These incisions are joined by a horizontal cut made in the fourth intercostal space.

The 4th, 5th, and 6th ribs and cartilages are divided and the outer cutaneous flaps turned up; pushing aside the pleura with the finger, expose the pericardium and incise it longitudinally; suture the heart-wound by interrupted sutures.

Del Vecchio adds that Fischer has collected records of 376 cases of wounds of the heart with a mortality two to three minutes after the injury of 20 per cent.

Death may occur from a few seconds to nine months after the accident.

Keen and Da Costa quote Del Vecchio, and, in comment on his observations, remark that death in cases of wound of the heart is due to pressure of effused blood in the pericardial sac, and, because this pressure is itself a cheek to further hemorrhage, there seems, as far as hemorrhage is concerned, to be rather a question whether operative interference may not be itself more harmful than beneficial.