It is probably not advisable to drink so soon after your surgery. This is because after the surgery, most people take about a week to be able to recover to the point they can walk a hundred or two hundred metres without getting out of breath. In many cases, they will need to take this walk slowly to ensure you do not get too breathless, but also to ensure you keep good balance. Drinking alcohol can affect your ability to walk properly, and often people find they are wonky and cannot balance properly. In these cases, they are usually at an increased risk of falling than someone who has not been drinking - a significantly increased risk.
Following your surgery, you want to make sure you don't have any falls as they could break a bone, or you could instinctively put your arm or hand out to balance you and cause problems with either the stitching in your chest or even in the surgical spots in your heart. This could be fatal. It is best to leave drinking alcohol until you are fully recovered and then, only partake of it in small quantities. General recommendations are to stick to no more than two standard drinks a day for healthy adults (i.e. without medical conditions, including liver disease). A standard drink contains 10g of alcohol and varies in quantity from beverage to beverage.
You can check out how much alcohol is in different beverages here: www.health.gov.au/