Figure 2.

Electrical and histological characteristics of left atrial (LA) and right atrial (RA) remodelling with chronic arterial hypertension. (A) Example of an atrial fibrillation (AF) episode induced by repetitive burst pacing in an 11‐deoxycorticosterone acetate (DOCA)‐treated pig [50 ms (pacing) cycle length for 10 s]. Traces from top to bottom: two surface electrocardiograms, bipolar electrogram from stimulation site in high right atrium, and five bipolar electrograms from decapolar catheter in coronary sinus. (B) AF inducibility after 50 ms burst pacing is significantly higher in the DOCA group. Data are expressed as mean inducibility during five burst repetitions in each subject. (C) Right atrial effective refractory period (AERP, ms) assessed by a S1–S2 protocol at three different S1 cycle lengths (240/300/400 ms). Average data of eight control (CTRL) and seven DOCA pigs (mean ± standard error of the mean, n.s.). (D) Representative Sirius Red stainings of atrial tissue from a DOCA and CTRL pig for assessment of collagen content. Pooled data show no difference in LA and RA or between groups. (E) Histological analysis of myocyte area from haematoxylin–eosin (HE) stainings. Samples are from the same animals as in (D) (N _CTRL = 7; N _DOCA = 8).