Effect of haemodialysis on left atrial mechanical function in patients with chronic renal failure

OBJECTIVE: The aim of this study was to investigate the potential effects of haemodialysis on left atrial (LA) mechanical functions in patients with chronic renal failure. METHODS: Thirty-two patients with chronic renal failure (mean age 42.8 +/- 19.6 years) were included in this study. LA volumes were determined echocardiographically at the time of mitral valve opening (maximal,Vmax), at the onset of atrial systole (p wave at the electrocardiography = Vp) and at the mitral valve closure (minimal, Vmin) according to the biplane area-length method in apical 4-chamber and 2-chamber view. All volumes were corrected to the body surface area, and the following left atrial emptying functions were calculated. LA passive emptying volume = Vmax - Vp, LA passive emptying fraction = LA passive emptying volume/Vmax. Conduit volume = LV stroke volume-(Vmax - Vmin), LA active emptying volume = Vp Vmin. LA active emptying fraction = LA active emptying volume/Vp, LA total emptying volume = (Vmax - Vmin), LA total emptying fraction = LA total emptying volume/Vmax. RESULTS: Mean fluid removal was 1,875 +/- 812 milliliter.There was no difference between in the LA passive emptying volume before and after dialysis (10.83 +/- 7.44 vs. 11.47 +/- 7.73 cm3/m2, p > 0.05). Conduit volume (from 15.30 +/- 10.68 to 10.31 +/- 6.83 cm3/m2, p < 0.05), LA active emptying volume (from 12.61 +/- 6.39 to 9.25 +/- 4.40 cm3/m2, p < 0.005), LA total emptying volume (from 23.44 +/- 8.52 to 20.72 +/- 8.58 cm3/m2, p < 0.05), LA maximal volume (from 39.44 +/- 14.07 to 28.89 +/- 11.80 cm3/m2, p < 0.001), LA minimal volume (from 15.99 +/- 9.70 to 8.17 +/- 4.52 cm3/m2, p < 0.001), and the volume at the onset of atrial systole (from 28.61 +/- 10.36 to 17.42 +/- 7.20 cm3/m2, p < 0.001) decreased significantly after the haemodialysis session, whereas LA passive emptying fraction (from 0.27 +/- 0.14 to 0.38 +/- 0.14%, p < 0.001), LA active emptying fraction (from 0.46 +/- 0.18 to 0.53 +/- 0.17%, p < 0.05), LA total emptying fraction (from 0.61 +/- 0.14 to 0.72 +/- 0.09%, p < 0.001) increased significantly after haemodialysis. CONCLUSION: The results of this study suggest that left atrial mechanical functions improve after haemodialysis in patients with chronic renal failure.     

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 mechanical function in patients with essential hypertension

OBJECTIVE: This study was carried out to assess the left atrial (LA) mechanical function in patients with essential hypertension with two-dimensional echocardiography by means of left atrial volume measurements. METHODS: LA volumes were measured echocardiographically in 36 untreated hypertensive patients and 20 age-sex-matched healthy controls according to biplane area-length method. LA volume measurements were done at the time of mitral valve opening (Vmax), at the onset of atrial systole (p wave at the electrocardiography = Vp) and at closure (Vmin). All volumes were indexed for body surface area, and the following left atrial emptying functions were calculated: LA passive emptying volume = Vmax -Vp, LA passive emptying fraction = LA passive emptying volume /Vmax, conduit volume = left ventricular stroke volume-(Vmax-Vmin), LA active emptying volume = Vp-Vmin, LA active emptying fraction = LA active emptying volume /Vp, LA total emptying volume = (Vmax-Vmin), LA total emptying fraction = LA total emptying volume /Vmax. RESULTS: Vmax (p < 0.01),Vmin (p < 0.005) and Vp (p < 0.001) were significantly greater in hypertensives than in controls. Although LA passive emptying volume (p < 0.001), LA passive emptying fraction (p < 0.001), conduit volume (p < 0.005) and LA total emptying fraction (p < 0.05) were found to be significantly lower in hypertensives than in controls, LA active emptying volume (p < 0.001) and LA active emptying fraction (p < 0.01) were found to be significantly greater in hypertensives than in controls. LA total emptying volume (p > 0.05) was similar in both groups. CONCLUSION: The results of the present study indicate that chronic hypertension is associated with an increased in left atrial volumes, a decrease in left atrial passive emptying function, and an increase systolic pump function. Increased left atrial pump function represents a compensatory mechanism in hypertensive patients with left ventricular hypertrophy.     

Effects of dipper and non-dipper status of essential hypertension on left atrial mechanical functions

AIM: This study was designed in order to investigate the effects of dipper and non-dipper status of hypertension on left atrial mechanical (reservoir, conduit and booster pump) functions with left atrial volume measurements by means of two-dimensional echocardiography in untreated systemic hypertensive patients. METHOD: A total of 27 untreated dipper hypertensive patients, group I (15 female, 12 male, mean age 57+/-12 years); 23 untreated non-dipper hypertensive patients, group II (12 female, 11 male, mean age: 53+/-18 years); and 25 voluntary healthy individuals, group III (13 female, 12 male, mean age 53+/-10 years) were included into the study. Twenty-four hour blood pressure (BP) measurement was performed by the cuff-oscillometric method to evaluate the nocturnal decrease of BP. The patients whose night time mean blood pressure measurements were found 10% or more lower compared to mean day time measurements were classified as dipper hypertensive patients and the ones with a decrease of less than 10% were classified as non-dipper hypertensive patients. Left atrial (LA) volumes were measured echocardiographically according to biplane area-length method in apical four-chamber and two-chamber views. LA maximal volume (V(max)) was recorded at the onset of mitral opening, LA minimal volume (V(min)) was recorded at the onset of mitral closure and LA presystolic volume (V(p)) was recorded at the beginning of the atrial systole (p wave on ECG). All volume measurements were corrected to body surface area, and following LA emptying functions parameters were calculated: LA passive emptying volume (LAPEV)=V(max)-V(p), LA passive emptying fraction (LAPEF)=LAPEV/V(max), Conduit volume (CV)=left ventricular output volume-(V(max)-V(min)), LA active emptying volume (LAAEV)=V(p)-V(min), LA active emptying fraction (LAAEF)=LAAEV/V(p), LA total emptying volume (LATEV)=V(max)-V(min), LA total emptying fraction (LATEF)=LATEV/V(max). RESULTS: LA volume indexes, V(max), V(min), and V(p), were significantly increased in the hypertensive subgroups (groups I and II) than in controls (p<0.001, p<0.001, p<0.001, respectively), but no significant difference was found in the V(p) values between group I and group II. V(max) and V(min) were larger in non-dipper hypertensive group than in dipper hypertensive group (p<0.05 and p<0.05, respectively). LAPEV and LAPEF were observed to be significantly reduced in both dipper and non-dipper hypertensives than in control (p<0.001 and p<0.05, respectively), and this difference was more obvious in non-dipper than dipper cases (p<0.001). Conduit volume was significantly lower in hypertensive groups than controls (p<0.05). LA active emptying volume (p<0.001) and LAA active emptying fraction (p<0.001) were significantly greater in hypertensive cases than in controls. Furthermore, LA active emptying volume in non-dipper hypertensive subjects was significantly greater than dipper hypertensive cases (p<0.05). Left atrial total emptying volume and left atrial total emptying fraction in both hypertensive groups were similar to control (p>0.05). CONCLUSIONS: Atrial reservoir and booster pump functions increase in hypertensive patients, but this result is more prominent in non-dipper hypertensives than in dipper hypertensive patients.     

Effect of age and sex on left atrial morphology and function.

AIMS: Left atrial function is abnormal in a wide range of cardiac diseases. This study was designed to assess the effects of normal ageing and sex on left atrial morphology and function. METHODS AND RESULTS: Echocardiography was performed in 123 subjects (age 57 +/- 19 years, range 22 to 89 years, 59 women) with no evidence of cardiovascular disease. M-mode derived left atrial size, B-mode derived left atrial maximal and minimal volumes, and the volume at onset of atrial systole (P-volume) were measured. Left atrial filling, active and passive emptying volumes and ejections fractions, and expansion index were calculated. Subjects were divided into four groups according to age. Left atrial diameter increased with age, with significantly smaller left atrial size in younger subjects. The oldest subjects had significantly higher (P<0.05) left atrial minimal, maximal and P-volume indices. Filling volume index was highest in the oldest subjects (21.9 +/- 5.6 ml/m(2)). Passive emptying volume index was the lowest in those of middle age (10.5 +/- 2.8 ml/m(2)). Active emptying volume index progressively increased with age (P<0.001). Left atrial expansion index and active emptying fraction were not different between the age groups. There was significant difference in passive emptying fraction (P<0.001) with highest values in the youngest (44.7 +/- 7.3%) and lowest values in the oldest subjects (33.6+/-5.4%). CONCLUSIONS: Age- and sex-related reference values of echocardiographic indices of left atrial morphology and function are reported. Ageing is associated with left atrial dilatation. Left atrial conduit function deteriorates with age while reservoir and pump function are maintained. Left atrial anteroposterior diameter is smaller in women than in men, but overall left atrial function is not influenced by sex.     

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

OBJECTIVE: To evaluate left atrial functional reserve in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM). BACKGROUND: Left ventricular functional status has been investigated using echocardiographic dobutamine. METHODS: In 35 consecutive patients (29 men and 6 women; mean +/- SD age, 42.37 +/- 13.5 years), peak oxygen consumption (O(2)max) was measured; the day after, a low-dose dobutamine (5 to 10 micro g/kg/min, of 5 min each step) study was performed. Left atrial volumes at mitral valve opening, onset of left atrial systole, and mitral valve closure were measured by using two-dimensional echocardiography. Left atrial active emptying volume (LAEV) [volume at onset of atrial systole - minimal volume] was calculated, as was left atrial active emptying fraction (LAEF): [(volume at onset of atrial systole - minimal volume)/volume at onset of atrial systole] x 100. The changes (values obtained after inotropic stimulation minus those obtained at baseline) of the above-mentioned echocardiographic variables were considered as left atrial functional reserve. RESULTS: In the entire study group after dobutamine infusion, increases in LAEV (3.34 +/- 7.54 mL, p = 0.01) and LAEF (6 +/- 13.2%, p = 0.01) were observed. The changes in the above-mentioned parameters were correlated with O(2)max values (r = 0.73 and r = 0.71, respectively; p < 0.001). After inotropic stimulation, LAEV and LAEF were increased in patients with O(2)max values > 14 mL/kg/min (5.62 +/- 7.28 mL and 10.04 +/- 13.13%, respectively) and decreased in patients with O(2)max values < 14 mL/kg/min (- 1.08 +/- 6.13 mL and - 1.6 +/- 9.9%, respectively; p = 0.01 for both). CONCLUSION: Echocardiographic dobutamine can evaluate left atrial functional reserve in patients with nonischemic DCM.     

Left atrial systolic function in primary and familial amyloidosis: assessment from left atrial volume change

The severity of left ventricular involvement may differ between primary (PA) and familial amyloidosis (FA). This study examined whether differences in left atrial (LA) systolic function are also present. Twenty-eight patients (18 men, 10 women, aged 59 +/- 12 years) with PA, 17 (11 men, 6 women, aged 40 +/- 11 years) with FA, and 25 normal controls (18 men, 7 women, aged 56 +/- 14 years) underwent transthoracic M-mode, two-dimensional, and Doppler echocardiography. Left atrial volumes were determined at mitral valve (MV) opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp), and MV closure (minimal, Vmin) from the apical two-and four-chamber views using the biplane area-length method. Left atrial systolic function was assessed with the LA active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp. The E/A ratio was increased (1.34 +/- 0.93 vs. 0.89 +/- 0.3), whereas deceleration time was decreased (168.1 +/- 33.7 vs. 196.2 +/- 34.2 ms) in PA compared with FA (p<0.05). Vmax and Vp were similar in PA and FA and greater than in the controls (46.6 +/- 14 vs. 40 +/- 11.4 vs. 27.1 +/- 6.3 cm3/m2, p<0.01, and 33.4 +/- 11.6 vs. 29.7 +/- 10.8 vs. 16.8 +/- 3.8 cm3/m2, p<0.01, respectively). The ACTEV was lower in PA and in the controls than in FA (6.7 +/- 2 vs. 6.2 +/- 2.2 vs. 8.5 +/- 3.3, respectively, p<0.05). The ACTEF was lower in PA than in FA and both were lower than those in the controls (20 +/- 5% vs. 28 +/- 7% vs. 36 +/- 11%, respectively, p<0.01). Despite a similar increase in LA volume, LA systolic dysfunction is more pronounced in PA than in FA. This is most likely due to the restrictive left ventricular physiology possibly associated with depressed LA contractility in the former.     

Left atrial function, cytokines and soluble apoptotic markers in mitral stenosis: effects of valvular replacement

BACKGROUND: Patients with mitral stenosis (MS) and heart failure (HF) are characterized by changes in the left atrial (LA) function and activation of the apoptotic process. The purpose of the present study was the evaluation of the effect of mitral valve replacement on the LA function, on inflammatory process and apoptotic markers in patients with MS and HF. METHODS: We studied 30 patients with MS and HF (15 in NYHA III-IV and 15 in NYHA IV) in sinus rhythm (mean age 56.2 +/- 4.6 years), and 20 age and gender matched healthy volunteers. Blood samples were obtained before and 6 months after surgical mitral valve replacement, and plasma levels of soluble Fas/APO-1 receptor (sFas), tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6) were measured. Echocardiographically, LA volumes were measured at mitral valve opening (Vmax), at the onset of left atrial systole (P wave of the electrocardiogram, Vp) and at the mitral valve closure (Vmin). LA contractile function was assessed by the LA active emptying fraction (ACTEF). RESULTS: After mitral valve replacement, TNF-a, IL-6 and sFas levels, as well as the Vmax LA volume, were significantly reduced (p < 0.05). ACTEF showed a significant postoperative decrease (0.29 +/- 0.09 vs. 0.23 +/- 0.06, p < 0.01) and it was significantly correlated with sFas (r = -0.88, p = 0.001), TNF-a (r = -0.81, p = 0.001) and IL-6 (r = -0.74, p = 0.001) levels. CONCLUSION: The present findings indicate that mitral valve replacement in patients with mitral valve stenosis, reduces the size of the left atrium, improves left atrial contractile function and depresses inflammatory and apoptotic process.     

Left atrial reservoir function as a potent marker for first atrial fibrillation or flutter in persons > or = 65 years of age

The aim of this prospective study was to evaluate the incremental value of left atrial (LA) function for the prediction of risk for first atrial fibrillation (AF) or atrial flutter. Maximum and minimum LA volumes were quantitated by echocardiography in 574 adults (mean age 74 +/- 6 years, 52% men) without a history or evidence of atrial arrhythmia. During a mean follow-up period of 1.9 +/- 1.2 years, 30 subjects (5.2%) developed electrocardiographically confirmed AF or atrial flutter. Subjects with new AF or atrial flutter had lower LA reservoir function, as measured by total LA emptying fraction (38% vs 49%, p <0.0001) and higher maximum LA volumes (47 vs 40 ml/m(2), p = 0.005). An increase in age-adjusted risk for AF or atrial flutter was evident when the cohort was stratified according to medians of LA emptying fraction (< or =49%: hazard ratio 6.5, p = 0.001) and LA volume (> or =38 ml/m(2): hazard ratio 2.0, p = 0.07), with the risk being highest for subjects with concomitant LA emptying fractions < or =49% and LA volume > or =38 ml/m(2) (hazard ratio 9.3, p = 0.003). LA emptying fraction (p = 0.002) was associated with risk for first AF or atrial flutter after adjusting for baseline clinical risk factors for AF or atrial flutter, left ventricular ejection fraction, diastolic function grade, and LA volume. In conclusion, reduced LA reservoir function markedly increases the propensity for first AF or atrial flutter, independent of LA volume, left ventricular function, and clinical risk factors.     

Effects of aging on left atrioventricular coupling and left ventricular filling assessed using cardiac magnetic resonance imaging in healthy subjects

Left ventricular (LV) filling results from diastolic suction of the left ventricle and passive left atrial (LA) emptying at early diastole and LA contraction at end-diastole. Effects of aging on LA and LV geometric characteristics and function and its consequences for LV filling are incompletely understood. Insight into these effects may increase the understanding of diastolic function. Cardiac magnetic resonance imaging was used to study effects of aging on left atrioventricular coupling and LV filling. Forty healthy volunteers underwent cardiac magnetic resonance imaging and were subdivided into 2 age groups of 20 to 40 (younger group) and 40 to 65 years (older group). For the older group, LA volumes were larger (p <0.05) and LV volumes, including stroke volumes, were smaller (p <0.05), whereas ejection fraction remained constant. LA/LV volume ratios were larger (0.27 +/- 0.06 vs 0.19 +/- 0.03; p <0.001) and correlated with LV mass-volume ratio (r = 0.42, p <0.01). The older group also had lower LA passive emptying (15 +/- 3.0 vs 19 +/- 4.8 ml/m(2); p <0.05) and higher LA active emptying volumes (13 +/- 3.1 vs 11 +/- 3.9 ml/m(2); p <0.05). For both groups, conduit volume contributed most to LV filling, but was lower in the older group (21 +/- 5.1 vs 27 +/- 9.0 ml; p <0.05). In conclusion, changes in LA volume and function were age dependent and related to changes in LV mass-volume ratio. Conduit volume contributed most to LV filling and decreased with age, suggesting it to be an indicator of diastolic function.     

Doppler echocardiographic evaluation of right and left ventricular diastolic function in normal neonates

Doppler echocardiograms of the tricuspid and mitral valves were recorded along with the electrocardiogram and respiration in 22 normal full-term neonates. A computer-interfaced digitizer pad was utilized to measure the following: peak E and A velocities (cm/s); E and A areas (the components of the total velocity-time integral in the early passive period of ventricular filling [E] and the late active period of atrial emptying [A], respectively) and the 1/3 area fraction (or the proportion of filling in the first 1/3 of diastole). All of the variables of right (tricuspid) versus left (mitral) ventricular filling were significantly different on the 1st day of life. Respective values were peak E velocity (cm/s) 44.6 +/- 10.0 (tricuspid) versus 53.2 +/- 9.3 (mitral), p less than 0.01; peak E/A ratio 0.84 +/- 0.14 versus 1.15 +/- 0.17, p less than 0.0001; E/total area 0.58 +/- 0.07 versus 0.63 +/- 0.05, p less than 0.005; E/A area ratio 1.05 +/- 0.23 versus 1.63 +/- 0.40, p less than 0.0001; 1/3 area fraction 0.31 +/- 0.04 versus 0.41 +/- 0.04, p less than 0.0001; peak A velocity (cm/s) 53.0 +/- 8.4 versus 47.6 +/- 5.8, p less than 0.05 and A/total area 0.57 +/- 0.09 versus 0.41 +/- 0.09, p less than 0.001; the mean heart rate (beats/min) was not significantly different: 121 +/- 8 versus 120 +/- 7. Most of the variables remained significantly different on the 2nd day of life, but the level of significance was the same or less for all measurements.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Impact of Mitral Stenosis on Left Atrial Function Assessed by Two‐Dimensional Speckle Tracking Echocardiography

Aims: The aim of this study is to investigate the effect of mitral stenosis (MS) on left atrial (LA) function using two‐dimensional speckle tracking echocardiography (2DSTE). Methods and Results: The study subjects consisted of 52 patients with asymptomatic MS and 52 control subjects. LA function was assessed using prototype speckle tracking software and manual tracking method. Maximal LA volume (LAVmax) and minimal LA volume (LAVmin) and LA volume before atrial contraction (LAVpre‐a) were measured. Using these volumes, LA reservoir, conduit and booster pump fuction parameters were calculated. Indexed LAVmax, LAVmin, and LAVpre‐a measurements via speckle tracking were highly correlated with manual tracing methods in both groups. Expansion index (67.8 ± 36.4 vs. 148.3 ± 44.2), diastolic emptying index (37.7 ± 12.9 vs. 58.0 ± 8.5), passive emptying (37.3 ± 14.1 vs. 70.4 ± 10.4) and passive emptying index (13.3 ± 6.3 vs. 41.3 ± 10.6) were decreased significantly in MS patients (P < 0.001). In contrast active emptying index (62.6 ± 4.1 vs. 29.5 ± 10.1) increased in MS group (P < 0.001) while active emptying (28.1 ± 13.0 vs. 28.3 ± 6.9) remained same among both groups. Conclusions: This is the first study relating LA volumes and function assessed by 2DSTE to MS. 2D speckle tracking analysis of LA volume is relatively easy and provides more detailed information regarding the changes in LA volumes during the cardiac cycle.     

Left atrial volumes, function and work before and after mitral valve repair in chronic mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: Despite the effect of mitral valve repair in left ventricular (LV) function having been extensively studied, investigations of left atrial (LA) performance indices are minimal. This prospective study was undertaken to analyze LA volumes, function and work in patients with chronic mitral valve regurgitation (MR) who underwent mitral valve repair; the analyses were conducted both before and six months after surgery. METHODS: Twenty patients (15 males, five females; mean age 51.4 +/- 12.5 years) with severe MR (grade IV) due to floppy mitral valve/mitral valve prolapse (FMV/MVP; anterior, posterior or both) underwent mitral valve repair. LA volumes, maximal at mitral valve opening (LAmax); minimal at valve closure (LAmin); and at onset of atrial systole (P-wave on ECG, LAP); and transmitral Doppler A-wave velocity were measured before and six months after surgery. LA stroke volume (LASV) = LAP - LAmin; LA ejection fraction (LAEF) = LASV/LAP; LA kinetic energy (LAKE) = 1/2 x LASV x 1.06 (specific gravity of blood) x A2 (dyne x cm x 10(3)); LA and LV dimensions and functions were assessed at the same time. RESULTS: NYHA functional class was improved postoperatively by at least one grade. LV systolic and diastolic dimensions were reduced significantly in all patients (p <0.001). LA volumes (LAmax, LAmin and LAP) were decreased significantly in all patients (p <0.001); LASV remained unchanged. LAEF and LAKE were increased significantly (both p <0.001). The A-wave was also increased (p <0.001). CONCLUSION: Increased LA work (LAKE) after mitral valve repair, despite a decrease in LA volumes, suggests that LA muscle dysfunction was present before surgery. LA involvement may precede LV involvement. The determination of LA performance and work will help to optimize the timing of surgery in patients with FMV/MVP and MVR.     

Disturbed Left Atrial Function is Associated with Paroxysmal Atrial Fibrillation in Hypertension

Background

Hypertension is the most prevalent and modifiable risk factor for atrial fibrillation. The pressure overload in the left atrium induces pathophysiological changes leading to alterations in contractile function and electrical properties.

Objective

In this study our aim was to assess left atrial function in hypertensive patients to determine the association between left atrial function with paroxysmal atrial fibrillation (PAF).

Method

We studied 57 hypertensive patients (age: 53±4 years; left ventricular ejection fraction: 76±6.7%), including 30 consecutive patients with PAF and 30 age-matched control subjects. Left atrial (LA) volumes were measured using the modified Simpson''s biplane method. Three types of LA volume were determined: maximal LA(LAVmax), preatrial contraction LA(LAVpreA) and minimal LA volume(LAVmin). LA emptying functions were calculated. LA total emptying volume = LAVmax−LAVmin and the LA total EF = (LAVmax-LAVmin )/LAVmax, LA passive emptying volume = LAVmax− LAVpreA and the LA passive EF = (LAVmax-LAVpreA)/LAVmax, LA active emptying volume = LAVpreA−LAVmin and LA active EF = (LAVpreA-LAVmin )/LAVpreA.

Results

The hypertensive period is longer in hypertensive group with PAF. LAVmax significantly increased in hypertensive group with PAF when compared to hypertensive group without PAF (p=0.010). LAAEF was significantly decreased in hypertensive group with PAF as compared to hypertensive group without PAF (p=0.020). A'' was decreased in the hypertensive group with PAF when compared to those without PAF (p = 0.044).

Conclusion

Increased LA volume and impaired LA active emptying function was associated with PAF in untreated hypertensive patients. Longer hypertensive period is associated with PAF.     

Compensatory changes in atrial volumes with normal aging: is atrial enlargement inevitable?

OBJECTIVES: The aim of this study was to evaluate left atrial volume and its changes with the phases (active and passive) of atrial filling, and to examine the effect of normal aging on these parameters and pulmonary vein (PV) flow patterns. BACKGROUND: Atrial volume change with normal aging has not been adequately described. Pulmonary vein flow patterns have not been volumetrically evaluated in normal aging. Combining atrial volumes and PV flow patterns obtained using transthoracic echocardiography could estimate shifts in left atrial mechanical function with normal aging. METHODS: A total of 92 healthy subjects, divided into two groups: Group Y (young <50 years) and Group O (old > or =50 years), were prospectively studied. Maximal (Vol(max)) and minimal (Vol(min)) left atrial volumes were measured using the biplane method of discs and by three-dimensional echocardiographic reconstruction using the cubic spline interpolation algorithm. The passive filling, conduit, and active emptying volumes were also estimated. Traditional measures of atrial function, mitral peak A-wave velocity, velocity time integral (VTI), atrial emptying fraction, and atrial ejection force were measured. RESULTS: As age increased, Vol(max), Vol(min), and total atrial contribution to left ventricle (LV) stroke volume were not significantly altered. However, the passive emptying volume was significantly higher (14.2 +/- 6.4 ml vs. 11.6 +/- 5.7 ml; p = 0.03) whereas the active emptying volume was lower (8.6 +/- 3.7 ml vs. 10.2 +/- 3.8 ml; p = 0.04) in Group Y versus Group O. Pulmonary vein flow demonstrated an increase in peak diastolic velocity (Group Y vs. Group O) with no corresponding change in diastolic VTI or systolic fraction. CONCLUSIONS: Normal aging does not increase maximum (end-systolic) atrial size. The atrium compensates for changes in LV diastolic properties by augmenting active atrial contraction. Pulmonary vein flow patterns, although diastolic dominant using peak velocity, demonstrated no volumetric change with aging.     

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.     

Atrial systole and left ventricular filling in hypertrophic cardiomyopathy: effect of verapamil

Many patients with hypertrophic cardiomyopathy (HC) have impaired left ventricular (LV) rapid diastolic filling. To quantitate the contribution of atrial systole to LV filling, we used radionuclide angiography to study 30 normal volunteers and 42 patients with HC before and after oral administration of verapamil (320 to 560 mg/day). LV time-activity curves were constructed by combined forward and reverse gating from the R wave, and the onset of atrial systole was determined by the P-R interval. The percent of LV stroke volume filled during rapid diastolic filling and atrial systole was then computed. Peak LV filling rate during rapid diastolic filling was expressed in end-diastolic volume (EDV)/second. Peak rate of rapid diastolic filling was not different in normal patients and those with HC (3.3 +/- 0.6 versus 3.3 +/- 1.1 EDV/s) and was within the normal range in 34 patients with HC (81%). However, the contribution to LV filling volume by rapid diastolic filling was diminished in patients with HC (83 +/- 7% normal, 67 +/- 17% HC, p less than 0.001) and the contribution of atrial systole was increased (16 +/- 8% normal, 31 +/- 18% HC, p less than 0.001). LV filling volume during atrial systole was above the upper normal limit of 31% in 17 patients (40%), including 13 patients with a normal peak filling rate. After verapamil, peak filling rate increased (to 4.2 +/- 1.2 EDV/s, p less than 0.001), percent LV filling during rapid diastolic filling increased (to 83 +/- 7%, p less than 0.001), and percent LV filling during atrial systole decreased (to 16 +/- 9%, p less than 0.001). Percent LV filling volume during atrial systole was abnormal after verapamil in only 3 patients (7%). Hence, although the peak rate of rapid diastolic filling may be normal in patients with HC, the contribution to LV filling by rapid diastolic filling is reduced and that of atrial systole is thereby increased. Increased rate and magnitude of rapid diastolic filling during verapamil is associated with decrease and normalization of the contribution of atrial systole to LV filling. These data suggest that many patients with HC are at risk of hemodynamic decompensation with the onset of atrial fibrillation or other tachyarrhythmias and loss of the atrial contribution to LV filling. This risk may be reduced during verapamil therapy.     

The long-term effect of successful mitral balloon valvotomy on left atrial size.

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine the extent of regression of left atrial (LA) enlargement following mitral balloon valvotomy (MBV) for mitral stenosis. METHODS: Data obtained from 205 patients before, and at a mean of 31.0 +/- 21.1 months (range: 6 to 86.3 months) after successful MBV were analyzed retrospectively. RESULTS: The invasively determined mitral valve area increased from 0.81 +/- 0.27 cm2 at baseline to 1.73 +/- 0.54 cm2 immediately after valvotomy (p <0.0001), and the mean mitral gradient fell from 15.6 +/- 5.3 to 5.4 +/- 2.5 mmHg (p <0.0001). Similar changes were noted in Doppler-determined mitral valve area (0.89 +/- 0.16 to 1.97 +/- 0.29 cm2; p <0.0001) and gradient (12.6 +/- 5.3 to 4.9 +/- 1.7 mmHg; p <0.0001). In comparison with baseline, significant (p <0.0001) reductions were noted at follow up in the echocardiographic anteroposterior (48.7 +/- 6.9 to 42.4 +/- 6.6 mm), superior-inferior (68.5 +/-8.1 to 59.6 +/- 8.2 mm) and medial-lateral LA dimension (51.2 +/- 6.7 to 44.1 +/- 7.7 mm) and calculated LA volume (91.6 +/- 29.1 to 60.7 +/- 23.8 cm3) Patients in atrial fibrillation had larger LA dimensions, but substantially smaller absolute and relative reduction in LA size at follow up than patients in sinus rhythm. Among patients with prevalvotomy LA enlargement, normalization of LA dimension at follow up was seen in 29.2% of patients in sinus rhythm, but in none of the 32 with atrial fibrillation. CONCLUSIONS: Successful MBV results in significant long-term reduction in LA size in most patients, but normalization of LA size is unusual.     

Two-dimensional echocardiographic determination of right atrial emptying volume: a noninvasive index in quantifying the degree of tricuspid regurgitation

Contrast echocardiography and inferior vena cava ultrasonography are useful techniques in diagnosing tricuspid regurgitation (TR) but are not helpful in estimating the severity. Using a computerized light-pen method for tracing the right atrial (RA) border during systole and diastole in the apical 4-chamber view, single-plane volume determinations were calculated in 10 normal subjects (Group I), 18 patients with atrial fibrillation (AF) and no TR (Group II), 14 patients with mitral stenosis and mild TR (Group IIIa), and 8 patients with mitral stenosis and severe TR (Group IIIb). TR was quantitated as absent, mild or severe by contrast right ventriculography. The RA end-systolic volume was 36.4 +/- 13.1 ml in Group I patients, 59.1 +/- 16.8 ml in Group II patients, 76.9 +/- 55.4 ml in Group IIIa patients, and 154.6 +/- 57.3 ml in Group IIIb patients (all Groups versus Group I, p less than 0.001). The mean RA emptying volume, which equals RA end-systolic volume--RA end-diastolic volume, was 15.3 +/- 5.0 for Group I, 17.7 +/- 3.0 for Group II, 30.4 +/- 8.0 for Group IIIa, and 71.6 +/- 25.4 for Group IIIb. All 8 patients with severe TR but none of the 14 patients with mild TR had an RA emptying volume greater than 40 ml (p less than 0.001). In addition, all 28 patients in Groups I and II but only 4 of 14 patients in Group III had an RA emptying volume less than 26 ml (p less than 0.01). The mean RA pressure measured at cardiac catheterization correlated with RA emptying volume (r = 0.71, p less than 0.001). Thus, RA emptying volume is useful for separating severe TR from mild TR in patients with mitral stenosis.     

Usefulness of phased-array intracardiac echocardiography for the assessment of left atrial mechanical "stunning" in atrial flutter and comparison with multiplane transesophageal echocardiography(*)

We compared transesophageal and phased-array intracardiac echocardiography (TEE/ICE) for the 2-dimensional and spectral Doppler assessment of left atrial (LA) mechanical function. TEE is commonly used to assess LA body and LA appendage mechanical function in patients who are undergoing radiofrequency ablation of typical atrial flutter. Fifteen patients underwent TEE and ICE imaging before and after ablation of typical atrial flutter. The following parameters were measured: (1) LA appendage emptying velocity and fractional area change, (2) severity of LA spontaneous echo contrast (graded 0 to 4), (3) maximal inflow velocity of the left and right upper pulmonary veins, and (5) maximal mitral valve E- and A-wave inflow velocities in sinus rhythm. Diagnostic quality imaging was achieved in all patients with TEE and ICE. Comparing TEE and ICE, the following absolute values and linear correlation coefficient (R) were obtained: preablation LA appendage emptying velocity: 0.45 +/- 0.21 versus 0.44 +/- 0.21 m/s (r = 0.95, p = <0.001); postablation LA appendage velocity: 0.33 +/- 0.24 versus 0.34 +/- 0.24 m/s (r = 0.97, p <0.001); LA appendage fractional area change: 35.3 +/- 13.7 versus 35.9 +/- 17.1% (r = 0.81, p <0.001); left upper/right upper pulmonary vein inflow velocity: 0.50 +/- 0.17/0.49 +/- 0.18 versus 0.51 +/- 0.17/0.47 +/- 0.20 m/s (r = 0.93/0.90, p <0.001); mitral valve E/A wave: 0.66 +/- 0.14/0.31 +/- 0.14 versus 0.69 +/- 0.17/0.35 +/- 0.23 (r = 0.84/0.97, p <0.002); LA spontaneous echo contrast (pre- and postablation): 1.1 +/- 1.2/1.3 +/- 1.2 versus 1.2 +/- 1.3/1.4 +/- 1.3 (r = 0.92/0.90, p <0.001). No patients were identified with LA appendage thrombus. Thus, TEE and phased-array ICE provided equivalent imaging data with high statistical correlation. ICE may be an imaging alternative to TEE in the evaluation of a "stunned" left atrium.