A patient recovered from ventricular tachycardia type torsades de pointes, presents in the following hours weakness, nausea, vomiting, hypotension, and absent tendon reflexes. Which of the following are ECG features are chacarcteristic of this clinical picture?:
a) Prolonged PR and QT intervals:
b) T wave flattening:
c) AV – block:
d) ST – segment depression: