Hello,Thanks for your query. After going through your query I came to know that you are probably suffering from reactive arthritis. It occur as a body reaction to the underline infection. There is no relation between reactive arthritis and irregular heartbeat .There can be some relation between hypothyroidism and reactive arthritis as in both immune system is deranged. I treat my reactive arthritis patients by local triamcilone injection and analgesic such as diclofenac. You can discuss with your treating Doctor about it. I do hope that you have found something helpful and I will be glad to answer any further query. Take care.