Application of implantable telemetry in swine heart failure models

Abstract

Swine animal models are commonly used to study the mechanism of heart failure (HF) and to develop new therapies. Continuous recordings of blood flow, ventricular and systemic blood pressures in awake, free‐roaming animals without the effects of anesthesia will provide valuable data on the progression and treatment of HF. The objective of this study was to evaluate simultaneous, totally implantable, telemetric measurements of these parameters in swine HF models. Solid‐state blood pressure catheters were placed in the right or left ventricle and descending aorta for pressure measurements while Doppler probes were placed around the LAD and branchocephalic arteries for blood flow velocity measurements. ECG electrodes were attached to the left ventricle. Each telemetry unit was implanted subcutaneously for up to 6 weeks into various HF models including A‐V fistula, aortic banding and high‐rate pacing. Sudden and chronic changes of hemodynamics were captured during the progression of HF. Systemic pressure progressively decreased within first 2 weeks in HF with pacing and recovered by 4 weeks; while the pressure increased progressively in HF with aortic banding for 4 weeks. The pressure did not significantly change within first 4 weeks, but LAD flow increased within 2 weeks in animals with A‐V fistula. The results showed that this biotelemetry system is capable of long‐term accurate monitoring of simultaneous blood flow, pressure and ECG. This system will have significant utility in chronic models of cardiovascular physiology and pathology.