Caucasian woman with chest pain and abnormal Electrocardiogram

Caucasian woman, 58 years old, married, housewife, elementary school, from rural area of Bahia, Brazil.
Main complaint: atypical prolonged and recurrent precordial chest discomfort/pain, but with no clear provocative factors.
She refers that approximately three months ago had oppressive chest pain during the night, having consulted an emergency room, where after performing blood tests and an electrocardiogram, was released with the query recommendation cardiologist. At that time, she was treated with acetylsalicylic acid, rosuvastatin daily and sublingual isosorbide dinitrate, if necessary.
Physical examination: within normal limits.(WNL)
General appearance: patient is alert and oriented.
Vital signs: Temp: 36.3°C, respiratory rate 17 breaths per minute, HR 53bpm BP: 110/60mmHg,
Head: Normocephalic, pupils are equal and reactive. Missing numerous dental pieces
Neck: Supple without lymphadenopathy. Neck Veins- JVD at 45° . Normal amplitude and contour of carotid arteries. Not murmurs.
Heart: Regular rate and rhythm without murmurs. S1- heard best at apex, nl intensity S2- heard best at base splitting, A2 > P2 Extra Sounds- S3, S4 absent Absent murmurs
Lungs: vesicular breathing present. Absence of adventitious lung sound: wheezing, rhonchi and crackles.
Abdomen: Soft, nontender, nondistended with good bowel sounds heard, normal. No hepatosplenomegaly.
Extremities: Without cyanosis, clubbing or edema.
Neurological: WNL
Skin: Warm and dry without any rash.

Questions:

1. Wich is the ECG/VCG diagnoses?

2. What are the differential diagnosis?