[Assessment of haemodynamic parameters using a scintillation camera and ECG-triggered data acquisition (author's transl)].

Useful ECG-gated scintigrams of the heart can only be obtained when using a suitable tracer (99mTc-HSA or labeled red cells), a good camera and a computer system with special hard and software. The haemodynamic parameters of left (and right) heart function as derived from scintigrams are only precise when the representative cycle was reconstructed correctly. In patients with arrhythmia, counts should be only summed up when the cardiac cycle follows a preceding heart beat of well defined length. The frames composing the representative cycle must be normalized to the same recording time. When these prerequisites are fulfilled, correct values for ejection fraction and maximal rates of systolic emptying and diastolic filling as global parameters of heart function can be derived. Evaluation of these parameters by means of a completely automated computer program is difficult in pathologically altered heart function. In our nuclear medicine department an interactive computer program has been developed which supplies the investigator with certain information facilitating the definition of the end-diastolic and end-systolic ROI. The program allows for an exact and reproducible evaluation within a short time. Functional images of both amplitudes and phases are very helpful. Functional scintigraphy of the heart is only possible when using certain instrumentation, which is much more expensive than when using a 'cardiac probe', but the additional visual information obtained does significantly improve diagnostic sensitivity.