Why is it different from Fibrillation in the Dog and Pig Heart?
Sudden cardiac death is one of the major health problems in the industrialised world, leading to over 300,000 mortalities in the US alone annually. In most cases, it is caused by a cardiac arrhythmia called ventricular fibrillation (VF). Under normal conditions, the coordinated contraction of the heart leads to an effective pumping of blood through the body. In contrast, during fibrillation coordination of contraction is completely lost, rendering the heart incapable of pumping around blood. Despite the huge socio-economical costs of VF and decades of research its causes and mechanisms still remainpoorly understood. In experimental studies into the mechanisms of VF, pig and dog hearts are considered the best model systems for the human heart given their comparable size. In such studies it is found that fibrillation is caused by highly disorganised electrical wave patterns consisting of 50 or more rotating spiral waves. It has been assumed that a similar organisation underlieshuman VF.
