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1.
J Am Coll Cardiol ; 37(3): 691-704, 2001 Mar 01.
Article in English | MEDLINE | ID: mdl-11693739

ABSTRACT

Electrical cardioversion of patients with atrial fibrillation (AF) is frequently performed to relieve symptoms and improve cardiac performance. Patients undergoing cardioversion are treated conventionally with therapeutic anticoagulation for three weeks before and four weeks after cardioversion to decrease the risk of thromboembolism. A transesophageal echocardiography (TEE)-guided strategy has been proposed as an alternative that may lower stroke and bleeding events. Patients without atrial cavity thrombus or atrial appendage thrombus by TEE are cardioverted on achievement of therapeutic anticoagulation, whereas cardioversion is delayed in higher risk patients with thrombus. The aim of this review is to discuss the issues and controversies associated with the management of patients with AF undergoing cardioversion. We provide an overview of the TEE-guided and conventional anticoagulation strategies in light of the recently completed Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) clinical trial. The two management strategies comparably lower the patient's embolic risk when the guidelines are properly followed. The TEE-guided strategy with shorter term anticoagulation may lower the incidence of bleeding complications and safely expedite early cardioversion. The inherent advantages and disadvantages of both strategies are presented. The TEE-guided approach with short-term anticoagulation is considered to be a safe and clinically effective alternative to the conventional approach, and it is advocated in patients in whom earlier cardioversion would be clinically beneficial.


Subject(s)
Atrial Fibrillation/therapy , Echocardiography, Transesophageal , Electric Countershock , Therapy, Computer-Assisted , Anticoagulants/therapeutic use , Coronary Thrombosis/complications , Coronary Thrombosis/prevention & control , Humans , Randomized Controlled Trials as Topic , Stroke/physiopathology , Stroke/prevention & control , Surgery, Computer-Assisted
2.
J Am Coll Cardiol ; 29(3): 582-9, 1997 Mar 01.
Article in English | MEDLINE | ID: mdl-9060897

ABSTRACT

OBJECTIVES: This study sought to determine whether left atrial appendage stunning occurs in patients with atrial flutter and to compare left atrial appendage function in the pericardioversion period with that in patients with atrial fibrillation. BACKGROUND: Left atrial appendage stunning has recently been proposed as a key mechanistic phenomenon in the etiology of postcardioversion thromboembolic events in atrial fibrillation. Atrial flutter is thought to be associated with a negligible risk of thromboembolic events; therefore, anticoagulation is commonly withheld before and after cardioversion in these patients. METHODS: Sixty-three patients with atrial flutter (n = 19) or atrial fibrillation (n = 44) underwent transesophageal echocardiography immediately before and after electrical cardioversion. In addition to assessing the presence of thrombus and spontaneous echo contrast, we measured left atrial appendage emptying velocity and calculated shear rates by pulsed wave Doppler and two-dimensional echocardiography. RESULTS: Patients with atrial flutter exhibited greater left atrial appendage flow velocities before cardioversion than those with atrial fibrillation (42 +/- 19 vs. 28 +/- 15 cm/s [mean +/- SD], p < 0.001). Left atrial appendage shear rates were also higher in patients with atrial flutter (103 +/- 82 vs. 59 +/- 37 s-1, p < 0.001). After cardioversion, left atrial appendage flow velocities decreased compared with precardioversion values in patients with atrial fibrillation (28 +/- 15 before to 15 +/- 14 cm/s after cardioversion, p < 0.001) and atrial flutter (42 +/- 19 to 27 +/- 18 cm/s, respectively, p < 0.001). Shear rates decreased from 59 +/- 37 before cardioversion to 30 +/- 31 s-1 after cardioversion in atrial fibrillation (p < 0.001), and from 103 +/- 82 s to 65 +/- 52 s-1, respectively (p < 0.001), in atrial flutter. This decrease in flow velocity from before to after cardioversion occurred in 36 (82%) of 44 patients with atrial fibrillation and 14 (74%) of 19 with atrial flutter. The impaired left atrial appendage function after cardioversion was less pronounced in the group with atrial flutter (27 +/- 18 cm/s for atrial flutter vs. 15 +/- 14 cm/s for atrial fibrillation, p < 0.001). New or increased spontaneous echo contrast occurred in 22 (50%) of 44 patients with atrial fibrillation versus 4 (21%) of 19 with atrial flutter (p < 0.05). CONCLUSIONS: Left atrial appendage stunning also occurs in patients with atrial flutter, although to a lesser degree than in those with atrial fibrillation. These data suggest that patients with atrial flutter are at risk for thromboembolic events after cardioversion, although this risk is most likely lower than that in patients with atrial fibrillation because of better preserved left atrial appendage function.


Subject(s)
Atrial Fibrillation/therapy , Atrial Flutter/therapy , Electric Countershock , Aged , Atrial Fibrillation/complications , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/physiopathology , Atrial Flutter/complications , Atrial Flutter/diagnostic imaging , Atrial Flutter/physiopathology , Atrial Function, Left , Coronary Thrombosis/etiology , Coronary Thrombosis/physiopathology , Echocardiography, Doppler , Echocardiography, Transesophageal , Electric Countershock/adverse effects , Female , Humans , Male , Middle Aged
3.
J Am Coll Cardiol ; 23(2): 533-41, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8294710

ABSTRACT

The management of anticoagulant therapy in patients with atrial fibrillation undergoing electrical cardioversion remains controversial, largely because of inadequate studies demonstrating risk or benefit, a relatively inconvenient anticoagulation management strategy and the increasing use of transesophageal echocardiography. Recent investigations into the potential mechanisms involved in the development of thrombus and systemic embolism in patients undergoing electrical cardioversion of atrial fibrillation may provide insight into underlying predisposing factors, with subsequent modification of management strategies. Conventional wisdom suggests that preexisting thrombus is responsible for thromboembolic events after cardioversion. However, development of a thrombogenic milieu after cardioversion, particularly in the left atrial appendage, may also be an important predisposing factor. To protect against both potential mechanisms of embolization, these data support therapeutic anticoagulation for all patients with atrial fibrillation of > 2 days in duration from the time of, as well as after cardioversion for a total of 4 weeks, undergoing cardioversion, even in the absence of thrombus on echocardiography. Therefore, the role of transesophageal echocardiography in this setting should be to enable early cardioversion if atrial thrombus is excluded and to identify high risk patients with atrial thrombi so as to postpone cardioversion and avoid the risk of embolization. Ultimately, however, a controlled, randomized and prospective clinical trial will be required to compare conventional management with a transesophageal echocardiography-guided strategy.


Subject(s)
Atrial Fibrillation/therapy , Echocardiography, Transesophageal , Electric Countershock , Heart Diseases/diagnostic imaging , Thrombosis/diagnostic imaging , Anticoagulants/therapeutic use , Atrial Fibrillation/complications , Atrial Fibrillation/diagnostic imaging , Embolism/prevention & control , Heart Atria/diagnostic imaging , Heart Diseases/complications , Humans , Thrombosis/complications
4.
J Am Coll Cardiol ; 22(5): 1359-66, 1993 Nov 01.
Article in English | MEDLINE | ID: mdl-8227792

ABSTRACT

OBJECTIVES: This study assessed the function of the left atrial appendage in the pericardioversion period to gain insights into mechanisms involved in thromboembolism after cardioversion of atrial fibrillation. BACKGROUND: Systemic embolization associated with electrical cardioversion of atrial fibrillation is thought to originate from the left atrium or left atrial appendage, or both. However, the mechanism involved is poorly understood. METHODS: We studied left atrial appendage function with transesophageal echocardiography in 20 patients with atrial fibrillation before and after successful electrical cardioversion. We measured left atrial appendage emptying and filling velocities by pulsed wave Doppler echocardiography, characterized Doppler emptying patterns, measured atrial appendage areas and assessed the presence or absence of spontaneous echo contrast or thrombus. RESULTS: Organized left atrial appendage function returned in 16 (80%) of 20 patients immediately after cardioversion. Atrial appendage emptying velocities before cardioversion were greater in patients without (0.39 +/- 0.02 m/s) than in those with (0.25 +/- 0.12 m/s) spontaneous echo contrast (p = 0.045). Furthermore, emptying velocities before cardioversion were significantly greater than late diastolic emptying velocities after cardioversion (0.31 +/- 0.15 vs. 0.14 +/- 0.12 m/s, p = 0.0001), as well as in both the group with (0.25 +/- 0.12 vs. 0.13 +/- 0.13 m/s, p = 0.001) and the group without (0.39 +/- 0.02 vs. 0.15 +/- 0.12 m/s, p = 0.01) spontaneous echo contrast. In addition, left atrial and atrial appendage spontaneous echo contrast developed in 4 of 20 patients and increased in intensity in 3 of 20 patients in the immediate postcardioversion period. CONCLUSIONS: Organized left atrial appendage function returns in most patients immediately after cardioversion of atrial fibrillation. However, its function is impaired compared with that before cardioversion. Furthermore, spontaneous echo contrast increased in 7 (35%) of 20 patients after cardioversion. These observations suggest that stunned left atrial appendage function after cardioversion may predispose the chamber to thrombus formation, which may play a role in the mechanism involved in the occurrence of embolization after cardioversion.


Subject(s)
Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/therapy , Atrial Function, Left , Echocardiography, Doppler , Echocardiography, Transesophageal , Electric Countershock/adverse effects , Heart Diseases/etiology , Thromboembolism/etiology , Aged , Analysis of Variance , Atrial Fibrillation/pathology , Atrial Fibrillation/physiopathology , Causality , Diastole , Evaluation Studies as Topic , Female , Heart Diseases/diagnostic imaging , Heart Diseases/epidemiology , Humans , Male , Middle Aged , Myocardial Stunning/epidemiology , Myocardial Stunning/etiology , Observer Variation , Thromboembolism/diagnostic imaging , Thromboembolism/epidemiology , Ventricular Function, Left
5.
J Am Coll Cardiol ; 34(3): 795-801, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10483962

ABSTRACT

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


Subject(s)
Atrial Function, Left/physiology , Mitral Valve/physiology , Pulmonary Veins/physiology , Adult , Aged , Cardiac Surgical Procedures/statistics & numerical data , Echocardiography, Doppler/methods , Echocardiography, Doppler/statistics & numerical data , Female , Hemodynamics , Humans , Linear Models , Male , Middle Aged , Mitral Valve/diagnostic imaging , Models, Cardiovascular , Monitoring, Intraoperative/statistics & numerical data , Pulmonary Veins/diagnostic imaging , Systole/physiology
6.
J Am Coll Cardiol ; 28(1): 222-31, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8752818

ABSTRACT

OBJECTIVES: This study was designed to develop a quantitative method of spontaneous echo contrast (SEC) assessment using integrated backscatter and to compare integrated backscatter SEC measurement with independent qualitative grades of SEC and clinical and echocardiographic predictors of thromboembolism. BACKGROUND: Left atrial SEC refers to dynamic swirling smokelike echoes that are associated with low flow states and embolic events and have been graded qualitatively as mild or severe. METHODS: We performed transesophageal echocardiography in 43 patients and acquired digital integrated backscatter image sequences of the interatrial septum to internally calibrate the left ventricular cavity and left atrial cavity under different gain settings. Patients were independently assessed as having no, mild or severe SEC. We compared intensity of integrated backscatter in the left atrial cavity relative to that in the left ventricular as well as to the independently assessed qualitative grades of SEC. Fourier analysis characterized the temporal variability of SEC. The integrated backscatter was compared with clinical and echocardiographic predictors of thromboembolism. RESULTS: The left atrial cavity integrated backscatter intensity of the mild SEC subgroup was 4.7 dB higher than that from the left ventricular cavity, and the left atrial intensity of the severe SEC subgroup was 12.5 dB higher than that from the left ventricular cavity. The left atrial cavity integrated backscatter intensity correlated well with the qualitative grade. Fourier transforms of SEC integrated backscatter sequences revealed a characteristic dominant low frequency/high amplitude spectrum, distinctive from no SEC. There was a close relationship between integrated backscatter values and atrial fibrillation, left atrial size, left atrial appendage flow velocities and thrombus. CONCLUSIONS: Integrated backscatter provides an objective quantitative measure of SEC that correlates well with qualitative grade and is closely associated with clinical and echocardiographic predictors of thromboembolism. The relationship between integrated backscatter measures and cardioembolic risk will be defined in future multicenter studies.


Subject(s)
Echocardiography, Transesophageal/methods , Heart Diseases/diagnostic imaging , Aged , Case-Control Studies , Female , Fourier Analysis , Heart Atria/diagnostic imaging , Heart Diseases/complications , Humans , Male , Middle Aged , Risk Factors , Signal Processing, Computer-Assisted , Thromboembolism/epidemiology , Thromboembolism/etiology
7.
Am J Cardiol ; 82(7): 892-5, 1998 Oct 01.
Article in English | MEDLINE | ID: mdl-9781973

ABSTRACT

Atrial fibrillation (AF) commonly develops after cardiac valvular surgery. The objective of this study was to identify risk factors for postoperative AF following valvular surgery. A cohort of 915 consecutive adult patients undergoing isolated valvular surgery with preoperative sinus rhythm was analyzed. Univariate and independent multivariate risk factors for postoperative AF were determined. A second cohort of 305 patients with the same inclusion criteria was used to validate the multivariate predictors. Patients studied had a mean age of 56.1 +/- 14.7 years, 57.9% were men, 79.6% had a normal left ventricular ejection fraction, and their mean left atrial size was 46.2 +/- 9.3 mm. The incidence of postoperative AF was 36.7%. Independent predictors of postoperative AF included: advanced age (odds ratio [OR] 1.506 per decade, 95% confidence interval, [CI] 1.35 to 1.68, p = 0.0001); mitral stenosis (OR 2.066, CI 1.21 to 3.52, p = 0.0077); left atrial enlargement (OR 1.468, CI 1.07 to 2.01, p = 0.0165); use of systemic hypothermia (OR 0.572, CI 0.422 to 0.776, p = 0.0003); and a history of cardiac surgery (OR 0.676, CI 0.465 to 0.981, p = 0.0393). Among these variables, advanced age, mitral stenosis, and left atrial enlargement were confirmed as independent risk factors in the validation cohort.


Subject(s)
Atrial Fibrillation/epidemiology , Heart Valves/surgery , Postoperative Complications/epidemiology , Atrial Fibrillation/etiology , Cardiac Surgical Procedures , Cohort Studies , Databases, Factual , Female , Heart Valve Prosthesis Implantation , Humans , Incidence , Male , Middle Aged , Mitral Valve Stenosis/epidemiology , Multivariate Analysis , Retrospective Studies , Risk Factors
8.
Am J Cardiol ; 85(2): 239-44, 2000 Jan 15.
Article in English | MEDLINE | ID: mdl-10955384

ABSTRACT

Transesophageal echocardiographic (TEE)-guided cardioversion of patients in atrial fibrillation (AF) of >2 days' duration is used as an alternative to conventional therapy. The purpose of this study was to investigate practice patterns employed for stroke prophylaxis in patients with AF who underwent cardioversion, and to determine the relative use of conventional and TEE-guided management strategies. We forwarded regionally stratified survey questionnaires to 947 clinical practices within the United States. The 10-question questionnaire queried demographic and clinical practice volumes and practices for managing patients with AF who underwent cardioversion. In addition, we used historical data to determine longitudinal use patterns of the TEE-guided approach for a large institution over 7 years. The 197 completed and returned surveys yielded a return rate of 20.8%. The TEE-guided approach was employed in approximately 12% of total cardioversions, but 75% of practices indicated that they employed transesophageal echocardiography only occasionally. The TEE-guided approach was associated with community size (r = 0.19; p<0.008), type of practice (r = 0.26; p = 0.001), total use of transesophageal echocardiography (r = 0.48; p<0.001), and volume of cardioversions (r = 0.28; p<0.001). Importantly, there was little consensus on the most appropriate clinical indications for TEE-guided cardioversions, and the proportions of TEE-guided cardioversion to total number of electrical cardioversions remained stable over 7 years. Practice volume and physician training may be the most important variables in the adoption of the TEE approach.


Subject(s)
Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/therapy , Echocardiography, Transesophageal/statistics & numerical data , Electric Countershock/methods , Ambulatory Care , Hospitalization , Humans , Practice Patterns, Physicians' , Surveys and Questionnaires , United States
9.
Am J Cardiol ; 84(6): 744-7, A9, 1999 Sep 15.
Article in English | MEDLINE | ID: mdl-10498151

ABSTRACT

We report a cohort of our first 100 minimally invasive cardiac valvular operations matched 1:1 by age and valvular surgery type with patients undergoing a traditional midline sternotomy approach. The prevalence of postoperative atrial fibrillation among patients with minimally invasive procedures versus traditional midline sternotomy was 26.3% versus 38.0%, respectively (p = 0.08). Neither multiple logistic regression nor Kaplan-Meier distribution analysis identified differences in postoperative atrial fibrillation between the 2 surgical techniques.


Subject(s)
Atrial Fibrillation/etiology , Heart Valve Diseases/surgery , Minimally Invasive Surgical Procedures , Postoperative Complications/etiology , Adult , Aged , Aortic Valve/surgery , Bioprosthesis , Female , Heart Valve Prosthesis Implantation , Humans , Male , Middle Aged , Mitral Valve/surgery , Retrospective Studies , Sternum/surgery , Thoracotomy
10.
Am J Cardiol ; 86(9): 1026-9, A10, 2000 Nov 01.
Article in English | MEDLINE | ID: mdl-11053722

ABSTRACT

In this study, we sought evidence for an underlying atrial or ventricular myopathy in patients with paroxysmal lone atrial fibrillation using standard echocardiographic parameters in addition to Doppler tissue imaging of mitral annular motion. No impairment in atrial contractile function was found, but there was evidence for impaired diastolic function in these patients.


Subject(s)
Atrial Fibrillation/complications , Mitral Valve/diagnostic imaging , Ultrasonography, Doppler, Pulsed/methods , Ventricular Dysfunction, Left/diagnostic imaging , Adult , Aged , Atrial Fibrillation/diagnostic imaging , Female , Humans , Male , Middle Aged , Mitral Valve/physiology , Myocardial Contraction/physiology , Reference Values , Sensitivity and Specificity , Ventricular Dysfunction, Left/complications
11.
J Thorac Cardiovasc Surg ; 119(6): 1205-12, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10838540

ABSTRACT

OBJECTIVE: We sought to investigate the relationship of female sex, aortic pathology, and left ventricular function to outcome after an operation for aortic regurgitation. METHODS: One hundred nine women underwent aortic valve replacement (n = 92) or repair (n = 17) for pure aortic regurgitation between 1985 and 1996. Mean follow-up was 5.7 +/- 2.6 years. New York Heart Association functional class III-IV symptoms were present in 70 patients, whereas left ventricular function was normal in 60 patients. Ascending aortic diameter in 97% exceeded the 90th percentile for a size-matched healthy population. A concomitant aortic operation was performed by means of root replacement in 31 patients and by means of interposition graft in 28 patients. Of 50 patients undergoing isolated valve procedures, 19 had aortas of 4.0 cm or larger. RESULTS: At 5 and 10 years, survival was 78% and 44%, respectively. Fatal aortic rupture occurred in 13 patients, and 2 others underwent emergency operations for impending aortic rupture, for a total of 15 late aortic events. Freedom from aortic events was 87% and 76% at 5 and 10 years, respectively. Risk factors for aortic events were older age (P =.07) and increasing ascending aortic diameter indexed to body surface area (P =.03) in women who had not undergone replacement of the ascending aorta. Rupture location was at the ascending aorta in 71% without ascending replacement and the descending aorta in 62% with ascending grafts. CONCLUSION: In women, late survival after an operation for aortic regurgitation is importantly decreased by coexisting aortic pathology with subsequent aortic rupture. Aortic replacement at the time of a valve operation should be considered on the basis of indexed aortic size.


Subject(s)
Aortic Valve Insufficiency/mortality , Aortic Valve Insufficiency/surgery , Heart Valve Prosthesis , Postoperative Complications/mortality , Aged , Aortic Valve/pathology , Aortic Valve Insufficiency/pathology , Female , Follow-Up Studies , Humans , Middle Aged , Risk Factors , Rupture , Survival Rate
12.
Ann Thorac Surg ; 61(5): 1516-8, 1996 May.
Article in English | MEDLINE | ID: mdl-8633971

ABSTRACT

We present a patient with severe pedunculated ascending atherosclerosis associated with recurrent cerebral vascular accidents. We recommend that endarterectomy be considered for patients with recurrent cerebral vascular accidents associated with severe atherosclerosis of the ascending aorta when no other cause is found to explain the symptoms.


Subject(s)
Aorta/surgery , Aortic Diseases/surgery , Arteriosclerosis/surgery , Cerebrovascular Disorders/etiology , Endarterectomy , Aged , Aortic Diseases/complications , Arteriosclerosis/complications , Cerebrovascular Disorders/surgery , Humans , Ischemic Attack, Transient/etiology , Ischemic Attack, Transient/surgery , Male
13.
Cancer Chemother Pharmacol ; 4(3): 195-7, 1980.
Article in English | MEDLINE | ID: mdl-7397943

ABSTRACT

Actinomycin D is generally administered by serial low-dose injection over 5-10 days. Recent recognition of prolonged serum and tissue half-lives suggests that high-dose intermittent injecton should be equally effective and less toxic. An intermitten single dose schedule was selected for this phase II trial of actinomycin D in 23 patients with advanced breast cancer refractory to standard combination chemotherapy. The drug was given in doses of 0.75-1.5 mg/m2 at 2-week intervals or on days 1 and 8 of 28-day treatment cycles. One patient obtained a partial response with a duration of 5.7 months. Four patients experienced stabilization of advanced disease, with a mean duration of response of 6.4 months. Gastrointestinal toxicity occurred in 47% of patients and mild to moderate myelosuppression in 39%. We conclude that actinomycin D in this dosage and schedule has limited activity in advanced breast cancer. Higher doses might result in increased response rates but would be associated with greater toxicity.


Subject(s)
Breast Neoplasms/drug therapy , Dactinomycin/therapeutic use , Dactinomycin/adverse effects , Drug Evaluation , Female , Humans , Neoplasm Metastasis
14.
Brain Res ; 301(2): 363-9, 1984 Jun 03.
Article in English | MEDLINE | ID: mdl-6329452

ABSTRACT

An earlier work demonstrated that electrical stimulation of newt brachiospinal nerves produces a 20% increase in protein synthesis in the regenerating limb bud at 6 h post-stimulation. The present study shows that if stimulation of nerve cell bodies is prevented by placing procaine between the cell bodies and the stimulating electrode, there is no increase in limb bud protein synthesis compared to the non-stimulated, contralateral control limb bud. Similarly, if colchicine is applied to the brachiospinal nerves at the site of and prior to stimulation, there is no increase in limb bud protein synthesis after stimulation. Colchicine applied to brachiospinal nerves in the absence of stimulation results in a reduction of limb bud protein synthesis that is of the same magnitude as the increase seen with stimulation. The results suggest that the neurotrophic increase in limb bud protein synthesis after stimulation is under the control of the cell body and that this control is mediated by changes in fast axonal transport. A neuronotrophic increase in axonal density in the stimulated side limb bud is seen at the same time as the increase in protein synthesis after stimulation.


Subject(s)
Axons/physiology , Forelimb/innervation , Nerve Regeneration , Spinal Cord/physiology , Synaptic Transmission , Animals , Electric Stimulation , Nerve Tissue Proteins/metabolism , Notophthalmus viridescens
15.
J Am Soc Echocardiogr ; 14(2): 122-7, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11174446

ABSTRACT

BACKGROUND: Previous studies have reported the clinical and echocardiographic findings of patients with left atrial spontaneous echo contrast (SEC) and thrombi. We sought to study these characteristics in patients with right atrial SEC and thrombi. METHODS: We reviewed 580 consecutive patients from the ACUTE (Assessment of Cardioversion Using Transesophageal Echocardiography) Registry and found 79 patients (14%, aged 67 +/-13 years, 67 male) with transesophageal echocardiography (TEE) findings of right atrial SEC or thrombi (group 1). This group was compared with a control group of 75 consecutive patients (group 2) (aged 68 +/- 13 years, P = not significant; 49 male, P <.005) from the registry with no TEE findings of SEC or thrombi in the left or right atrium. RESULTS: Atrial fibrillation was present in 60 of 79 group 1 patients (76%). Five right atrial (6%) and 11 left atrial (14%) thrombi were identified. Both left ventricular ejection fraction (39% +/- 16% versus 47% +/- 14%; P =.0005) and presence of right ventricular dysfunction (n = 44 versus 18; P =.0001) differed significantly between groups 1 and 2, respectively. Right atrial area (24 +/- 6 cm(2) versus 22 +/- 6 cm(2); P = .02) was larger in patients in group 1. Left atrial SEC was present in 68 of 79 group 1 patients (86%). Patients with right atrial thrombi and right atrial SEC had a longer duration of arrhythmia (524 +/-812 days versus 147 +/-368 days, P <.05) than patients with right atrial SEC only. CONCLUSIONS: Right atrial SEC has a prevalence of 14% in patients with atrial arrhythmia who undergo TEE-guided cardioversion. Right atrial thrombi are a rare finding and were seen in fewer than 1% (5/580) of patients with atrial arrhythmia. Right atrial thrombi among patients on anticoagulation therapy were not associated with clinically significant pulmonary embolism.


Subject(s)
Atrial Fibrillation/diagnostic imaging , Echocardiography, Transesophageal , Heart Atria/diagnostic imaging , Heart Diseases/diagnostic imaging , Thrombosis/diagnostic imaging , Adult , Aged , Aged, 80 and over , Atrial Fibrillation/epidemiology , Comorbidity , Female , Heart Diseases/epidemiology , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Thrombosis/epidemiology
16.
J Am Soc Echocardiogr ; 14(3): 200-8, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11241016

ABSTRACT

An alternative clinical management strategy and cost analysis model is presented for patients with atrial fibrillation of >2 days' duration who may benefit from immediate cardioversion with self-administered low-molecular-weight heparin (enoxaparin) as a bridge antithrombotic therapy to warfarin, after a negative transesophageal echo-cardiography (TEE) screening for thrombus. Assuming no difference in stroke or bleeding rates, our cost minimization model shows that the TEE-guided enoxaparin treatment costs are $1353 lower per patient than an intravenous unfractionated heparin approach. Sensitivity analyses for stroke and bleeding reveal that the treatment-cost economic dominance of the TEE-guided enoxaparin approach may be enhanced by an expected improvement in clinical outcome.


Subject(s)
Anticoagulants/economics , Anticoagulants/therapeutic use , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/therapy , Echocardiography, Transesophageal/economics , Electric Countershock/economics , Enoxaparin/economics , Enoxaparin/therapeutic use , Thrombolytic Therapy/economics , Cost-Benefit Analysis , Humans , Treatment Outcome
17.
J Am Soc Echocardiogr ; 8(6): 879-87, 1995.
Article in English | MEDLINE | ID: mdl-8611288

ABSTRACT

Right and left upper pulmonary venous flow is usually assessed with monoplane transesophageal echocardiography (TEE) in the transverse imaging plane. Pulmonary venous flow in the transverse imaging plane may be relatively difficult to record because of the larger angle between the pulmonary vein and the transducer beam. To compare the quality of echocardiographically derived Doppler flows of the right and left upper pulmonary veins between the longitudinal and transverse imaging planes with TEE, we performed pulsed-wave Doppler TEE of both upper pulmonary veins in transverse and longitudinal imaging planes in 36 patients with various diseases. We also recorded a quality index for each flow profile and the angle between the transducer beam and the pulmonary vein. The quality index of the left pulmonary venous flow assessed with the longitudinal and transverse imaging planes was similar in 35 (95%) of 36 patients, whereas the longitudinal imaging plane was superior to the transverse plane in one patient (3%). In contrast, the quality index of the right pulmonary venous flow assessed with the longitudinal and transverse imaging planes was similar in only 19 (53%) of 36 patients, whereas in 17 patients (47%) the longitudinal imaging plane was superior to the transverse imaging plane. The quality index had a significant effect on the Doppler flow recordings; suboptimal-quality flow recordings significantly underestimated the pulmonary venous diastolic flow integrals. The left atrium was larger in those patients with unobtainable flows than in those patients with exclusively obtainable flows (p < 0.001). The angle between the sample volume and the right pulmonary vein was larger in the transverse imaging plane than in the longitudinal plane (p < 0.001). In conclusion, the longitudinal imaging plane is generally superior to the transverse imaging plane for assessing right pulmonary venous flow and is recommended for performing a comprehensive assessment of pulmonary venous flow. The ability to obtain quality images and accurate assessment of flow may be related to the size of the left atrium and angle of the pulmonary vein.


Subject(s)
Echocardiography, Transesophageal/methods , Pulmonary Veins/physiopathology , Adult , Aged , Aged, 80 and over , Analysis of Variance , Blood Flow Velocity , Echocardiography, Doppler, Pulsed/methods , Female , Humans , Male , Middle Aged , Prospective Studies , Pulmonary Veins/diagnostic imaging , Regional Blood Flow
18.
Cardiol Clin ; 16(3): 477-89, ix, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9742326

ABSTRACT

The widespread use and popularity of intraoperative echocardiography (IOE) has resulted from advances in cardiac surgery, reparative procedures for valvular heart disease and, most specifically, mitral valve repair. IOE has grown exponentially and is becoming an integral part of the planning and evaluation of many types of surgical procedures such that it is now considered standard of care especially for the perioperative management of patients undergoing mitral and aortic valve repair. This article discusses the application of intraoperative echocardiography and focus specifically on valvular heart disease as this represents the most widely accepted indication for the procedure in current clinical practice.


Subject(s)
Echocardiography , Heart Valve Diseases/surgery , Heart Valve Prosthesis Implantation , Heart Valves/diagnostic imaging , Monitoring, Intraoperative/methods , Echocardiography, Transesophageal , Heart Valve Diseases/diagnostic imaging , Humans , Retrospective Studies
19.
Am J Occup Ther ; 30(4): 234-40, 1976 Apr.
Article in English | MEDLINE | ID: mdl-779488

ABSTRACT

The purpose of this investigation were to study the relationships between hand function abilities and tactile perception, and the level of spinal cord lesion and status of hydrocephalus in a sample of 17 children with myelomeningocele. Fourteen children showed impaired hand function, and eight showed tactile dysfunction. Statiscally significant differences in hand function scores and graphesthesia scores were obtained for children with increased severity of hydrocephalus and high-level lesions. Of the 48 correlation coefficients computed between the hand function and tactile perception measures used, only one was statistically significant. This lack of correlation may indicate that hand function and tactile perception in children with myelomeningocele are unrelated factors. Clinical implications of impaired hand function and tactile perception were discussed.


Subject(s)
Hand/physiopathology , Meningomyelocele/physiopathology , Perception , Spinal Dysraphism/physiopathology , Touch/physiology , Child , Female , Humans , Hydrocephalus/physiopathology , Male , Meningomyelocele/pathology
20.
Nutr Diabetes ; 2: e39, 2012 Aug 06.
Article in English | MEDLINE | ID: mdl-23448803

ABSTRACT

BACKGROUND: Obesity is a major public health epidemic and is associated with increased risk of heart failure and mortality. We evaluated the impact of body mass index (BMI) on the prevalence of diastolic dysfunction (DD). METHODS: We reviewed clinical records and echocardiogram of patients with baseline echocardiogram between 1996 and 2005 that showed normal left ventricular ejection fraction (LVEF). Diastolic function was labeled as normal, stage 1, stage 2 or stage 3/4 dysfunction. Patients were categorized as normal weight (BMI <25 kg m(-2)), overweight (25-29.9 kg m(-2)), obese (30-39.9 kg m(-2)) and morbidly obese (40 kg m(-2)). Multivariable ordinal and ordinary logistic regression were performed to identify factors associated with DD, and evaluate the independent relationship of BMI with DD. RESULTS: The cohort included 21 666 patients (mean (s.d.) age, 57.1 (15.1); 55.5% female). There were 7352 (33.9%) overweight, 5995 (27.6%) obese and 1616 (7.4%) morbidly obese patients. Abnormal diastolic function was present in 13 414 (61.9%) patients, with stage 1 being the most common. As BMI increased, the prevalence of normal diastolic function decreased (P<0.0001). Furthermore, there were 1733 patients with age <35 years; 460 (26.5%) and 407 (23.5%) were overweight and obese, respectively, and had higher prevalence of DD (P<0.001). Using multivariable logistic regression, BMI remained significant in both ordinal (all stages of diastolic function) and binary (normal versus abnormal). Also, obesity was associated with increased odds of DD in all patients and those aged <35 years. CONCLUSIONS: In patients with normal LVEF, higher BMI was independently associated with worsening DD.

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