Persistent Hiccups as an Atypical Sole Manifestation of ST-Segment Elevation Myocardial Infarction: An Interesting...

Myocardial infarction (MI) commonly presents with chest pain, dyspnea, diaphoresis, and nausea; however, atypical and nonclassical presentations are increasingly recognized and may delay diagnosis and management. Persistent hiccups as the sole presenting manifestation of ST-elevation myocardial infarction (STEMI) are exceedingly rare, with only a few cases reported. Awareness of such unusual presentations is essential to avoid missed or delayed diagnoses.

A 60-year-old male presented to the outpatient clinic with a 1-month history of persistent hiccups without chest pain or other associated symptoms. He had no significant past medical history, cardiovascular risk factors, or prior medication use. Physical examination and vital signs were within normal limits. Laboratory evaluation revealed markedly elevated cardiac troponin levels (20 ng/mL), whereas creatine kinase, AST, lactate dehydrogenase, and B-type natriuretic peptide levels were within normal ranges. Electrocardiography showed normal sinus rhythm with ST-segment elevation and deep Q waves in the inferior leads, more prominent in Lead III than Lead II, suggestive of right coronary artery (RCA) involvement. Transthoracic echocardiography demonstrated preserved left ventricular systolic function (ejection fraction 64%) with inferior wall hypokinesia. Urgent coronary angiography revealed total occlusion of the distal RCA, with no significant disease in the left anterior descending or circumflex arteries. The patient underwent successful percutaneous coronary intervention with balloon angioplasty and drug-eluting stent implantation, resulting in restoration of coronary blood flow. His hospital course was uneventful, and he was discharged on dual antiplatelet therapy planned for 12 months.

The proposed mechanism of hiccups in inferior wall MI involves irritation of the phrenic or vagus nerves due to ischemia or inflammation near the diaphragm, particularly in RCA territory infarctions. Review of previously reported cases demonstrates a consistent association between persistent hiccups and inferior wall ischemia, most often related to RCA occlusion. This case reinforces the need to consider cardiac etiologies in patients with unexplained or refractory hiccups, even in the absence of classical ischemic symptoms.

Persistent hiccups may represent a rare but important atypical presentation of inferior wall STEMI. Early cardiac evaluation, including electrocardiography and cardiac biomarkers, should be considered in such cases to enable timely diagnosis and intervention, potentially improving patient outcomes.