Differential Diagnosis for Asymptomatic Patient with Sinus Tachycardia and Possible Anteriolateral Infarct on EKG

• Single Most Likely Diagnosis
  • Myocardial Infarction (MI): The presence of possible anteriolateral infarct signs on the EKG in conjunction with sinus tachycardia, which can be a response to pain, stress, or decreased cardiac output, makes MI a highly plausible diagnosis. The fact that the patient is asymptomatic does not rule out MI, as some patients can have silent MIs.
• Other Likely Diagnoses
  • Acute Coronary Syndrome (ACS): This encompasses a range of conditions including unstable angina and non-ST elevation MI, which could present with similar EKG findings and may not always have overt symptoms.
  • Cardiac Ischemia: Ischemia without infarction could lead to EKG changes and tachycardia, especially if the patient has underlying coronary artery disease.
  • Electrolyte Imbalance: Certain electrolyte imbalances, such as hyperkalemia or hypokalemia, can cause EKG changes that mimic infarction patterns and lead to tachycardia.
• Do Not Miss Diagnoses
  • Pulmonary Embolism (PE): Although the EKG findings do not directly suggest PE, sinus tachycardia is a common finding in PE, and it can be asymptomatic or have atypical presentations. Missing a PE can be fatal.
  • Aortic Dissection: This is a life-threatening condition that can sometimes present with EKG changes mimicking MI due to involvement of the coronary arteries. It often causes severe pain but can be asymptomatic in rare cases.
  • Cardiac Tamponade: While typically associated with hypotension and specific echocardiographic findings, cardiac tamponade can cause tachycardia and, in rare instances, EKG changes that might be confused with infarction.
• Rare Diagnoses
  • Myocarditis: Inflammation of the heart muscle can lead to EKG changes and arrhythmias, including sinus tachycardia, and might mimic infarction patterns.
  • Cardiac Sarcoidosis: This condition can cause various EKG abnormalities, including those that resemble MI, due to granulomatous infiltration of the heart.
  • Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): Although more commonly associated with ventricular arrhythmias, ARVC can lead to EKG changes and might, in rare cases, present with findings that could be mistaken for anteriolateral infarct.