I was coughing and felt fatigued, weak, and somewhat dizzy after running. i have no known of asthma. what could be a possibility?

Heart rate?: Do not have enough information. If your echocardiogram is normal(no anatomical or valve issues) then symptoms may be heart rate, volume, pressure related. If you did not drink enough fluids during the day and before running that can result in severe tachycardia and exhaustion. You may try drinking accelerade before running and enduroxr4 as a recovery drink if dehydration was the cause.