Transvascular diaphragm pacing systems (TDPS) and methods are disclosed for providing respiratory therapy to a patient. The TDPS can provide rapid insertion and deployment of endovascular pacing electrodes in critically ill patients who require intubation and invasive PPMV in order to support the physiological requirements of the human ventilatory system. The systems and methods make best use of the contractile properties of the diaphragm muscle and prevent muscle disuse and muscle atrophy. This can be carried out by engaging the phrenic nerves using patterned functional electrical stimulation applied to endovascular electrodes that are temporarily and reversibly inserted in central veins of the patient, such as the left subclavian vein and the superior vena cava. The TDPS can be designed to seamlessly interface with any commercially available positive-pressure ventilatory assistance/support equipment such as is commonly in use in hospital intensive care units (ICU) for treating critically ill patients with breathing insufficiencies, pain, trauma, sepsis or neurological diseases or deficits.
