A 37-year-old male is admitted to the trauma service following a serious motor vehicle accident.
He’s wearing his seatbelt and the air bag deployed correctly.
On physical exam, he’s awake and alert. His blood pressure is elevated at 155/69
and his heart rate elevated at 106, his peripheral oxygen saturation is normal,
his chest and leg are painful and there are multiple minor superficial contusions or bruises.
He gets a lot of x-rays, he has multiple rib fractures, a femur fracture
but fortunately he doesn’t have a pneumothorax and a CT shows unremarkable abdomen which is good.
Often these patients will have spleen rupture.
His EKG shows non-specific ST T wave changes and sinus tachycardia.
An echocardiogram shows normal left ventricular systolic function but reduced right ventricular systolic function
and the only interesting lab value is a blood troponin that’s elevated -
this is the high sensitivity blood troponin at 44 ng/mL.
So what’s critical here? Obviously the accident, we knew about that.
His blood pressure’s up and his heart rate’s up
but that’s almost certainly the sympathetic response to the injury,
to pain and to the frightening experience he's just had.
Oxygen saturation is good which means the lungs are okay.
He has multiple rib fractures and a femur fracture that are going to have to be taken care of
and his EKG shows non-specific ST T changes possibly from a marked cardiac injury
or possibly just through the metabolic abnormalities when sympathetic activity
from his automobile accident.
The echocardiogram has good news, the left ventricular function is normal
and they partly bad news is that he has somewhat reduced right ventricular systolic function
probably the result of trauma from the accident and his blood troponin is elevated
which means there is a myocardial injury.
So this is a cardiac contusion.
The heart is located in such a way that the right ventricle is right under the sternum
when somebody has the airbag or hits the sternum
because of the seatbelt you can have a blow to the sternum that is transmitted through the sternum
to the right ventricle causing a bruise or a contusion that affects the right ventricle.
Now, how do we take care of this?
Well, first of all, we’ve got as I say bigger fish to fry.
We got to take care of the femur fracture he’s gonna go to surgery for that.
The rib fractures we’d just deal with pain control
and they usually heal themselves particularly when there is no pneumothorax.
Now the myocardial contusion there’s no specific therapy needed
we just do close ECG monitoring for arrhythmias that would be treated if they occurred.
We follow the blood troponin value to see how big the injury is.
We would probably also do an echo down the road to make sure that the right ventricle recovers.
Normally the heart recovers well from a contusion, this is not a myocardial infarction,
it’s not a heart attack and the prognosis is usually good for total recovery
once all of the traumatic events that have affected the body heal.