Investigate the effect of external diaphragmatic pacemaker on chronic cor pulmonale, the indicators include: respiratory muscle force, diaphragmatic degree of excursion and thickness, pulmonary artery pressure, respiratory distress, feeling of fatigue and quality of life, pulmonary function,NT-proBNP,PaO2 and PaCO2.
This study evaluates the effect of external diaphragmatic pacemaker on the patients with chronic cor pulmonale. Half of participants will receive external diaphragmatic pacemaker, while the other half will receive routine therapy.