Jennifer Matthews: The only thing Elton Cain remembers about being rushed to the hospital was the tightness in his chest.
Elton Cain: They just pushed me in the emergency room there and went to work, and after that it's all history to me.
Jennifer Matthews: But cardiologist Kevin Wei remembers it well. He was called to the ER to determine if Cain was having a heart attack. The first thing he did was look at Cain's EKG...
Dr. Kevin Wei: It doesn't tell us definitively that he's having an acute heart attack.
Jennifer Matthews: In fact, up to 30 percent of heart attacks won't show up on an EKG. A blood test can also detect a heart attack, but it can take hours.
Dr. Kevin Wei: Time is muscle, and the longer that the heart muscle is starved of blood, the more serious the injury, or the heart attack could be.
Jennifer Matthews: Dr. Wei used something new, an ultrasound picture enhanced with microbubbles. The tiny bubbles are injected into the bloodstream and travel to the heart muscle.
This is the ultrasound of Elton's heart without the bubbles.
Dr. Kevin Wei: We can not actually see very well where the heart muscle is.
Jennifer Matthews: And this is the picture with microbubbles.
Dr. Kevin Wei: We can see very clearly this horseshoe shaped area, which is the heart muscle, and how one area is not contracting.
Jennifer Matthews: Elton was indeed having a heart attack. Doctors immediately started him on medication. If they'd waited for his blood test to come back, treatment would have been delayed by about seven hours. And its that precious time that may have saved his life. This is Jennifer Matthews reporting.