Atriogenic Diastolic Reflux in Patients with Atrioventricular Block

Abstract

In five patients with total A-V block studied by thermodilution, infusion of 10 to 25 ml of cold saline into the right ventricle over a period of several seconds resulted in lowering right atrial temperature usually 0.25 to 0.7 second after P waves not followed in normal temporal sequence by QRS complexes. In three of these patients, in whom left heart catheterization was performed, the same phenomenon could be detected during and after infusion of cold saline into the left ventricle while temperature was measured by a thermistor introduced by transseptal route into the left atrium. Isolated atrial contractions, although capable of partially closing the A-V valves as indicated by the higher ventricular than atrial pressure, lead to atriogenic reflux from the ventricle. Ventricular contraction, however, whether normal or extrasystolic, produced efficient closure of the A-V valves.