Cardiac Cycle Imaging
Cardiac Cycle Imaging - Related Videos
01:29
Cardiac Cycle
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2025
The cardiac cycle refers to the sequence of events that occur in the heart from the beginning of one heartbeat to the next. It's characterized by alternating periods of contraction (systole) and relaxation (diastole) of the heart muscles. During the cardiac cycle, blood flow through the heart is regulated entirely by changing pressure gradients. This sequence of events begins with the heart in a state of total relaxation, known as mid-to-late diastole, during which blood passively flows from...
01:13
The Cardiac Cycle
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2025
The heart beats rhythmically in a sequence called the cardiac cycle—a rapid coordination of contraction (systole) and relaxation (diastole). The Process Electrical signals—sent from the sinoatrial (SA) node in the right atrial wall to the atrioventricular (AV) node between the right atrium and right ventricle—cause both atria to simultaneously contract. When the signal reaches the AV node, it pauses for approximately a tenth of a second, allowing the atria to contract and empty blood into the...
11:37
Cardiac Magnetic Resonance Imaging
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2023
Source: Frederick W. Damen and Craig J. Goergen, Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana In this video, high field, small-bore magnetic resonance imaging (MRI) with physiological monitoring is demonstrated to acquire gated cine loops of the murine cardiovascular system. This procedure provides a basis for assessing left-ventricular function, visualizing vascular networks, and quantifying motion of organs due to respiration. Comparable small animal...
01:18
Physiology of the Heart: The Cardiac Cycle
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2025
The cardiac cycle describes the events from one heartbeat to the next. It includes three main phases: diastole, atrial systole, and ventricular systole, all driven by changes in chamber pressures and the function of heart valves. Diastole: The Relaxation Phase During diastole, all four heart chambers relax. The atrioventricular (AV) valves open, and the semilunar valves close. This phase sees the lowest chamber pressures, promoting ventricular filling. Venous blood enters the heart through the...
09:14
Cardiac Magnetic Resonance Imaging at 7 Tesla
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Cited by 10 •
2019
The sensitivity gain inherent to ultrahigh field magnetic resonance holds promise for high spatial resolution imaging of the heart. Here, we describe a protocol customized for functional cardiovascular magnetic resonance (CMR) at 7 Tesla using an advanced multi-channel radio-frequency coil, magnetic field shimming and a triggering concept.
FAQs
Systole provides the reference for ventricular contraction and chamber emptying, whereas diastole captures relaxation and filling. Reviewing both phases helps relate ventricular motion to valve opening and closure and to the timing of blood flow. This phase-based comparison can reveal whether abnormal function reflects impaired contraction, altered relaxation, or disrupted valve behavior.
ECG gating assigns image acquisition to defined points in the cardiac cycle, allowing motion to be evaluated against a consistent timing reference. For ECG-gated CT in particular, this approach links each image to systole or diastole rather than treating the heart as a static structure. Consistent phase selection supports more reliable comparisons of anatomy and function.
Phase-specific studies can examine ventricular motion, wall thickness, and the timing of valve opening and closure. They also support measurement of ejection fraction, which summarizes how effectively a ventricle ejects blood during contraction. Considering these findings together connects structural changes with chamber performance instead of interpreting anatomy or motion in isolation.
Echocardiography, cardiac MRI, and ECG-gated CT all provide ways to acquire cardiac images at defined phases, but they represent complementary imaging approaches within the same cycle-based framework. Their phase-linked observations can be used to evaluate ventricular motion, valves, wall thickness, and ejection fraction, supporting assessment of both anatomy and changing cardiac function.
A typical workflow begins by selecting the cardiac phases relevant to the clinical or research question, followed by image acquisition with an appropriate modality such as echocardiography, cardiac MRI, or ECG-gated CT. The resulting phases are then reviewed for ventricular motion, valve behavior, wall thickness, and ejection fraction, producing measurements that link structure with function.
Clinicians use these measurements when evaluating or monitoring heart failure, coronary disease, valvular disorders, and congenital abnormalities. The value lies in tracking functional changes alongside anatomical findings, such as altered ventricular motion, abnormal wall thickness, or changes in ejection fraction. Repeated assessments can help show whether cardiac status is stable, worsening, or changing during care.
In research, phase-specific imaging provides quantitative observations of how cardiac structure and function change over time or respond to treatment. Investigators can compare ventricular motion, wall thickness, valve timing, and ejection fraction across evaluations. This creates a framework for relating therapeutic response or disease progression to measurable changes in the heart’s anatomy and performance.