Renal Function During Cardiac Pacemaking

Abstract

A hemodynamic and renal study was carried out on eight pacemaker‐treated patients with complete heart block. At the time of study the patients were normotensive and well compensated. Cardiac output, brachial arterial pressure, inulin‐ and PAH‐clearances as well as the excretion of electrolytes were determined on two or three selected heart rate levels between 45–118 for each patient during four to six 20‐minute periods. A change of the ventricular rate from low to high level gave a significant decrease of stroke volume and pulse pressure, but cardiac output, GFR and RPF were unchanged. The most interesting result was the finding of a significantly increased sodium excretion and sodium/potassium quotient on high heart rates. Possible explanations of the mechanisms responsible for this action are discussed.