Southern Regional Meeting, New Orleans, February 18–20, 2016

2016 Journal of Investigative Medicine  
Purpose of Study The purpose of this study was to determine whether repeated administration of amphetamine would alter function of the autonomic nervous system (ANS) in the rat, and to thereby assess changes in heart rate variability (HRV). We hypothesized that the acute and chronic administration of amphetamine would not only increase heart rate (HR) and systolic blood pressure (BP), but would also decrease HRV which could in time lead to cardiovascular pathology. Methods Used Telemetry blood
more » ... ressure (BP) transducers were surgically implanted into male Sprague-Dawley rats (n=6). One week later (day 0), each rat received intraperitoneal (ip) injections of saline (0.1 ml) in the morning and afternoon. On days 1-17, amphetamine (2 mg/kg, ip) was administered in both the AM and PM. End-diastolic nadir points were taken from blood pressure waveforms sensed by the telemetry probes in order to generate R-R intervals. From this an in-house computer program was written (MATLAB R2014b) to calculate time domain measures of HR, SDNN, pNN5, and also frequency domain measures of LF, HF, and LF/HF. Average mean arterial pressure and heart rate were computed off-line. Summary of Results BP and HR rose acutely for at least 6 hours after each AM injection throughout the study. Baseline (1 hr before AM injection) BP appears to remain unchanged over time, but baseline HR diminished as the study progressed. The time domain measure pNN5 acutely diminished after each injection, but baseline measures tended to increase over time. LF/HF acutely increased after each AM injection. Over the first 12 days baseline values diminished, but appeared to rise toward the end of the study. Conclusions Acute ip injections of amphetamine increased HR and BP. pNN5 acutely decreased, suggesting a drop in parasympathetic nervous system (PNS) tone, and LF/HF acutely increased, suggesting a relative increase in SNS/PNS tone. These acute findings are suggestive of a sudden drop in PNS activity and a relative increase in SNS activity. Over time, baseline HR, but not BP diminished, and pNN5 increased suggesting an increase in basal PNS tone. Together these studies show that acute administration of amphetamine can alter HRV in the rats. Purpose of Study The purpose was to find a preliminary distribution of lipids in a community (Puerto Rico) a Commonwealth of the U.S.A. with a lower coronary artery disease (20-30%) than the U.S.A. Methods Used A retrospective analysis of 500 patients (P.) seen at the cardiology clinic of the University of Puerto Rico were analyzed. Emphasis was done to the first visit. All were receiving statins. Abstract 482 Figure 1 Covariate-adjusted means of HR in adults by birth weight quartiles 686 J Investig Med 2016;64:488-726
doi:10.1136/jim-2015-000035.483 fatcat:fu3i2vitnfckrbqgkiwjent22a