Differential Diagnosis for Minimal ST Elevation in Inferior Leads, Intermittent Palpitations, and No Chest Pain

Single Most Likely Diagnosis

• Early or mild acute coronary syndrome (ACS) without significant myocardial damage: This could be a non-ST elevation myocardial infarction (NSTEMI) or unstable angina, given the minimal ST elevation and absence of chest pain. The intermittent palpitations could be related to arrhythmias secondary to ischemia.

Other Likely Diagnoses

• Atrial fibrillation or other supraventricular tachycardias: These conditions can cause palpitations and may lead to minimal ST changes due to rapid heart rates or aberrant conduction.
• Ventricular ectopy or premature ventricular contractions (PVCs): Frequent PVCs can cause palpitations and may result in minor ST segment changes due to the abnormal ventricular depolarization.
• Pericarditis: Although typically associated with chest pain, pericarditis can sometimes present with minimal or no pain, and the ST elevation can be subtle, especially in the early stages.

Do Not Miss Diagnoses

• Acute pulmonary embolism (PE): While less common, a large PE can cause right ventricular strain, leading to ST elevation in the inferior leads and palpitations due to arrhythmias or anxiety. Missing this diagnosis can be fatal.
• Cardiac tamponade: Although rare, cardiac tamponade can present with minimal symptoms, including palpitations and subtle ECG changes. It is a life-threatening condition that requires immediate intervention.
• Aortic dissection: This is a medical emergency that can sometimes present with atypical symptoms, including palpitations and minimal ECG changes if the dissection involves the coronary arteries or affects cardiac function indirectly.

Rare Diagnoses

• Arrhythmogenic right ventricular cardiomyopathy (ARVC): A rare condition that can cause ventricular arrhythmias, leading to palpitations, and may result in minor ECG abnormalities, including ST elevation in the inferior leads.
• Brugada syndrome: Characterized by specific ECG patterns (notably in the right precordial leads) and can cause palpitations due to ventricular arrhythmias. While it's more associated with ST elevation in the right precordial leads, it's a rare condition that could be considered in the differential diagnosis of palpitations and ECG abnormalities.
• Myocarditis: Inflammation of the heart muscle can lead to a variety of ECG changes, including ST elevation, and may cause palpitations due to arrhythmias. It is a rare but potentially serious condition.