Interaction Between Mechanical Ventilation and Biventricular Pacemaker: Haemodynamic Studies Using Medical Simulation Software Platform

Introduction: Patients affected by symptomatic heart failure (HF) re-sulting from systolic dysfunction can be helped by cardiac resynchroni-zation therapy (CRT). This therapy is realized using a biventricular pacemaker that produces a simultaneously pacing of both the left and right ventricles. Mechanical ventilation (MV) is a form of artificial res-piration which uses a mechanical ventilator in order to assist the breathing of patients. It is used when the lungs are not functioning properly. By means of MV and CRT it is possible to assist some critically ill patients affected by cardiorespiratory failure, induced by complex cardiac surgery or emergency cardiac intervention. In silico modelling of the cardiovascular system can help both in understanding pharmacological or pathophysiological process and in providing information which could not be obtained by means of traditional clinical research methods due to practical or ethical reasons. In this chapter will be presented a study on the effect induced by simultaneous application of mechanical ventilation and biventricular pacemaker by haemodynamic and energetic point of view. Methods: Starting from literature data on patients with intra and/or in-ter-ventricular activation time delay and treated using biventricular pacemaker, we used in silico simulator to analyze the effects induced by mechanical ventilatory assistance. After reproducing baseline and cardiac resynchronization therapy conditions, the ventilatory assistance was simulated changing the mean intrathoracic pressure value. Results: Results show that simultaneous application of CRT and MV yields a reduction of cardiac output, left ventricular end-diastolic and end-systolic volume when positive mean intrathoracic pressure is ap-plied. In the same conditions, when MV is applied, left ventricular ejec-tion fraction, mean left (right) atrial and pulmonary arterial pressure in-crease.