I too have had similar experiences. My doctor likewise has brushed it off. I have read where there is a connection, via the vagus nerve which can be stimulated and cause palpitations. Google it, you will find there is a lot of information about the connection. I was recently weaned off Metoprolol, and have experienced both palpitations and a fast heartbeat. However there seems to be a connection with eating. I have only gotten those symptoms, when I had eaten a large meal, and like you had to burp a lot. On days where I ate a salad for dinner, or a less filling meal, I had none.