Banca de DEFESA: NESTOR RODRIGUES DE OLIVEIRA NETO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NESTOR RODRIGUES DE OLIVEIRA NETO
DATE: 28/07/2023
TIME: 14:00
LOCAL: Hospital Universitário Onofre Lopes, Av. Nilo Peçanha, 620, Petrópolis, Natal RN
TITLE:

Development and Testing of a Device for External Cardiac Pacing and Evaluation of the Efficacy of Mechanical Cardiac Stimulation

KEY WORDS:

Artificial cardiac pacing, pacemaker, atrioventricular block, excitation-contraction coupling.

PAGES: 98
BIG AREA: Ciências da Saúde
AREA: Fisioterapia e Terapia Ocupacional
SUMMARY:

The transcutaneous pacemaker has been used as therapy in cases of bradycardia with hemodynamic impairment, but it has important limitations, due to the high energy required to promote myocardial activation, causing discomfort and muscle stimulation. Thus, alternative forms of artificial cardiac stimulation have been the object of studies. Mechanical stimulation is capable of causing cardiac activation and functioning as a pacemaker, similarly to activation by an electrical stimulus. A mechanical stimulus of a certain intensity can generate a mechanical deformation in the myocardium capable of initiating myocardial excitation, resulting in ventricular contraction.This work comprises two parts: the development and testing of a prototype electropneumatic device for transthoracic cardiac pacing in humans, and the performance of an experimental study to evaluate the effectiveness of mechanical cardiac pacing in promoting and maintaining cardiac ventricular contraction in toad's heart (Rhinella jimi). The main objective of this experimental study is to evaluate whether it is possible to obtain and maintain ventricular myocardial capture through mechanical cardiac stimulation applied to the ventricular wall in toads, comparing mechanical cardiac stimulation with electrical stimulation, regarding cardiac activation, repolarization ventricular arrhythmia and induction of ventricular arrhythmiaThe pneumatic device tested showed a linear correlation between the mechanical energy released and the pressure of the compressed air, providing increasing energy values within the predicted range for transthoracic cardiac pacing (considering a threshold of 0.04 to 1.5 J), reaching up to about 2.8J, with the maximum pressures provided by the hospital medical air network (average pressure of 5 bar). Initial data from the animal study suggest that mechanical cardiac stimulation can be maintained continuously for a certain time, in toads, without loss of capture (capture 1:1), similarly to what is observed in electrical cardiac pacing.

COMMITTEE MEMBERS:
Presidente - 1545315 - GUILHERME AUGUSTO DE FREITAS FREGONEZI
Externo ao Programa - 1696755 - BRUNO LOBAO SOARES - UFRNExterno ao Programa - 2190521 - HINDIAEL AERAF BELCHIOR - UFRNExterno à Instituição - FERNANDO AUGUSTO LAVEZZO DIAS - UFPR
Externo à Instituição - FRANCISCO IROCHIMA PINHEIRO - UnP