Lack of correlation between intracavitary thrombosis detected by cross sectional echocardiography and systemic emboli in patients with dilated cardiomyopathy

The correlation between intracavitary thrombosis detected by cross sectional echocardiography and systemic embolism was studied in 126 consecutive patients with idiopathic dilated cardiomyopathy who were examined from January 1980 to September 1987. A total of 1041 serial echocardiograms were obtained with 3.5 and 5 MHz transducers. The mean follow up period was 41.2 months. The survival rate was 88% at two years and 56% at five years. Echocardiography showed intracavitary thrombi in 14 (11.1%) patients; 13 were mural and 11 were localised at the apex of the left ventricle. Twelve patients (8.4%) had systemic emboli; this corresponded to an incidence of new embolic events of 1.4 for 100 patient-years. Patients with intracavitary thrombi or systemic emboli were treated with oral anticoagulants, as were nine in functional class IV of the New York Heart Association, for 61 patient-years. The cumulative observation period for the whole population study was 418 patient-years. None of the patients with intracavitary thrombosis had embolic complications and none of those with embolism had intracavitary thrombi. Rates of intracavitary thrombosis and systemic embolism in this series were low and there was no overlap between the two events. This may have been because the patients did not have severe dilated cardiomyopathy, because echocardiography did not detect all the thrombi, or because patients were treated with oral anticoagulants. The presence of intracardiac thrombosis detected by cross sectional echocardiography is not predictive of systemic embolism in patients with idiopathic dilated cardiomyopathy. Criteria for the use of the anticoagulant treatment remain largely empirical in these cases.     

Self-paced frequency of a simple motor task and brain activation. An fMRI study in healthy subjects using an on-line monitor device

Application of fMRI to clinical neurology implies the selection of a simple task and control of the task performance. The capability to objectively monitor variables related to task execution is, therefore, important and could improve accuracy of clinical fMRI studies. We assessed the influence of different self-paced frequencies of a simple motor task on brain activation in healthy subjects. A device was developed to measure the force exerted by a subject in pressing an air-filled rubber bulb with the last four fingers of the dominant hand. The task frequency was determined by analysis of the force signal. Nine healthy subjects performed twice the task with self-paced slow (0.35+/-0.09 Hz), intermediate (0.58+/-0.21 Hz) or fast (0.98+/-0.32 Hz) frequency. The device revealed impaired task execution in 1 subject. The coefficient of variation of frequency was 8.7% for slow, 12.2% for intermediate and 15.8% for fast paced task. No significant differences were found comparing the activation maps obtained at slow, intermediate and fast frequencies in the contralateral sensorimotor cortex and ipsilateral cerebellum. Cluster reproducibility was good for location (standard deviation相似文献   

In vivo antiviral activity and pharmacokinetics of (-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine in woodchuck hepatitis virus-infected woodchucks.

The (-) enantiomer of cis-5-fluoro-1l-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine [(-)-FTC)], a substituted oxathiolane compound with anti-hepatitis B virus activity in vitro, was assessed for its efficacy in woodchucks with naturally acquired woodchuck hepatitis virus (WHV) infection. Pharmacokinetics and in vitro anabolism were also determined. (-)-FTC was anabolized to the 5'-triphosphate in a dose-related fashion, reaching a maximum concentration at about 24 h in cultured woodchuck hepatocytes. Following administration of a dose of 10 mg/kg of body weight intraperitoneally (i.p.), the clearance of (-)-FTC from plasma was monoexponential, the terminal half-life was 3.76 +/- 1.4 h, and the systemic clearance was 0.12 +/- 0.06 liters/h/kg. The antiviral efficacy of (-)-FTC in the woodchuck model was assessed by quantitation of serum WHV DNA levels and by WHV particle-associated DNA polymerase activity at two dosages, 30 and 20 mg/kg given i.p. twice daily (b.i.d.), respectively. The level of WHV DNA in serum was reduced 20- to 150-fold (average, 56-fold) in the 30-mg/kg-b.i.d. treatment group and 6- to 49-fold (average, 27-fold) in the 20-mg/kg-b.i.d. treatment group. Viral DNA polymerase levels diminished accordingly. One week after treatment was discontinued, WHV levels returned to pretreatment levels in both studies. These animals were biopsied before and following treatment with 30 mg of (-)-FTC per kg. Their livers were characterized by a mild increase in cytoplasmic lipid levels, but this change was not associated with altered liver enzyme levels. Serum chemistry and hematology results were within the normal ranges for all treated animals. We conclude that (-)-FTC is a potent antihepadnaviral agent and that it has no detectable toxic effects in woodchucks when given for up to 25 days. Further development of (-)-FTC as an anti-hepatitis B virus therapy for patients is warranted.     

Colchicine for the prevention of the postpericardiotomy syndrome: the COPPS trial

Preliminary data have shown that colchicine may be considered for the prevention of the postpericardiotomy syndrome (PPS). The COlchicine for the Prevention of Post-pericardiotomy Syndrome (COPPS) study is a multicenter, double blind, placebo-controlled, randomized trial that will enroll 360 patients after cardiac surgery. The primary end point will be the PSS rate at 12 months. The study will be the first large randomized placebo-controlled trial in this area, and will provide important evidence regarding the possible benefit of colchicine for the primary prevention of the PPS.     

Timing and significance of exercise-induced left ventricular outflow tract pressure gradients in hypertrophic cardiomyopathy

The relation of exercise-induced left ventricular (LV) outflow tract obstruction to functional capacity in hypertrophic cardiomyopathy (HC) is incompletely defined. Thus, we assessed the patterns of onset of physiologically provoked LV outflow gradients and exercise performance in 74 consecutive patients with HC (age 45 ± 16 years; 74% men) without LV outflow obstruction at rest. The subaortic gradients were measured serially using echocardiography in these 74 patients during maximum, symptom-limited, upright bicycle exercise testing. The time course of the provoked gradients and the relation to exercise performance were assessed. Of the 74 patients, 30 (41%) developed a dynamic LV outflow gradient of ≥30 mm Hg (mean 78 ± 37 mm Hg) during upright exercise testing that correlated highly with the gradients measured with the patients supine during the immediate recovery period (R2 = 0.97). The 16 patients in whom outflow obstruction developed rapidly at low exercise levels (≤5 METs) had a significantly reduced exercise capacity (6.1 ± 1.3 vs 8.0 ± 1.6 METs; p <0.01) compared to the other 14 patients in whom obstruction appeared later at greater exercise levels of >5 METs. The timing of the gradient onset was not predictable from the baseline clinical and echocardiographic features, peak exercise LV outflow tract gradient, or symptoms. In conclusion, in patients with HC without outflow obstruction at rest, the earlier onset of LV outflow tract gradients during physiologic exercise was associated with impaired exercise performance. These findings have provided insights into the determinants of functional impairment in HC and support the potential value of exercise echocardiography in the clinical assessment of patients with HC.