aVR: It ain't squat

In Paramedic college and beyond I was always taught that AVR was the square root of squat, so when I brought in a patient in with aVR elevation I was not concerned about a STEMI.  The ECG looked like this:

The patient had no previous medical history, which was no surprise since he had been decades without seeing a physician.  His family were able to tell us that he had no SOBOE, no prior episodes of nocternal dyspnea and had never complained of chest pain or discomfort.  EMS was called because the patient awoke from sleeping with profound SOB.  On arrival his vitals were: BP 240/140 P 115 R 40 SpO2 was 82% with high concentration O2 and Pupils were 3 reactive.  His physical exam revealed one word dyspnea, bilateral pulmonary edema that was audible from his bedroom door, supraclavicular in indrawing and head bobbing. The patient was also complaining about lethargy and denied chest discomfort.

The patient was treated with NTG and CPAP; his O2 saturations climbed during transport.  The attending physician was concerned about the elevation in aVR, a sign of Left Main Coronary Artery occlusion and the interventionalist was called.  The patient was refused because of his high blood pressure and admitted for stabilization.

In patients with Cardiac complaints elevation in aVR in the presence of global ST depression is indicative of:

1. Left Main Coronary Artery Stenosis
2. Proximal LAD Lesion
3. Triple Vessel Disease

All three of these potential diagnosis carry a high morbidity and mortality.  With LMCA occlusion carrying the highest mortality.

@amalmattu notes that the diagnosis can be narrowed using 3 simple rules:

1. If elevation in aVR and aVL then LMCA occlusion
2. If elevation in aVR and V1 then LMCA or Proximal LAD occlusion
3. If elevation in aVR > elevation in V1 then LMCA occlusion

In the setting of profound hypertension elevation in aVR with global ST depression can occur.  The morphology of the ST segment can offer a hint: down sloping ST depression.  In the first ECG down sloping ST depression can be seen in II, III, aVF, V5 and V6.  This patient turned out to be a typical hypertensive crisis with acute pulmonary edema and an interesting ECG.  The patient's blood pressure was treated and his ST segments returned to normal.  

Although this patient wasn't having a LMCA or proximal LAD occlusion he opened my eyes to the utility of aVR as an indicator of possible disease.