A single-center retrospective study on the incidence and clinical significance of the electrocardiographic "Triangular QRS-ST-T Waveform" pattern*.

BACKGROUND

The triangular QRS-ST-T waveform is a rare presentation of ST-segment elevation acute myocardial infarction associated with a poor in-hospital prognosis.

OBJECTIVE

To evaluate the incidence and clinical implications of the QRS-ST-T waveform pattern.

METHODS

Clinical data from non-pregnant adult patients who presented as STEMI activations at a single institution between 2017 and 2021 were reviewed. Patients who met electrocardiographic criteria for triangular QRS-ST-T waveform - a giant wave from the fusion of the QRS complex, the ST-segment, and the T-wave - were included in the study.

RESULTS

There were 417 STEMI activations, eight (1.9%) of which fulfilled the criteria for the triangular QRS-ST-T waveform pattern on electrocardiography. Coronary angiography was performed in five of these patients, four of whom demonstrated a significant lesion to the left anterior descending artery. Three patients did not undergo angiography secondary to hemodynamic instability. Seven of the patients in our study experienced cardiogenic shock requiring vasopressor, inotropic, and/or mechanical support. Only two patients survived to discharge; one was successfully bridged to coronary artery bypass grafting via intra-aortic balloon pump, while the other underwent a staged percutaneous coronary intervention.

CONCLUSIONS

The triangular QRS-ST-T waveform pattern is a rare ECG finding that may indicate hyper-acute STEMI and is an ominous sign of impending hemodynamic instability. Patients who survived received prompt aggressive therapeutic management.