[General cardiocirculatory effects in chronic respiratory insufficiency]

Blood gas and haemodynamic changes caused by chronic respiratory insufficiency affect the right ventricle and produce chronic cor pulmonale. Equally important but less well known modifications affect the left ventricle and the general circulation and are the subject of the present report. Hypoxemia, hypercapnia and acidosis caused by severe hypoxia create functional disturbances in both ventricles that are manifested in a volume overload that added to other major malfunctions provoke congestive heart failure. The coronary circulation is affected by metabolic factors, perfusion alterations, right ventricular hypertrophy and concomitant coronary lesions. Advanced respiratory insufficiency caused by poorly compensated respiratory acidosis and metabolic acidosis reduces cardiac output and frequency so that tissue perfusion is compromised. Furthermore alterations in transmembrane electrolytic concentrations produce repeated multifocal ventricular arrhythmias that expose the patient to the risk of sudden death. Cardiac failure is reflected in other organs like the kidney and the central nervous system and also contributes to tissue and cerebral hypoxia. The later depresses the respiratory centres and develops into often irreversible coma. A better knowledge of these elements may contribute to the development of appropriate treatment.