Gosh, why go to all this trouble? Just have an unnecessary heart valve transplant, and have the doctor inscribe your password on the new valve. Then develop a serious booze-and-sodium problem (I guess margaritas are the most efficient way to do this) until you absolutely cannot live without that last remaining valve. At that point, nobody can access your password until you're dead. Or, at least, once someone can access your password, you're definitely dead, which is more or less the same thing.