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Cardiac cycle
About: Cardiac cycle is a research topic. Over the lifetime, 3290 publications have been published within this topic receiving 96159 citations.
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114 citations
TL;DR: Cinefluorographic analysis of mitral valve motion in intact dogs provided evidence that the motility of the valve cusps is restrained by tension exerted through the chordae tendineae throughout the cardiac cycle, except for the rapid filling phase.
Abstract: Cinefluorographic analysis of mitral valve motion in intact dogs provided evidence that the motility of the valve cusps is restrained by tension exerted through the chordae tendineae throughout the cardiac cycle, except for the rapid filling phase. At the onset of ventricular systole, early contraction of the papillary muscles may play an important role in approximating the mitral valve cusps. During ventricular ejection, the mitral cusps and valve ring move toward the apex of the heart. During diastole, separation of the valve cusps is remarkably slight. The valves were observed to fling wide during rapid ventricular filling when the heart was much smaller than normal, immediately after surgery.
113 citations
TL;DR: AV delay optimization by Doppler echocardiography for patients with severe heart failure treated with a CRT device yields a greater systolic improvement when guided by the aortic VTI method compared with the mitral inflow method.
113 citations
TL;DR: Real‐time cardiac MR imaging can be used to quantify LV volumes accurately throughout the cardiac cycle, over the physiologic range of heart rates, thereby decreasing the time required for a complete functional cardiac examination.
Abstract: The application of real-time magnetic resonance imaging (MRI) techniques to cardiac imaging is particularly attractive because current MR examinations of left ventricular (LV) function can be prohibitively long and are dependent on electrocardiographic triggering. We conducted a study of the minimum spatial and temporal resolution requirements necessary for real-time ventricular function MR imaging to quantify LV volumes accurately, both at resting conditions and during cardiac stress tests. In addition, we implemented a real-time segmented echoplanar imaging pulse sequence and used it to quantify LV volume in 10 healthy volunteers. We compared these results with those obtained using conventional gradient-echo cine imaging and found good agreement throughout the cardiac cycle (mean difference -0.8 +/- 10.6 ml). In conclusion, real-time cardiac MR imaging can be used to quantify LV volumes accurately throughout the cardiac cycle, over the physiologic range of heart rates, thereby decreasing the time required for a complete functional cardiac examination. J. Magn. Reson. Imaging 2000;12:430-438.
112 citations
TL;DR: It is concluded that cine MR imaging can be used to obtain quantitative information about the heart and has the potential to become a valuable noninvasive means of cardiac evaluation.
Abstract: Cine MR imaging provides tomographic images of the heart with both high spatial and high temporal resolution. As many as 32 images per cardiac cycle can be acquired with up to four separate anatomic slices and a total imaging time of 128 cardiac cycles. End-diastolic and end-systolic volumes were determined in 11 patients, and ejection fractions were calculated. The results correlated linearly with those from cardiac catheterization (correlation coefficient of .88). We conclude that cine MR imaging can be used to obtain quantitative information about the heart and has the potential to become a valuable noninvasive means of cardiac evaluation.
111 citations