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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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Journal ArticleDOI
01 Sep 2012
TL;DR: A system to synchronously acquire echocardiography, EKG, and SCG data was designed and implemented, allowing for direct visualization of quiescent phases of the cardiac cycle with respect to heart rate.
Abstract: Seismocardiography (SCG), a representation of mechanical heart motion, may more accurately determine periods of cardiac quiescence within a cardiac cycle than the electrically derived electrocardiogram (EKG) and, thus, may have implications for gating in cardiac computed tomography. We designed and implemented a system to synchronously acquire echocardiography, EKG, and SCG data. The device was used to study the variability between EKG and SCG and characterize the relationship between the mechanical and electrical activity of the heart. For each cardiac cycle, the feature of the SCG indicating Aortic Valve Closure was identified and its time position with respect to the EKG was observed. This position was found to vary for different heart rates and between two human subjects. A color map showing the magnitude of the SCG acceleration and computed velocity was derived, allowing for direct visualization of quiescent phases of the cardiac cycle with respect to heart rate.

43 citations

Patent
11 Apr 1969
TL;DR: In this paper, an automatic arrythmia diagnosing system for diagnosing heart disease employs a plurality of detector elements for detecting both the components and the time interval between components of the portions of an electrocardiagraph wave.
Abstract: An automatic arrythmia diagnosing system for diagnosing heart disease employs a plurality of detector elements for detecting both the components and the time interval between components of the portions of an electrocardiagraph wave. The values of cardiac potentials which are detected during one cardiac cycle are compared with those of a later cardiac cycle when the frequency of the presence of the arrhythmia is high. The number of cardiac potentials of a cardiac cycle is averaged over a predetermined number during an earlier cardiac cycle when the frequency of the presence of arrhythmia is low. Digital logic circuitry is employed to be responsive to code signals representative of various portions of the electrocardiagraph signal to produce signals indicative of different forms of heart disease.

42 citations

Journal ArticleDOI
TL;DR: Experimental work is presented to prove that many extrasystoles, classically diagnosed as ventricular premature beats, are not, and a new definition is proposed based on experimental work performed in the dog's heart.
Abstract: Experimental work is presented to prove that many extrasystoles, classically diagnosed as ventricular premature beats, are not. Most of them correspond to atrial or nodal extrasystoles with some degree of aberrancy. On the other hand, there are ventricular premature beats with normal QRS duration and supraventricular beats with QRS duration greater than 0.12 second. The differentiation of ventricular and supraventricular premature beats must be established by considering the morphology of the extrasystolic complex as well as the time in the cardiac cycle when the premature beat is recorded. Definitions of ventricular extrasystoles from several recent textbooks are reviewed. A new definition is proposed based on experimental work performed in the dog's heart.

42 citations

Journal ArticleDOI
24 May 1965-JAMA
TL;DR: Any comprehensive theory of myocardial function must take into consideration the stresses developed within the myocardium during the cardiac cycle, and the mechanical properties of the papillary muscles are intimately related to a number of clinical problems.
Abstract: Any comprehensive theory of myocardial function must take into consideration the stresses developed within the myocardium during the cardiac cycle. The moment-to-moment variations in myocardial tension during the cardiac cycle have been discussed in previous papers from this as well as other laboratories. 1-4 However, relatively little attention has been given to the mechanical stresses and strains placed upon the papillary muscles during the cardiac cycle. Nevertheless, the mechanical properties of the papillary muscles are intimately related to a number of clinical problems. For example, mechanical failure of a papillary muscle may result in valvular insufficiency and congestive heart failure, or a damaged papillary muscle may rupture under certain loads. It was reported previously that, because of the mechanical nature of the heart as a pump, it was possible to apply physical principles towards an estimation of the "load" which must be supported by the ventricles of the heart during

42 citations

Patent
11 Sep 1998
TL;DR: In this paper, a spiral scan of a measurement volume containing a patient's heart is conducted, the production of the scanning data during the spiral scanning being synchronized with an ECG signal from the patient.
Abstract: In a computed tomography apparatus, and a method for operating same, for obtaining cardiac images, a spiral scan of a measurement volume containing a patient's heart is conducted, the production of the scanning data during the spiral scanning being synchronized with an ECG signal from the patient, in order to produce a graphic representation of the examination volume, and thus an image of the patient's heart. The ECG signal is employed to control the generation of the data during the spiral scanning at phase of the cardiac cycle wherein minimum movement of the heart takes place. The chronological correlation between the recording of the scanning data and the ECG signal is fixed, so that within each number of successive time intervals, a dataset is obtained completely within that time interval. The datasets from the successive time intervals are then combined to produce an image of the heart. Since the component images are all obtained in a low-motion phase of the heart, the resulting overall image is particularly sharp.

42 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202377
2022178
202169
202068
201979
201876