Prognosis

Look for evidence of ventricular rupture ^c - it is often fatal ^b

• cardiac tamponade
• pulseless electrical activity
• a large pericardial effusion (>5 mm diameter on echocardiography)
• haemopericardium on pericardiocentesis 

Note:

Ventricular rupture is uncommon

Complication c	%  (95% CI)	NNF at 30 days  (95% CI)
ventricular rupture	0.89%  (0.41% to 1.4%)	110  (73 to 240)

• One in fifty patients develop ventricular septal rupture (2.0%: 95% CI: 1.2% to 2.7%) ^b
• Over half die from it (56%: 95% CI: 37% to 76%) ^b

Cardiac tamponade and a large pericardial effusion increase the risk of ventricular rupture

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
myocardial infarction c (pre-test probability: 0.9%)	subacute ventricular rupture (surgery or autopsy)	cardiac tamponade	140	56%	0.30	0.3%
		pericardial effusion >5 mm	14	11%	0.0	0.0%
		electromechanical dissociation	71	39%	0.79	0.7%
		haemopericardium (pericardiocentesis)	4.3	4%	0.0	0.0%