Graduation Year

2022

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Degree Granting Department

Medical Sciences

Major Professor

Siva Kumar Panguluri, Ph.D.

Committee Member

Mark Kindy, MSc, Ph.D.

Committee Member

Ji Li, Ph.D.

Keywords

Arrhythmia, Electrocardiogram, Echocardiogram, Guinea pig, Hyperoxia

Abstract

Hyperoxia is widely implemented in critical care and ICU patients. The administration of a high concentration of inspired oxygen to the lung can unknowingly cause hyperoxia and thereby damaging the lungs and heart due to oxidative stress. Technically, hyperoxia occurs when the patient receives PaO2 > 200 mmHg. Major research focused on hyperoxia-induced lung injury, but nothing is known on its effect on heart. Our lab is the pioneer in understanding the effect of hyperoxia on cardiovascular remodeling using mice model. Previous results show that mice under 72 hours of hyperoxia present severe cardiac pathophysiology. This research uses Guinea pigs, which are better animals in terms of physiological similarities to humans. The study aims are to unveil the pathophysiology of the cardiovascular system concurrent with the age and sex that influence the outcome led to clinical use in the future. In this study, we exposed year old age, female guinea pig (n= 12) assessing the physiology, functional, and electrical data (ECG).

We found that hyperoxia groups show a severe reduction of body weight and severe lung edema. Comparing to male Guinea pigs, females show more severity considering lung edema, weight loss, and some ECG parameters including a decrease in QTc, PR interval, and increase in RR interval. In Guinea pigs even though some echocardiogram parameters are similar to the mice reports (LVIDs increase and CO, SV, %FS decrease), ECG data presents interestingly in a different trend. Since PR, QTc, JT, and QRS intervals in mice increase significantly but in Guinea pigs, QTc and PR intervals decrease significantly.

Even though the significant severity effect from hyperoxia to Guinea pigs are occur similar to mice. The distinct expression between species suggests that each species has a unique response when exposed to high oxygen level. This data is another step toward expanding our boundaries in hyperoxia exposure in Guinea pigs in aspects of sex and species comparison and will pave the way for potential capabilities for precision medicine.

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