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    Two postero-anterior chest roentgenograms were exposed, one during diastole and one during systole, on each of 359 patients, 35 sets of films being later discarded because of technical errors. Fifty-two per cent of the patients showed changes of 0.3 cm or less, 41 per cent showed alterations of 0.4 to 0.9 cm, and 7 per cent a variation of 1.0 to 1.7 cm in transverse cardiac diameter. It is concluded that the set of films is more useful in evaluating heart size than one film exposed at a random point along the cardiac cycle.
    Cardiac cycle
    Systole
    Citations (19)
    Gated radionuclide cardiac blood pool scans (GCS) of end-systole and end-diastole or eight images subtending the entire cardiac cycle were performed on seven patients with left atrial myxomas documented by pulmonary cineangiography with left atrial follow-through. The ethocardiogram was either suggestive or diagnostic in all patients. In addition to demonstration of the tumor (6 patients), the GCS detected three patterns of tumor motion: 1) a defect which moved from the left atrium in end systole to the left ventricle in end diastole (2 patients); 2) a defect which remained within the region of the left atrium but decreased in size between end diastole and end systole (3); and 3) a defect which was observed within the region of the left ventricle in end diastole but disappeared in end systole (1). Thus, the GCS is a noninvasive method for detection and evaluation of motion of left atrial myxomas.
    Systole
    Cardiac cycle
    Cineangiography
    Citations (55)
    A realistic model of the left ventricle of the heart was previously constructed, using a cast from a dog heart which was in diastole. Previous studies of the three-dimensional heart model were conducted in systole only. The purpose of this investigation was to extend the model to both systole and diastole, and to determine what the effect of a previous cardiac cycle was on the next cardiac cycle. The 25.8 cc ventricular volume was reduced by 40% in 0.25 seconds, then increased to the original volume in another 0.25 seconds and then allowed to rest for 0.25 seconds. Runs done with an ejection fraction of 60% showed little variation from one cardiac cycle to another after the third cardiac cycle was completed; the maximum velocity could vary by over 30% between the first and second cardiac cycles. In systole, centerline and cross-sectional velocity vectors greatly increased in magnitude at the aortic outlet. Most of the pressure drop occurred in the top 15% of the heart. The diastolic phase showed complex vortex formation not seen in the systolic contractions; these complex vortices could account for experimentally observed turbulent blood flow fluctuations in the aorta.
    Cardiac cycle
    Systole
    Citations (34)