Measurement of right ventricular pressure by telemetry in conscious moving rabbits

Abstract

Implantable radiotelemetry methodology has been used to continuously monitor pulmonary hemodynamics including right ventricular pressure (RVP) or pulmonary arterial pressure (PAP) in conscious, untethered and freely moving animals such as mice and rats. The use of implantable radiotelemetry to monitor RVP or PAP has never previously been described in rabbits. The aim of the present study was to use implantable radiotelemetry to continuously monitor RVP in conscious adult rabbits. Telemetry transmitters were implanted in 44 adult male New Zealand rabbits using a trans-diaphragm approach for the catheter placement. RVP, heart rate (HR) and activity were monitored every 15 min for 20 s. Body mass was recorded once a week. A total of 39 (88%) rabbits were successfully implanted. Thirty rabbits survived the surgical procedure resulting in an overall survival rate of 73%. RVP, HR and activity were long-term monitored in 17 rabbits for an average period of 103 AE 15 days. Weekly body mass follow-up showed that implantable radiotelemetry did not impair the normal development of the animal. Twenty-four-hour period monitoring of RVP, HR and activity showed concomitant changes in RVP, HR and activity according to the dark/light cycle applied to the rabbits. To conclude, implantable radiotelemetry methodology can be safely used to continuously monitor RVP in conscious rabbits. KeywordsTelemetry, right ventricular pressure, pulmonary circulation, rabbit Pulmonary hypertension is a medical condition mainly affecting the pulmonary circulation. Various rodent animal models have been developed to better understand the physiopathology of pulmonary hypertension and to test potential new drugs.1 Hemodynamic data from these animal models are usually restricted to a single measurement of pulmonary arterial pressure (PAP) and/or right ventricular pressure (RVP), in anesthetized, mechanically ventilated and often openchest animals.2,3 More recently, high-resolution echocardiography and magnetic resonance imaging (MRI) techniques have been developed to accurately estimate hemodynamics in small animals including rats, mice and rabbits, and to allow for serial monitoring of experimental pulmonary hypertension.4,5 Although these techniques are non-invasive, they are performed on anesthetized animals, which implies respiratory and cardiovascular depression resulting in various artifacts. Continuous monitoring of RVP and PAP in conscious, untethered and freely moving animals was introduced by Hess et al. in the 1990s and has consequently and considerably improved hemodynamic pulmonary measurement in rodent models of pulmonary hypertension. 6 Since then, telemetry has been widely described as a method for measuring RVP and PAP in rodent models of pulmonary hypertension.7-10 However, the original procedure of implantable radiotelemetry methodology included extremely invasive thoracic surgery resulting in significant stress, potentially disturbing the cardiovascular system, and in delayed recovery. More recently, a trans-diaphragm surgi...

Impairment of Angiogenesis-Driven Clot Resolution Is a Key Event in the Progression to Chronic Thromboembolic Pulmonary Hypertension: Validation in a Novel Rabbit Model

“…Surprisingly, Deng et al 38 described a CTEPH model obtained by 2 repeated embolizations of one day-old clots combined with daily injection of TXA in rats with restricted activities to mimic blood stasis. In the present study, we aimed to develop a model mimicking the early steps of the human CTEPH without using foreign material in an animal with less efficient fibrinolysis than rodents and using telemetry 33 for continuous follow-up of pulmonary hemodynamics.…”

“…Radiotelemetry equipment for conscious and freely moving laboratory animals was implanted to monitor RV pressure. 33 The fluid-filled pressure catheter of a telemetry transmitter (Model TA11PA-D70; Data Science International) was placed in the RV using a trans-diaphragm surgical approach, as previously described. 33 During a postsurgical recovery period of about 2 weeks, the transmitter was switched off.…”

“…33 The fluid-filled pressure catheter of a telemetry transmitter (Model TA11PA-D70; Data Science International) was placed in the RV using a trans-diaphragm surgical approach, as previously described. 33 During a postsurgical recovery period of about 2 weeks, the transmitter was switched off. Data, including RV pressure and heart rate, were continuously monitored during the transmitter implantation procedure to ensure proper placement of the pressure catheter into the RV and during each embolization.…”

Commonly Used Animal Models

“…The production of polyclonal antibodies is preferentially performed in the rabbit due to its relatively large blood volume compared to rodents (Hanly et al, 1995). Their tractable nature and larger body size also make them suitable for surgical implantation of biomedical devices (Gotfredsen et al, 1995;Swindle et al, 2005;Ronisz et al, 2013). Additionally, rabbits are a favored model in pharmacologic studies for teratogenicity testing of novel pharmaceutic compounds (Gibson et al, 1966;Lloyd et al, 1999;Foote and Carney, 2000;Jiangbo et al, 2009;Oi et al, 2011).…”

Techniques of Experimentation

“…Telemetry to obtain physiologic data has been described in most laboratory animal species, including rodents (Kramer and Kinter, 2003), rabbits (Varosi et al, 1990;Brackee et al, 1995;Ronisz et al, 2013), ferrets (Percie du Sert et al, 2009), swine (Myrie et al, 2012), marmosets (Schnell and Wood, 1995), rhesus monkeys (Sadoff et al, 1992), and baboons (Pearce et al, 1989;Crean et al, 2007). Current devices now have batteries that can be turned on and off magnetically to extend their life and battery life has been improved considerably.…”