British heart journal
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The belief that there is total irregularity of the pulse in atrial fibrillation has been re-examined. In a computerised analysis of R-R intervals and pulse volumes, 100-500 (mean 237) consecutive cycles were examined in 74 patients with atrial fibrillation, of whom 36 were on digoxin and 38 were not taking any antiarrhythmic treatment. A Doppler ultrasound technique was used to assess pulse volumes, against which R-R intervals were correlated. ⋯ The proportion of patients with a non-random sequence of R-R intervals or pulse volumes was the same whether or not they were taking digoxin. Thus patients with atrial fibrillation often have patterns of regularity of the pulse, with the ventricular rhythm being non-random in almost one third and the sequence of pulse volumes being non-random in over a half. Contrary to classic teaching, in many patients with atrial fibrillation the pulse is not irregularly irregular.
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Aortic dissection occurred in a nineteen year old woman during the thirty seventh week of pregnancy. Immediate elective delivery of a normal baby by caesarean section was followed by aortic root replacement 48 hours later. It was decided not to proceed immediately to operation on the aortic root because it was believed that the anticoagulation necessary for cardiopulmonary bypass might provoke dangerous haemorrhage from the raw placental site.
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Postoperative chest radiographs on 100 children who had undergone cardiac operations were evaluated to determine the frequency of subpulmonary effusions after surgery. Of the 83 patients in whom adequate erect postoperative radiographs were available, 9 (11%) had effusions confirmed by lateral decubitus radiographs. ⋯ When a subpulmonary effusion was detected diuretic treatment was started or continued. None of the patients had radiographic evidence of residual fluid when they were seen two weeks after their discharge from hospital.
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British heart journal · Aug 1985
Case ReportsArtefactual ST segment abnormalities due to electrocardiograph design.
Specifications recommended for electrocardiographs omit any reference to phase characteristics and place undue emphasis on an extended amplitude response. This does not, however, ensure faithful reproduction of the electrocardiogram and may result in less effective attenuation of unwanted noise than can be achieved with modern filters. ⋯ Case reports are presented in which distortion produced by commercial equipment impeded diagnosis. Specifications recommended as standard for electrocardiographs should be modified to include phase response and allow greater attenuation of frequencies below 0.5 Hz.