Coronary artery motion

Coronary artery motion shows a biphasic pattern of rapid movement the maximum of motion is observed during the ventricular contraction at early to mid-systole and during rapid filling in early diastole (Achen-... 

Achenbach S, Ropers D, Holle J et al. (2000) In-plane coronary arterial motion velocity measurement with electron-beam CT. Radiology 216 457 463... 

Husmann L, Leschka S, Desbiolles L etal. (2007) Coronary artery motion and cardiac phases dependency on heart rate—implications for CT image reconstruction. Radiology 245 567-576... 

Lu B, Mao SS, Zhuang N et al. (2001) Coronary artery motion during the cardiac cycle and optimal ECG triggering for coronary artery imaging. Invest Radiol 36 250-256... 

Ultrarapid computed tomography may minimize artifact from heart motion during contraction and relaxation and provides a semiquantitative assessment of calcium content in coronary arteries. 

Thormann J, Schlepper M, Kramer W, Gottwik M, Kindler M. Effects of AR-L 115 BS (Sulmazol), a new cardiotonic agent, in coronary artery disease improved ventricular wall motion, increased pump function and abolition of pacing-induced ischemia. J Am Coll Cardiol 1983 2(2) 332-7. 

Radionuclides such as technetium-99m and thallium-201 are used to assess wall motion and myocardial viability in patients with coronary artery disease and heart failure. 

An important determinate of outcome for the angina patient is the number of vessels obstructed. Twelve-year survivals from the Coronary Artery Surgery Study (CASS) for patients with zero-, one-, two-, and three-vessel disease were 88%, 74%, 59%, and 40%, respectively. Other factors that increase the risk of death in medically managed patients include the presence of heart failure (or markers such as poor ventricular wall motion and low ejection fraction), smoking, left main or left main equivalent CAD, diabetes, and prior MI. Twelve-year survivals for patients with at least one diseased vessel and ejection fractions in the ranges of 50% to 100%, 35% to 49%, and 0% to 34% are 73%, 54%, and 21%, respectively. Of particular note, patients with left main CAD (or left main equivalent) are... 

A new method using ultrarapid computed tomography (spiral CT, ultrafast CT, electron-beam CT) minimizes artifact owing to motion of the heart during contraction and relaxation and provides a semiquan-titative assessment of calcium content in coronary arteries. Calcium scores greater than 150 provide a sensitivity of 74% and specificity of 89%, and this method may be cost-effective compared with ETT. 

Sulmazole (AR-L 115) (37), an imidazopyridine derivative, increased dp/dt max. by 58% and heart rate by 12 beats/min in anesthetized cats after 1 mg/kg i.v. Systolic blood pressure was decreased by 13 mm Hg.l42 Oral administration augmented dp/dt max. up to 92% for 5 to 12 hours in conscious dogs.143 Despite similar PDE-inhibitory activity of 37 and theophylline, it seems likely that effects other than PDE-inhibi-tion contribute to the positive inotropic action.144 Measurement of the effect of 21 on relations between free Ca++, bound Ca ", and ATPase activity of dog cardiac myofibrils indicates that the positive inotropic actions may involve direct activation of myofibrils by an increased affinity of thin filament receptors for Ca++.145 Several clinical studies in heart failure showed that in patients with congestive cardiomyopathy and with coronary artery disease, 22 improved hemodynamics and regional wall motion via decrease in pre- and afterload and Increase in contractility, myocardial oxygen consumption and coronary sinus flow, with no myocardial ischemia.14 149... 

It should also be considered when interpreting coronary CTA that details like collateral vessels, contrast run-off and direction of filling of coronary arteries are not visualized by CTA. Finally, the hemo-dynamic relevance of coronary artery stenoses may not only be determined by its degree but also requires motion analysis of the myocardium or myocardium perfusion data under rest and exercise. However, more and more post-processing tools are under development trying to provide quantitative measurements for the degree of stenoses in the coronary arteries. These measurements correspond to the quantitative coronary assessment (QCA) known from cardiac catheter (Fig. 15.3). The reliability of these measurements has not yet been determined. 

Fig. 15.5. Retrospectively gated image acquisition by CT does not only contain information about the coronary arteries but also about the function of the myocardium. Newer postprocessing is under development, and tries to determine the axial CT slices reconstructed at different time points of the cardiac cycle. These workstations may provide data about the global functional parameter, as well as regional wall motion abnormalities...

Fig. 1.6. Case study illustrating the clinical performance of dual-source CT (DSCT) for ECG-gated cardiac imaging. VRT renderings of a 59-year-old male patient with suspicion of RCA stenosis. The mean heart rate of the patient during the scan was 85 bpm. Left Diastolic reconstruction at 65% of the cardiac cycle. Right End systolic reconstruction at 28% of the cardiac cycle. In both cases the coronary arteries are clearly depicted with few or no motion artifacts...

In order to freeze an image of the beating heart, the imaging modahty should provide high temporal resolution. This is necessary to compensate for motion of the coronary arteries, which demonstrate a complex and nonuniform movement pattern within and across the different coronary arteries, as well as within the different parts of the cardiac cycle (Achenbach et al. 2000). At heart rates below 80 bpm, the diastohc phase represents that phase of the cardiac cycle with the least... 

Wang Y, Vidan E, Bergman GW (1999) Cardiac motion of coronary arteries variability in the rest period and implications for coronary MR angiography. Radiology 213 751-758... 

In summary, a sufficient evaluation of the left ventricular function and waU motion is feasible with CTA datasets acquired for the examination of the coronary arteries, thus adding a comprehensive functional aspect to the static morphological assessment in CT and possibly rendering the modaUty a first choice for cardiac imaging in a wider range of indications. 

ZEUS [25], approved by the FDA, is a telesurgical assistant that was specifically designed for laparoscopic surgery by Computer Motion. The patient-side cart carries three robotic arms (Figure 5.1) including two instrument arms and one endoscope arm. Each arm has 4 active DOFs and two passive joints to enforce compliant motion with the fulcrum constraint at the port of entry. The system also has a surgeon s console that carries a pair of master control devices as weU as a display. The system has mainly been used for endoscopic coronary artery bypass procedures, and was discontinued in 2003. 

In the past 40 years, many attempts had been done to evaluate the ambulatory function and condition of humans. This kind of evaluation is considered as useful indicators of a person s condition. Most of the methods being developed are for the evaluation of the ambulatory function and condition of normal and healthy subject or certain patients like those who surfer coronary artery disease, multiple sclerosis, musculoskeletal disorders and etc. Their main focus is to find out about the static and dynamic activities, postural control, swaying motion, step counting, energy expenditure, fall risk of the elderly and etc. Yet, very little effort had been put in the research regarding the amputees ambulation with their prosthesis. 

MRA is already used routinely in many centres for evaluation of the carotid arteries and intracerebral vasculature, aortography and assessment of the ileofemoral system. MRA of the coronary arteries is technically more difficult due to their relatively small size, their complex 3D anatomy and their constantly changing position within the thoracic cavity due to cardiac motion and respiration. 

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