Non-invasive methods of investigative cardiology

Non-invasive assessment of heart and chamber size employs various techniques which yield different information. Overall size as estimated by biplane chest roentgenogram in the upright or - better - supine position is a valuable quantitative method. Correlation with individual chamber size is, however, only fair. Information on wall thickness can currently be obtained only by ultrasound echocardiography. ECG and vectorcardiography as a means for determining ventricular hypertrophy have remained semi-quantitative techniques, but can probably be developed into more quantitative information by means of computer analysis. A method of predicting left ventricular muscle mass using the Frank orthogonal lead system is described. Regional disorders of contraction and contractility have been difficult to assess non-invasively. Kymographic techniques describe only motion of the lateral wall. Ultrasound techniques, even using a two-dimensional approach, rarely include the ventricular apical region. Systolic time intervals and radionuclide minimal transit times have remained of limited importance. The value of ECG-gated computertomography cannot be assessed as yet. The greatest promise can be expected from radionuclide techniques with gated blood pool scanning and myocardial scintigraphic techniques. (orig.)