Left atrial functional reserve in patients with nonischemic dilated cardiomyopathy: an echocardiographic dobutamine study

Evaluation of left atrial function in patients with iron-deficiency anemia by two-dimensional speckle tracking echocardiography

Background

Iron-deficiency anemia (IDA) is a global health problem and a common medical condition that can be seen in everyday clinical practice. And two-dimensional speckle tracking echocardiography (2D-STE) has been reported very useful in evaluating left atrial (LA) function, as well as left ventricular (LV) function. The aim of our study is to evaluate the LA function in patients with IDA by 2D-STE.

Methods

65 patients with IDA were selected. This group of patients was then divided into two groups according to the degree of hemoglobin: group B (Hb > 90 g/L) and group C (Hb60 ~ 90 g/L). Another 30 healthy people were also selected as control group A. Conventional echocardiography parameters, such as left atrial diameter (LAD), peak E and A of mitralis (E, A), E/A, end-diastolic thickness of ventricular septum (IVST d), end-diastolic thickness of LV posterior wall (PWTd) and left ventricular end-diastolic dimension (LVDd) were obtained from these three groups. Left atrial minimum volume (LAVmin), left atrial pre-atrial contraction volume (LAVp) and left atrial maximum volume (LAVmax) were measured by Simpson’s rule, whereas left atrial active ejection fraction (LAAEF) and left atrial passive ejection fraction (LAPEF) were obtained from calculation. Two-dimensional images were acquired from apical four-chamber view and two-chamber view to store images for offline analysis. The global peak atrial longitudinal strain and strain rate of systolic LV (GLSs, GLSRs) as well as early and late diastolic LV strain rate (GLSRe, GLSRa) curves of LA were acquired in each LA segment from basal segment to top segment of LA by 2D-STE.

Results

Compared with group A, there were no differences between group B and group A (all P > 0.05). The LAAEF and GLSRa were significantly higher in group C compared with those of group A and group B (all P < 0.01). The LAPEF, GLSs, GLSRs and GLSRe were significantly lower in group C compared with those of group A and group B (all P < 0.01).

Conclusions

2D-STE could evaluate the LA function in patients with IDA.

Study on Left Atrial Dimension and Function After Modified Endoscopic Procedure for Atrial Fibrillation at Two Years' Follow-Up

BACKGROUND

Modified endoscopic procedures for atrial fibrillation (AF) have a greater success rate because of the increased number of linear lesions. Concerns have been raised about the impact of ablation scars on the left atrium. This study aimed to examine the impact of ablation on left atrial dimension and systolic function after modified endoscopic procedures with echocardiographic measurement.

METHODS

Of 107 patients undergoing modified endoscopic ablation, 58 had paroxysmal AF and 49 had persistent or long-standing AF. The procedure was performed on the beating heart through three ports on the left chest wall. Three circular and two linear lesions were made on the left atrium. The left atrial appendage was excised by stapler. Echocardiography was performed preoperatively and at the 2-year follow-up.

RESULTS

Most patients (86.9%) patients were in sinus rhythm (SR) postoperatively. Fourteen patients (5 with paroxysmal AF and 9 with persistent/long-standing AF) failed to maintain SR. Echocardiographic data indicated that the left atrial diameter decreased only in the patients with postoperative SR but continued to increase in patients with fail SR maintenance. Left atrial function was also improved after the procedure, especially in patients with preoperative nonparoxysmal AF or with postoperative SR maintenance. Furthermore, left atrial function in patients who failed to restore SR was not worsened even with left atrial appendage excision.

CONCLUSIONS

Modified endoscopic procedure for AF improved post-procedural left atrial function of patients with SR maintenance. The left atrial function of patients with failed SR maintenance was also not worsened after left atrial appendage excision.

Normal response of cardiac flow and function to adenosine stress as assessed by cardiac MR

AIMS

To establish the response of cardiac flow and function to adenosine stress using phase-contrast magnetic resonance (pcMR) and cine steady-state free precession (SSFP) cardiac magnetic resonance (CMR).

METHODS

Healthy volunteers (n = 10) were scanned on 1.5T at rest and under adenosine stress utilizing short-axis SSFP sequences and pcMR of the aorta and pulmonary trunk.

RESULTS

Adenosine-induced increase in heart rate was 62.7% (P < 0.001). Left and right-ventricular stroke volumes (SVs) increased by 12.2% (P = 0.048) and 11.9% (P = 0.044), left-ventricular ejection fraction by 11.8% (P = 0.002), and left-ventricular and right-ventricular cardiac output (CO) by 81.0% (P < 0.001) and 81.8% (P = 0.005). Average flow velocities in the ascending aorta and pulmonary trunk increased by 77.3% (P < 0.001) and 73.6% (P < 0.001), and peak flow velocities in the ascending aorta and pulmonary trunk by 27.2% (P < 0.001) and 22.4% (P = 0.003). End-systolic volumes in the left ventricle (LV) and right ventricle (RV) decreased by 16.4% (P = 0.020) and 19.2% (P = 0.028). Planimetric cine SSFP and pcMR-derived SV showed an excellent correlation.

CONCLUSION

In healthy volunteers, response to adenosine stress is characterized by an increase in heart rate, CO and SV of both ventricles. Excellent correlation is demonstrated between these increases and the increased blood flow velocities in the aorta and the pulmonary trunk. Thus, results support the use of flow measurements as an internal control of planimetric measurements of ventricular SV and CO.

Right atrium contractility and right ventricular diastolic function assessed by pulsed tissue Doppler imaging can predict brain natriuretic peptide in adults with acquired pulmonary hypertension

PURPOSE

We evaluated right atrial (RA) contractility and right ventricular (RV) diastolic function in adult patients with acquired chronic pulmonary hypertension (PH) by pulsed Tissue Doppler Imaging (TDI) and assessed their relationship with serum brain natriuretic peptide (BNP).

MATERIALS AND METHODS

Systolic myocardial wave (Sa), early diastolic myocardial wave (Ea), and late diastolic myocardial wave (Aa) at the tricuspid annulus were recorded in 77 consecutive patients with acquired PH. Early (E) RV inflow waves were recorded from 4-chamber views. RV Aa was regarded as the parameter of RA contractility and RV E/Ea was taken as the parameter of RV diastolic function using TDI.

RESULTS

All subjects had elevated BNP (mean 188.9 +/- 244.0 pg/dl) and pulmonary arterial systolic pressure (PASP) estimated at 62.9 +/- 26.7 mm Hg. BNP levels were positively correlated with RV E/Ea, Aa and PASP (r = 0.47, p < 0.0001 and r = 0.35, p < 0.01, respectively) but negatively with Aa (r = -0.29, p < 0.05). Next, all predictor variables were used in a multiple regression model with serum BNP values as dependent variables, refined to include 3 predictors: RV E/Ea, Aa, and PASP, which were all found to influence serum BNP values (p < 0.0001) by the formula Y = 34.1X1**-19.11X2**+2.95X3* (**p < 0.001, *p < 0.01) where Y = BNP, X1 = E/Ea of RV, X2 = Aa, and X3 = PASP (standard regression coefficients were 0.37, -0.34 and 0.34, respectively).

CONCLUSION

Serum BNP correlates with RA contractility and RV diastolic dysfunction by RV TDI in adults with acquired PH. Increased BNP may be related to decreased RA systolic function and RV diastolic function in these patients.

Left atrial reverse remodeling in dogs with moderate and advanced heart failure treated with a passive mechanical containment device: an echocardiographic study

BACKGROUND

Assessment of global left ventricular (LV) remodeling is important in evaluating the efficacy of pharmacologic and device therapies for the treatment of chronic heart failure (HF). The effects of pharmacologic or device therapies on global left atrial (LA) remodeling in HF, although also important, are not often examined. We showed that long-term therapy with the Acorn Cardiac Support Device (CSD), a passive mechanical ventricular containment device, prevents or reverses LV remodeling in dogs with HF. This study examined the effects of the CSD on global LA remodeling in dogs with moderate and advanced HF.

METHODS AND RESULTS

Studies were performed in 24 dogs with coronary microembolization-induced HF. Of these, 12 had moderate HF (ejection fraction, EF 30% to 40%) and 12 advanced HF (EF < or = 25%). In each group, the CSD was implanted in 6 dogs and the other 6 served as controls. Dogs were followed for 3 months in the moderate group and 6 months in the advanced HF group. LA maximal volume (LAVmax), LA volume at the onset of the p-wave (LAVp), LA minimal volume (LAVmin), LA active emptying volume (LAAEV), and LA active emptying fraction (LAAEF) were measured from 2-dimensional echocardiograms obtained before CSD implantation and at the end of the treatment period. Treatment effect (delta) comparisons between CSD-treated dogs and controls showed that CSD therapy significantly decreased LA volumes (deltaLAVmax: 3.33 +/- 0.70 vs. -2.87 +/- 1.31 mL, P = .002; 7.77 +/- 1.76 versus -0.37 +/- 0.87 mL, P = .002) and improved LA function (deltaLAAEF: -6.00 +/- 1.53 versus 1.85 +/- 1.32%, P = .003; -2.39 +/- 1.10 versus 3.13 +/- 1.66%, P = .02) in the moderate HF and advanced HF groups, respectively.

CONCLUSIONS

Progressive LA enlargement and LA functional deterioration occurs in untreated dogs with HF. Monotherapy with the CSD prevents LA enlargement and improves LA mechanical function in dogs with moderate and advanced HF indicating prevention or reversal of adverse LA remodeling.

Carvedilol Improves Left Atrial and Left Ventricular Function and Reserve in Dilated Cardiomyopathy After 1 Year of Treatment

BACKGROUND

The aim of this study was to evaluate the effects of carvedilol therapy on left atrial (LA) function in patients with heart failure from nonischemic dilated cardiomyopathy.

METHODS AND RESULTS

Thirty-five patients (42.4 +/- 13.5 years) in New York Heart Association functional Class II-III have been studied. A low-dose (20 mug.kg.min) echo-dobutamine study has been performed, before and 12 months after carvedilol therapy. Twelve months after carvedilol therapy, a significant improvement in LA and left ventricular (LV) function was observed. To investigate the beneficial effects of carvedilol, patients were separated into 2 groups according to the presence of pretreatment LV contractile reserve (CR) (ejection fraction [EF] increases >20% after dobutamine infusion): Group A consisted of 18 patients with CR and Group B of 17 patients without CR. After carvedilol treatment, both the LV and LA function were improved in group A (P < .01 for all). However, in group B, only the LA function was significantly improved (left atrial ejection volume increased from 10.4 +/- 3 mL to 15.4 +/- 6.7, P < .01 and LA ejection fraction from 19.6 +/- 45.3% to 29.4 +/- 12.5%, P < .01), whereas the LV contractile reserve has partially reappeared (EF from 29.9 +/- 4.5% at baseline, increased after dobutamine infusion to 35.8 +/- 6.8%, P < .0001).

CONCLUSIONS

In conclusion, carvedilol therapy is associated with improvement in both LV and LA functions in nonischemic dilated cardiomyopathy. In a subgroup of these patients, carvedilol may act differently on LV and LA function.

Effect of Age and Heart Rate on Atrial Mechanical Function Assessed by Doppler Tissue Imaging in Healthy Individuals

BACKGROUND

The potential usefulness of Doppler tissue imaging (DTI) to assess atrial mechanical function in cardiac disease has been demonstrated. However, there are few reports on normal values of atrial function by DTI analysis.

METHODS

Echocardiography with color-coded DTI was performed in 131 healthy control subjects. The peak atrial contraction velocity (V(A)) and the timing of mechanical events were assessed offline at the left atrial (LA) and right atrial (RA) free wall and interatrial septum.

RESULTS

V(A) was higher in the RA (9.0 +/- 2.6 cm/s) than the LA (7.5 +/- 2.4 cm/s, P < .001), and both sites were higher than the interatrial septum (5.6 +/- 1.3 cm/s, both P < .001). The interatrial delay was 24 +/- 21 milliseconds. V(A) at the LA was higher in the participants aged 60 years or older than those who were younger than 60 years (8.1 +/- 2.7 vs 6.7 +/- 1.4 cm/s, P < .001), as was the velocity at the RA (9.6 +/- 2.8 vs 8.0 +/- 2.1 cm/s, P < .01). V(A) at the LA was higher in the participants with heart rate of 60/min or higher than those with lower heart rate (7.9 +/- 2.5 vs 6.8 +/- 1.8 cm/s, P < .05). Sex difference had no effect on V(A) and timings of atrial events.

CONCLUSIONS

Assessment of atrial mechanical function by DTI is feasible in healthy individuals. The V(A) is the highest at the RA, followed by LA, and the lowest at the interatrial septum. Older age and faster heart rate seems to augment V(A) in the atrial walls.

Reverse Remodeling of the Left Cardiac Chambers After Catheter Ablation After 1 Year in a Series of Patients With Isolated Atrial Fibrillation

Background— Isolated atrial fibrillation (AF) is associated with mild enlargement of the left atrium (LA) and left ventricular (LV) diastolic dysfunction. The impact of ablation of isolated AF on left chamber size and function is unclear, and whether diastolic dysfunction is the cause or the consequence of AF remains unknown. The objective of this prospective study was to evaluate the impact of sinus rhythm restoration by catheter ablation on LV diastolic dysfunction, LA morphology, and mechanical function.

Methods and Results— Forty-eight patients with isolated AF were studied by serial echocardiographic studies at baseline and at 1-, 3-, 6-, 9-, and 12-month intervals after radiofrequency ablation. LA dimensions and mechanical function and LV systolic and diastolic functions were evaluated at each time interval. Diastolic function was assessed with conventional Doppler parameters and new indexes such as tissue Doppler imaging, mitral flow propagation velocity, and combined criteria. LV diastolic dysfunction was present in paroxysmal and chronic AF patients with a reduction of tissue Doppler imaging lateral early diastolic peak velocity in 37% ( P <0.001) and 48% ( P <0.01), respectively, compared with healthy control subjects. At the end of the follow-up, LA area decreased significantly by 18% ( P <0.001) in paroxysmal and 23% ( P <0.05) in chronic AF patients. Diastolic function improved significantly with an increase in lateral early diastolic peak velocity of 29% ( P <0.001) in paroxysmal AF and 46% ( P <0.05) in chronic AF patients. A significant increase in LV ejection fraction was also noted for both groups: 7.7% and 18.8%, respectively.

Conclusions— This study demonstrates reverse morphological remodeling of the LA and improvement of LV diastolic and systolic functions after restoration of sinus rhythm by ablation for isolated AF. Because patients with isolated AF have none of the traditional causes of LV diastolic dysfunction, our findings suggest that AF may be partly the cause rather than the consequence of diastolic dysfunction.

Left atrial systolic reserve in idiopathic vs. ischaemic-dilated cardiomyopathy

PURPOSE

There are studies indicating more pronounced left atrial (LA) systolic dysfunction at rest in idiopathic (IDDC) than in ischaemic-dilated cardiomyopathy (ISDC). It was hypothesized that the findings would be similar with regards LA systolic reserve.

METHODS

Twenty-six patients with IDDC, 28 with ISDC and 25 normal controls underwent low-dose dobutamine stress echocardiography (5-10 microg kg(-1) min(-1) IV). Left atrial volumes were echocardiographically determined at rest and during stress at the mitral valve opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp) and mitral valve closure (minimal, Vmin) from the apical 4- and 2-chamber views (biplane area-length method). Left atrial systolic function was assessed with the LA-active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp.

RESULTS

Vmax at rest was similar in IDDC and ISDC and greater than in the controls (54.2 +/- 12 vs. 48.5 +/- 18 vs. 27.1 +/- 6.3 cm(3) m(-2), respectively, P < 0.001) and did not change with stress (53.9 +/- 13.8 vs. 46.9 +/- 16.2 vs. 25.8 +/- 5.9 cm(3) m(-2), P < 0.001). The ACTEV at rest was similar in IDDC and ISDC and greater than in the controls (8.6 +/- 3.5 vs. 9.7 +/- 2.9 vs. 6.1 +/- 2.2 cm(3) m(-2) P < 0.01), whereas during the dobutamine infusion it remained unaltered in IDDC (10.8 +/- 4.6 cm(3) m(-2), P = NS vs. rest) and increased in ISDC (11.8 +/- 3.3 cm(3) m(-2), P < 0.05) and the controls (13.1 +/- 3.2 cm(3) m(-2), P < 0.01). The ACTEF was lower in IDDC than ISDC and the controls at rest (20 +/- 10% vs. 33 +/- 8% vs. 36 +/- 10%, P < 0.01). Dobutamine infusion was associated with no significant increase in ACTEF in IDDC (25 +/- 12%, P = NS vs. rest), and with an increase in this variable in ISDC (39 +/- 10%, P < 0.05) and the controls (49 +/- 12%, P < 0.01).

CONCLUSIONS

Dobutamine infusion is associated with an increase in LA ACTEV and fraction in ISDC and no significant change in these indices in IDDC. These findings indicate a reduced LA systolic reserve in IDDC.

Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals

Background

The appropriate evaluation of atrial electrical function is only possible by means of invasive electrophysiology techniques, which are expensive and therefore not suitable for widespread use. Mechanical atrial function is mainly determined from atrial volumes and volume-derived indices that are load-dependent, time-consuming and difficult to reproduce because they are observer-dependent.

Aims

To assess the feasibility of tissue velocity echocardiography (TVE) to evaluate atrial electromechanical function in young, healthy volunteers.

Subjects and methods

We studied 37 healthy individuals: 28 men and nine women with a mean age of 29 years (range 20–47). Standard two-dimensional (2-D) and Doppler echocardiograms with superimposed TVE images were performed. Standard echocardiographic images were digitized during three consecutive cardiac cycles in cine-loop format for off-line analysis. Several indices of regional atrial electrical and mechanical function were derived from both 2-D and TVE modalities.

Results

Some TVE-derived variables indirectly reflected the atrial electrical activation that follows the known activation process as revealed by invasive electrophysiology. Regionally, the atrium shows an upward movement of its walls at the region near the atrio-ventricular ring with a reduction of this movement towards the upper levels of the atrial walls. The atrial mechanical function as assessed by several TVE-derived indices was quite similar in all left atrium (LA) walls. However, all such indices were higher in the right (RA) than the LA. There were no correlations between the 2-D- and TVE-derived variables expressing atrial mechanical function. Values of measurement error and repeatability were good for atrial mechanical function, but only acceptable for atrial electrical function.

Conclusion

TVE may provide a simple, easy to obtain, reproducible, repeatable and potentially clinically useful tool for quantifying atrial electromechanical function.

Quantitative regional analysis of left atrial function by Doppler tissue imaging–derived parameters discriminates patients with posterior and anterior myocardial infarction

BACKGROUND

Doppler tissue imaging can now be used for the assessment of left atrial (LA) function. LA function was evaluated by this technique in a group of patients hospitalized for acute myocardial infarction and in a control population.

METHODS

Patients were all prospectively imaged with a scanner. To study the LA, a region of interest was located in the proximal part of the lateral and septal LA walls. Doppler tissue imaging, tissue tracking, strain, and delays were recorded.

RESULTS

In all, 12 patients with posterior (age 54 +/- 9 years) and 13 with anterior (age 64 +/- 16 years) acute myocardial infarction, along with 16 control patients (age 54 +/- 9 years), were analyzed. Early diastolic septal velocity was found to be the best parameter for discriminating among the 3 groups. Peak strain was also relevant and did not correlate with left ventricular function.

CONCLUSIONS

LA is accessible to Doppler tissue imaging analysis. Strain can quantify LA function relatively independently of left ventricular function, and may provide new insights on LA function.

Prognostic usefulness of echocardiographic dobutamine in younger (14 to 25 years) and older (40 to 55 years) patients with idiopathic dilated cardiomyopathy

We studied 16 younger patients (<25 years old) and 16 older patients (>40 years old) to investigate the prognostic value of echocardiographic dobutamine-induced changes. The results of this study showed that although the percent achieved of predicted oxygen consumption was lower in the younger group, no prognostic information was given regarding the outcome of this particular group. In contrast, echocardiographic dobutamine-induced changes can distinguish high-risk younger patients.

Effects of dobutamine on left ventricular shape and geometry: an easy way to detect the functional status of chronic heart failure in patients with dilated cardiomyopathy

OBJECTIVE

Changes in left ventricular geometry and shape are prominent characteristics of cardiomyopathy. The aim of this study was to investigate left ventricular geometry and shape changes after inotropic stimulation in patients with chronic nonischemic dilated cardiomyopathy.

METHODS

A low infusion rate echocardiography-dobutamine study was performed in 35 consecutive patients (age: 50 +/- 8 years) with known dilated cardiomyopathy. Peak exercise oxygen consumption was measured the day before. Overall left ventricular chamber shape was assessed by using the long-/minor-axis dimension ratio obtained at end-diastole and end-systole.

RESULTS

After dobutamine infusion, in the entire study group an increase in systolic long-/minor-axis dimension ratio (0.11 +/- 0.13 mm, P <.001) was observed. The study population was further divided according to whether peak exercise oxygen consumption was less (group I) or more (group II) than 14 mL/kg/min. Although at baseline systolic long-/minor-axis dimension ratio was similar between groups, after dobutamine infusion it was higher in group II (1.51 +/- 0.19) than in group I (1.31 +/- 0.2, P <.01) indicating the abnormal response of systolic sphericity index to inotropic stimulation in patients with advanced functional class heart failure.

CONCLUSION

The response of systolic sphericity index to dobutamine infusion might be an alternative index of the functional status of the failing heart in patients with nonischemic dilated cardiomyopathy.