A condition less known...

Dextrocardia situs inversus refers to a condition in which the heart is a mirror image of normal placement. With dectrocardia the main mass of the heart sits right of the mediastinum. When all visceral organs are mirrored the condition is dextrocardia situs totalis.

Dextrocardia occurs in approximately 1 in 12,000 people (according to wikipedia).

The above chest X-ray is not reversed, that is a patient with dextrocardia.
All of the heart chambers and great vessels are reversed, as seen above.
Left Ventricle (LV), Right Ventricle (RV), Left Atrium (LA), Right Atrium (RA), Pulmonary Artery (PA), Aorta (Ao).

Above is a comparison of a normal heart and the heart of a patient with dextrocardia

As you can imagine, there are multiple ECG changes found on the patient with dextrocardia. If you know the patient has this condition, it may be in your best interest to mirror normal electrode placement.

Take a look at some 12-leads of dextrocardic patients below:

Notice the obvious change in axis. A negatively deflected lead I would indicate right axis deviation. When leads II & III become deflected in addition, this would indicate extreme right axis deviation (ERAD). ERAD is most often seen when impulses originate in the ventricles as with ventricular tachycardia, or ventricular pacemakers. ERAD may appear with dextrocardia.

When you see a negative QRS in lead I, and a positive QRS complex in aVR, you should first suspect misplaced leads. If they are placed correctly, dextrocardia should enter your differential.
Common ECG findings:

not all of these are always present

- Global negativity in lead I, (a negative p wave, QRS, and negative T wave).

- Positively deflected QRS in aVR

- Negative p wave in lead II

- Reverse R wave progression in precordial leads

Causes of Dextrocardia:

- Marden-Walker Syndrome: A rare genetic disorder characterized by blepharophimosis, joint contractures and fixed facial expression.

- Kartagener syndrome: A rare genetic disorder characterized by enlarged bronchial tubes, sinusitis and cross-positioning of body organs.

- Campomelia Cumming type: A rare syndrome characterized by limb and multiple abdominal organ abnormalities. The disorder results in death before birth or soon after.

Things to consider:

So, if you ever have the idea that the ECG you are looking at, looks as if your leads are all reversed, maybe the heart is.

When defibrillating these patients, traditional pad placement should be mirrored to the right chest. Anterior/posterior placement should be just right of the mediastinum.


Tazambo said...
This comment has been removed by the author.
Tazambo said...

I've seen/had a patient with this condition.

I was a newish student at the time and I can't remember what we transported him for.
His 3 lead EKG looked a little weird.
He denied ANY previous medical history when asked.

At the ER the 12 lead looked weird, a junior Dr showed the EKG to a senior Dr who picked it straight away.
When questioned, the patient said, "Yea, I've got that reversed heart thing".

An x-ray confirmed it, as did his hospital notes.

Shaggy said...

You mean that is not common for all you Aussies down there?

Shaggy said...

My God Adam, are you temporarily out of work or something? Where do you have time for all these great posts?

akroeze said...

Another great post!

Can I get permission from you guys to print this out and post it at my station so others can learn from it too?

Adam Thompson, EMT-P said...

Tazambo, that is pretty cool. Now I guess you'd know to reverse the leads. Obviously the dextrocardia itself requires no emergent treatment.

My God Adam, are you temporarily out of work or something? Where do you have time for all these great posts?

I work 24/48s man, I got all the time in the world. I was at a slow station on Sanibel island as well..

Can I get permission from you guys to print this out and post it at my station so others can learn from it too?

Permission granted

Jinx said...

Just curious if anyone can tell me if you had a patient with Dextrocardia and they were in VF or VT would you place the defib pads on the opposite sides for a better electrical pathway thru the heart on the right hand-side? Is it actually possible to know a patient has Dextrocardia if in VF/VT or can you only tell with a normal sinus rhythm?



Adam Thompson, EMT-P said...


Sorry for the delay...

... Yes, as I stated, put the pads on the opposite side if you know they have dextrocardia.

If they have V-fib, it may be impossible to discover the history of dextrocardia without someone actually telling you they have it.

I am sure there is a way to tell, if they are in V-Tach. I just don't know how, since V-tach can present with an extreme axis deviation.

Remember, it would be pretty uncommon to find a patient in arrest with this condition. Anterior/posterior placement should work, even if you are slightly left of the main mass of the heart.