How do the patients present? Well, most of them have rather striking aching precordial chest pain.
Of course, that makes us worry about heart disease. But this is quite different from heart disease type pain.
The pain itself may be slightly similar in the sense that it’s aching. But this kind of pain is actually
aggravated by the patient lying back. The patient by gravity, the pericardium is stretched a little bit
by lying supine. That’s why the pain may get worse. Certainly, when they cough, they jar the pericardial sac
and that may make the pain worse. Of course, deep inspiration produces pain because as the lungs
expand, they put pressure on the inflamed pericardium. You might be able to predict what would relieve it.
Having the patient sit upright especially leaning forward would perhaps relieve it to some degree.
It doesn’t go away but it does ease somewhat. When they splint their respirations, in other words,
when they try not to take a deep breath, that may give them some relief. The other thing is the radiation
of pericardial pain actually is into the neck region. That can be the case with a myocardial infarction pain
but the difference is that a pain of myocardial infarction stays unchanged with exertion or rest.
So, maneuvers may relieve the pericardial pain but not generally so with acute MI.
Furthermore, the patients with acute MI are usually dyspneic. They’re usually sweating.
They may have labile blood pressure. They will have a characteristic cardiac examination.
On exam, and I think physicians today are not doing what I would call the world class exam anymore,
but if you listen carefully in most patients with pericarditis, you can hear what we call
a pericardial friction rub. That’s either a scratchy or leathery sound that’s got three components.
The first component is during atrial contraction. That would be just before systole.
The next component would be that scratching sound during ventricular systole. Then early in diastole
during rapid ventricular filling, you get another scratching sound. So, it’s kind of a three component rub
that's not affected that much by inspiration. The other thing is that the heart sounds in pericarditis,
if there’s a sizable accumulation of fluid in the pericardium, the heart sounds can be rather distant or muffled.
On X-ray, what we find is an enlarged cardiac silhouette. But it’s not an enlarged heart.
It’s just representative that there’s fluid present in the pericardium giving the cardiac silhouette
sort of a water bottle sized heart. It’s rather huge. If the fluid has accumulated rapidly
then the pericardium hasn’t had time to stretch. So, large amounts of fluid getting into a small sac
that won’t stretch can cause cardiac tamponade or compromise the filling of the heart.
So, it’s actually a filling problem of the heart and may produce pulsus paradoxus.
This is kind of a misnomer. Normally, the blood pressure drops slightly during inspiration.
But it usually doesn’t drop by more than 10 mmHg. In pericardial tamponade with pulsus paradoxus
on inspiration, the pressure drops substantially more than 10 mmHg. Some laboratory findings
may show you an increased CPK and troponin I, even though it’s not the heart that’s severely damaged
by this process. The electrocardiogram is pretty characteristic in acute pericarditis. The main thing
to notice in these leads is that there is elevation of the ST segment in essentially all leads
and occasionally depression in AVR. So, notice the elevation of the leads of the ST segment in these leads.