A new method of studying the mammalian heart / by H. Newell Martin.

  • Martin, H. Newell (Henry Newell), 1848-1896.
Date:
[1881]
Catalogue details

Licence: Public Domain Mark

Credit: A new method of studying the mammalian heart / by H. Newell Martin. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    clavians and aorta are tied (the carotid flow being already stopped) anaemic or dyspnoeic convulsions occur, and arterial pressure rises very high, as evidenced by the great size to which the stumps connected with the aortic ai’ch become distended; to obviate this strain on the heart, the aortic arch is tied as quickly as possible after putting the cannula in the left subclavian, and before the dyspnoea is extreme a large quantity of blood drawn off through the cannula, s, in the right carotid; when what appears sufficient is drawn the screw-clamp u is tightened up again. Finally the inferior cava, e, is ligatured, and the azygos vein, /; and a can- nula, h, put in the superior cava, g. This finishes the operative procedure. To get rid of the blood now present in the heart and lungs, which would be apt to clot in the cannula during a subsequent prolonged observation, and to replace it by defibrinated blood, of which about two litres are obtained from other dogs before the ex- periment, is the next step. The cannula h is filled with whipped blood and connected with a funnel containing the same warmed to 35° C.; the clamp t on the right carotid is then again opened and from 300 to 400 c. c. of defibrinated blood run through the heart and lungs—in by the superior cava and out by the carotid—wash- ing out and rejdacing the blood previously present; the blood drawn is whipped and strained and added to the stock on hand. The supply should be slow and sent in under a pressure equal to that exerted by a column of blood about 20 centimetres in height. The carotid is then again clamped and the vena cava a second or two later, after the heart and lungs have filled up with blood. The funnel is now removed and the heart, still lying in the chest, is ready for transference to the chamber in which it is to be kept warm and moist and fed with fresh defibrinated blood. This chamber consists of a box five feet long, three high, and two and a half wide. It has no floor; has one wooden end, I; a wooden back; a glass front; a glass roof, Iv ; and a glass end, L. The front can be entirely removed and has also a door in it through which matters can from time to time be arranged inside and temperatures read off without removing the whole front. 1 he chamber rests on a galvanized iron trough, DD, which contains about an inch and a half of water. In it is a Bunsen’s regulator connected with the burners CC, and serving to maintain a uniform