Effects of left ventricular systolic dysfunction on left atrial appendage and left atrial functions in patients with chronic nonvalvular atrial fibrillation

OBJECTIVE: It has been claimed that left ventricular (LV) systolic dysfunction impairs left atrial (LA) and left atrial appendage (LAA) functions. In this study, we compared the LA and LAA function parameters in patients with chronic nonvalvular atrial fibrillation (AF) with and without LV systolic dysfunction. METHODS AND RESULTS: The study population consisted of 28 patients with chronic nonvalvularAF. Group I consisted of 12 patients with LV systolic dysfunction (mean age: 61 +/- 14 years; LV ejection fraction: 44 +/- 6%), group II of 16 patients with normal LV systolic function (mean age: 52 +/- 15 years; LV ejection fraction: 65 +/- 3%). LV ejection fraction (EF) was measured by echocardiography utilizing bi-plane area length method.The following LA and LAA transoesophageal echocardiography parameters were obtained: I) LA diameter, 2) LAA ejection velocity, 3) LAA filling velocity, 4) LAA ejection fraction, 5) pulmonary venous (PV) systolic velocity, 6) PV diastolic velocity, 7) PV systolic velocity/diastolic velocity ratio.The left atrium diameter was significantly larger in group I than in group 11 (4.7 +/- 0.7 cm vs. 3.8 +/- 0.6 cm, p < 0.05).The LAA ejection velocity and LAA ejection fraction were significantly lower in group I than in group 11 (22.6 +/- 15.5 cm/s vs 37.5 +/- 11.3 cm/s and 26.9 +/- 20.8% vs. 41.3 +/- 10.9%, p < 0.05 for both comparisons).The PV systolic velocity and PV systolic velocity/diastolic velocity ratio were significantly smaller in group I than in group II (26.2 +/- 14.8 cm/s vs. 51.5 +/- 22 cm/s and 0.7 +/- 0.6 vs. 1.2 +/- 0.5, p < 0.05 for both comparisons).Although decreased LAA filling and PV diastolic velocities were determined in group I, no significant difference existed between groups I and II.Thrombus and/or spontaneous echo contrast (SEC) in the LA and/or LAA were more frequent in group I (75% vs. 18%, p < 0.05). CONCLUSION: These results indicate that LV systolic dysfunction impairs various LA and LA function parameters and is associated with an increased frequency of SEC and/or LA thrombus in patients with chronic nonvalvularAF.     

Prevention of atrial fibrillation by inter-atrial septum pacing guided by electrophysiological testing, in patients with delayed interatrial conduction.

AIMS: Interatrial septum (IAS) pacing seems efficient in synchronizing atrial depolarization in patients (pts) with delayed inter-atrial conduction, but its clinical role in preventing atrial tachyarrhythmias is still debated. This study was conducted in order to evaluate the clinical efficacy of IAS pacing guided by pace mapping of the IAS, as an alternative treatment modality in pts with drug refractory paroxysmal atrial fibrillation (PAF). METHODS AND RESULTS: We evaluated 29 pts (13 male, 16 female, 60 +/- 11 years), with drug refractory PAF, normal sinus node function and prolonged inter-atrial conduction time (P wave 142 +/- 10 ms). Multipolar catheters were inserted and the electrograms from the high right atrium (HRA) and proximal, middle and distal coronary sinus (CS) were recorded. The IAS was paced from multiple sites. The site of IAS where the timing between HRA and distal CS was <20 ms was considered the most suitable for synchronizing the atria. This site was found to be superior to the CS os. near the fossa ovalis in all pts. An active fixation atrial lead was positioned at this site and a standard lead was placed in the right ventricle. During IAS pacing, the P wave duration decreased significantly to 107 +/- 15 ms (P<0.001). At implant, the atrial sensing was 2.3 +/- 0.7 mV, the atrial pacing threshold was 0.95 +/- 0.15 V (0.5 ms) and the impedance was 760 +/- 80 Ohm. We evaluated the pts during four periods of 3 months duration each. The first period (control) was before pacemaker implantation, while the pts were under antiarrhythmic treatment. During the subsequent two periods, we evaluated the clinical efficacy of IAS pacing to prevent PAF recurrences, in AAT (75 bpm) and AAIR (75-140 bpm) mode, with random selection of the order and after discontinuation of antiarrhythmic treatment. During the fourth period, the same AAIR mode was assessed, but antiarrhythmic drugs were also administered. We compared the arrhythmia free interval among the four periods. The proportion of atrial paced beats in AAIR pacing mode plus antiarrhythmics was significantly higher compared with the drug-free period in AAIR mode (57 +/- 9% and 49 +/- 9% respectively, P=0017) and with AAT pacing mode (44 +/- 10%,(, P<0.001). In AAT mode, the arrhythmia free interval was 24.2 +/- 5.1 days, while it was 26.2 +/- 5.7 days in AAIR mode. These intervals did not differ significantly from the pre-implantation period (24.1 +/- 6.3 days). The arrhythmia free interval in AAIR pacing in combination with antiarrhythmic drug therapy was 38.7 +/- 8.1 days and this was significantly longer than the previous periods (P<0.05). CONCLUSION: Atrial septal pacing in combination with antiarrhythmic drug therapy reduced the incidence of PAF in pts with prolonged inter-atrial conduction times. Pace mapping of the IAS is an attractive technique to assess the shortest atrial activation time between HRA and distal CS. Whether placement of the atrial lead based on the shortest HRA--distal CS time is the best place in the IAS to prevent PAF still remains to be proven.     

Restrictive left ventricular filling pattern and risk of new-onset atrial fibrillation after acute myocardial infarction

Mechanisms for atrial arrhythmias that occur in the context of acute myocardial infarction (AMI) have not been well characterized. AMI often leads to alterations in left ventricular (LV) filling dynamics, which may result in advanced diastolic dysfunction. Diastolic dysfunction may produce increased left atrial (LA) pressure and initiate LA remodeling, promoting the progression to atrial fibrillation (AF). We studied 1,169 patients admitted with AMI. Advanced diastolic dysfunction was defined as a restrictive filling pattern (RFP), defined as ratio of early to late transmitral velocity of mitral inflow >1.5 or deceleration time <130 ms. The relation between RFP and the primary end point of new-onset AF occurring within 6 months was analyzed using multivariable Cox models. Of 1,169 patients (70% men, mean ± SD 64 ± 10 years of age), 110 (9.4%) developed new-onset AF (19.6% and 7.5% in patients with and without RFP, respectively, p <0.0001). RFP was associated with a hazard ratio of 2.72 for AF (95% confidence interval 1.83 to 4.05, p <0.0001). After multivariable adjustments for clinical variables, LV ejection fraction (EF) and LA size, RFP remained an independent predictor of AF (hazard ratio 2.17, 95% confidence interval 1.42 to 3.32, p <0.0001). Risk of AF was higher in patients with RFP for preserved (≥45%, hazard ratio 2.14, 95% confidence interval 1.09 to 4.20, p = 0.03) or decreased (hazard ratio 2.80, 95% confidence interval 1.63 to 4.82, p <0.0001) LVEF. In contrast, decreased LVEF in the absence of RFP was similar to that of patients with preserved LVEF and without RFP. In conclusion, in patients with AMI, presence of advanced diastolic dysfunction was independently associated with new-onset AF, suggesting that increased filling pressures may contribute to the development of AF after AMI.     

A real-time three-dimensional echocardiographic quantitative analysis of left atrial function in left ventricular diastolic dysfunction

The evaluation of left ventricular diastolic function provides important information about hemodynamics and has prognostic implications for various cardiac diseases. In particular, left atrial (LA) volume is an increasingly significant prognostic biomarker for diastolic dysfunction. The aim of this study was to assess left ventricular diastolic function by measuring changes in LA volume using real-time 3-dimensional echocardiography. The 106 subjects were divided into 4 groups (normal, impaired relaxation, pseudonormal, and restrictive) on the basis of diastolic function, as assessed by transmitral flow patterns. LA volume was measured during a heart cycle using real-time 3-dimensional echocardiography. LA stroke volume (maximum LA volume - minimum LA volume) and the LA ejection fraction (LA stroke volume/maximum LA volume x 100) were calculated using Doppler imaging to assess their correlation with other parameters used to evaluate left ventricular diastolic function, including transmitral flow pattern and early diastolic mitral annular velocity (E'). LA volume indexed to body surface area was dilated in subjects with left ventricular diastolic dysfunction, whereas the LA ejection fraction was lower. The maximum LA volume, minimum LA volume, and LA ejection fraction were significantly different between each group, and each was significantly correlated with the ratio of early diastolic transmitral flow velocity (E) to E' (E/E'). The LA ejection fraction correlated best with E/E' (r = -0.68, p <0.0001). In conclusion, cyclic changes in LA volume could be measured using real-time 3-dimensional echocardiography, and measuring LA function with this method may be a viable alternative for the accurate assessment of left ventricular diastolic function.     

Evidence of atrial mechanical dysfunction by acoustic quantification in abnormal relaxation and restrictive filling patterns of diastolic dysfunction in patients with coronary artery disease.

AIM: This study made use of acoustic quantification (AQ) to investigate if left atrial (LA) mechanical function was impaired in patients with diastolic dysfunction, which might not be detected by conventional Doppler echocardiography. METHODS: One hundred and ten patients with coronary artery disease (mean age 65+/-11 years, 80% male) underwent echocardiography prospectively while AQ was performed using harmonic imaging at the apical four-chamber view to evaluate LA function. RESULTS: By Doppler echocardiography, left ventricular (LV) diastolic dysfunction in the form of abnormal relaxation pattern (ARP) was present in 84, pseudonormal (PN) in nine and restrictive filling pattern (RFP) in 10 patients. LA mechanical dysfunction with impaired total fractional area change (FAC) of 相似文献   

Intra- and interatrial asynchrony in patients with heart failure

Heart failure (HF) is associated with atrial conduction delay. Color tissue Doppler imaging was used to evaluate intra- and interatrial asynchrony in patients with HF, patients with structural heart disease without HF, and controls. Twenty-three controls (mean age 65 +/- 13 years), 29 patients with structural heart disease without HF (mean age 68 +/- 9 years), and 29 patients with HF (mean age 67 +/- 9 years) were studied. Patients had no histories of atrial fibrillation. Echocardiographic color tissue Doppler imaging of the atria was performed. Measurements below the atrioventricular plane were selected on the right atrial (RA) free wall, interatrial septum (IAS), and left atrial (LA) free wall. The time difference from the onset of the P wave to the onset of the A wave at the right atrium (P-RA), the IAS (P-IAS), and the left atrium (P-LA) was measured. Asynchrony was defined as the differences between P-IAS and P-RA (RA asynchrony), P-LA and P-IAS (LA asynchrony), and P-LA and P-RA (interatrial asynchrony). In patients with HF, a significant increase in RA asynchrony was observed compared with controls and patients without HF (30 +/- 21 vs 12 +/- 13 and 14 +/- 15 ms, p <0.001). LA asynchrony was not different (19 +/- 26 vs 25 +/- 13 vs 25 +/- 14 ms, p = NS). Interatrial asynchrony was significantly increased in patients with HF (49 +/- 24 vs 37 +/- 9 and 39 +/- 17 ms, p = 0.04). There were moderate but significant correlations of RA asynchrony with log N-terminal-pro-B-type natriuretic peptide (r = 0.3, p = 0.01) and the ejection fraction (r = -0.4, p <0.001). In conclusion, in patients with HF, significant RA and interatrial asynchrony was documented, evaluated by noninvasive color tissue Doppler imaging. Asynchrony was related to N-terminal-pro-B-type natriuretic peptide and to the ejection fraction.     

Left atrial function as a predictor of haemodynamic response in patients with mitral stenosis: a dobutamine stress echocardiographic study

OBJECTIVE: The mechanisms of the different haemodynamic and clinical responses to dobutamine infusion in mitral stenosis (MS) are not clearly established. The aim of this study was to evaluate the relation between left atrial (LA) function and haemodynamic response in patients with MS during dobutamine infusion. METHODS AND RESULTS: Forty-two consecutive moderately symptomatic patients (33 women, 9 men; mean age 46+/-9, range from 26 to 66), New York Heart Association (NYHA) class II with MS (mean mitral valve area 1.7+/-0.1 cm2) were evaluated with dobutamine stress echocardiography. Haemodynamic measurements were obtained at rest and during peak dobutamine infusion. LA fractional shortening at rest was used as an index of global LA function. Group I consisting of patients with significantly elevated pulmonary artery pressure (> 60 mm Hg) and mean transmitral gradient (> 15 mm Hg) at peak dobutamine infusion were defined as haemodynamically serious MS. Group II consisted of the remaining 30 patients whose haemodynamic data were below these levels. While baseline haemodynamic parameters and mitral valve characteristics were not different between the two groups, LA fractional shortening was significantly lower (18.9+/-2.8 vs. 32.3+/-5.1%, p<0.0001) and left atrial dimension was significantly larger in group I (49.7+/-2.3 mm vs 43.6+/-5.3 mm, p<0.0001). Left atrial fractional shortening was negatively correlated with the increase in mean transmitral gradient (r:-0.58, p<0.01). When the patients were divided using a LA fractional shortening level of 25% as the cut-off point, we observed that the patients with low LA fractional shortening had a greater increase in mean transmitral gradient (7.3+/-3.1 mm Hg vs. 4.6+/-1.4 mm Hg), p = 0.005) and pulmonary artery pressure (22.4+/-3.5 mm Hg vs. 16.1+/-8.5 mm Hg, p = 0.001) compared to the patients with high LA fractional shortening. Based on these haemodynamic results, management was changed in 12 patients (28%): 5 underwent percutaneous mitral balloon commissurotomy and 7 received intensive medical treatment. CONCLUSIONS: The present study demonstrates that haemodynamic response during dobutamine stress echocardiography correlates with LA fractional shortening in patients with MS. The evaluation of left atrial function at rest in patients with ambiguous symptoms and mild mitral stenosis may be useful in clinical decision making. Atrial dysfunction at rest may predict the haemodynamic response during stress echo in these patients.     

Relation of left atrial maximal volume measured by real-time 3D echocardiography to demographic, clinical, and Doppler variables

Left atrial (LA) enlargement is a negative prognostic factor for survival in patients with stroke, congestive heart failure, and myocardial infarction. In the absence of mitral valvular disease it is also a marker of chronic elevated left ventricular filling pressures. The aim of our study was to examine whether the currently considered factors such as demographic, clinical, and Doppler parameters fully correspond to LA maximal volume measured by real time three-dimensional echocardiography (RT3DE). Two-hundred-twenty-four patients (age 58+/-12 years) were studied. Of these, 66 were healthy volunteers and 158 were patients with more than 2 cardiovascular risk factors (109), documented coronary heart disease (CHD) and normal LV function (33), and patients with (10) and without (6) IHD and LV systolic dysfunction. Two-dimensional Doppler and tissue Doppler (TDI) echocardiographic parameters and LA maximal volume, assessed by RT3DE were analyzed. LA maximal volume values were positively and highly significantly associated, after adjustment for age and sex, with LV mass, mitral flow peak E velocity and E/A ratio, TDI E'/A' ratio and E/e' ratio (P<0.001). There were highly significant inverse associations of LA maximal volume and ejection fraction and peak A' velocity detected by TDI (P<0.0001). LA maximal volume was significantly correlated with the progression of diastolic dysfunction from normal to grade III. In particular, there was a clear difference between the normal and pseudonormal filling patterns (p<0.001) in terms of LA maximal volume. In conclusion, progressive LA volume increase is directly correlated with age, LV mass, and LV diastolic dysfunction, and inversely correlated with LV systolic function.     

Prognostic value of pulse-wave tissue Doppler parameters in patients with systolic heart failure

The aim was to study the prognostic value of left ventricular (LV) function using pulse-wave tissue Doppler imaging (TDI) in an ordinary population with heart failure (HF). One hundred fifty-six patients hospitalized for HF and LV ejection fraction 13 had sensitivity of 84% and specificity of 45% to identify patients who died within 2 years of cardiac reasons. In conclusion, in the acute stage of HF, E/e' ratio is a strong independent predictor of long-term cardiovascular mortality in an ordinary population with HF and systolic dysfunction. Systolic and diastolic velocities had no independent prognostic value.     

Plasma nitric oxide level in heart failure secondary to left ventricular diastolic dysfunction.

Nitric oxide (NO) is a free radical that is elevated in the plasma of patients with systolic heart failure. However, its relation to diastolic function is unknown. This study investigated the relation between the level of stable end-products of plasma NO (NOx level) and diastolic function in patients with heart failure. We performed echocardiographic Doppler studies in 76 patients (mean age of 66 +/- 10 years, 75% men) with congestive heart failure. Left ventricular (LV) diastolic dysfunction was classified as either a restrictive (RFP) or nonrestrictive filling pattern (non-RFP). Same day venous total nitrite plus nitrate levels were measured by chemiluminscence. Both patients with isolated diastolic heart failure (ejection fraction >50%) (77 +/- 9 micromol/L, n = 33) and systolic failure (ejection fraction < or = 50%) (115 +/- 17 micromol/L, n = 43) had significantly higher plasma NOx levels than controls (37 +/- 2 micromol/L, both p <0.001). RFP coexists mostly in patients with systolic heart failure (15 of 18), and these patients had a higher NOx level than patients with systolic failure and a non-RFP (n = 28) (163 +/- 35 vs 88 +/- 16 micromol/L, p <0.05). Patients who were not on oral nitrate drugs had insignificant lower plasma NOx levels than those on regular nitrate therapy, although it was still higher than controls. Plasma NOx level did not correlate with LV ejection fraction. Stepwise multiple regression analysis confirmed that the presence of RFP was the only independent predictor of NOx, and hence NO production. Plasma NOx level is elevated in patients with isolated diastolic heart failure. In addition, in patients with LV systolic failure, the severity of LV diastolic dysfunction determines the amount of NO production.     

Influence of age and cardiovascular factors on regional pulsed wave Doppler myocardial imaging indices.

AIMS: To describe the influence of age and other cardiovascular factors on regional pulsed wave Doppler myocardial imaging (DMI), and to compare DMI with conventional transmitral echocardiography and the atrioventricular plane displacement (AVPD) method. METHODS AND RESULTS: Eighty-eight healthy subjects aged 20-81 years were examined by DMI, performed in the intraventricular septum just below the mitral annulus and in the corresponding lateral region, by transmitral pulsed wave Doppler echocardiography, and by AVPD. The DMI peak velocity during the left ventricular (LV) early filling phase (e), decreased with age from 12.3 +/- 2.3 cm/s in the youngest to 7.0 +/- 1.7 cm/s in the oldest tercentile (r=- 0.76, P<0.001). The DMI peak velocity during atrial contraction (a), increased from 7.5 +/- 2.2 cm/s in the youngest to 9.7 +/- 1.7 cm/s in the oldest tercentile (r=0.41, P<0.001). The DMI systolic peak velocity (s), decreased with age from 8.2 +/- 1.1 (youngest tercentile) to 6.9 +/- 1.1 (oldest tercentile), r=-0.39, P<0.001 cm/s, while the fraction shortening of the LV increased from 33.7 +/- 4.1 to 38.2 +/- 5.9% (r=0.36, P<0.01). The DMI e/a correlated with the transmitral early/atrial (E/A) (r=0.83, P<0.001) and with the AVPD measurement of diastolic function AV-LA/AV-mean (r=0.82, P<0.001). The DMI e velocity correlated with the transmitral E velocity (r=0.38, P<0.001). In the multiple regression analysis of DMI e, age was the strongest factor and LV mass index correlated inversely and independently with e. No DMI variables were influenced by gender, while transmitral E correlated with gender. The LV dimension variables explained 35% (R2 adjusted) of the DMI e velocity changes; only 7% of the transmitral E changes were explained by those variables. CONCLUSION: Regional DMI indices are highly age-dependent. In comparision with conventional echocardiography, regional DMI might be more influenced by LV geometry and by myocardial structural changes. These findings suggest a complementary role for regional DMI to conventional echocardiography for the assessment of myocardial function.     

Alterations in left ventricular structure and diastolic function in professional football players: assessment by tissue Doppler imaging and left ventricular flow propagation velocity

BACKGROUND: Long-term regular exercise is associated with physiologic and morphologic cardiac alterations. Tissue Doppler imaging (TDI) and ventricular early flow propagation velocity (Vp) are new tolls in the evaluation of myocardial function. We sought to compare TDI and Vp findings in professional football players and age-adjusted sedentary controls to assess the effect of regular athletic training on myocardial function. METHODS: Twenty-four professional football players and age-, sex-, and weight-adjusted 20 control subjects underwent standard Doppler echocardiography pulsed TDI, performed parasternal four-chamber views by placing sample volume septal and lateral side of mitral annulus and lateral tricuspid annulus. Vp values were obtained by measuring the slope delineated by first aliasing velocity from the mitral tips toward the apex by using apical four-chamber color M-mode Doppler images. RESULTS: Age, body surface area, blood pressure, and heart rate were comparable between two groups. Football players had significantly increased LV mass, mass index (due to both higher wall thickness and end-diastolic diameter), end-systolic and end-diastolic volume, left atrial diameter, and decreased transmitral diastolic late velocity. In athletes TDI analysis showed significantly increased mitral annulus septal DTI peak early diastolic (e) velocity (0.22 +/- 0.04 vs 0.19 +/- 0.04, P < 0.05), lateral DTI peak e velocity (0.19 +/- 0.03 vs 0.16 +/- 0.02, P < 0.05) and lateral DTI e/a peak velocity ratio (1.96 +/- 0.41 and 1.66 +/- 0.23, P < 0.05). The ratio of transmitral peak early diastolic velocity (E) to e in both lateral (4.72 +/- 1.20 vs 5.95 +/- 1.38, P = 0.007) and septal (3.90 +/- 0.80 vs 5.25 +/- 1.50, P = 0.002) side of mitral annulus were significantly lower in athletes. In Vp evaluation, we found higher Vp values (60.52 +/- 6.95 in athletes and 56.56 +/- 4.24 in controls, P = 0.03) in football players. CONCLUSIONS: Professional football playing is associated with morphologic alteration in left ventricle and left atrium and improvement in left ventricle diastolic function that can be detected by TDI and Vp. These techniques may be new tools to define and quantitate the degree of LV diastolic adaptations to endurance exercise.     

Do the Left Atrial Substrate Properties Correlate with the Left Atrial Mechanical Function? A Novel Insight from the Electromechanical Study in Patients with Atrial Fibrillation

Background: The atrial substrate is the determinant of occurrence and maintenance of atrial fibrillation (AF), which can induce remodeling of atrial function and structure. This study investigated the relationship between the left atrial (LA) substrate properties and LA mechanical function.
Methods: Forty-four consecutive patients (50.3 ± 10.7 years old, 33 men) who presented with sinus rhythm during echocardiographic study before receiving catheter ablation for AF were enrolled. The LA diameter, LA volume, ratio of early and late transmitral filling flow velocities (E/A), LA appendage flow velocity, and transmitral velocity-time integral (VTI) were measured by the echocardiography. The LA empty fraction (LAEF), which was obtained via dividing the difference between maximal and minimal LA volume by maximal LA volume, was calculated as a parameter of the global LA contractile function. The LA global contact voltage mapping (NavX system) was performed before pulmonary vein isolation.
Results: Mean LA voltage and LA low voltage zone index (LVZ index, area with voltage < 0.5 mV, divided by total LA surface area) showed significant correlation with LA diameter and volume, but only the LA LVZ index showed significant correlation with A-wave velocity, transmitral A-wave VTI, and LAEF (r =–0.340, –0.411, –0.426; P = 0.024, 0.006, 0.005, respectively). We divided the LA LVZ index into three groups (< 10%, 10–20%, > 20%). The LAEF got worse and the transmitral A-wave VTI percentage (divided by transmitral VTI) decreased as LA LVZ index increased.
Conclusions: The LA substrate properties showed close correlation with LA size, but only the LA LVZ index correlated with the LA mechanical function.     

Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow.

OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p < 0.005), confirming the presence of the Frank-Starling mechanism in the LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p < 0.001). Among pulmonary venous flow parameters, no single parameter was sufficient to estimate LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity of pulmonary venous flow during atrial contraction. This equation was tested in the latter 10 patients of the test group. Predicted and measured LA dP/dt(max) correlated well (r = 0.90, p < 0.0001). Numerical simulation verified that this relationship held across a wide range of atrial elastance, ventricular relaxation and systolic function, with LA dP/dt(max) predicted by the above equation with r = 0.94. CONCLUSIONS: A combination of transmitral and pulmonary venous flow parameters can provide a hemodynamic assessment of LA systolic function.     

Left atrial anatomy and function after conversion from atrial fibrillation in hypertrophic hearts

The aim of the study was to evaluate the influence of left ventricular (LV) hypertrophy on left atrial (LA) electrical and mechanical function after cardioversion atrial fibrillation (A-Fib) of brief duration. Study group A included 100 patients with a first diagnosis of hypertension who had a moderate LV hypertrophy. The patient population included 64 men and 36 women with a mean age of 55 +/-7 years who were hospitalized because of A-Fib and were cardioverted with external DC shock. Control group B included 100 patients without cardiac hypertrophy cardioverted because of lone A-Fib. Atrial function and size were assessed by Doppler echocardiography and the following parameters were measured: transmitral peak A velocity, atrial filling fraction, atrial ejection force, peak E velocity, deceleration time, and isovolumic relaxation time, LA maximal and minimal volume, and LV cardiac mass index. Baseline echocardiography showed that LA diameters and volumes were enlarged in all patients during A-Fib. After the restoration of sinus rhythm LA diameters and volumes decreased and the reduction was more evident in group B compared to group A. LA function as a continuous variable was negatively related to LV mass index (r = -0.77), LA diameter (r = -0.66 and r = -0.69 for the superoinferior diameter), LA maximal volume (r = -0.61) and LA minimal volume (r = -0.55) (all p<0.01). Atrial ejection force as a continuous variable was positively related to age (r =0.78), peak A wave velocity (r =0.71), systolic blood pressure (r =0.51), and IVRT (r =0.41) (all p<0.01). Hypertrophy influenced the recovery of atrial function after cardioversion of A-Fib. Atrial function was reduced in patients with LV hypertrophy even after A-Fib of brief duration.     

Influence of regression of left ventricular hypertrophy on left atrial size and function in patients with moderate hypertension

OBJECTIVES: The aim of the study was to evaluate the effect of regression of left ventricular (LV) hypertrophy on left atrial (LA) size and function in patients treated with telmisartan, an angiotensin II receptor blocker. METHODS: Patients population included 80 patients with mild-moderate LV hypertrophy treated with telmisartan. Patients were followed over a period of 12 months from the start of telmisartan treatment. LA size was measured during systole from the parasternal long-axis view from M-mode. Atrial function was assessed by Doppler-echocardiography and the following parameters were measured: transmitral peak A velocity, atrial filling fraction, atrial ejection force (AEF), peak E velocity, deceleration time and isovolumic relaxation time, LA maximal and minimal volume, and LV cardiac mass index (LVMI). RESULTS: All patients had an increased LVMI and decrease during follow-up. LA dimensions were greater at baseline and reduced after 1 year of treatment. LA volume indexes maximal volume, minimal volume and P volume were reduced compared with baseline value (maximal volume from 35+/-5 to 32+/-5, p<0.05; minimal volumes from 14+/-2 to 10+/-4, p<0.05). AEF, a parameter of atrial systolic function, increased from 12+/-3 to 15+/-2.4 (p<0.01). The reduction of LA volumes correlate with reduction of LVMI (LA maximal volume and LVMI r = 0.45; p<0.01; LA minimal volume and LVMI r = 0.34; p<0.05). A positive correlation was also found between LV mass index and P volume (r = 0.41; p<0.01), LV mass index and LA active emptying volume (r = 0.39; p<0.01), and LV mass index and LA total emptying volume (r = 0.38; p<0.05). CONCLUSIONS: The present study suggests that regression of LV hypertrophy due to telmisartan is associated with reduction of LA volumes that expresses variation of LV end-diastolic pressure. The reduction of LV end-diastolic pressure is associated with an increase in diastolic filling and with a significant reduction of active and passive emptying contribution of left atrium to LV stroke volume.     

Left atrial velocity vector imaging for the detection and quantification of left ventricular diastolic function in type 2 diabetes

Left ventricular (LV) diastolic dysfunction (DD) is diagnosed by Doppler echocardiography (DE) and Tissue Doppler imaging (TDI). Velocity vector imaging (VVI) evaluates myocardial deformation (strain). We studied left atrial (LA) deformation and volumes by VVI in relation to established Doppler-derived indices of LV diastolic function in diabetic patients. MATERIAL: Using DE and TDI , 87 patients (males 49%; age 60+/-7 years) with type 2 diabetes mellitus were classified as having no (n=60), mild (n=13) or moderate (n=14) DD. RESULTS: LA volume was larger in moderate (72.3+/-22.4 ml) than in mild DD (58.8+/-16.1 ml; p=0.01) and no DD (57.9+/-16.0 ml; p=0.01). LA roof strain distinguished no DD from mild and moderate DD (p=0.0073). Systolic LA strain correlated to total emptying fraction (r=0.70, p<0.0001), and inversely to LA volume (r=-0.35, p=0.0009). A cross-validated analysis of no versus mild or moderate DD expressed by LA strain revealed a positive predictive value of 48% and negative of 84%. CONCLUSION: LA strain by VVI is impaired in patients with type 2 diabetes mellitus and mild or moderate LV DD. LA strain seems of value in distinguishing normal from abnormal diastolic function. VVI offers new information on regional LA function and LA volumes but has too limited discriminative power to detect early LV DD.     

Detection of a pseudonormal mitral inflow pattern: an echocardiographic and tissue Doppler study

OBJECTIVE: The aim of this study was to assess the ability of several echocardiographic and tissue Doppler imaging (TDI) derived parameters to improve the noninvasive diagnosis of a pseudonormal mitral inflow pattern. METHODS: Ninety-eight consecutive patients with age-related normal transmitral Doppler profile underwent echocardiography including TDI and measurement of left ventricular end-diastolic pressure (LVEDP) using fluid-filled catheters. Peak transmitral velocities were determined at rest (E, A) and during the strain phase of a Valsalva maneuver. The difference in duration between the pulmonary venous retrograde velocity and the transmitral A-velocity (PVR-A) was calculated from pulsed Doppler recordings. Propagation velocity of the early mitral inflow (VP) was determined by color M-mode. Early diastolic peak mitral annulus velocities (E') and the early diastolic transmyocardial velocity gradient of the posterior basal wall (MVG) were obtained by TDI. RESULTS: Fifty-two patients presented with normal diastolic function (group I: LVEDP9.5 +/- 3 mm Hg, E/A1.1 +/- 0.19), while pseudonormalization, defined as LVEDP 15 mm Hg and E/A > 0.9, was found in 46 patients (group II: LVEDP23 +/- 7 mm Hg, E/A1.43 +/- 0.83). The coefficient of linear correlation (r) and the area under ROC - curve (AUC) to predict LVEDP values 15 mm Hg were maximal for the index PVR-A (AUC = 0.92, r = 0.77), followed byE/E' (AUC = 0.80, r = 0.46), MVG (AUC = 0.65, r = 0.33) and E/VP (AUC = 0.69, r = 0.30), P < 0.01, whereas the decrease in E/A ratio during Valsalva maneuver failed to reach significance. Similar results were observed when echocardiographic parameters were used to estimate the left ventricular diastolic pressure before atrial contraction. CONCLUSIONS: PVR-A enabled the most accurate estimation of LVEDP. TDI-derived indices E/E' and MVG are also reliable alternatives superior to the classical Valsalva maneuver to detect a pseudonormal transmitral Doppler profile.     

Improvement in sympatho-vagal imbalance and heart rate variability in patients with mitral stenosis after percutaneous balloon commissurotomy.

Elevated sympathetic nerve activity in patients with mitral stenosis (MS) may be an index of the severity of the disease. Percutaneous mitral balloon commissurotomy (PMBC) is now a standard treatment for many patients with symptomatic MS. We aimed to show the effects of PMBC on autonomic nervous system activity in the patients with MS by heart rate variability (HRV) analysis. Fifty-four consecutive patients with mitral stenosis and sinus rhythm who underwent percutaneous mitral commissurotomy were enrolled. Apart from significant haemodynamic improvements, mean heart rate (HR), LF day, LF night, LF/HF day and night significantly decreased and SDNN, RMSSD, PNN50, HF day and night significantly increased in the early period after PMBC and these changes were preserved for up to one month. SDNN was positively correlated with left ventricle ejection fraction (LVEF) but negatively correlated with mean valve area (MVA), left atrial (LA) diameter and pressure, right atrial (RA) pressure; LF/HF day ratio was positively correlated with LA diameter and pressure, mean transmitral gradient and negatively correlated with LVEF; LF/HF night ratio was positively correlated with LA pressure and mean transmitral gradient. The increase in SDNN was correlated with the change in LA and RA pressure. The decrease in LF/HF ratio after PMBC was significantly correlated with the changes in the mean transmitral gradient, LA pressure and RA pressure. As a result, the heart rate variability and autonomic nervous system function in patients with mitral stenosis are correlated with the atrial pressures and left ventricular function. These parameters significantly change in the early period after PMBC and are preserved at one month. The improvement in the heart rate variability and sympatho-vagal balance are significantly affected by the early changes in atrial pressures after PMBC.     

Regression of left ventricular hypertrophy and improvement of diastolic function in hypertensive patients treated with telmisartan

OBJECTIVES: The study was designed to test whether or not the angiotensin II receptor blocker telmisartan brings about regression of left ventricular (LV) concentric hypertrophy and whether or not these changes are associated with improved diastolic filling. METHODS: An echocardiographic follow-up study was performed in 85 hypertensive patients (systolic blood pressure [SBP] >140 mmHg, diastolic blood pressure [DBP] >90 mmHg) and mild-to-moderate LV hypertrophy (LV mass index related to body surface area [LVMI] 117-150 g/m2 for men and 105-150 g/m2 for women) treated with telmisartan monotherapy 40-80 mg once daily for 1 year. Blood pressure, LVMI, left atrial (LA) volumes, and diastolic function were determined at baseline and after 3, 6, 9, and 12 months of treatment. Blood pressure was also monitored at all visits. Diastolic function was assessed by examination of transmitral inflow and pulmonary vein flow patterns. RESULTS: Telmisartan reduced blood pressure; after 12 months, the mean+/-S.D. SBP and DBP were reduced from 144+/-10 to 126+/-8 mmHg (p<0.001) and from 98+/-8 to 86+/-7 mmHg (p<0.001), respectively. The LVMI was decreased from 119+/-7 to 109+/-3 g/m2 (p<0.001) after 12 months' telmisartan treatment. All patients had diastolic dysfunction at baseline. After 12 months' telmisartan treatment, a normal pattern of transmitral inflow was present in 21% of patients. The regression of LV hypertrophy observed after 12 months was associated with increased peak early diastolic velocity/peak late diastolic velocity ratio from 0.60+/-0.18 to 0.83+/-0.20 (p<0.001), shortened isovolumic relaxation time (IVRT) from 110+/-13 to 105+/-13 ms (p<0.001), and decreased deceleration time from 229+/-30 to 215+/-28 ms (p=0.002). Univariate analysis showed that shortened IVRT was related to a reduction in the LVMI and LA maximal and minimal volumes. In the multivariate analysis, the reduction in LVMI and the reduction in LA maximal and minimal volumes were independently associated with IVRT reduction. CONCLUSIONS: Telmisartan 40-80 mg is effective in LV hypertrophy regression in hypertensive patients. The reduction in LVMI due to telmisartan monotherapy was associated with a significant improvement of diastolic filling parameters and with a significant reduction of LA volumes.