Several methods for enhancing the functioning of defibrillators in cases of heart attack

This release is available in Spanish.

The PhD, defended by engineer Sofía Ruiz de Gauna Gutiérrez at the University of the Basque Country (UPV/EHU) puts forward various methods for the elimination of interference caused by compressions and ventilations of cardiopulmonary resuscitation in the context of cardiac defibrillation.

A heart attack, also known as myocardial infarction or coronary thrombosis, is the most dramatic manifestation of cardiovascular illness, the main cause of death in developed countries.

In more than 40% of heart attacks patients can have two types of cardiac arrhythmias: ventricular or tachycardial ventricular fibrillation without pulse. The optimum treatment in these cases is the immediate initiation of cardiopulmonary resuscitation (CPR) to maintain artificial circulation by means of the application of thoracic compressions and ventilations, followed by an electrical discharge on the patient’s chest (defibrillation) when the cardiac rhythm is defibrillable. There is evidence that the success of the defibrillation is directly related to the immediacy with which the discharge is administered.

The automatic external defibrillator (AED) is a device capable of analysing the electrocardiogram and applying, if necessary, defibrillation. The mechanical activity of the thoracic compressions and ventilations induces interference on the electrocardiogram that compromises the reliability of the AED diagnosis. Consequently, cardiopulmonary resuscitation has to be interrupted during the intervals of automatic analysis, causing the absence of circulation and reducing the probability of success of electrical therapy.

This was the theme of the PhD thesis by Ms Sofía Ruiz de Gauna Gutiérrez at the higher technical School of Engineering of the UPV/EHU, a work in which various methods for the elimination of this interference caused by compressions and ventilations of the cardiopulmonary resuscitation itself were proposed. The interference-free electrocardiograph signal enables the defibrillator to correctly diagnose during the CPR procedure, avoiding the interruption of compressions and enabling the administration of the discharge as soon as possible.