During data entry, all information will be maintained in SherlockMD, a HIPAA-complaint electronic secure database with access only to the principal investigator. At study completion, de-identified data will be exported into a Microsoft Excel spreadsheet (Microsoft Corporation, Redmond WA). Statistical analyses will be performed using SAS 9.4 (SAS Institute, Cary, NC). The study outcomes will be presented as proportions with exact binomial confidence intervals. P-values for univariate associations will be calculated using Chi-square or Fisher's exact test, as appropriate. Adjusted outcome estimates will be determined using multiple logistic regression. A power analysis is not applicable to the primary outcome: proportion of hypotensive episodes related to nitroglycerin use for STEMI in the field, with no comparative group. For the secondary outcome of pain relief, the investigators determined a sample size of 73 patients per group to achieve 90% power to detect the minimum clinically significant difference of 1.39, assuming, base on prior literature, an average pain score of 6.6 and standard deviation of 2.58. Kappa statistic will be used to assess agreement between data abstractors.