Adult Emergency Medicine: Pericarditis...and Cardiac Tamponade

Monday, 26 December 2016

Pericarditis...and Cardiac Tamponade

I have seen a fair few patients that I have diagnosed with pericarditis. It seems that I've probably over-diagnosed it in quite a lot of people! 5% of patients presenting to the ED with non-ischaemic chest pain have acute pericarditis - so my numbers are probably right.

The Pain
- Relieved by leaning forward
- Can radiate to the trapezius ridge as the phrenic nerve travels

Signs
- Pericardial friction rub in 85% of cases
- Rub still heard on breath holding

ECG
- Diffuse concave or saddle shaped ST changes, with ST elevation in 90% of cases, typically leads Ι, ΙΙ, V5 and V6
- Associated ST depression in aVR and V1 is seen in 64% of cases [6].
- PR depression
- Look carefuly at V6. If ST elevation to T wave height ratio is greater than 0.25, acute pericarditis is more likely than BER.

Diagnosis - needs 2/4
Characteristic chest pain
Pericardial friction rub
Suggestive ECG changes
New or worsening pericardial effusion

High Risk features
Temperature greater than 38ºC
Raised WCC
Large pericardial effusion
Cardiac tamponade
Acute trauma
Immunosuppression
Oral anticoagulants
Failure of NSAID therapy
Recurrent pericarditis
Troponin levels are elevated in 30-70% of patients with 'pericarditis'; they offer no prognostic information.

Pericardial Effusion
A true diagnosis needs relief of symptoms from pericardiocentesis.
Signs - Pulsus paradoxus is an exaggerated fall in systolic blood pressure of 10 mmHg or more during inspiration.
The Beck triad is present in only a minority of patients