Conductor dies during funeral march – an update and a warning
The late Herbert von Karajan, terrified of dying on the job, commissioned research at Salzburg University on the effects of stress on music making. His particular concern was that Felix Mottl and Joseph Keilberth had collapsed and died at exactly the same spot in the third act of Tristan und Isolde (see The Maestro Myth, 130-1).
In addition to these misfortunes, Dmitri Mitropoulos died while rehearsing Mahler’s third symphony at La Scala, Giuseppe Sinopoli died during Aida in Berlin and Mariss Jansons near-as died at the end of La Boheme in Oslo. Only the adjacency of a good hospital restored his heart function.
The research that Karajan commissioned at Salzburg has not, to my knowledge, been published (if it has, please let me know). But there do seem to be sufficient instances connecting podium exertions and cardiac infarction to warrant further scientific study.