Tag Archives: Mechano-electric feedback
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 15)
The putative contribution of mechanosensitive fibroblasts to mechanically induced electrophysiological disturbances observed in ischemically damaged or scarred tissue has yet to be elucidated experimentally. Damaged tissue is expected to display reduced contractility and to contribute less to ventricular muscle shortening. … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 14)
In the present study the contribution of cardiac mechanosensitive fibroblasts to the stretch-induced increase in heart rate was simulated. The results presented support the hypothesis that cardiac mechanosensitive fibroblasts could contribute to this response, functioning as an alternative mechanosensor. The … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 13). DISCUSSION
DISCUSSION The cardiac SA node is known to respond to stretch by an increase in spontaneous depolarization rate. This response has been observed both in animal experiments and in healthy humans . Neither the sensor nor the pathway that allows … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 12)
Simulation of fibroblast cardiomyocyte interaction: The impact that ventricular fibroblast-rich tissue may have on heart rhythm was studied in a network of over 16,000 ventricular cardiomyocytes. In these simulations a scar model was implemented in the centre of a 128×128 … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 11)
In Figure 2, six individual frames of a networked simulation of a fibroblast-rich region, embedded within a grid of normal ventricular myocytes, are presented. The damaged tissue region measured 32 cells in diameter. Under mechanically stable, resting conditions cardiomyocytes are … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 10)
The duration of the very first diastole during which a stretch was applied decreased, reducing the oscillation period to 296 ms. Within the four contecutive ditstoles during which a stretch was applied, the oscillation period reached a cycle length of … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 9)
The stretch conductance in each fibroblast was held at 20 nS until a positive threshold crossing in the reference cell occurred. This simulation of atrial diastolic stretch was repeated during four consecutive cardiac cycles, before the initial protocol was reinstated. … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 8). RESULTS
A ventricular scar region was modelled by defining a circular region in the network within which each model ventricular cell was coupled to one model fibroblast by a conductance Gcf. The electrophysiological characteristics of heterologous gap junctions between cardiac fibroblasts … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 7)
Ventricular network modelling: Individual ventricular cells were modelled using the formulations of Noble et al based on data from the guinea-pig. Ventricular networks were modelled using two-dimensional cell lattices in which each interior cell of the lattice was coupled resistively … Continue reading
Computational study of the impact of cardiac mechanosensitive fibroblasts on heart rhythm (part 6)
Each model SA node cell is coupled to a single model fibroblast by a conductance, Gcf, of 300, 600 or 900 pS. To allow simulation of an increase in diastolic atrial wall stretch (eg, during a rise in venous … Continue reading