I have dcm and bi vent pacemaker. is it possible that if i had too much salt i can have shortness of breath? within how many hours of eating?

Not: Salt draws in fluid. People with dcm don't handle excess fluid well. That's why diuretics like lasix(furosemide) are used. If a single meal with extra salt causes you to tip over into decompensated chf, you need an adjustment in your overall regimen. It's not a 1:1 ratio with a fixed time course like a the effects of a drug.

Couple of days: By ventricular pacemaker can improve symptoms for up to 70% of people who receive one, however it does not prevent heart failure from existing. If you eat too much salt, your body will retain fluid the same way as any other heart failure patient. The effects are usually seen within 12 to 48 hours.