Introduction: Heart failure (HF) is a prevalent and burdensome chronic disease, with a characteristic high rate of hospital admissions. Left ventricular filling pressure is the earliest, most objective sign of impending HF exacerbation. Previous implantable devices, positioned in the pulmonary artery, have shown good safety and clinical efficacy. The Vectorious Left Atrial Pressure (V-LAP) monitoring system is a robust, miniature, battery-less sensor. It uses advanced application-specific integrated circuit (ASIC)-based technologies, enabling left-sided daily pressure readings with a wirelessly connected external unit. Our aim was to examine the safety and the functionality of the device in animal subjects. Methods: Using a dedicated repositionable delivery system, through a standard transseptal approach, adult sheep were implanted with a V-LAP device. Aspirin (325mg) and clopidogrel (750mg) were given prior to the procedure, the latter continued (225mg daily) during follow-up. An external wearable belt was used to remotely power the implant, interrogate the bi-directional digital data from the sensor, and transmit detailed wireless left atrial pressure waveforms to a web-based database. Results: The device was implanted in 10 animals, and was able to communicate well with the external belt, at depths of up to 30 cm in the thorax, for periods of up to 100 days, generating accurate and precise waveforms, with high temporal resolution. No peri-implant thrombotic events were observed (figure). There were no device-related complications. Conclusions: Using an advanced, left sided, intracardiac monitoring system, safety and feasibility were demonstrated with good functionality in animals, as evidenced by high resolution pressure wave outputs. Data in human subjects will determine whether the V-LAP is a safe and an effective monitoring system of hemodynamic data in heart failure patients, thus reducing readmission, morbidity and mortality rates.