The 60-year-old man Harishankar Sah suffered a cardiac arrest at his home in Garban Danga village under Karuamani panchayat in Dighalbank block and died on the spot, the Circle Officer Rakesh Kumar said.
The body has been sent for post-mortem, he said.
A powerful earthquake measuring 6.8 on the Richter Scale rocked the Eastern region states, including Bihar, early this morning.
The tremor was also felt in several districts of Bihar, the MeT Department said.