BACKGROUND:

Left atrial three-dimensional shape and contraction patterns are not well described. We quantified the LA using three-dimensional cardiac MRI (CMR) in a group of normal subjects.

METHODS:

Three-dimensional vectors were used to quantitate atrial shape and contraction using a geometric model as a three-dimensional prolate ellipsoid. Atrial area and length at end-systole and end-diastole were made in the horizontal long axis (HLA) and vertical long axis (VLA) planes. Biplane area-length products and the orthogonal LA long axis vector comprised 3 orthogonal vector lengths composed of axis measures for shape and volume calculations at end-diastole and end-systole. Vector fractional shortening in 3 dimensions was calculated for each 3-space orthogonal vector. Echocardiograms were used for comparison.

RESULTS:

The normal LA is an oblate ellipsoid with significantly longer HLA short axis than the vertical VLA short axis (p<0.001). LA contraction in the long axis dimension is smaller than both HLA and VLA short axis dimensional changes (p<0.001). Linear correlations between LAEDV vs. LASV and LAESV vs. LAEF were highly significant.

CONCLUSIONS:

This dimensional analysis quantitates normal left atrial shape for the first time, modeled as a prolate 3-D ellipsoid. LA contractile functions and derives mostly from contraction in the HLA and VLA short axis directions. Though LA end-diastolic volume is considered the marker of left atrial health or disease, this notion should be reconsidered in view of LA static and functional modeling in 3 dimensions.

BACKGROUND:

Left ventricular filling pressure (LVFP) is raised by the compromised contraction and impaired ventricular compliance in dilated hearts with systolic dysfunction. Timely recognition and staging of this condition are important for planning of the treatment strategy and making the prognosis. Two-dimensional speckle- tracking echocardiography (2D-STE) has recently enabled the quantification of left atrial (LA) myocardial deformation dynamics. In this study, echocardiographic indicators of increased LVFP and NT-pro-BNP were compared with LA strain measured by 2D-STE.

METHODS:

A total of 49 nonischemic dilated cardiomyopathy (DCMP) patients were included in the study. All patients underwent standard 2D echocardiography. In the 2D-STE analysis of the LA, global longitudinal LA strain during ventricular systole (GLAs-res) and strain during late diastole (GLAs-pump) were obtained. NT-pro-BNP levels were measured. The patients were divided into two groups-normal (group 1) and increased (group 2) LVFP-according to E/A ratio, E velocity, and E/E' ratio.

RESULTS:

LAVi-max, LAVi-min, and NT-pro-BNP were higher in group 2, whereas LAtotalEF, LAactiveEF, GLAs-res, and GLAs-pump were lower. In univariate analysis, a good negative correlation was seen between GLAs-res vs. NT-pro-BNP, GLAs-res vs. LAVi-max, and GLAs-res vs. E/E' ratio; a good negative correlation was present between GLAs-pump vs. NT-pro-BNP, GLAs-pump vs. LAVi-max, and GLAs-pump vs. E/E' ratio. LAVi-max, LAactiveEF, NT-pro-BNP, GLas-res, and GLAs-pump were studied by logistic regression analysis. GLAs-res (p = 0.009, OR = 0.593, 95 % CI 0.4-0.877), NT-pro-BNP (p = 0.028, OR = 1.027, 95 % CI 1.003-1.052), and LAactiveEF (p = 0.022, OR = 0.001, 95 % CI 0.001-0.024) were found to be independent predictors of increased LVFP.

CONCLUSION:

2D-STE-based LA function is impaired in patients with nonischemic DCMP. LA reservoir and pump function parameters together with NT-pro-BNP levels might be useful in estimating LVFP in this patient group.

This review article focuses on functional tricuspid regurgitation (FTR) that has long been a neglected and underestimated entity. FTR is defined as leakage of the tricuspid valve during systole in the presence of structurally normal leaflets and chordae. FTR may be secondary to several heart diseases, more commonly mitral valve disease, pulmonary hypertension, atrial fibrillation, cardiomyopathies, right ventricular dysplasia, and idiopathic annular dilatation. The reported prevalence of moderate or greater FTR is roughly 16%, but it rises up to 89% when considering FTR of any grade. According to the recommendations of the European Association of Echocardiography, two-dimensional transthoracic echocardiography (TTE) is the first-line imaging modality for the assessment of valvular regurgitation, whereas three-dimensional TTE may provide additional information in patients with complex valve lesions. Transesophageal echocardiography may be used when TTE results are inconclusive. The natural history of FTR is unfavorable, even in less than severe tricuspid regurgitation. Data from the literature suggest that moderate or greater FTR is a risk factor for worse survival. In addition, FTR of any grade may worsen over time, which makes it reasonable to consider the correction of FTR at an early stage, preferably at the time of mitral valve surgery. Tricuspid valve annuloplasty is the gold standard surgical treatment for FTR and is associated with a recurrence rate, defined as postoperative moderate or severe FTR, ranging from 2.5 to 5.5% at 1-year follow-up.

BACKGROUND:

Despite a few experimental studies showing a dose-dependent myocardial depressive effect of propofol anesthesia induction, few clinical data are available to determine its precise impact on myocardial function, probably because of its brevity and a lack of appropriate evaluation tools. The purpose of this study was to examine the impact of propofol-based anesthesia induction on left ventricular (LV) function using Doppler tissue and speckle-tracking imaging.

METHODS:

In 19 low-risk patients with normal LV systolic and diastolic function undergoing noncardiac surgery (all women; mean age, 42 years), propofol bolus (2.0 mg/kg) was administered intravenously for anesthesia induction. LV ejection fraction, global peak systolic longitudinal strain, and tissue Doppler-derived indices of mitral annular velocity during systole (S'), early diastole (e'), and atrial contraction (a') were determined by intraoperative transthoracic echocardiography before and 1, 3, and 5 min after propofol bolus (T0, T1, T2, and T3, respectively).

RESULTS:

The following at T1, T2, and T3 were significantly less in magnitude than at T0: septal S' (5.61, 5.61, and 5.51 vs 7.60 cm/sec, P < .001), lateral S' (5.75, 5.89, and 5.94 vs 8.12 cm/sec, P < .001), septal e' (10.10, 10.26, and 10.07 vs 11.4 cm/sec, P < .01), septal a' (6.70, 6.21, and 6.13 vs 8.58 cm/sec, P < .01), lateral a' (7.29, 6.81, and 6.85 vs 9.01 cm/sec, P < .01), and longitudinal strain (-19.36%, -19.71%, and -19.61% vs -22.28%, P < .001). LV ejection fraction was not significantly changed (P = .361).

CONCLUSIONS:

Propofol anesthesia induction diminished LV and atrial contraction in low-risk patients with prior normal LV function. Further studies are needed to understand the clinical implications, particularly for higher risk populations.

Myxoma is the most common primary tumor of the heart and can arise in any of the cardiac chambers. This paper reports A 50 -year-old woman without medical history and any cardiovascular risk factors was hospitalized for exertional dyspnea and palpitations from three months and signifiant weight loss. Transthoracic echocardiogram showed a giant left atrial myxoma mobile confined to the left atrium in systole, in diastole the tumor was seen prolapsing across the mitral valve into the left ventricle and partially obstructing it and causing severe functional mitral stenosis with a mean gradient of 21,3 mmHg. Severe pulmonary hypertension was confirmed by Doppler PAPs =137 mmHg. The patient was scheduled for cardiac surgery with good outcome.

Left atrial (LA) size is related to cardiovascular morbidity and mortality. The relative role of multiple determinants of LA morphology in healthy subjects remains incompletely defined. The aim of this study is to define normal ranges for LA diameters and volume index (LAVi), and to investigate clinical and echocardiographic correlates. A total of 1480 healthy individuals (mean age 36.1 ± 15.5 years, range 20-80; 61% males) underwent a comprehensive transthoracic echocardiography exam including assessment of LAVi calculated using the biplane area-length method at the apical four-chamber and two-chamber views at ventricular end systole (maximum LA size) and indexed for body surface area (BSA). Mean LAVi in the overall population was 29.5 ± 10.8 mL/m(2) (range: 26.1-41.8 mL/m(2) ). Distinct higher values were found in subjects ≥50 years as compared with those <50 years of age (33.4 ± 12.5 vs. 29.1 ± 13.5; P < 0.001). On univariate analysis, LA volume was significantly associated with age (r = 0.48, P < 0.0001), male gender (r = 0.28, P < 0.05), BSA (r = 0.51, P < 0.0001), mitral E/E' (r = 0.47, P < 0.0001), LV end-diastolic volume (r = 0.52, P < 0.0001), and LV mass index (r = 0.31, P < 0.05). Multivariable analysis identified age, BSA, LV end-diastolic volume, and mitral E/E' ratio as the only independent determinants of LA volume (model R(2)  = 0.54, P < 0.0001). Gender was an independent predictor of most absolute LA volume, but following normalization to BSA, some associations became nonsignificant. In healthy individuals LAVi vary significantly by age, BSA, diastolic function, and LV dimensions, with lesser effects of gender.

BACKGROUND:

Three-directional phase velocity mapping (PVM) is capable of measuring longitudinal, radial and circumferential regional myocardial velocities. Current techniques use Cartesian k-space coverage and navigator-gated high spatial and high temporal resolution acquisitions are long. In addition, prospective ECG-gating means that analysis of the full cardiac cycle is not possible. The aim of this study is to develop a high temporal and high spatial resolution PVM technique using efficient spiral k-space coverage and retrospective ECG-gating. Detailed analysis of regional motion over the entire cardiac cycle, including atrial systole for the first time using MR, is presented in 10 healthy volunteers together with a comprehensive assessment of reproducibility.

METHODS:

A navigator-gated high temporal (21 ms) and spatial (1.4 x 1.4 mm) resolution spiral PVM sequence was developed, acquiring three-directional velocities in 53 heartbeats (100% respiratory-gating efficiency). Basal, mid and apical short-axis slices were acquired in 10 healthy volunteers on two occasions. Regional and transmural early systolic, early diastolic and atrial systolic peak longitudinal, radial and circumferential velocities were measured, together with the times to those peaks (TTPs). Reproducibilities were determined as mean +/- SD of the signed differences between measurements made from acquisitions performed on the two days.

RESULTS:

All slices were acquired in all volunteers on both occasions with good image quality. The high temporal resolution allowed consistent detection of fine features of motion, while the high spatial resolution allowed the detection of statistically significant regional and transmural differences in motion. Colour plots showing the regional variations in velocity over the entire cardiac cycle enable rapid interpretation of the regional motion within any given slice. The reproducibility of peak velocities was high with the reproducibility of early systolic, early diastolic and atrial systolic peak radial velocities in the mid slice (for example) being -0.01 +/- 0.36, 0.20 +/- 0.56 and 0.14 +/- 0.42 cm/s respectively. Reproducibility of the corresponding TTP values, when normalised to a fixed systolic and diastolic length, was also high (-13.8 +/- 27.4, 1.3 +/- 21.3 and 3.0 +/- 10.9 ms for early systolic, early diastolic and atrial systolic respectively).

CONCLUSIONS:

Retrospectively gated spiral PVM is an efficient and reproducible method of acquiring 3-directional, high resolution velocity data throughout the entire cardiac cycle, including atrial systole.

Obtaining diagnostic coronary CT angiography with low radiation exposure in patients with irregular heart rhythms such as atrial fibrillation (AF) remains challenging.We evaluated image quality and inter-reader variability with the use of prospective electrocardiographic (ECG)-triggered sequential dual-source acquisition at end systole for coronary artery disease (CAD) evaluation in patients with AF.Thirty consecutive patients with AF who underwent prospective ECG-triggered sequential dual-source acquisition were evaluated. Images were reconstructed every 50 milliseconds from 250 to 400 milliseconds after the R wave. Two independent, blinded readers evaluated the coronaries for image quality on a 5-point scale (worst to best) and stenosis on 5-point semiquantitative (none to severe) and binary scales (>50% or <50%). Diagnostic image quality was graded for each reconstruction.Eleven patients (37%) had significant (≥50% stenosis) CAD. Average heart rate was 82 ± 20 beats/min and variability range was 71 ± 22 beats/min. Mean effective radiation dose was 6.5 ± 2.4 mSv. Diagnostic image quality was noted in 97.9% of 304 coronary segments with median image quality of 3.0. The 300-millisecond reconstruction phase provided the highest image quality; 70% of patients showed diagnostic image quality. Combination of all phases (250-400 milliseconds) performed significantly better than single or other phase combinations (P < 0.0005 for all comparisons). Inter-reader variability for stenosis detection was excellent, with 98.4% concordance by using a binary scale (50% stenosis cutoff).Prospective ECG-triggered sequential dual-source CT acquisition with the use of end-systolic acquisition provides diagnostic image quality with potentially low radiation doses for evaluation of CAD in patients with AF. Use of multiple end-systolic phases over a 150-millisecond window improves diagnostic image quality.

Our aim was to investigate the relationships between left atrial (LA) structural and functional changes and left ventricular (LV) dysfunction related to LV pressure overload in asymptomatic patients with hypertension. One hundred and twenty-six asymptomatic patients with hypertension and LV ejection fraction (EF) ≥60% were studied. Conventional, pulsed and tissue Doppler, and two-dimensional speckle-tracking echocardiography (2DSTE) were performed to seek the independent determinants for alterations in LA structure and function. LA volume index (LAVI) correlated with age, body mass index (BMI), end-diastolic ventricular septal thickness (VSth), end-diastolic LV posterior wall thickness, relative LV wall thickness (RWT), LV mass index, peak A velocity of transmitral flow, E/e', and peak systolic and early diastolic LA strains and strain rates. Peak LA strain during ventricular systole (S-LAs) correlated with age, BMI, heart rate (HR), end-systolic LV diameter, LAVI, VSth, RWT, LVEF, e', E/e', peak systolic LV radial strain, and peak early diastolic LV longitudinal strain rate. Multivariate regression analyses indicated that LV mass index, peak A velocity, E/e', and S-LAs are defined as strong predictors related to LAVI, and that BMI, HR, LAVI, and peak systolic LV radial strain are defined as strong predictors related to S-LAs. In conclusion, 2DSTE demonstrated that alterations in LA structure and function are mainly associated with LV diastolic and systolic dysfunction, respectively, in preclinical patients with hypertension.

BACKGROUND:

Myocardial perfusion cardiovascular magnetic resonance (CMR) is a well-established method for detection of ischemic heart disease. However, ECG gating problems can result in image degradation and non-diagnostic scans, particularly in patients with arrhythmias.

METHODS:

A turboFLASH saturation recovery pulse sequence was used without any ECG triggering. One saturation pulse followed by 4--5 slices of undersampled radial k-space images was acquired rapidly, on the order of 40--50 msec per image. The acquisition of the set of 4--5 slices was continuously repeated approximately 4 times per second. An iterative constrained reconstruction method was used to reconstruct the ungated images. The ungated perfusion images were post-processed into three different sets of images (ungated, self-gated to near systole, and self-gated to near diastole). To test the ungated approach and compare the different processing methods, 8 patients scheduled for coronary angiography underwent stress and rest perfusion imaging with the ungated acquisition. Six patients had a history of atrial fibrillation (AF). Three blinded readers assessed image quality and presence/absence of disease.

RESULTS:

All 8 subjects successfully completed the perfusion CMR protocol and 7/8 underwent coronary angiography. Three patients were in atrial fibrillation during CMR. Overall, the CMR images were of high quality as assessed by the three readers. There was little difference in image quality between patients in AF compared to those in sinus rhythm (3.6+/-0.7 vs. 3.3+/-0.5). Stress/rest perfusion imaging showed normal perfusion in 4 patients, fixed perfusion defects in 2 patients, and reversible perfusion defects in 2 patients, corresponding with angiographic results. Pooled results from the independent readers gave a sensitivity of 0.92 (CI 0.65-0.99) and specificity of 0.92 (CI 0.65-0.99) for the detection of coronary artery disease using ungated perfusion imaging. The same sensitivity, and a specificity of 1 (CI 0.76-1), was achieved when the images were self-gated after acquisition into near systole or near diastole.

CONCLUSIONS:

Ungated radial dynamic perfusion CMR can give high quality imaging in patients in sinus rhythm and during atrial fibrillation. In this small cohort, high diagnostic accuracy was possible with this rapid perfusion imaging sequence. An ungated approach simplifies the acquisition and could expand the role of perfusion CMR to include patients with arrhythmia and those with gating problems.