Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Atrial Function, Left”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1998

Effects of postural changes on left atrial function in patients with hypertrophic cardiomyopathy.

BACKGROUND: We assessed left atrial function in normal subjects and in patients with hypertrophic cardiomyopathy (HCM) by using Doppler echocardiography at the supine position and after sudden standing. METHODS AND RESULTS: Twenty-seven patients with hypertrophic obstructive cardiomyopathy (HOCM), 17 patients with HCM, and 35 normal subjects were studied. From the transmitral Doppler flow velocities, peak early and late (E and A) waves, E/A ratio, and time velocity integrals (Ei and Ai) were calculated. Left atrial active contribution (LAAC) was assessed as the ratio Ei/(Ei + Ai). Furthermore, isovolumetric relaxation time (IVRT) was estimated by means of Doppler echocardiography. In the supine position, the E/A ratio was similar in the 3 groups. Conversely, LAAC was significantly higher in patients with HOCM (24.4 +/- 2.0) and in patients with HCM (23.3 +/- 3.3) compared with normal subjects (20.3 +/- 2.3, P <.001 and P <.05, respectively). After sudden standing, LAAC increased significantly in normal subjects by 11%, in patients with HOCM by 24%, and in patients with HCM by 13% (P <.001). Similarly, IVRT increased significantly in all study groups (P <. 001). By using stepwise forward multiple linear regression analysis, we found that LAAC was associated with age, IVRT, and body mass index in the supine position and with diastolic blood pressure and IVRT in the standing position. CONCLUSIONS: Left atrial contribution to left ventricular filling was increased after sudden changes of posture in normal subjects and in patients with HOCM or HCM.

Adult↗
PubMed1999

Sexual dimorphism in rat left atrial function and response to adrenergic stimulation.

A number of investigations in humans and animals suggest that there may be intrinsic sex-associated differences in cardiac function. Using left atrial preparations from male and female rat hearts, we examined differences in myocardial function and response to adrenergic agonists. Contractile parameters were measured in isolated atria by conventional isometric methods in the absence or presence of isoproterenol or phenylephrine. Responsiveness to Ca2+ was measured in detergent-skinned atrial fibers and actomyosin ATPase activity was measured in isolated myofibrils. Tetanic contractions were generated by treating the atrium with ryanodine followed by high frequency stimulation. Developed force was greater and maximal rates of contraction and relaxation were more rapid in the female atrium. The relationship between Ca2+ concentration and force in both intact atria and detergent-skinned atrial fibers in females fell to the left of that for males. At low Ca2+ concentrations, skinned fibers from female atria generated more force and myofibrils from female atria had higher myosin ATPase activity than males. Tetanic contraction in the presence of high extracellular Ca2+ was greater in female atria. Male atrium had larger inotropic responses to isoproterenol and to phenylephrine, but drug-elicited cAMP and inositol phosphate production did not differ between sexes. The results demonstrate sex-related differences in atrial function that can be partially explained by greater myofibrillar Ca2+-sensitivity in females. A potential contribution of sarcolemmal Ca2+ influx is suggested by greater tetanic contraction in ryanodine-treated female atrium. The larger response of males to adrenergic stimulation does not appear to be explained by higher production of relevant second messengers. Future studies will investigate the role of sex hormones in these sexually dimorphic responses and may indicate a need for gender-specific therapeutic interventions for myocardial dysfunction.

Adrenergic Agonists↗
PubMed2001

Cardiovascular effects of aging. Interrelationships of aortic, left ventricular, and left atrial function.

BACKGROUND: Previous studies have shown that elastic properties of the aorta decrease, while left atrial dimensions, the contribution of left atrial systole to left ventricular filling, and left ventricular mass increase with age. In most studies, however, aortic function, and ventricular and atrial parameters were performed in different populations, and thus, the earliest manifestation of aging in the cardiovascular system is not known. The present study was undertaken to define the earliest cardiovascular abnormality(ies) occurring in the cardiovascular system with age. PATIENTS AND METHOD: In 181 normotensive subjects (147 females and 34 males) age 22-64 years, left ventricular mass, volumes, function and work (echocardiography and blood pressure), left atrial volumes and stroke volume (biplane area-length method by echo), pulse wave velocity (PWV) (carotid to femoral artery, Doppler), and left atrial kinetic energy were measured simultaneously: left atrial kinetic energy = 1/2 mv2, where m = left atrial stroke volume x 1.06 (blood specific gravity), v = transmitral A wave velocity. Regression analyses were performed to correlate all measured cardiovascular parameters with age. RESULTS: Pulse wave velocity (r = 0.51), left atrial kinetic energy (r = 0.42), and A wave velocity (r = 0.38) were correlated to age, while left ventricular mass, function and work were not. Multiple regression analysis among ten clinical and echocardiographic parameters demonstrated that only age contributed independently to pulse wave velocity; only age and pulse wave velocity were contributed independently to left atrial kinetic energy; and only age contributed independently to A wave velocity. CONCLUSIONS: The data demonstrate that age-related alterations in aortic function and left atrial work (left atrial kinetic energy) can be defined prior to changes in left ventricular structure and systolic function. Simultaneous studies of left atrial, left ventricular, and aortic function are required to better understand the effect of aging on the cardiovascular system.

Adult↗
PubMed1994

Effect of dynamic exercise on left atrial function in conscious dogs.

1. Dynamic changes in left atrial (LA) function during treadmill exercise were studied in ten conscious dogs instrumented to measure left ventricular (LV) pressure and diameter, LA pressure and diameter, and pulmonary venous blood flow (PVF, transit time flowmeter). 2. Systolic PVF volume (reservoir volume; a measure of LA reservoir function) increased from 38 +/- 4% of total PVF volume at baseline to 52 +/- 8% of total PVF volume during exercise, and diastolic PVF volume (conduit volume; a measure of LA conduit function) decreased from 62 +/- 5% at baseline to 48 +/- 8% during exercise (P < 0.005). 3. The increases in reservoir volume and the decrease in conduit volume were due not only to a greater decrease in diastolic interval than systolic interval but were also caused by a significantly greater increase (P < 0.05) in the mean systolic filling rate (93%) than in the mean diastolic filling rate (51%). 4. During exercise the pattern of LV filling derived from changes in LV diameter showed that a greater percentage of LV filling occurred during the second half of diastole at the time of atrial contraction (P < 0.05), suggesting that LA booster function was enhanced. 5. Changes in LA dimension revealed that during exercise more blood volume was reserved in the LA during systole and that this change was associated with an increase in the LA dimension at the beginning of LA contraction (r = 0.61, P < 0.05). 6. We conclude that LA reservoir and booster functions were augmented during exercise, whereas conduit function was not. Increased reservoir function may play an important role in accelerating LV filling by helping to maintain an enhanced atrioventricular pressure gradient during diastole and also by increasing LA booster function through an increase in LA preload.

Animals↗
PubMed2006

Hemodynamic change in transmitral gradient during Valsalva maneuver and its relation with left atrial function, functional capacity, and pulmonary artery pressure in patients with mitral stenosis in sinus rhythm.

BACKGROUND: The hemodynamic factors contributing to the clinical symptomatology in patients with mitral stenosis (MS) have been under investigation. The objective of this study was to evaluate the use of the Valsalva maneuver in patients with MS and whether there is an association between the degree of the hemodynamic changes in transmitral gradient (TG) in response to Valsalva maneuver and functional status, systolic pulmonary artery pressure, and left atrial function in patients with MS in sinus rhythm. METHODS: The study prospectively evaluated 42 patients (37 female, mean age 40 +/- 10 years) with a diagnosis of pure MS in sinus rhythm. Patients were divided into 3 groups according to their New York Heart Association (NYHA) functional class. In all, 12 patients were in NYHA functional class I, 17 patients in class II, and 13 patients in class III. TG, including the mitral peak, mean, and late filling gradients, were calculated by the modified Bernoulli equation at rest and during the strain phase of Valsalva maneuver. The percentage changes in all TG in response to Valsalva were calculated. Traditional echocardiographic parameters for atrial function were also measured. RESULTS: We found that, in patients who were more symptomatic according to NYHA classification, a reduction in TG in response to Valsalva maneuver was blunted and associated with higher systolic pulmonary artery pressure compared with those who were asymptomatic or had mild symptoms. Patients in NYHA class III decreased mitral mean pressure gradient by only 13.5%, significantly less (P < .001) than those in classes I (53.9%) and II (41.7%). However, despite the fact that left atrial ejection fraction was low in all patients, it was not associated with functional status in patients with MS. CONCLUSION: This study, for the first time, suggests that echocardiographically determined changes in TG in response to the Valsalva maneuver may provide an objective, noninvasive means of evaluating patients with MS.

Adaptation, Physiological↗
PubMed1992

Left atrial function in ischemic heart disease assessed by intravenous digital subtraction angiography.

To investigate changes in left atrial morphology and dimensions during the cardiac cycle, the atrium was visualized by intravenous digital subtraction angiography (DSA). The study subjects consisted of 22 male patients whose average age was 54.5 +/- 8.6 years. They had ischemic heart disease without mitral valve disease and were in sinus rhythm. They were 11 patients with old myocardial infarction (OMI group) and 11 who had chest pain without evidence of infarction (AP group). DSA was performed in the continuous mode. Contrast material (35 ml) was injected at a rate of 18 ml/sec via a catheter in the superior vena cava and subtraction images were obtained at a speed of 30 frames/sec in the right anterior oblique projection. The left atrial and left ventricular margins were traced manually, their areas were calculated, and fractional changes in area were analyzed. The left ventricular ejection fraction (LVEF) was calculated by densitometry. Cardiac catheterization was performed in 16 patients and the left ventricular end-diastolic pressure (LVEDP) and mean pulmonary arterial wedge pressure (PAWP) were measured. The entire left atrium was clearly imaged using DSA. Phase analysis of the time-area curves in the right anterior oblique projection revealed that the left atrial area was maximal during left ventricular end-systole (%LA1 = 100%), it decreased during early left ventricular diastole (%LA2), and then increased slightly again during mid-diastole (%LA3). After left atrial contraction, the minimum area was obtained (%LA4). The left atrium showed a two-stage decrease in the area due to passive emptying and active contraction during left ventricular diastole. Passive emptying (%LA1-%LA2) was significantly less in the OMI group than in the AP group (6.3 +/- 3.6 vs 13.3 +/- 4.8%, p < 0.01, respectively). In all 22 subjects, passive emptying correlated with LVEF (r = 0.70, p < 0.001) and LVEDP (r = -0.58, p < 0.05). There was no difference in active contraction (%LA3-%LA4) between the 2 groups (26.0 +/- 5.7% in the OMI group, 28.2 +/- 8.4% in the AP group), and it did not correlate with LVEF or LVEDP. The ratio of passive emptying to active contraction [(%LA1-%LA2)/(%LA3-%LA4)] correlated with LVEF (r = 0.63, p < 0.01). These findings suggested that impaired left ventricular diastolic function and a relative increase in atrial contraction were present in patients with a lower LVEF. The %LA4 correlated with LVEDP and PAWP (r = 0.65, r = 0.63, p < 0.01, respectively). In conclusion, DSA proved to be a useful method for investigating left atrial morphology and function.

Aged↗
PubMed1997

Effects of volume loading on pulmonary venous flow and its relation to left atrial functions.

Although pulmonary venous (PV) flow is closely related to left atrial (LA) pressure dynamics, few investigators have discussed it in relation to LA functions, i.e., reservoir, conduit, and booster pump functions. We examined changes in PV flow rate, LA dimension, and left ventricular filling volume in 11 dogs, and assessed the effects of multistaged volume loading on PV flow and LA functions. Systolic PV flow rate (S) increased significantly and reached a plateau, reflecting a limited LA reservoir function. Diastolic PV flow rate (D) increased significantly with an increase in LA pressure. S/D ratio increased non-significantly from 0.87 +/- 0.07 before volume loading to 0.96 +/- 0.08 until S reached a plateau and then decreased to 0.76 +/- 0.08 (p < 0.05) because of a significant increase in D without an increase in S at the higher stages of volume loading. During atrial contraction, increases in LA active shortening and left ventricular filling volume were limited, indicating a limited LA forward ejection. The difference between PV flow rate just before and at the end of atrial contraction increased and correlated positively with left ventricular end-diastolic pressure (r = 0.57, p < 0.01). PV flow varies according to the degree of volume loading and reflects LA functions, which exhibit limited increases in response to volume loading.

Animals↗
PubMed1989

[Evaluation of left atrial function by 99mTc gated blood pool scan].

99mTc gated blood pool scans were studied to assess the left atrial function. Relationship between filling time and rapid emptying time was y = 0.695 x + 109 (r = 0.761, p less than 0.05, n = 14) in LAO and LPO projections. On the other hand, relationship between slow filling and rapid emptying time was good closely (y = 0.846 x + 16.9 (p less than 0.01, r = 0.975, n = 8] in standard and retrograde acquisition. To assess the left atrial function by standard acquisition in LAO projection should be available for clinical use.

Aged↗
PubMed2005

Value of left atrial function in predicting exercise capacity in heart failure with moderate to severe left ventricular systolic dysfunction.

Left atrial (LA) function is associated with left ventricular (LV) diastolic filling and cardiac output response to exercise. But the relation between LA function and exercise performance has not been adequately evaluated. The aim of this study was to investigate the relation between LA function and exercise capacity in dilated cardiomyopathy (DCM) with cardiopulmonary exercise testing. Forty-four patients with a left ventricular end-diastolic dimension (LVDd) > or = 60 mm and an ejection fraction (EF) < or = 40%, and in normal sinus rhythm were included in this study. Patients were divided into group 1 and group 2 according to their exercise peak oxygen uptake (VO2) (group 1: peak VO2 >14 mL/kg/min, group 2: peak VO2 < or = 14 mL/ kg/min). LA function indices were defined as follows: LA end-systolic diameter (LASd), end-diastolic diameter (LADd), LA systolic volume (LASV), LA diastolic volume (LADV), LA ejection volume (LAEV), and LA ejection fraction (LAEF). LASd, LADd, LASV, and LADV were significantly increased in group 2 (P < 0.001, P < 0.001, P < 0.05, P < 0.005). Group 1 had significantly higher LAEF (P < 0.001 ) and LVEF (P < 0.05). Group 2 had significantly shorter exercise duration, and decreased anaerobic threshold levels and minute ventilation volumes (P < 0.001, P < 0.001, P < 0.005 ). There was a positive correlation between peak VO2 and LVEF (r = 0.46, P = 0.002), and LAEF (r = 0.61, P < 0.001), peak A wave velocity (r = 0.39, P = 0.009), E wave deceleration time (r = 0.56, P < 0.001), and isovolumic relaxation time (IVRT) (r = 0.35, P = 0.04). There was a negative correlation between peak VO2 and LASd (r = -0.53, P < 0.001) LADd (r = -0.59, P < 0.001), LASVI (r = -0.34, P = 0.027), LADVI (r = -0.37, P = 0.001), and the E/A ratio (r = -0.41, P = 0.006), Decreased LAEF and increased LA sizes were associated with decreased peak VO2. The results clearly demonstrate that LA functions at rest are related to exercise performance in patients with heart failure.

Atrial Function, Left↗
PubMed2002

Propofol alters left atrial function evaluated with pressure-volume relations in vivo.

UNLABELLED: The effects of IV anesthetics on left atrial (LA) function in vivo are unknown. We tested the hypothesis that propofol alters LA mechanics evaluated with pressure-volume relations in barbiturate-anesthetized dogs (n = 9) instrumented for measurement of aortic, LA, and left ventricular (LV) pressures (micromanometers) and LA volume (epicardial orthogonal sonomicrometers). LA myocardial contractility (E(es)) and dynamic chamber stiffness were assessed with end-systolic and end-reservoir pressure-volume relations, respectively. Relaxation was determined from the slope of LA pressure decline after contraction corrected for peak LA pressure. LA stroke work and reservoir function were assessed by A and V loop area, respectively, from the steady-state pressure-volume diagram. LA-LV coupling was determined by the ratio of E(es) to LV elastance. Dogs received propofol (5, 10, 20, or 40 mg. kg(-1). h(-1)) in a random manner, and LA function was determined after a 15-min equilibration at each dose. Propofol decreased heart rate, mean arterial blood pressure, and the maximal rate of increase of LV pressure. Propofol caused dose-related reductions in E(es), dynamic chamber stiffness, and E(es)/LV elastance. An increase in V loop area and declines in LA stroke work, emptying fraction, and the active LA contribution to LV filling also occurred. Relaxation was unchanged. The results indicate that propofol depresses LA myocardial contractility, reduces dynamic chamber stiffness, maintains reservoir function, and impairs LA-LV coupling but does not alter LA relaxation in vivo. IMPLICATIONS: Propofol depresses contractile function of left atrial (LA) myocardium, impairs mechanical matching between the LA and the left ventricular (LV), and reduces the active LA contribution to LV filling in vivo. Compensatory decreases in chamber stiffness contribute to relative maintenance of LA reservoir function during the administration of propofol.

Anesthesia↗
PubMed2002

Are left atrial appendage flow velocities adequate surrogates of global left atrial function? A population-based transthoracic and transesophageal echocardiographic study.

BACKGROUND: Left atrial appendage (LAA) contraction velocities are used frequently as surrogates of global left atrial (LA) function, but the validity of this approach has not been confirmed. OBJECTIVE: The objective of our study was to assess the relationship between LAA flow velocities and multiple global LA variables. METHODS: The correlations between LAA contraction velocities and global LA variables (difference between maximal and minimal LA volumes, mitral inflow A velocity, atrial ejection force, mitral annulus late diastolic [a'] velocity, pulmonary vein atrial reversal velocity) were assessed in 349 subjects participating in the Stroke Prevention: Assessment of Risk in a Community study (age, 67 +/- 11 years; 53% men; all subjects in sinus rhythm), who were examined with transthoracic and transesophageal echocardiography. RESULTS: The correlations between LAA contraction velocities and multiple global LA variables were poor or nonsignificant. The best correlations, albeit weak, were between LAA velocities and mitral annulus a' velocities (r = 0.32 and r = 0.35 for correlations with septal and lateral annulus a' velocities, respectively, P <.001). Low LAA contraction velocities (lowest 10%, velocities <56 cm/s) were not sensitive in detecting low values (lowest 10%) of LA variables (sensitivity <0.2 for most LA variables). In a subgroup of subjects with lower left ventricular ejection fraction (< or =50%), the correlations between LAA velocities and LA variables were not apparently better than those in the total population. LAA velocities correlated negatively with LAA orifice diameter (r = -0.29, P =.002). The correlations between LAA velocities and global LA variables remained poor after correcting for LAA orifice size. CONCLUSION: LAA contraction velocities correlate poorly with multiple LA variables. Therefore, LAA flow velocities should not be used as surrogates of global LA function.

Aged↗
PubMed2001

The effect of cardiomyoplasty on left atrial function in experimental canine models.

BACKGROUND: Cardiomyoplasty utilizes the latissimus dorsi muscle to boost the failing ventricle. However, the mechanism for clinical improvement still remains controversial. We have previously shown that left ventricular contraction was improved in the long-term periods after cardiomyoplasty in the normal canine heart model and in the dilated failing heart model. On the other hand, right ventricular filling was impaired if a rapid volume loading test was employed in the long-term period after cardiomyoplasty. The purpose of the present study was to determine whether cardiomyoplasty impairs the left atrial function and affects ventricular filling. METHOD: Eleven mongrel dogs that had undergone cardiomyoplasty (study group, n = 5) or a sham operation (control group, n = 6) were studied for 12 weeks postoperatively. An IV 4.5% albumin solution (10 mL/kg) was infused into the right atrium, and hemodynamic changes in right cardiac catheterization and left atrial volume (LAV) were obtained by two-dimensional echocardiography. Atrial function was assessed by hemodynamic changes in Doppler echocardiography and hormonal changes. RESULTS: Stroke volume was significantly increased, from 17.0 +/- 4.4 to 21.1 +/- 7.0 mL, respectively, before and 15 min after albumin infusion in the control group (p < 0.05). Heart rate and cardiac output were significantly increased, from 131.2 +/- 18.1 to 152.0 +/- 9.8 beats/min and 2.72 +/- 1.29 to 4.03 +/- 1.67 L/min, respectively, before and 15 min after albumin infusion in the study group (p < 0.05). No changes were observed in mean right atrial pressure and pulmonary capillary wedge pressure. LAV and atrial natriuretic peptide (ANP) levels increased significantly, from 5.8 +/- 2.1 to 8.5 +/- 3.8 mL and 22.5 +/- 7.5 to 44.5 +/- 31.7 pg/mL, respectively, before and 15 min after albumin infusion in the control group (p < 0.05). In the study group, LAV and ANP levels were also increased, from 10.1 +/- 2.4 to 12.7 +/- 2.8 mL and 64.2 +/- 60.6 to 232.6 +/- 272.2 pg/mL, respectively, before and 15 min after albumin infusion (p < 0.05). The peak velocities and the time-velocity integrals in the pulmonary venous flow of the systolic and diastolic waves, as well as their ratios (systolic to diastolic peak velocity ratio and systolic to diastolic time-velocity integral ratio) showed no significant differences between the two groups. CONCLUSIONS: Cardiomyoplasty preserves left atrial filling and transport function; therefore, cardiomyoplasty may also activate ANP production by stimulating the atrium in the long-term period after cardiomyoplasty.

Albumins↗
PubMed2002

[Echocardiographic evaluation of left atrial function in dilated cardiomyopathy with restricted and non-restricted Doppler transmitral flow].

UNLABELLED: Left atrial (LA) function is of great importance in left ventricular (LV) filling. There is evidence that echocardiographic Doppler evaluation of transmitral flow, routinely used for LV filling estimation, is dependent on LA function. Information regarding the relation of LA size and function to transmitral flow in heart failure is limited. We used 2D echocardiographic acoustic quantification methods to assess LA function in patients with dilated, (non-ischemic) cardiomyopathy (DCM) and a control group. The DCM group was divided into 2 subgroups: Group 1-with restrictive LV Doppler filling pattern-18 patients (DCM-R) and Group 2-with non-restrictive LV Doppler filling pattern-11 patients (DCM-NR) with similar heart rate, age and degree of mitral regurgitation. LA maximal area, total emptying fraction and absolute and fractional area change during rapid emptying and atrial contraction were calculated. The LA was enlarged only in DCM-R. Both DCM groups had decreased total emptying fractions and rapid emptying area changes compared to controls. An enlarged LA area and more decreased total emptying were found in DCM-R with high LV filling pressures compared to DCM-NR. The restrictive group had a significantly smaller LA rapid emptying area change, as well as a smaller LA area change and emptying fraction during atrial contraction compared to DCM-NR. Within < or = 2 hrs after the echocardiography study, cardiac catheterization was performed in the DCM group. We found significantly higher LV filling pressures and lower LV ejection fractions in DCM-R compared to DCM-NR. Significant correlations were found between LA function and invasive parameters like capillary wedge and LV enddiastolic pressures and LV EF. CONCLUSION: Patients with DCM-R had significantly enlarged LA areas with more depressed total emptying fractions and smaller LA area changes during contraction compared to DCM-NR. Thus, left atrial function plays an important role in LV filling and its dysfunction can be a marker of poor prognosis.

Adult↗
PubMed2001

Effect of interatrial block on left atrial function.

Interatrial block produces prolonged P-waves due to conduction delay mainly in the Bachmann bundle, the most direct route from right to left atrium. It is prevalent in patients over age 60 with its main clinical significance its association with eventual atrial fibrillation and/or flutter. Having demonstrated a mean delay in the onset of active left ventricular filling of 37 msec, we defined the electromechanical abnormality further by measuring left atrial volume at key points in the atrial cycle to produce 10 measurements of left atrial function. Compared to the normal left atrium, interatrial block is correlated with a large, poorly contractile left atrium with a delayed and markedly reduced contribution to left ventricular filling and the kinetic energy with which atrial systole propels blood.

Atrial Fibrillation↗
PubMed1999

Stroke in paced patients with sick sinus syndrome: influence of left atrial function and size.

Patients with sick sinus syndrome have a high prevalence of cerebral ischemia. The present study was designed to establish the prevalence of stroke in patients with sick sinus syndrome and the role of atrial size and function. This prospective study analyzed 100 consecutive patients with sick sinus syndrome without atrial fibrillation who received either dual chamber or ventricular pacemakers. Patients underwent a cranial CT scan at the time of enrollment and again at the end of the study 24 months later. Endpoint of the study was cerebral ischemia. Clinical and echocardiographic features were assessed at the beginning of the study. A multivariate regression analysis was applied to all variables that had at least a marginal univariate predictive value. Cerebral ischemia occurred in 18 patients. Univariate predictors for embolism were age >65 years (p < 0.001), low atrial ejection force (p < 0.01) and a dilated left atrium with spontaneous echo contrast (p < 0.05). These findings identified patients at high risk for the development of peripheral embolism among the group of patients paced for sick sinus syndrome.

Aged↗
PubMed1997

Dobutamine and nitroprusside infusion in patients with severe congestive heart failure: hemodynamic improvement by discordant effects on mitral regurgitation, left atrial function, and ventricular function.

OBJECTIVES: In patients with severe heart failure additional therapeutic support with intravenous inotropic or vasodilator drugs is frequently used in the attempt to obtain hemodynamic control. The nature and extent to which diastolic filling, atrial function, and mitral regurgitation are modified by these drugs have not been fully explored. The aim of this study was to compare the acute adaptations of the left ventricular performance, left atrial function, and mitral regurgitation that accompanied hemodynamic improvement during intravenous dobutamine and nitroprusside infusions in patients with severe chronic heart failure. METHODS: Forty consecutive patients with severe heart failure were evaluated by simultaneous echo-Doppler and hemodynamic investigations at baseline and during nitroprusside and dobutamine administration. Mitral flow velocity variables, left atrial and ventricular volumes, left atrial reservoir, conduit and pump volumes, and mitral regurgitation jet area were compared by analysis of variance for repeated measurements. RESULTS: Nitroprusside increased cardiac output (2.1 +/- .5 vs 2.6 +/- .5 L/min/m2, p < 0.004), reduced left ventricular filling pressure (25 +/- 6 vs 14 +/- 4 mm Hg, p < 0.0001), and improved left atrial pump volume (19 +/- 3 vs 26 +/- 12 ml, p < 0.02) without variations in left atrial reservoir and conduit volume. The restoration of preload reserve and improvement of the atrial contribution to left ventricular diastolic filling were demonstrated by the Doppler mitral flow pattern, which moved from a restrictive to a normal pattern. Furthermore mitral regurgitation decreased in all patients (9 +/- 4.6 vs 4.6 +/- 3.4 cm2, p < 0.0001). Dobutamine increased cardiac output (2.1 +/- .5 vs 2.8 +/- .6 L/min/m2), but the effects on pulmonary wedge pressure and mitral regurgitation were variable and unpredictable. Left atrial reservoir and conduit volumes increased, whereas left atrial pump volume did not change (19 +/- 13 vs 22 +/- 14 ml, p = NS). Furthermore Doppler mitral flow showed a persistent restrictive pattern. CONCLUSIONS: In patients with advanced congestive heart failure both nitroprusside and dobutamine improve cardiac output, with different adaptations of left ventricular performance and left atrial function. Nitroprusside seems to restore both atrial and ventricular pump function better. Careful echo-Doppler monitoring during drug infusion provides information relevant to the clinical treatment of individual patients.

Atrial Function, Left↗
PubMed2002

Echocardiographic [correction of Ehocardiographic] evaluation of regional left atrial function after rapid atrial pacing.

Rapid regular atrial pacing (RAP) produces changes in atrial function similar to those caused by atrial fibrillation in animal models. Left atrial appendage (LAA) function represents regional atrial function. The aim of our study was to investigate the influence of RAP on left atrial regional function and to evaluate the reversibility of changes after termination of pacing in a canine model. Eight dogs were subjected to RAP (400 bpm) for 16 days. Transesophageal echocardiography was performed at baseline, immediately after RAP and 4 weeks after the termination of RAP. The LAA peak late emptying velocity (LAA-E) and filling wave (LAA-f) were measured. LAA-E velocities were significantly reduced and filling wave velocities (LAA-f) were significantly less negative after RAP compared with the baseline values. Four weeks after termination of pacing, the LAA-E and LAA-f velocities were normal. RAP results in impaired regional atrial systolic and diastolic function. The changes were completely reversible 4 weeks after termination of pacing. These results suggest that the LAA is mechanically stunned after RAP.

Animals↗