Navickas RS, Kinduris SJ, Kastanauskas RI. Cor Vasa 1987;29(3):167-73. 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.