It was on the eve of New Year a doctor whom I knew since many years, came to me at around 3.30 PM with history of chest pain squeezing type not associated with sweating or breathlessness and no radiation. Actually I was about to leave for my lunch and later in late evening I had planned New Year celebration with my kids.
I asked my nurse to take ECG. ECG showed around 0.5mm ST depression in lead I and aVL and other wise ECG was not remarkable. I told him that ECG is showing minimal changes. I asked him, how severe is chest pain? he replied “not very much”. I felt it is wiser to observe him but it was New Year eve so he was also not very keen.
At last we decided that, if pain recurs, we will repeat ECG after 1 or 2 hours. His house was very near to my hospital so he went home. I came to my home. I was about have lunch, his wife called me and said his husband is having pain somehow he is not feeling well. I told her to send him to hospital, she said after finishing lunch he will come.
He came to hospital at around 4.30PM, before I reached hospital nurse had repeated ECG. I saw the ECG it was showing evolved inferior wall MI.
In patients with inferior wall MI reciprocal changes i.e. ST depression in lateral leads i.e. aVL appears before ST elevation over the inferior leads.
In a study published in euro heart around 7.5 % of patients of inferior wall had no ST elevation in inferior but had ST depression in lead aVL. In this study they concluded that lead aVL is early sensitive marker of inferior wall MI. check this link click here
One more characteristic of lead aVL is, it will be just upside down the lead three in inferior wall MI due to RCA lesion. In case of inferior wall MI due to LCX disease there may ST elevation in lead aVL . Check this article for vessel localization in MI click here