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PubMed2001

Predictors for atrial transport function after mini-maze operation.

BACKGROUND: Restoration of atrial transport function (ATF) is a major goal of the maze procedure. This prospective study was undertaken to evaluate predictors of left atrial transport function in patients undergoing a mini-variant of the maze III procedure 3 and 12 months postoperatively. METHODS: Mini-maze operation was performed in 72 patients with a mean age of 64 +/- 8.7 years during a 5-year period. Seventy of 72 (97%) had combined procedures. Clinical and electrophysiologic examination was carried out before surgery, and 3 and 12 months postoperatively. RESULTS: Early mortality was 1.4% (1 of 72 patients) and late death occurred in 5.6% (4 of 71 patients). After 3 months, 54 of 68 (80%) patients showed sinus rhythm, and 48 of 60 (80%) after 12 months. ATF was restored in 87% (echocardiography) and 82% (magnetic resonance imaging) after 3 months, and in 86% (echocardiography) and 78% (magnetic resonance imaging) after 12 months. Independent predictors for ATF restoration after 12 months were better preoperative left ventricular function (p = 0.02), and smaller preoperative left atrial diameter (p = 0.005). Correlation between echocardiography and magnetic resonance imaging was 80% after 12 months. CONCLUSIONS: Restoration of ATF after mini-maze procedure is achieved in over 80%. Independent predictors for ATF restoration are smaller preoperative left atrial diameter and better preoperative left ventricular ejection fraction.

Adult↗
PubMed1993

Atrial ejection force: a noninvasive assessment of atrial systolic function.

OBJECTIVES: The purpose of this study was to define atrial ejection force and to develop a method for its noninvasive measurement from echocardiographic data. BACKGROUND: Assessment of diastolic function through measurement of the components of ventricular filling has largely neglected the vigor of atrial systole, in part because this has been difficult to quantify. However, atrial ejection force, defined as that force exerted by the left atrium to accelerate blood into the left ventricle during atrial systole, can be assessed noninvasively by combined two-dimensional imaging and Doppler echocardiography. This index of atrial function, based on classic newtonian mechanics, provides a physiologic assessment of atrial systolic function. METHODS: To evaluate the usefulness of atrial ejection force, we studied the return of left atrial ejection force in 29 patients after elective cardioversion for atrial fibrillation. Transmitral Doppler inflow patterns at rest were assessed immediately after cardioversion and at 24 h, 1 week, 1 month and > 3 months later. A healthy adult group (n = 10) served as control subjects. RESULTS: After successful cardioversion, atrial ejection force was significantly depressed compared with that in the control group (5.2 +/- 6.8 vs. 16.3 +/- 4.7 kdynes; p < 0.0001). Over successive weeks, atrial ejection force improved in the subgroup of patients who remained in sinus rhythm (n = 18), whereas no improvement was seen during the period of maintained sinus rhythm in the patients with subsequent reversion to atrial fibrillation (n = 11). CONCLUSIONS: Atrial ejection force provides a physiologic assessment of atrial systolic function and is a potentially useful index for assessing atrial contribution to diastolic performance. In patients who successfully underwent cardioversion from atrial fibrillation, atrial ejection force improved over several weeks only in the subgroup in which sinus rhythm was maintained.

Adult↗
PubMed2000

Left atrial appendage function in patients with cardioembolic stroke in sinus rhythm and atrial fibrillation.

The purpose of this study was to determine the left atrial appendage (LAA) function in patients with stroke. The study group consisted of 61 patients with stroke and 37 control subjects. Patients with stroke were divided into 2 groups on the basis of the presence of atrial fibrillation (group 1) or sinus rhythm (group 2). Group 1 showed a significant reduction of LAA flow velocities (13.2 +/- 6.4 cm/s versus 27.5 +/- 8 cm/s, P <.05) and significant increase in LAA areas (minimum area: 360.5 +/- 204 mm(2) versus 217.7 +/- 113.9 mm(2), P =.004). Group 2 showed a decrease in LAA flow velocities (17.7 +/- 8.2 cm/s versus 27.5 +/- 8 cm/s, P <.05), but no significant change was found in LAA areas. No significant difference was found in other parameters related to LAA. These findings show that a decreased LAA flow velocity is a risk factor for stroke in patients in sinus rhythm without LAA enlargement. Left atrial appendage area was increased in size only in patients with atrial fibrillation.

Adult↗
PubMed1997

[Pharmacological cardioversion of isolated atrial fibrillation: recovery of atrial mechanical function and correlation with duration of arrhythmia].

To evaluate how the duration of atrial fibrillation before cardioversion affects the recovery of atrial systolic function, serial transthoracic pulsed Doppler echocardiographic studies were performed within 2 hours and at 2 days, 7 days, 1 month and 2 months after chemical cardioversion to sinus rhythm. Peak A wave velocity (A), velocity time integral of A wave (A-VTI) and percent A-wave filling (A/VTI-tot) were assessed in 60 patients with lone atrial fibrillation of brief (> or = 12 to < or = 72 hours, 20 patients), moderate (> 72 hours to < or = 4 weeks, 20 patients) or prolonged (> 4 to < or = 24 weeks, 20 patients) duration. The three groups were well matched for age and left atrial size and none of the patients underwent antiarrhythmic therapy during follow-up. Atrial mechanical function is greater immediately and at 2 and 7 days after cardioversion in patients with brief atrial fibrillation, as compared moderate and prolonged atrial fibrillation (A and A/VTI-tot values: p < 0.05, p < 0.005 and p < 0.05, respectively). In addition, at 7 days after cardioversion, atrial systolic function is greater in patients with moderate atrial fibrillation as compared to prolonged atrial fibrillation (A value, p < 0.005 and A/VTI-tot value, p < 0.05). In all groups, atrial mechanical function increases over time and ultimately achieves similar levels. Full recovery of atrial mechanical function is achieved within 2 days in patients with brief atrial fibrillation, within 7 days in patients with atrial fibrillation of moderate duration and within 1 month in patients with prolonged atrial fibrillation. Recovery of the mechanical function of the left atrium is related to the duration of atrial fibrillation before cardioversion. These findings have important implications for assessing the early hemodynamic benefits of successful cardioversion.

Adult↗
PubMed1991

Mechanism of augmented left atrial pump function in myocardial infarction and essential hypertension evaluated by left atrial pressure-dimension relation.

To analyze left atrial (LA) pump function in normal subjects, in patients with essential hypertension and in patients with a healed myocardial infarction, LA dimension (aortic-root echogram) and pressure (catheter-tip manometer) were simultaneously recorded in 25 patients (8 normal subjects, 7 with hypertension and 10 with myocardial infarction). The pressure-dimension relation of the left atrium was composed of 2 loops: the A loop (expressing the pump function of the left atrium) and the V loop. LA dimension at the beginning of active LA shortening was significantly greater in hypertensive subjects (33 +/- 3 mm) and in those with myocardial infarction (32 +/- 4 mm) than in normal subjects (28 +/- 3 mm) (p less than 0.01, p less than 0.05, respectively). The area of the A loop significantly increased in subjects with hypertension (48 +/- 3 mm Hg.mm, p less than 0.01) and in subjects with myocardial infarction (29 +/- 10 mm Hg.mm, p less than 0.05), compared with normal subjects (20 +/- 8 mm Hg.mm). The mean fractional shortening velocity of the left atrium significantly increased in subjects with hypertension, compared with normal subjects and those with myocardial infarction (p less than 0.05 for both). LA peak wall tension during the LA active contraction period significantly increased with hypertension and with myocardial infarction, compared with normal subjects (p less than 0.01, p less than 0.05, respectively). The area of the A loop was directly proportional to the LA dimension at the beginning of active LA shortening (r = 0.53), p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Maintenance of sinus rhythm and recovery of atrial mechanical function after cardioversion with bepridil or in combination with aprindine in long-lasting persistent atrial fibrillation.

BACKGROUND: The aim of this study was to evaluate pharmacological cardioversion of long-lasting persistent atrial fibrillation (AF) using bepridil in terms of recovery of atrial mechanical function and maintenance of sinus rhythm. Bepridil alone or in combination with aprindine is effective for termination of persistent AF. METHODS AND RESULTS: The study group comprised 38 consecutive patients (24 men, 58.8+/-9.3 years) with successful conversion of persistent AF lasting >1 month either pharmacologically (Group I) or electrically (Group II). Fast Fourier transform analysis of fibrillation waves was performed and fibrillation cycle length (FCL) was calculated from the peak frequency. In Group I, sinus rhythm was pharmacologically restored in 22 patients after an average 30 days (7-49 days) of bepridil administration, either alone (11) or in combination with oral aprindine (11); they were followed up while using the same drugs. In Group II, electrical conversion restored sinus rhythm in 16 patients, and they were followed up with conventional antiarrhythmic drugs other than bepridil and aprindine. After bepridil treatment FCL increased and became significantly longer in Group I than in Group II (190+/-39 vs 150+/-29 ms, p<0.001). Atrial peak velocity in transmitral flow within the first week after cardioversion was greater in Group I than in Group II (68+/-35 vs 32+/-20 cm/s, p<0.05). By Kaplan-Meier analysis, 83% of Group I patients were free of AF recurrence at the 12-month follow-up, compared with 36% in Group II (p<0.005). CONCLUSIONS: In patients with long-lasting AF, pharmacological conversion with bepridil alone or in combination with aprindine recovered atrial mechanical function better and maintained sinus rhythm longer than electrical conversion.

Anti-Arrhythmia Agents↗
PubMed2006

Effect of age and heart rate on atrial mechanical function assessed by Doppler tissue imaging in healthy individuals.

BACKGROUND: The potential usefulness of Doppler tissue imaging (DTI) to assess atrial mechanical function in cardiac disease has been demonstrated. However, there are few reports on normal values of atrial function by DTI analysis. METHODS: Echocardiography with color-coded DTI was performed in 131 healthy control subjects. The peak atrial contraction velocity (V(A)) and the timing of mechanical events were assessed offline at the left atrial (LA) and right atrial (RA) free wall and interatrial septum. RESULTS: V(A) was higher in the RA (9.0 +/- 2.6 cm/s) than the LA (7.5 +/- 2.4 cm/s, P < .001), and both sites were higher than the interatrial septum (5.6 +/- 1.3 cm/s, both P < .001). The interatrial delay was 24 +/- 21 milliseconds. V(A) at the LA was higher in the participants aged 60 years or older than those who were younger than 60 years (8.1 +/- 2.7 vs 6.7 +/- 1.4 cm/s, P < .001), as was the velocity at the RA (9.6 +/- 2.8 vs 8.0 +/- 2.1 cm/s, P < .01). V(A) at the LA was higher in the participants with heart rate of 60/min or higher than those with lower heart rate (7.9 +/- 2.5 vs 6.8 +/- 1.8 cm/s, P < .05). Sex difference had no effect on V(A) and timings of atrial events. CONCLUSIONS: Assessment of atrial mechanical function by DTI is feasible in healthy individuals. The V(A) is the highest at the RA, followed by LA, and the lowest at the interatrial septum. Older age and faster heart rate seems to augment V(A) in the atrial walls.

Aging↗
PubMed2005

Effect of left atrial circumferential ablation for atrial fibrillation on left atrial transport function.

BACKGROUND: The effects of left atrial (LA) circumferential ablation on LA function in patients with atrial fibrillation (AF) have not been well described. OBJECTIVES: The purpose of this study was to determine the effect of LA circumferential ablation on LA function. METHODS: Gated, multiphase, dynamic contrast-enhanced computed tomographic (CT) scans of the chest with three-dimensional reconstructions of the heart were used to calculate the LA ejection fraction (EF) in 36 patients with paroxysmal (n = 27) or chronic (n = 9) AF (mean age 55 +/- 11 years) and in 10 control subjects with no history of AF. Because CT scans had to be acquired during sinus rhythm, a CT scan was available both before and after (mean 5 +/- 1 months) LA circumferential ablation (LACA) in only 10 patients. A single CT scan was acquired in 8 patients before and in 18 patients after LACA ablation. Radiofrequency catheter ablation was performed using an 8-mm-tip catheter to encircle the pulmonary veins, with additional lines along the mitral isthmus and the roof. RESULTS: In patients with paroxysmal AF, LA EF was lower after than before LACA (21% +/- 8% vs 32 +/- 13%, P = .003). LA EF after LA catheter ablation was similar among patients with paroxysmal AF and those with chronic AF (21% +/- 8% vs 23 +/- 13%, P = .7). However, LA EF after LA catheter ablation was lower in all patients with AF than in control subjects (21% +/- 10% vs 47% +/- 5%, P < .001). CONCLUSION: During medium-term follow-up, restoration of sinus rhythm by LACA results in partial return of LA function in patients with chronic AF. However, in patients with paroxysmal AF, LA catheter ablation results in decreased LA function. Whether the impairment in LA function is severe enough to predispose to LA thrombi despite elimination of AF remains to be determined.

Adult↗
PubMedDate not supplied

[Endocrine function of the heart. Structure and biological properties of peptides secreted by the heart atrium].

Apart from the generally known functions, the heart has also an endocrine function. Atrial cardiocytes, being typical secretory cells, release peptide hormones into the blood stream: atrial natriuretic peptide containing 28 amino acids and cardiodilatin. The structure of atrial peptides was determined. It was shown that both peptides were derived from their common precursor, a protein containing 151 amino acids. The presence of specific receptors is demonstrated on plasmatic membranes of cells of kidney epithelium, arterial smooth muscle, arterial endothelium, kidney cortex and hypophysis. The interaction of atrial peptides with these receptors activates the guanylate cyclase system. The biological action of atrial peptides manifests itself in the quick, massive and instantaneous increase of diuresis and electrolyte excretion, elevated clearance of creatinine, decrease of kidney vascular resistance, intensification of glomerular filtration, inhibition of stimulated secretion of aldosterone, relaxation of blood vessels, elimination of arterial and intestinal spasm induced by various endogenous and exogenous vasoconstrictors and in correction of kidney hypertension. Various radioimmunoassays for the presence of atrial peptides in human plasma were developed; it was shown that in patients with congestive heart failure the content of atrial peptides is increased.

Amino Acid Sequence↗
PubMed1985

The role of the atria in fluid volume control.

Neural reflexes from the heart, in particular the atria, are well documented and are involved in sodium and water excretion. Current work also indicates that the atria have an important endocrine function. Atrial peptides, which have been recently characterized and synthesized, may play a significant role in the homeostasis of body fluids.

Animals↗
PubMedDate not supplied

Predictors of left atrial appendage clot: a transesophageal echocardiographic study of left atrial appendage function in patients with severe mitral stenosis.

BACKGROUND: The purpose of this study was to prospectively evaluate a large group of consecutive, non-anticoagulated patients with severe rheumatic mitral stenosis and to analyze the left atrial appendage function in relation to left atrial appendage clot and spontaneous echo contrast formation. METHODS AND RESULTS: We prospectively studied left atrial appendage function in 200 consecutive patients with severe mitral stenosis who underwent transesophageal echocardiography and correlated it with spontaneous echo contrast and left atrial appendage clot. The mean age was 30.2 +/- 9.4 years. Fifty-five (27.5%) patients were in atrial fibrillation. Left atrial appendage clot was present in 50 (25%) patients and 113 (56.5%) had spontaneous echo contrast. The older age, increased duration of symptoms, atrial fibrillation, spontaneous echo contrast, larger left atrium, depressed left atrial appendage function and type II and III left atrial appendage flow patterns correlated significantly (p<0.05) with the left atrial appendage clot. Left atrial appendage ejection fraction was significantly less in patients with clot (21.8 +/- 12.8% v. 39.1 +/- 13.2%, p<0.0001) and in those with spontaneous echo contrast (30.3 +/- 16.2 % v. 40.3 +/- 11.8%, p<0.001). Left atrial appendage filling (18.0 +/- 11.7 v. 27.6 +/- 11.8 cm/s, p <0.0001) and emptying velocities (15.4 +/- 7.0 v. 21.5 +/- 9.6 cm/s, p<0.001) and filling (1.4 +/- 1.0 v. 2.5 +/- 1.4 cm, p<0.0001) and emptying (1.5 +/- 1.2 v. 2.1 +/- 1.2 cm, p <0.05) velocity time integrals were also significantly lower in patients with clot as compared to those without clot. On multivariate regression analysis, atrial fibrillation (odds ratio 6.68, 95% CI 1.85-24.19, p=0.003) and left atrial appendage ejection fraction (odds ratio 1.06, 95% CI 1.00 - 1.11, p=0.04) were the only two independent predictors of clot formation. Incidence of clot was 62.59% in patients with left atrial appendage ejection fraction < or = 25% as compared to 10.4% in those having left atrial appendage ejection fraction >25%. Similarly patients with spontaneous echo contrasthadlower filling (21.7 +/- 11.5 v. 29.4 +/- 12.7 cm/s, p<0.0001) and emptying (17.0 +/- 8.1 v. 23.9 +/- 10.9 cm/s, p<0.0001) velocities, as well as filling (1.9 +/- 1.3 v. 2.7 +/- 1.3 cm, p<0.01) and emptying (1.7 +/- 1.0 v. 2.3 +/- 1.4 cm, p<0.01) velocity time integrals as compared to patients without spontaneous echo contrast. In a subgroup of the patients with normal sinus rhythm, the left atrial appendage ejection fraction was significantly less in patients with clot compared to those without clot (31.2 +/- 13.2 v. 41.3 +/- 11.5 %, p<0.01). CONCLUSIONS: In the patients with severe mitral stenosis, besides atrial fibrillation, a subgroup of patients in normal sinus rhythm with depressed left atrial appendage function (left atrial appendage ejection fraction < or = 25%) had a higher risk of clot formation in left atrial appendage and these patients should be routinely anticoagulated for prevention of clot formation.

Adult↗
PubMed2003

Left atrial appendage function and abnormal hypercoagulability in patients with atrial flutter.

STUDY OBJECTIVES: The prevalence of thromboembolism might be higher than previously recognized in patients with atrial flutter (AFL) based on findings of transesophageal echocardiography (TEE). To evaluate the potential prothrombotic state in patients with AFL, TEE findings and hemostatic markers were compared among patient groups with AFL, normal sinus rhythm (NSR) and chronic nonvalvular atrial fibrillation (AF). DESIGN AND SETTINGS: Cross-sectional study at a university hospital. METHODS: In 28 patients (mean age, 63 years) with AFL, 58 patients (mean age, 66 years) with AF, and 27 patients (mean age, 61 years) with NSR who underwent TEE, plasma levels of markers for platelet activity (platelet factor 4 and beta-thromboglobulin [beta-TG]), thrombotic status (thrombin-antithrombin III complex and prothrombin fragments 1 and 2) and fibrinolytic status (d-dimer and plasmin-alpha(2)-plasmin inhibitor complex) were determined. RESULTS: Left atrial appendage (LAA) blood flow velocity in patients with AFL was higher (p < 0.05) than that in patients with AF, but was lower (p < 0.05) than that in patients with NSR (AF, 25 +/- 2; AFL, 44 +/- 4; NSR, 60 +/- 4 cm/s). Dense left atrial spontaneous echo contrast (SEC) was found in 4 patients (14%) with AFL and 16 patients (28%) with AF. There was no significant difference in plasma levels of hemostatic markers between the AFL group and the NSR group. AFL patients with impaired LAA function (LAA flow < 30cm/s, dense SEC, or both), however, showed higher level of d-dimer and beta-TG than those without impaired LAA function (d-dimer, 1.9 +/- 0.6 microg/mL vs 0.4 +/- 0.1 microg/mL; beta-TG, 73 +/- 17 ng/mL vs 33 +/- 5 ng/mL, p < 0.05). CONCLUSIONS: Patients with AFL as a whole are not in the prothrombotic state as compared with those with AF. However, patients with AFL and impaired LAA function are at potentially high risk for thromboembolism and might require anticoagulation.

Aged↗
PubMed1989

Atrial wall function and plasma atriopeptin during volume expansion in conscious dogs.

Mean left atrial pressure is believed to be an accurate estimate of atrial stretch in vivo and is used to assess the stimulus for atriopeptin release in both animals and humans. However, for a number of years it has been known that atrial stretch receptor discharge occurs during specific phases of the atrial cycle and that B-receptor discharge correlates with the passive filling of the atrium, which occurs during the V wave. The purpose of this study was to develop the concept that phase-specific changes in atrial wall stress are responsible for atriopeptin secretion. In chronically instrumented conscious dogs, volume expansion (1,000 ml of saline in 5 min) increased left atrial pressure and dimensions and caused a 663 +/- 189% increase in plasma immunoreactive atriopeptin from 44 pg/ml. At this time, mean left atrial pressure increased only 202 +/- 36% (mean +/- SE), whereas A wave pressure increased 146 +/- 19% and V wave pressure increased 290 +/- 67%. A and V wave dimensions increased only a few percent. After developing atrial wall thickness constants for diastole (KCl fixation) and systole (BaCl2 fixation), calculated atrial A wave wall stress increased 163 +/- 25%, and V wave wall stress increased 346 +/- 85%. Minute wall stress (wall stress times heart rate) gave an even better correlation with changes in plasma atriopeptin. V wave minute wall stress increased 690 +/- 168%, whereas A wave wall stress increased 366 +/- 56%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Left atrial and left atrial appendage functional abnormalities in patients with cardioembolic stroke in sinus rhythm and idiopathic atrial fibrillation.

Thrombogenesis in the left atrial appendage (LAA) has been related to the special morphology of this cavity and to its size and degree of dysfunction. However, no study has focused on LAA function in conjunction with left atrial (LA) function in both sinus rhythm (SR) and nonrheumatic idiopathic atrial fibrillation (AF) in relation to clinical status (cardioembolic stroke). Forty-three patients in SR (14 patients with stroke, 29 control subjects) and 45 patients in AF (27 patients with stroke, 18 control subjects) were examined by transthoracic and transesophageal echocardiography. Baseline clinical characteristics and standard transthoracic and transesophageal measurements of the LA and LAA (size, fractional area change, flow measurements, spontaneous echo contrast, and thrombus) were recorded and compared in relation to cardiac rhythm. Patients in the stroke-SR group showed a significant decrease of fractional area change in the LA (32%+/-15%) and LAA (34%+/-15%) in relation to control subjects (43%+/-10%, p = 0.035, 49%+/-13%, p = 0.006, respectively). Patients in the stroke-AF group showed significant reduction of appendage flow measurements (outward velocity = 22+/-13 vs 33+/-19 cm/sec, p = 0.036), whereas no differences were detected in the center of the LA. In multiple regression analysis, the presence of cardioembolic stroke was positively associated with the presence of spontaneous echo contrast (p = 0.0253) and spontaneous echo contrast negatively associated with appendage inward flow velocity (p<0.001). Cardioembolic stroke in patients in SR is associated with a global decrease of shortening in both cavities and in patients with AF, with a reduction of LAA flow parameters. Patients with spontaneous echo contrast, thrombus, or both showed further reduction of shortening and flow velocities in both cavities, indicating a more advanced stage of dysfunction.

Aged↗
PubMed2006

Effects of Cilazapril on atrial electrical, structural and functional remodeling in atrial fibrillation dogs.

BACKGROUND AND PURPOSE: The effects of angiotensin-converting enzyme inhibitor on long-term atrial electrophysiologic and structural remodeling are still unclear. The purpose of this study is to investigate the effects of Cilazapril on atrial electrical, structural, and functional remodeling in atrial fibrillation (AF) dogs induced by chronic rapid atrial pacing. METHODS: Twenty dogs were randomly divided into sham-operated group (n = 6), control group (n = 7), and Cilazapril group (n = 7). One thin silicon plaque containing 4 pairs of electrodes was sutured to each atrium. A pacemaker was implanted in a subcutaneous pocket and attached to a screw-in epicardial lead in the right atrial appendage. The dogs in control group and Cilazapril group were paced at 400 beats per minute for 6 weeks. The dogs in Cilazapril group received Cilazapril (0.5 mg x kg(-1) x d(-1)) 1 week before rapid atrial pacing until pacing stop. Before and after 6-week rapid atrial pacing, atrial effective refractory period (AERP) at 8 sites, AERP dispersion, intraatrium conduction time, inducibility, and duration of AF were measured. Transthoracic and transesophageal echocardiographic examinations included left atrium (LA) maximal volume, LA minimal volume, LA ejection fraction, left atrial appendage (LAA) maximal volume, LAA minimal volume, LAA ejection fraction, LAA maximal forward flow velocity, and LAA minimal backward flow velocity were performed. Atrial collagen volume fraction was analyzed by Masson staining. RESULTS: After 6-week rapid atrial pacing, although there was no significant difference in AERP shortening and AERP rate adaptation reduction between the control group and the Cilazapril group, the inducibility and duration of AF were found to be dramatically lower in the Cilazapril group than those in the control group (AF inducibility, 65.7% vs 95.7%, P < .05; AF duration, 531.5 +/- 301.2 vs 1432.2 +/- 526.5 s, P < .01). The post-tachycardia intraatrium conduction times after 6 weeks with Cilazapril were significantly shorter than those in the control group. Cliazapril could partially prevent AERP dispersion increase induced by chronic rapid atrial pacing. Compared with the control group, the LA and LAA volumes were significantly smaller; LA ejection fraction, LAA ejection fraction, LAA maximal forward flow velocity, and LAA minimal backward flow velocity were dramatically higher in the Cilazapril group. The Cilazapril group had a significantly lower percentage of interstitial fibrosis than the control group. CONCLUSIONS: Cilazapril can suppress structural and functional remodeling and prevent the induction and promotion of AF in chronic rapid atrial pacing dogs.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Left atrial appendage function assessed by transesophageal echocardiography before and on the day after elective cardioversion for nonvalvular atrial fibrillation.

We investigated left atrial appendage function by transesophageal echocardiography, on the day after external electrical cardioversion to sinus rhythm, in 41 patients with nonvalvular atrial fibrillation. After cardioversion, appendage contraction synchronized with the electrical and mechanical activity of the atrium, which was restored in about 70% of the patients.

Adult↗
PubMed1998

Severely reduced left atrial appendage function: a cause of embolic stroke in patients in sinus rhythm?

Recently, attention has been focused on transesophageal echocardiographic detection of left atrial appendage function to assess of risk of thrombus formation because of potential benefit of anticoagulation therapy. However, most of these studies have been conducted in patients with atrial fibrillation or mitral valve disease. In this article we review cases of 2 patients without valvular disease who had embolic stroke in sinus rhythm. Transesophageal echocardiography revealed thrombi in the left atrial appendage in both patients. The left atrial appendage function in these patients was compared with that in patients with chronic atrial fibrillation and a control group in sinus rhythm. Left atrial appendage function in the patients with stroke and sinus rhythm was significantly lower than that of patients in the control group in sinus rhythm (P < .001) and was similar to the appendage function in patients with chronic atrial fibrillation. These observations provide further evidence that the finding of reduced left atrial appendage function can be a cause of stroke in patients with sinus rhythm even in the absence of mitral valve disease. Reduced left atrial appendage function may identify patients with unexplained stroke who should receive anticoagulation therapy even in the absence of detectable appendage thrombi.

Adult↗