Ventricular arrhythmia post-concealed myocarditis

Male, 67 y/o, Caucasian, hypertensive, with history of long-standing ventricular arrhythmia (20 years).
Family background irrelevant. Negative Chagas disease serology.
He described that it all started more or less 20 years ago, in a trip to São Paulo. On the occasion, after being exposed to cold weather, he presented symptoms of flu with palpitations after some days. He requested help from the Beneficência Portuguesa hospital where he was asked to do periodical consultations with a cardiologist. For a while he just presented a single symptom, i.e. intense night sweating. The symptom disappeared during evolution. Currently asymptomatic and taking ramipril 5 mg daily, carvedilol 25 mg 2x/day, spironolactone 25 mg daily.
Physical examination: unremarkable.
We also performed VCG, Holter monitoring, transthoracic echocardiography(September 2017), CMRI (September 2017), and coronary angiography with ventriculography(September 2016).

Questions:

1. Which is the ECG and VCG diagnosis?
2. What is the appropriate approach?