34 Which patients with post-infarct septal rupture
should be treated surgically, and what are the
success rates?
Tom Treasure
Myocardial rupture is a more common cause of death after
infarction than is generally appreciated.^1 It complicates about 3%
of all myocardial infarctions and is the cause of death in about
17% of fatal infarcts. Myocardial rupture can involve the LV wall,
the septum and the papillary muscles and occurs in proportion to
the amount of muscle at risk with a ratio of about 10:2:1. Rupture
of the LV wall is almost always immediately fatal and is the cause
of death in about 13% (75% of 17%) of all fatal infarcts, as
“electromechanical dissociation”.
The minority who rupture only through the septum (loosely
known as post-infarct VSD) may be saved by surgery. The
hospital mortality for surgical repair is probably 40% (without
reporting bias – but there is surgical selection and natural
selection – most have had to survive transfer to a surgical centre).
The mortality is close to 100% without surgery. Favourable
features are younger age, anterior rather than inferior infarcts,
more surviving left and right ventricular myocardium, and
functioning kidneys. There was a vogue for holding these
patients on a balloon pump to operate on them when the infarcted
tissue is better able to take stitches. It is a long wait before there is
any material advantage, and any benefit in reported figures of
percentage operative survival was due to loss of patients along
the way. If you are going to operate on these cases, it is probably a
case of the sooner the better.
Current data would suggest that concomitant coronary artery
bypass grafting does little to improve mortality rates from
surgical post-infarct VSD.^2
RReeffeerreennccee
1 Dellborg M, Held P, Swedberg K et al.Rupture of the myocardium.
Occurrence and risk factors. Br Heart J1985; 5544 : 11–16.
2 Dalrymple-Hay MJ, Langley SM, Sami SA et al. Should coronary artery
bypass grafting be performed at the same time as repair of a post-infarct
ventricular septal defect? Eur J Cardio-Thorac Surg1998; 1133 : 286–92.