from her 2 year old automatic internal cardiac defibrillator (AICD), the patient called an ambulance. On arrival to the ED, she explains that she gets VT but says that she doesn't know why and it generally only makes her feel a bit dizzy for the first 20 minutes or so. This time however, she had passed out each time before she was shocked.
She is sent to cardiology and her chart reveals her to have Idiopathic VT and the only treatment provided was the AICD.

A 12 lead ECG if found from a previous admission...

 

 a new one is is performed, and...

 

 12 lead ECG monitoring by your friends in the cardiac sciences department catch the arrhythmia brilliantly (in both standard 25mm/s...

 

  and slow 100mm/s format.

What are your thoughts?
What is the tachycardia?
From the first two ECGs, can you guess a likely diagnosis/cause of this lady's tachyarrhythmia?
And for the electrophysiologists in the audience, where is this arrhythmia arising from?

17 year old Female with black-outs and SOBOE

Presents to ED after a seizure like episode, when she regained consciousness it took around 30min to 'catch her breath'. She had been diagnosed with asthma from an early age but even with Rx was not able to participate in physical activities.
O/E she had no heart murmur and only a slight wheeze, she felt fine at the time. She is not on any medications apart from relieving and preventative asthma inhalers.

FHx was spotty due to poor communication with foreign relatives.

This ECG was obtained.
What abnormalities are seen here?
What could these indicate?
What investigations should be conducted?
What Rx should be considered?

17 year old female with presyncope

A young lady presents with frequent dizzy spells associated mainly with physical activity and stress.
She appears healthy and has never had any other complaints or medical conditions. Among other things, this ECG is obtained.

The ECG has 3 diagnostic markers for her cardiac condition present. What is not present (which is common) is axis deviation.
What are they? What does she have?