CD4 and Hypertension: Patients with interatrial block had a lower nadir lymphocyte CD4 count (124 vs 198 cells, p = 0.02) while advanced interatrial blocks were associated to older age (62.16 vs. 54.95 years, p = 0.046) and hypertension (77.8% vs. 32.3%, p = 0.009).