MMP1 and atrioventricular block: The MMP1 genotype distribution in the AVB patients and controls did not significantly deviate from the HWE for the AVB patients (P-values were 0.724, 0.5952, 0.1116, 0.5434 and 0.1621, respectively) and control groups (P-values were 0.934, 0.838, 0.08, 1.0 and 0.2327, respectively).