Left atrial spontaneous contrast echoes--markers of thromboembolic risk in patients with atrial fibrillation

A consecutive series of 80 patients with atrial fibrillation were studied with both precordial and transoesophageal echocardiography. Left atrial spontaneous contrast echoes were observed in one patient with precordial echocardiography and in 26 patients (33%) with transoesophageal echocardiography. They were found most commonly in patients with rheumatic mitral valve disease (67%) but were observed in 28% of patients with lone atrial fibrillation. Their presence was unrelated to the age, gender and therapy of the patient. Although they were more common in patients with a large left atrium, they were sometimes observed in a normal sized atrial chamber. They were more common in chronic (40%) than in paroxysmal atrial fibrillation (5.6%). No patient had severe mitral regurgitation, but contrast echoes were observed in some patients with mild or moderate mitral regurgitation. Of the 26 patients with spontaneous contrast echoes, six (23%) had echoes consistent with left atrial thrombus compared to one of the 54 patients without these echoes (1.9%) (P = 0.006); 17 (65%) had suffered a previous thromboembolic event compared to 17 of the 54 without these echoes (32%) (P = 0.009). These data support the concept that spontaneous contrast echoes in the left atrium are associated with sluggish blood flow and a thrombogenic environment. Transoesophageal echocardiography may thus be useful in assessing which patients with atrial fibrillation might most benefit from anticoagulation. This hypothesis needs to be evaluated further in a prospective study.     

Antithrombotic therapy prescribed for patients with non-rheumatic atrial fibrillation

Patients with non-rheumatic atrial fibrillation have a fivefold increased risk of stroke. Warfarin reduces this risk by approximately two thirds, but evidence for benefit from aspirin is less compelling. We assessed whether our current practice reflects the message of the trials. In a retrospective case record study we reviewed notes of 131 patients with atrial fibrillation (AF), mean age 79 (range 53-95) years, admitted to a medical unit (72) or geriatric assessment unit (59). Thirty-two patients had paroxysmal AF. Of 115 patients with nonrheumatic AF, 36 (31%) had one or more recorded contraindication to anti-coagulation. Although 79 patients (69%) had no recorded contraindication to warfarin, only 2 took warfarin and 15 aspirin prior to admission. Ten patients commenced warfarin and 8 aspirin before discharge. Thirty-nine patients (53%) without contraindication, were discharged without antithrombotic therapy. Despite evidence to support anticoagulating patients with non-rheumatic AF, this rarely occurs.     

Stroke prevention in non-rheumatic atrial fibrillation

The aim of this study was to appreciate the accuracy of the technique for sensitivity test for M. tuberculosis. We have tested the same bacterial strains (101) using the same drugs concentrations, by absolute concentration method, and we have compared the results obtained in two different laboratories. The concordance of the obtained results (94.05% for SM, 97.03% for INH, 99.01% for RMP, 100% for EMB) is in the limits of reproducibility obtained by other authors. The obtained results show a good technique for sensitivity test in the two laboratories.     

Preventing strokes in non-rheumatic atrial fibrillation

Almost 1 in 10 patients with non-rheumatic atrial fibrillation is at risk of stroke. This article describes the risk factors and assesses the role of aspirin and warfarin in stroke prevention.     

Reversible left atrial dysfunction possibly due to afterload mismatch in patients with left ventricular dysfunction

OBJECTIVE: The aim of this study was to define the clinical-therapeutical approach to endometrial cancer now being followed in some of the most important centers of reference for gynecological cancer in North America by means of a questionnaire. STUDY DESIGN: The questionnaire focused on four principal areas: (1) surgical staging and therapy; (2) adjuvant treatment; (3) treatment modifications; and (4) management of advanced stages (FIGO III-IV). RESULTS: There were 48 evaluable responses (77%) received by the end of December 1994 which were considered for this analysis. Lymphadenectomy is utilized routinely in 26/48 centers (54.2%) and in selective clinical-pathological conditions in another 21/48 centers (43.5%). In the majority of centers (31/48; 64.6%) radical surgery is utilized for selected indications such as cervical involvement. Only 3/48 (6.2%) centers consider the vaginal approach totally inappropriate. The great majority (40/48; 83.3%) of the centers considered postsurgical adjuvant therapy to be necessary in FIGO Stage Ic. Brachytherapy is routinely performed in 3 centers (6.2%) in postsurgical management of Stage I endometrial cancer, while the majority of the centers (31/48; 64.6%) perform brachytherapy of the vaginal vault in certain clinical-pathological conditions. A wide variety of treatments are used for advanced stages (FIGO III-IV). CONCLUSIONS: It emerges that some controversial aspects exist on endometrial cancer treatment, and these conflicting data need a large-scale multicenter randomized clinical trial.     

Risk of thromboembolic events in patients with atrial flutter

Based on multiple studies, clear, guided anticoagulation therapy is recommended for patients with atrial fibrillation. The value of anticoagulation therapy in patients with atrial flutter, however, is less well established. Little is known about the incidence of thromboembolism in patients with atrial flutter. We evaluated the risk of thromboembolism in 191 consecutive unselected patients referred for treatment of atrial flutter. A history of embolic events was noted in 11 patients. Acute embolism (<48 hours) occurred in 4 patients (3 after direct current cardioversion, 1 after catheter ablation). During follow-up of 26+/-18 months, 9 patients experienced thromboembolic events. During the follow-up, the overall embolic event rate (including acute embolism and thromboembolic events during follow-up) was 7 % in this patient population. Risk indicators for an embolic event in an univariate analysis were organic heart disease (p = 0.037), depressed left ventricular function (p = 0.02), history of systemic hypertension (p = 0.004), and diabetes mellitus (p = 0.0038). Using multivariate analysis, a history of hypertension was the only independent predictor for elevated embolic risk in this patient population (odds ratio = 6.5; 95% confidence intervals 1.5 to 45). Thus, the thromboembolic risk is higher than previously recognized for patients with atrial flutter. Anticoagulation therapy may decrease this risk.     

Mechanical dysfunction of the left atrium and the left atrial appendage following cardioversion of atrial fibrillation and its relation to total electrical energy used for cardioversion

In 39 patients undergoing electrical cardioversion for atrial fibrillation (AF), we examined the effect of total electrical energy used for cardioversion on postcardioversion peak left atrial (LA) rapid filling velocity (A) and the atrial emptying fraction, and recovery of LA effective mechanical atrial function (defined as peak A velocity > or = 0.50 m/s), as assessed by transthoracic echocardiography. In a subset of 27 patients who underwent pre- and postcardioversion transesophageal echocardiography, we assessed the relation between total electrical energy and LA appendage filling and emptying velocities and spontaneous echo contrast. Patients were randomized to receive an initial shock of 1.5 J/kg based on body weight, or 2.5, 3.5, 5 J/kg, or 360 J, followed sequentially by higher shock intensities until sinus rhythm was achieved. Patients were classified into 4 groups based on quartiles of total energy delivered for cardioversion. Conversion to sinus rhythm was associated with a significant decrease in the LA appendage filling velocities (0.42 +/- 0.20 m/s vs 0.29 +/- 0.14 m/s; p = 0.002) and LA appendage emptying velocities (0.40 +/- 0.22 m/s vs 0.29 +/- 0.18 m/s; p = 0.03), but no change in the incidence of spontaneous echo contrast (61% vs 70%, p = 0.08). The 4 groups of patients did not differ with respect to postcardioversion LA appendage filling velocities, LA appendage emptying velocities, incidence of spontaneous echo contrast, or worsening of spontaneous echo contrast. Similarly, the change in LA appendage filling and emptying velocities associated with cardioversion was not different between the groups. Furthermore, postcardioversion peak A velocity and atrial emptying fraction and recovery of effective mechanical atrial function were similar between the 4 groups. These results suggest that in patients undergoing electrical cardioversion for AF, the total electrical energy used for cardioversion has no effect on the mechanical function of the left atrium or LA appendage following cardioversion.     

Cerebral embolism in elderly patients with atrial fibrillation

Novalvular (nonrheumatic) atrial fibrillation (NVAF) is the most common cardiac condition associated with presumed embolic stroke, accounting for approximately half of the cardiogenic embolic infarctions. Of autopsied stroke patients in the Tokyo Metropolitan Geriatric Hospital, cerebral infarction was found in 75%, intracranial hemorrhage in 19%, and coexisting cerebral hemorrhage and cerebral infarction in 6%. Twenty-eight percent of the cerebral infarctions were embolic infarctions of cardiac origin, 56% of which were caused by NVAF. The incidence of cardiogenic brain embolism ranged from 6 to 23% of the ischemic strokes, and NVAF is the most frequent substrate for brain embolism. Atrial fibrillation increases in its incidence with increasing age. Chronic AF was observed in 10%, and paroxysmal AF in 7% of the autopsied elderly patients. Most of them were nonrheumatic AF. Twenty-two percent of the AF patients had large cerebral infarction, and 15% had medium-sized cortical infarction at the autopsy. NVAF is a very important cause of fatal massive cerebral infarction in the elderly. Of 56 patients with fatal massive cerebral infarction who died within 2 weeks after the strokes, 25 (45%) had embolic stroke associated with NVAF. Anticoagulant therapy prevents recurrent cerebral embolism of cardiac origin. The proper time to initiate anticoagulant therapy following cardiac brain embolism is controversial. Immediate initiation of anticoagulant therapy can reduce the early recurrence, but can result in secondary brain hemorrhage or hemorrhatic transformation. Patients with NVAF may have a lower risk of recurrence during the first 2 to 4 weeks following the initial embolic stroke compared with other cardioembolic sources. Cerebral embolism with NVAF can recur during a long period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dobutamine-atropine stress echocardiography for risk stratification in patients with chronic left ventricular dysfunction

OBJECTIVE: To assess the prognostic value of sustained improvement, scar and inducible ischemia with or without viability in patients with chronic left ventricular dysfunction (LVD). BACKGROUND: Dobutamine-atropine stress echocardiography (DASE) accurately detects scar, reversible dysfunction and the extent of coronary artery disease in LVD. METHODS: Three hundred fifty consecutive patients (age 62+/-13 years, mean+/-SD, 215 men/135 women) with moderate to severe LVD (LVEF < 40%, mean 30+/-8%) underwent DASE and were followed for > or =18 months. Dobutamine-atropine stress echocardiographic findings were classified according to sustained improvement in all vascular territories, scar, inducible ischemia (worsening wall motion at peak dose only or biphasic responses) and their extent. RESULTS: Sustained improvement occurred in 83 patients (24%), scar alone in 99 (28%) and inducible ischemia in 168 (48%, with biphasic responses in 104). Ischemia was induced in all vascular territories in 26 patients. Patients with sustained improvement or scar alone were treated medically, whereas 46% (78/168) with inducible ischemia were revascularized (coronary bypass surgery, n = 67 or angioplasty, n = 11). There were 76 hard events including cardiac death in 59, nonfatal myocardial infarction in 11, and resuscitated sudden death in 6. Hard events were rare in sustained improvement (5%, 4/83), uncommon in scar (13%, 13/99) and common (p < 0.01) in medically treated patients with inducible ischemia (59%, 53/90). Cardiac deaths were especially common (p < 0.01) in patients with biphasic responses (55%, 28/51). Inducible ischemia independently predicted hard events (chi2 = 75.35, p < 0.001) along with reduced LVEF at peak dose (chi2 = 8.38, p = 0.004). Hard cardiac events were uncommon (8%, 6/78, p < 0.001) in patients with inducible ischemia who underwent early revascularization. CONCLUSIONS: Inducible ischemia during DASE was the major determinant of outcome in LVD and independent of clinical data and left ventricular function. Improved wall thickening alone and scar alone predicted good outcome. Survival of patients with inducible ischemia was better after revascularization.     

Ischemic cerebrovascular disease in patients with atrial fibrillation

The purpose of this retrospective study was to elucidate 1) which subgroups are prone to have ischemic cerebrovascular disease (CVD) among patients with atrial fibrillation (Af), 2) vulnerable period of CVD after the diagnosis of chronic Af and 3) the clinical efficacy of antiplatelet therapy in chronic nonvalvular Af patients. During 9 years, a total of 479 patients included 124 cases with paroxysmal Af, 30 cases with paroxysmal Af initially which later changed to chronic Af and 325 cases with chronic Af were enrolled. Among these 355 cases with chronic Af, 57 cases had valvular heart disease (VHD). The results were as follows: 1) The high risk subgroups (incidence rate/100 person-years is more than 6) were chronic Af with VHD or hypertension. The low risk subgroups (less than 2) were paroxysmal Af under 60 years of age, chronic Af with mitral valve prolapse syndrome or with hyperthyroidism. 2) There was no vulnerable period for occurrence of CVD during 9 years' follow-up from the onset of Af. 3) No significant difference in the incidence of CVD was seen in the groups with antiplatelet therapy and without.     

Response of atrial fibrillation to therapy: role of etiology and left atrial diameter

Left atrial diameter was measured by echocardiography in 107 patients in atrial fibrillation. The etiology of atrial fibrillation was rheumatic heart disease with predominant mitral valve involvement (RHD) in 51 patients and idiopathic atrial fibrillation (IAF) in 56. The left atrial diameter was correlated to the patient's response to therapy. The mean left atrial diameter was 3.4 cm in patients with paroxysmal atrial fibrillation, 3.8 cm in those requiring direct current (DC) cardioversion, and 4.4 cm in patients with persistent atrial fibrillation. However, in each of these therapeutic response groups, the left atrial diameter was signficantly smaller in patients with idiopathic atrial fibrillation. In the group with paroxysmal atrial fibrillation, the mean left atrial diameter was 4.3 +/- .7 cm in patients with RHD, compared to 3.1 +/- .6 cm in those with IAF (p less than .001). In the group requiring DC cardioversion, the left atrial diameter was 4.7 +/- .8 cm in patients with RHD compared to 3.6 +/- .5 cm in those with IAF (p less than .01). In patients with persistent atrial fibrillation, the left atrial diameter was 5.2 +/- .9 cm in patients with RHD and 4.0 +/- 1.0 cm in IAF (p less than .001). Left atrial diameter as well as the etiology of the heart disease are important in determining the response of atrial fibrillation to therapy.     

Timing of thromboembolic events after electrical cardioversion of atrial fibrillation or flutter: a retrospective analysis

Pooled data from 32 studies were reviewed to assess the timing of thrombolic complications after cardioversion of atrial fibrillation or flutter. We found that 98% of embolic episodes occurred within 10 days of cardioversion.     

Cost-effectiveness of therapies for patients with nonvalvular atrial fibrillation

BACKGROUND: The most appropriate treatment(s) for patients with atrial fibrillation remains uncertain. OBJECTIVE: To examine the cost-effectiveness of anti-thrombotic and antiarrhythmic treatment strategies for atrial fibrillation. METHODS: We performed decision and cost-effectiveness analyses using a Markov state transition model. We gathered data from the English-language literature using MEDLINE searches and bibliographies from selected articles. We obtained financial data from nationwide physician-fee references, a medical center's cost accounting system, and one of New England's larger managed care organizations. We examined strategies that included combinations of cardioversion, antiarrhythmic therapy with quinidine, sotalol hydrochloride, or amiodarone, and anticoagulant or antiplatelet therapy. RESULTS: For a 65-year-old man with nonvalvular atrial fibrillation, any intervention results in a significant gain in quality-adjusted life years (QALYs) compared with no specific therapy. Use of aspirin results in the largest incremental gain (1.2 QALYs). Cardioversion followed by the use of amiodarone and warfarin together is the most effective strategy, yielding a gain of 2.3 QALYs compared with no specific therapy. The marginal cost-effectiveness ratios of cardioversion followed by aspirin, with or without amiodarone, are $33800 per QALY and $10800 per QALY, respectively. Cardioversion followed by amiodarone and warfarin has a marginal cost-effectiveness ratio of $92400 per QALY compared with amiodarone and aspirin. Strategies that include cardioversion followed by either quinidine or sotalol are both more expensive and less effective than competing strategies. CONCLUSIONS: Cardioversion of patients with nonvalvular atrial fibrillation followed by the use of aspirin alone or with amiodarone has a reasonable marginal cost-effectiveness ratio. While cardioversion followed by the use of amiodarone and warfarin results in the greatest gain in quality-adjusted life expectancy, it is expensive (ie, has a high marginal cost-effectiveness ratio) compared with aspirin and amiodarone. Finally, for patients who are bothered little by symptoms of atrial fibrillation, cardioversion followed by either aspirin or warfarin without subsequent antiarrhythmic therapy is the treatment of choice.     

Transient sinus node dysfunction after the Cox-maze III procedure in patients with organic heart disease and chronic fixed atrial fibrillation

OBJECTIVES: This prospective study examined types, frequency and time dependency of the electrophysiologic manifestation of the sinus node dysfunction after the Cox-maze III procedure--the technique of choice for the management of medically refractory atrial fibrillation-in patients with organic heart disease, chronic fixed atrial fibrillation and no preoperatively overt dysfunction of the sinus node. BACKGROUND: The original maze procedure was modified twice in order to reduce the high incidence of the sinus node inability to generate an appropriate sinus tachycardia in response to maximal exercise, and occasional left atrial dysfunction. Despite these modifications, postoperative disturbance of sinus node function can be frequently observed. METHODS: In 15 adult patients, standard electrocardiogram, 24-h Holter monitoring, power spectral analysis of heart variability, exercise testing, Valsalva maneuver and rapid positional changes were performed 3, 6 and 12 months after the Cox-maze III procedure and mitral valve surgery or closure of atrial septal defect. RESULTS: Electrocardiographic manifestations of sinus node dysfunction were identified in 12 patients at 3 months, in 6 patients at 6 months, and in 0 patients at 12 months after surgery. The heart rate response to exercise during the first 6 months was reduced in the maze group and became fully normal at 12 months. Power spectral analysis of heart rate variability showed very low power values at 1 month with inhibited cardiac autonomic activity and no response on sympathetic stress. A potential of recovery of cardiac autonomic activity was documented 12 months after surgery. CONCLUSIONS: The manifestations of sinus node dysfunction following the Cox-maze III procedure were time dependent and their frequency and intensity progressively decreased and disappeared within 12 months after surgery.     

Expression of cell adhesion molecules and the appearance of adherent leukocytes on the left atrial endothelium with atrial fibrillation: rabbit experimental model

To assess the expression of cell adhesion molecules and the appearance of leukocytes adhering to the left atrial endothelium with atrial fibrillation (AF), 10 Japanese white rabbits were anesthetized and 3 pacing leads were placed in the right atrium. For the AF model, the right atrium was stimulated by electrical pacing (the stimulation frequency of each lead being adjusted to different intervals) for 8h while the control model was subjected to a sham operation without atrial stimulation. The left atrial appendage was excised from the heart and examined immunohistochemically. P-selectin staining of the endothelium in both models was linear and regional, and intracellular adhesion molecule-1 (ICAM-1) in the AF model was confined to leukocytes and endothelial cells with adherent leukocytes. The expression of P-selectin (p<0.05) and the appearance of positively ICAM-1 stained adherent leukocytes (p<0.05) were significantly greater in the AF model than in the control model. In conclusion, AF could regulate the expression of at least 2 critical adhesion molecules, P-selectin and ICAM-1, and the appearance of adherent leukocytes; suggesting that these molecules may play an important role in left atrial thrombus formation with AF. Although anticoagulant therapy has generally been carried out with warfarin in AF patients, neutralizing antibodies to cell adhesion molecules should be tried to prevent thromboembolic complications.