Which of the following must NOT be present to certify a patient after an MI?

To understand why ischemic changes on the ECG must not be present to certify a patient after a myocardial infarction (MI), it's essential to recognize the implications of these changes. Ischemic changes typically indicate ongoing heart issues or inadequate blood flow to the heart muscle, which are critical factors when assessing a candidate's fitness to drive commercially.

When evaluating a driver following an MI, medical examiners look for signs that the individual is stable and not experiencing acute cardiovascular symptoms. The presence of ischemic changes on the ECG suggests that the heart is still under stress or has not fully recovered, which could pose a risk to the individual and others if they were to operate a vehicle.

In contrast, stable angina, no prior history of deep vein thrombosis (DVT), and controlled hypertension are all factors that support a patient's ability to be certified for driving. Stable angina indicates predictable heart symptoms that the patient can manage, a lack of DVT history suggests lower risk of complications from clotting issues, and controlled hypertension indicates that the patient's blood pressure is managed effectively, reducing the overall cardiovascular risk.

Therefore, the absence of ischemic changes on the ECG is critical for certifying a patient post-MI, as it reflects a better prognosis and a lower likelihood