Hi...Sad to hear about this loss. As you might be aware that alcohol in short term particularly affects liver causing liver dysfunction, cirrhosis, hepatic failure in that order. And once liver is affected, other body systems like heart, nervous system are also affected. There is a condition by name alcoholic cardiomyopathy in which heart is greately enlarged in size & hence becomes ineffective as a pump to circulate blood throughout the body. In this condition sudden death is a possibility. Secondly, sudden withdrawal after prolonged heavy consumption of alcohol can cause seizures which if not promptly treated/attended to can cause death. I hope you are reasonably satisfied with this response