Critical proximal obstruction of LAD, transient intraventricular conduction disturbances, and Brugada ECG pattern: BrS?

Male Asian patient, 58 years old, mesomorph biotype, reported that approximately 72 hours ago he had presented several episodes of constrictive

precordial pain, each of short duration (≤ 10 minutes) that ceased with rest, and some of them radiated to the mandible and the inner part of the

left upper arm until the wrist. The patient also reported cold sweating and nausea triggered by usual activities such as walking or driving a car.

Personal pathological antecedents: hypertension diagnosed five years ago, but well controlled. Familial type II dyslipidemic controlled by in

regular use of 10 mg of rosuvastatin daily, with recent normalized lipid laboratory exams. Smoker since adolescence that stopped two years ago.

Family history: A brother and a first-degree cousin (29 and 35 years old respectively) from father’s side both had sudden death during nighttime sleep. In both, a molecular autopsy was performed that revealed a mutation in the SCN5A gene. Genetic screening has not been performed yet in the rest of the family.

Physical examination: Nothing noteworthy.
An electrocardiogram was performed on admission (April 18, 2017 at 10:00 AM). in the emergency room (Figure 1) and the next day another (Figure 2). Only the second one placing the electrodes in high right precordial leads (V1H, V2H and V3H)
Transthoracic Two-dimensional Doppler Echocardiogram: Normal
Multi-slice Coronary computed tomography (MSCT) examination for evaluation of acute chest pain: showed a proximal critical obstruction of the left anterior descending artery (LAD) before the first perforator branch(S1) (Figure 3).

Questions

1. What is the diagnosis of ECG-1?
2. What is the diagnosis of ECG-2?
3. Do VCGs help us? Why?
4. What is the clinical-electrocardiographic diagnosis?
5. Mark the differences between both tracings and explain their mechanisms.