Heart attack A heart attack ( or myocardial infarction ) was the sudden interruption of oxygen - rich blood supply to the heart muscle . It occurred with people who had coronary artery disease or other conditions that restricted blood flow through the arteries , such as atherosclerosis . Build up within the arteries that resulted in plaque formation of different sizes were the main causes of a heart attack . A heart attack resulted in damage to the heart muscle - which , depending on the general health status of the heart and severity of blockage , could be reversible or not . A heart attack was different from cardiac arrest , in which the heart itself stopped due to failure to contract effectively . Depending on the severity , a heart attack could lead to death if not treated immediately . In February of 2154 , Major J . Hayes suffered a heart attack after being shot through the heart by a Xindi - Reptilian while being beamed away . Dr . Phlox tried to revive him , but was unsuccessful . ( ) In 2268 , Sarek had a malfunction in one of his heart valves . Dr . Leonard McCoy told James T . Kirk that it was similar to a heart attack , but with Vulcan physiology , it was impossible to tell without surgery . ( ) In 2287 , Captain James T . Kirk , Captain Spock , and Dr . Leonard McCoy climbed a turboshaft on the to evade Sybok ' s followers . Kirk told them " " look at it this way , we ' ll get a good workout " " to which McCoy replied " " yeah , or a heart attack . " " ( ) In 2313 , Acamarian Gatherer Penthor - Mul was killed by Yuta , the last surviving member of the Tralesta clan . She used a microvirus on him which caused a fatal heart attack . In 2366 , Yuta murder ed Volnoth , who like Penthor - Mul , also died from a heart attack caused by the microvirus . ( ) In 2370 , Julian Bashir told Jadzia Dax that he thought Chief Miles O ' Brien was going to have a heart attack after they played many games of racquetball together . ( ) In 2371 , Odo told Retaya that when three of his fragrances were mixed together , they created a gas eous mixture that could cause a fatal heart attack . ( ) In 2372 , while at a reception for the Trill scientists who had arrived at Deep Space 9 , Dr . Lenara Kahn suggested to Jadzia Dax that they should profess their love for each other and disregard the reassociation of the Trill . Dax replied that they should probably not do that , as Dr . Hanor Pren would probably have a heart attack . ( ) The Clown , a manifestation of fear produced by Viorsa ' s artificial reality , liked to behead people as a means of killing them . As he was not real , the actual deaths came in the form of a heart attack caused by unmanageable stress levels resulting from intense fear . ( ) When Grand Nagus Zek was deposed because he gave females equal rights , Ishka was set to meet with Nilva , an influential member of the Ferengi Commerce Authority , to convince him that women can live as equals . However , during an argument with Quark , Ishka suffered a possible heart attack or cardiac arrest and collapsed on the spot . She had to be given a new heart . ( ) In 2376 , The Doctor asked Lieutenant B ' Elanna Torres to delete his medical database . Torres sarcastically asked him if he was sure about doing that , in case he gave his Qomar fans a heart attack and couldn ' t revive them . ( )