Completed notes of the course

Pagina 1

1 Computational Biology of the Heart Notes from the course by J. Matas, Academic Year 2017-2018 Author: Guido Nannini 2 Bioelectricity and bioelectric models of the heart: a multi-scale presentation 1.1 Generalities on heart Heart is a volumetric pump that beats at 75 bpm, moving more than 5 litres of blood. The fact that is a volumetric pump implies that the volume of blood pumped in the systemic circulation is the same at every beat, no matter what’s the response of arteries. The whole function of the heart is a combination of a mechanical and an electric action. The ECG is the signal that we can get, to have information on heart activity. Heart puts in connection the systemic and the pulmonary circulation, pumping non-oxygenated blood to lungs from right ventricle, and oxygenated blood to aorta from the left ventricle. It is placed in the left thoracic part of our body, the right ventricle is in the anterior part, while the left ventricle is on the posterior part. In an ECG exam the precordial leads measure the activity of the right ventricle. Heart is composed by four chambers, two atriums and two ventricles. These are separated in a left and right side: right atrium receives blood from superior and inferior vena cava, then blood passes in the right ventricle and is pumped in pulmonary artery (left and right). In lungs, blood gets oxygenated and returns to the heart through pulmonary veins, entering the left atrium. From the left atrium it passes in the left ventricle and in pumped in the aorta, since it pumps blood in the systemic circulation, the left ventricle is thicker than the right one. The pumping function is achieved with two main motions, a contraction and a rotation. This is possible thanks to the particular structure of the muscle, that has very…