In the fоllоwing scenаriо, determine the principаl diаgnosis and provide the corresponding ICD-10-CM code. A 23-year-old male presents to the ED with SOB and fatigue. He tells the ED doctor that he has a feeling of "I am going to pass out, and my heart feels like it wants to jump out of my chest." The ED doctor ordered a CXR and gave the patient a vasodilator. CXR reveals that the patient has mitral regurgitation. He is placed on a low-sodium diet and diuretics. He is instructed to follow up with his PCP and a cardiologist.