“Following coronary ligation Porter noted that the procedure frequently resulted in fibrillary contractions of the heart and sudden death. However, death did not always occur and this led him to conclude that Cohnheim’s (1881) consistently fatal results were due to operative trauma and that the coronary arteries were not end arteries” (Willius & Dry).
Digital facsimile from PubMedCentral at this link.

Continued with his "Further researches on the closure of the coronary arteries," J. exp. Med., 1 (1896) 46-70. Digital facsimile from PubMedCentral at this link.