AORTIC DISSECTION – CHECK FOR PULSE DEFICITS AND DIASTOLIC MURMUR

Morgagni in 1761 described a man who presented with a swelling on the upper part of the sternum (Seats and Causes of Diseases). The skin became thinner and blood began to leak out. The original case describes the patient pulling at his bandages and being “ordered to keep himself still, and to think seriously and piously of his departure from this mortal life, which was very near at hand, and inevitable.” The following day Morgagni describes the lesion bursting. “Nevertheless, he had the presence of mind, (as soon as) he felt the blood gushing forth, not only to commend himself to God, but to take up with his own hands a basin that lay at his bedside; and, as if he had been receiving the blood of another person, put it beneath the gaping tumour, while the attendants immediately ran to him as fast as possible, in whose arms he soon expired.” Post-mortem examination revealed the cause to be an aortic aneurysm.

 

In the 1955 movie Not as a Stranger Robert Mitchum evaluates his chief of surgery who complained of chest pain. Mitchum listens to the chest (presumably hearing a diastolic murmur), recoils in horror, then checks the bilateral pulses (presumably feeling a pulse deficit), and rushes him off to the operating room.

 

Before one gets the conclusion that we were better at physical diagnosis then, a contemporary article of that era described the antemortem diagnosis rate of aortic dissection as 11% (Levinson 1950). Hollywood has always exaggerated the abilities of its heroes to overcome the limitations of our real world. One of the leading experts on this disease has said “…difficulty in diagnosis, delayed diagnosis or failure to diagnose are so common as to approach the norm for this disease…” (Elefteriades Cardiology 2008).

 

Is there anything we can we do at the bedside to improve our history and physical examination?

 

Full history beats partial history:

Physicians who ask about onset, location, and quality have a better chance at diagnosis. Of patients who turned out to have aortic dissection, when all 3 of those were documented the condition was suspected in 91% of cases. When at least one of those is missing from the chart, the diagnosis was initially suspected in 49%.(Rosman Chest 1998)

 

Pain that is sudden, severe, or radiating to the back

Sudden and severe pain are present in up to 90% of cases (Klompas JAMA 2002). Radiation to the back occurs in 47-64% of patients (Hiratzka JACC 2010).

 

Chest pain + neurologic deficits

Other specific findings include migration of pain along the territories of the aorta and new neurological deficits, both present in up to about a quarter of patients (Sullivan Am J Em Med 2000).

 

Diastolic murmur

It turns out that Robert Mitchum’s approach is still worth doing. A diastolic murmur of aortic regurgitation is a high risk finding, occurring in 45% of patients (Hagan JAMA 2000).

 

Pulse deficit

A “pulse deficit”, which refers to an absent or asymmetrically weak pulse, occurs in 26%(Pape 2007. Klompas says 31%). Do not bother with blood pressure limb differentials in low risk populations, as it has poor specificity, being found in 19% of chest pain patients without aortic dissection (Singer 1998). Instead, palpate both limbs feeling for a difference.

 

Although it is beyond the scope of this article, many advocate using d-dimer as a screening test in those with a low (but not zero) probability of disease because it is 97% sensitive and 47% specific, at least in the first 24 hours of disease (Suzuki Circulation 2009). With time that sensitivity goes down and most experts recommend not relying on this test.

 

TAKE HOME POINTS

-Sudden and severe pain raises your concern for aortic dissection

-Check for pulse deficits and diastolic murmurs

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s