In patients with acute pulmonary embolism who also have negative T‑waves on their ECG, the presence of ST‑segment deviation (a shift in the ECG line) signals a higher risk of serious problems like low blood pressure, shock, and death within 30 days. When the ECG looks relatively normal, the outlook is much better.

Common electrocardiogram (ECG) manifestations in acute pulmonary em-bolism (APE) include ST-segment deviation (STDV) along with negative T-waves (NTW). STDV could occur in 3 typical ischemic patterns: (i) the left ventricular (LV) subendocardial ischemic pattern; (ii) the right ventricular (RV) transmural ischemic pattern; and (iii) the LV subendocardial plus RV transmural ischemic pattern. The purpose of this study was to evalu-ate the relationship of STDV and adverse clinical outcomes and to identify the relationship of relatively normal ECG and favorable clinical outcomes. Retrospective analysis of electronic charts in APE patients was performed in a tertiary hospital. ECGs on admission were obtained and classified as with or without STDV. Adverse clinical outcomes were defined as need to intensify therapy and 30-day mortality. Relatively normal ECG was defined as without any STDV, abnormal QRS morphology in lead V1 and S1Q3T3. From a total of 210 patients with NTW, 131 had STDV ≥ 0.1 mV, while 79 did not. Patients with STDV had worse evolution: higher incidence of dyspnea, hypotension, cardiogen-ic shock, intensification of therapy, and death compared to patients without STDV (p = 0.001 for each variable). The majority (89%) of the patients with STDV presented with 1 of the 3 typical ischemic ECG patterns. LV subendocardial ischemic pattern (OR = 4.963, p = 0.004), RV transmural ischemic pattern (OR = 3.128, p = 0.021) and LV subendocardial plus RV transmural ischemic pattern (OR = 3.036, p = 0.017) independently predicted the need to intensify therapy. RV transmural ischemic pattern (OR = 4.227, p = 0.031) and LV subendocardial plus RV transmural ischemic pattern (OR = 4.022, p = 0.032) independently predicted 30-day mortality. Compared to the patients with abnormal ECG, the patients with relatively normal ECG had a significant lower incidence of death (0% vs. 16%; p = 0.001) and need to intensify therapy during hospitalization (6% vs. 30%; p = 0.002). Ischemic ECG patterns are common ECG manifestations of APE and predict worse evolution and 30-day mortality. Additionally, relatively normal ECGs may associate with favorable clinical outcomes.