Characterization of left and right atrial function in healthy volunteers by cardiovascular magnetic resonance.

BACKGROUND: Left and right atrial function show a different pattern in advanced age in order to maintain adequate ventricular filling. It has been shown that left atrial (LA) function has a prognostic value in a number of heart conditions. Cardiovascular magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. We used SSFP cines to characterize atrial function in healthy, normotensive, volunteers. METHODS: We measured maximum, preatrial contraction and minimum left and right atrial volumes in 120 healthy subjects after careful exclusion of cardiovascular abnormality (60 men, 60 women; 20 subjects per age decile from 20 to 80 years). Data were generated from 3-dimensional modeling, including tracking of the atrioventricular ring motion and time-volume curves analysis. With those measurements, all the usual parameters for left and right atrial function were calculated. RESULTS: Gender had significant influence on some parameters of left and right atrial conduit and booster pump function. Age significantly influenced the majority of parameters of both left and right atrial function, with typically lower reservoir and conduit functions and higher booster pump function, both in males and females belonging to older age groups. CMR normal ranges were modelled for clinical use with normalization, where appropriate, for body surface area and gender, displaying parameters with respect to age. CONCLUSIONS: CMR normal reference ranges for components of left and right atrial function are provided for males and females for a wide age range

Normal right- and left ventricular volumes and myocardial mass in children measured by steady state free precession cardiovascular magnetic resonance

BACKGROUND: Quantification of ventricular volume by steady state free precession (SSFP) cardiovascular magnetic resonance is accurate and reproducible. Normal values exist for adults, but are lacking for children.We sought to establish normal values for left and right ventricular volumes, mass and function in healthy children by using SSFP. METHODS AND RESULTS: Fifty children (27 females, 23 males) without cardiovascular disease were evaluated. Median age was 11 years (range 7 months - 18 years), weight 35 kg (range 7-77 kg), height 146 cm (range 66-181 cm). Thirty-six examinations were performed with breath holding, 14 in freely breathing sedated children.Ventricular volumes and mass were measured in the end systolic and end diastolic phase on SSFP cine images acquired in a short axis plane as a stack of 12 contiguous slices covering full length of both ventricles. Regression analysis showed an exponential relationship between body surface area (BSA) and ventricular volumes and mass (normal value = a*BSAb). Normative curves for males and females are presented in relation to BSA for the end-diastolic volume, end-systolic volume and mass of both ventricles. Intra- and interobserver variability of the measurements was within the limits of 2% and 7% respectively, except for right ventricular mass (10%). CONCLUSION: The exponential equation for calculation of normal values for each ventricular parameter and graphical display of normative curves for data acquired in healthy children by SSFP cardiovascular magnetic resonance are provided

How early can myocardial iron overload occur in Beta thalassemia major?

BACKGROUND: Myocardial siderosis is the most common cause of death in patients with beta thalassemia major(TM). This study aimed at investigating the occurrence, prevalence and severity of cardiac iron overload in a young Chinese population with beta TM. METHODS AND RESULTS: We analyzed T2* cardiac magnetic resonance (CMR), left ventricular ejection fraction (LVEF) and serum ferritin (SF) in 201 beta TM patients. The median age was 9 years old. Patients received an average of 13 units of blood per year. The median SF level was 4536 ng/ml and 165 patients (82.1%) had SF>2500 ng/ml. Myocardial iron overload was detected in 68 patients (33.8%) and severe myocardial iron overload was detected in 26 patients (12.6%). Twenty-two patients ≤10 years old had myocardial iron overload, three of whom were only 6 years old. No myocardial iron overload was detected under the age of 6 years. Median LVEF was 64% (measured by CMR in 175 patients). Five of 6 patients with a LVEF<56% and 8 of 10 patients with cardiac disease had myocardial iron overload. CONCLUSIONS: The TM patients under follow-up at this regional centre in China patients are younger than other reported cohorts, more poorly-chelated, and have a high burden of iron overload. Myocardial siderosis occurred in patients younger than previously reported, and was strongly associated with impaired LVEF and cardiac disease. For such poorly-chelated TM patients, our data shows that the first assessment of cardiac T2* should be performed as early as 6 years old

Cardiovascular magnetic resonance in systemic hypertension

Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR) provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue characterization of diffuse and focal fibrosis. In addition, CMR is well suited for exclusion of common secondary causes for hypertension. We review the current and emerging clinical and research applications of CMR in hypertension

The limited usefulness of real-time 3-dimensional echocardiography in obtaining normal reference ranges for right ventricular volumes

<p>Abstract</p> <p>Background</p> <p>To obtain normal reference ranges and intraobserver variability for right ventricular (RV) volume indexes (VI) and ejection fraction (EF) from apical recordings with real-time 3-dimensional echocardiography (RT3DE), and similarly for RV area indexes (AI) and area fraction (AF) with 2-dimensional echocardiography (2DE).</p> <p>Methods</p> <p>166 participants; 79 males and 87 females aged between 29–79 years and considered free from clinical and subclinical cardiovascular disease. Normal ranges are defined as 95% reference values and reproducibility as coefficients of variation (CV) for repeated measurements.</p> <p>Results</p> <p>None of the apical recordings with RT3DE and 2DE included the RV outflow tract. Upper reference values were 62 ml/m²for RV end-diastolic (ED) VI and 24 ml/m²for RV end-systolic (ES) VI. Lower normal reference value for RVEF was 41%. The respective reference ranges were 17 cm²/m²for RVEDAI, 11 cm²/m²for RVESAI and 27% for RVAF. Males had higher upper normal values for RVEDVI, RVESVI and RVEDAI, and a lower limit than females for RVEF and RVAF. Weak but significant negative correlations between age and RV dimensions were found with RT3DE, but not with 2DE. CVs for repeated measurements ranged between 10% and 14% with RT3DE and from 5% to 14% with 2DE.</p> <p>Conclusion</p> <p>Although the normal ranges for RVVIs and RVAIs presented in this study reflect RV inflow tract dimensions only, the data presented may still be regarded as a useful tool in clinical practice, especially for RVEF and RVAF.</p

Gated myocardial perfusion SPECT underestimates left ventricular volumes and shows high variability compared to cardiac magnetic resonance imaging -- a comparison of four different commercial automated software packages

Abstract Background We sought to compare quantification of left ventricular volumes and ejection fraction by different gated myocardial perfusion SPECT (MPS) programs with each other and to magnetic resonance (MR) imaging. Methods N = 100 patients with known or suspected coronary artery disease were examined at rest with 99 mTc-tetrofosmin gated MPS and cardiac MR imaging. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were obtained by analysing gated MPS data with four different programs: Quantitative Gated SPECT (QGS), GE MyoMetrix, Emory Cardiac Toolbox (ECTb) and Exini heart. Results All programs showed a mean bias compared to MR imaging of approximately -30% for EDV (-22 to -34%, p Conclusions Gated MPS, systematically underestimates left ventricular volumes by approximately 30% and shows a high variability, especially for ESV. For EF, accuracy was better, with a mean bias between -15 and 6% of EF. It may be of value to take this into consideration when determining absolute values of LV volumes and EF in a clinical setting.</p

Cardiac magnetic resonance imaging in Alström syndrome

<p>Abstract</p> <p>Background</p> <p>A case series of the cardiac magnetic resonance imaging findings in seven adult Alström patients.</p> <p>Methods</p> <p>Seven patients from the National Specialist Commissioning Group Centre for Alström Disease, Torbay, England, UK, completed the cardiac magnetic resonance imaging protocol to assess cardiac structure and function in Alström cardiomyopathy.</p> <p>Results</p> <p>All patients had some degree of left and right ventricular dysfunction. Patchy mid wall gadolinium delayed enhancement was demonstrated, suggesting an underlying fibrotic process. Some degree of cardiomyopathy was universal. No evidence of myocardial infarction or fatty infiltration was demonstrated, but coronary artery disease cannot be completely excluded. Repeat scanning after 18 months in one subject showed progression of fibrosis and decreased left ventricular function.</p> <p>Conclusion</p> <p>Adult Alström cardiomyopathy appears to be a fibrotic process causing impairment of both ventricles. Serial cardiac magnetic resonance scanning has helped clarify the underlying disease progression and responses to treatment. Confirmation of significant mutations in the <it>ALMS1 </it>gene should lead to advice to screen the subject for cardiomyopathy, and metabolic disorders.</p

Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients

AIMS: As coronary artery disease may also occur during childhood in some specific conditions, we sought to assess the feasibility and accuracy of perfusion cardiovascular magnetic resonance (CMR) in paediatric patients. METHODS AND RESULTS: First-pass perfusion CMR studies were performed under pharmacological stress with adenosine and by using a hybrid echo-planar pulse sequence with slice-selective saturation recovery preparation. Fifty-six perfusion CMR examinations were performed in 47 patients. The median age was 12 years (1 month-18 years), and weight 42.8 kg (2.6-82 kg). General anaesthesia was required in 18 patients. Mean examination time was 67 +/- 19 min. Diagnostic image quality was obtained in 54/56 examinations. In 23 cases the acquisition parameters were adapted to patient's size. Perfusion CMR was abnormal in 16 examinations. The perfusion defects affected the territory of the left anterior descending coronary artery in 11, of the right coronary artery in 3, and of the circumflex coronary artery in 2 cases. Compared to coronary angiography, perfusion CMR showed a sensitivity of 87% (CI 52-97%) and a specificity of 95% (CI 79-99%). CONCLUSION: In children, perfusion CMR is feasible and accurate. In very young children (less than 1 year old), diagnostic image quality may be limited