1. The cause of congenital third-degree heart block in many patients is unknown. 2. In first-degree heart block , the diseased AV node conducts the electrical activity more slowly. 3. Cardiac arrhythmias can cause heart block , in which the contractions lose any useful rhythm. 4. Therefore, most of the important heart blocks are AV nodal blocks and infra-Hisian blocks. 5. After 48 hours, the monitor defined an indiscriminate heart block . 6. Mutations in emerin cause PR prolongation to complete heart block . 7. It can cause arrhythmias, heart block , even sudden cardiac death. 8. A very slow heart rate ( bradycardia ) may be associated with heart block . 9. Accidental intravenous overdose in an infant caused severe heart block , resulting in residual encephalopathy. 10. Isolated first-degree heart block has no direct clinical consequences.
