1/9. Decreased left ventricular filling pressure 8 months after corrective surgery in a 55-year-old man with tetralogy of fallot: adaptation for increased preload.A 55-year-old man with tetralogy of fallot underwent corrective surgery. Left ventricular filling pressure increased markedly with increased left ventricular volume one month after surgery, then decreased over the next 7 months, presumably due to increased left ventricular compliance.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
2/9. Rapid evaluation of left ventricular volume and mass without breath-holding using real-time interactive cardiac magnetic resonance imaging system.OBJECTIVES: The purpose of this study was to validate cardiac measurements derived from real-time cardiac magnetic resonance imaging (MRI) as compared with well-validated conventional cine MRI. BACKGROUND: Although cardiac MRI provides accurate assessment of left ventricular (LV) volume and mass, most techniques have been relatively slow and required electrocardiogram (ECG) gating over many heart beats. A newly developed real-time MRI system allows continuous real-time dynamic acquisition and display without cardiac gating or breath-holding. methods: Fourteen healthy volunteers and nine patients with heart failure underwent real-time and cine MRI in the standard short-axis orientation with a 1.5T MRI scanner. Nonbreath-holding cine MRI was performed with ECG gating and respiratory compensation. Left ventricular end-diastolic volume (LVEDV), left ventricular endsystolic volume (LVESV), ejection fraction (EF) and LV mass calculated from the images obtained by real-time MRI were compared to those obtained by cine MRI. RESULTS: The total study time including localization for real-time MRI was significantly shorter than cine MRI (8.6 /- 2.3 vs. 24.7 /- 3.5 min, p < 0.001). Both imaging techniques yielded good quality images allowing cardiac measurements. The measurements of LVEDV, LVESV, EF and LV mass obtained with real-time MRI showed close correlation with those obtained with cine MRI (LVEDV: r = 0.985, p < 0.001; LVESV: r = 0.994, p < 0.001; EF: r = 0.975, p < 0.001; LV mass: r = 0.977, p < 0.001). CONCLUSIONS: Real-time MRI provides accurate measurements of LV volume and mass in a time-efficient manner with respect to image acquisition.- - - - - - - - - - ranking = 8keywords = volume (Clic here for more details about this article) |
3/9. Mechanisms of coronary microcirculatory dysfunction in patients with aortic stenosis and angiographically normal coronary arteries.BACKGROUND: Development of left ventricular hypertrophy in aortic stenosis (AS) is accompanied by coronary microcirculatory dysfunction, demonstrated by an impaired coronary vasodilator reserve (CVR). However, evidence for regional abnormalities in myocardial blood flow (MBF) and the potential mechanisms is limited. The aims of this study were to quantitatively demonstrate differences in subendocardial and subepicardial microcirculation and to investigate the relative contribution of myocyte hypertrophy, hemodynamic load, severity of AS, and coronary perfusion to impairment in microcirculatory function. methods AND RESULTS: Twenty patients with isolated moderate to severe AS were studied using echocardiography to assess severity of AS, cardiovascular magnetic resonance to measure left ventricular mass (LVM), and PET to quantify resting and hyperemic (dipyridamole 0.56 mg/kg) MBF and CVR in both the subendocardium and subepicardium. In the patients with most severe AS (n=15), the subendocardial to subepicardial MBF ratio decreased from 1.14 /-7 at rest to 0.92 /-7 during hyperemia (P<0.005), and subendocardial CVR (1.43 /-3) was lower than subepicardial CVR (1.78 /-35; P=0.01). Resting total LV blood flow was linearly related to LVM, whereas CVR was not. Increase of total LV blood flow during hyperemia (mean value, 89.6 /-6%; range, 17% to 233%) was linearly related to aortic valve area. The decrease in CVR was related to severity of AS, increase in hemodynamic load, and reduction in diastolic perfusion time, particularly in the subendocardium. CONCLUSIONS: CVR was more severely impaired in the subendocardium in patients with LVH attributable to severe AS. Severity of impairment was related to aortic valve area, hemodynamic load imposed, and diastolic perfusion rather than to LVM.- - - - - - - - - - ranking = 50.128970683487keywords = reserve (Clic here for more details about this article) |
4/9. Noncompaction of the ventricular myocardium associated with mitral regurgitation and preserved ventricular systolic function.Noncompaction of the ventricular myocardium is an embryonic cardiomyopathy that is increasingly being recognized. Mitral regurgitation, when present, is usually a result of the associated left ventricular systolic dysfunction. We report 4 patients with noncompaction of the ventricular myocardium in whom ventricular systolic function was preserved. Mitral regurgitation was associated with changes in the mitral valve leaflets and an abnormal coaptation pattern. This association of noncompaction of the ventricular myocardium with mitral regurgitation has not, to our knowledge, been reported.- - - - - - - - - - ranking = 250.64485341744keywords = reserve (Clic here for more details about this article) |
5/9. Coronary ectasia with slow flow related to apical hypertrophic cardiomyopathy--a case report.Coronary ectasia (CE) has been reported to be associated with a high risk of coronary events and caused by several etiologies. The authors present a patient with CE who was noted to have an ECG abnormality in routine health check. coronary angiography revealed diffuse ectasia in all 3 coronary arteries. The flow of contrast medium was slow and focal squeezing signs were observed in the left coronary artery. echocardiography indicated mild apical hypertrophy and significant reduction of coronary flow reserve. exercise thallium scintigraphy exhibited a transient perfusion defect in the inferior region. This is the first case report that a mild apical hypertrophy induced severe CE with slow coronary flow. The authors recommend a long-term prophylaxis of thrombotic complications with antiplatelet agents in patients with CE.- - - - - - - - - - ranking = 50.128970683487keywords = reserve (Clic here for more details about this article) |
6/9. Gd-enhanced cardiovascular MR imaging to identify left ventricular pseudoaneurysm.A pseudoaneurysm occurs when incomplete rupture of the heart seals within organizing thrombus, hematoma, and pericardium and maintains communication with the left ventricle. A pseudoaneurysm may cause arterial emboli and drain off a considerable portion of ventricular stroke volume. Cardiovascular magnetic resonance imaging proves to be an adequate technique to not only identify pseudoaneurysms but also quantify function measurements of the left ventricle and allow for projections of post-surgical function. When complemented with myocardial delayed enhancement, it is the best technique for identifying the viability of myocardial tissue, an important aspect in surgical planning.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
7/9. Erroneous Left ventricular cavity size measurements on myocardial perfusion SPECT resulting from transient arrhythmias.Transient ischemic dilatation (TID) of the left ventricle during stress on myocardial perfusion imaging is a sign of severe coronary artery disease. Factors other than ischemia can transiently influence left ventricular size, however, and TID ratios can be misleading if these factors are not properly identified. We describe 4 cases of stress-rest Tc-99m sestamibi SPECT myocardial perfusion imaging in which both abnormally high and low TID ratios were seen as a result of the presence of transient supraventricular tachyarrhythmias that reduced cardiac filling time and corresponding left ventricular volumes.- - - - - - - - - - ranking = 1keywords = volume (Clic here for more details about this article) |
8/9. Estimating myocardial damage and the need for surgery in patients with valvular heart disease by Tl-201 SPECT.Left ventricular myocardial disorders due to volume overload were investigated by Tl-201 myocardial SPECT (Tl-201 SPECT) in patients with aortic or mitral regurgitation, and its utility for timing cardiac valve replacement was studied. There were significant correlations between Tl-201 scores and electrocardiographic changes and the new york Heart association classification. There also were favorable correlations between Tl-201 scores and the left ventricular end-diastolic dimension and between Tl-201 scores and left ventricular ejection fraction, and a close relationship between the presence of a left ventricular myocardial disorder and left ventricular diameter. These results suggest that myocardial perfusion abnormalities and left ventricular myocardial disorders may accompany left ventricular dilatation owing to volume overload. After valve replacement, left ventricular end-diastolic dimension normalized, and Tl-201 scores improved slightly, suggesting normalization of myocardial perfusion. When moderate or more severe Tl-201 defects are present on Tl-201 SPECT images, in addition to inverted Tl-201 waves on the electrocardiogram or a left ventricular end-diastolic dimension of 65 mm or more, cardiac valve replacement should be considered.- - - - - - - - - - ranking = 2keywords = volume (Clic here for more details about this article) |
9/9. Concealed left ventricular hypertrophy and diastolic dysfunction in hypertrophic cardiomyopathy in the presence of acute left ventricular volume overload. A case report.We report a patient in whom hypertrophic cardiomyopathy, with both left ventricular hypertrophy and diastolic dysfunction, was masked by acute severe aortic regurgitation and marked left ventricular dilation. Upon admission, 1) two-dimensional echocardiogram of the left ventricle revealed a dynamic and flail vegetation on the aortic right coronary cusp and marked left ventricular dilation, 2) a massive aortic regurgitant signal was recorded by color Doppler flow imaging, and 3) transmitral flow velocity by pulsed Doppler echocardiogram revealed a pseudonormalization. However, symmetric hypertrophy of the left ventricular wall, a decrease in early diastolic wave and a compensatory increase in atrial systolic wave of the transmitral flow velocity appeared after successful aortic valve replacement.- - - - - - - - - - ranking = 4keywords = volume (Clic here for more details about this article) |