In a patient with suspected myocardial infarction, which initial test is most appropriate?

The initial test that is most appropriate in a patient with suspected myocardial infarction is the electrocardiogram (ECG). An ECG is critical for the immediate identification of myocardial ischemia or infarction. It provides real-time information about the electrical activity of the heart and can reveal characteristic changes associated with myocardial infarction, such as ST-segment elevation or depression, and T-wave inversions.

By conducting an ECG right away, healthcare providers can quickly determine if the patient has a STEMI (ST-elevation myocardial infarction) or a non-STEMI (non-ST-elevation myocardial infarction), which is crucial for guiding further management and treatment decisions. This rapid assessment can facilitate timely interventions such as reperfusion therapy, which can significantly improve patient outcomes.

While troponin levels, complete blood count (CBC), and echocardiograms are important diagnostic tools in the evaluation of myocardial infarction, they are not the immediate priorities. Troponin levels can confirm myocardial injury but take several hours to rise after the onset of symptoms. A CBC can help assess for other conditions but does not specifically indicate myocardial infarction. An echocardiogram is useful for assessing heart function and structure but is not suitable for immediate diagnosis of an acute event.