R wave amplitude changes during transoesophageal atrial pacing in patients with chronic ischaemic heart disease.

15 patients with intact coronary arteries (control group) and 49 patients with coronary stenosis were for the purpose of differential diagnosis of ischaemic heart disease [IHD] subjected to coronarography, left ventriculography and transesophageal atrial pacing. The possibility of using the sum R wave amplitude as a criterion of IHD was assessed, as well as the relation between the R wave amplitude and the left ventricular function indicators--the ejection fraction and the end-diastolic volume. It was found that the increase of the R wave amplitude has distinctly lower specificity (40%) and sensitivity (29%) than the ischaemic depression of the ST segment (73 and 74% respectively). No correlation was found between R wave amplitude changes and indicators of the left ventricular function. The increase in the R wave amplitude cannot be therefore regarded as a reliable criterion of IHD and is not a reflection of the functional state of the left ventricle.