Search PubMed⌕ Search

Biomedical subjects

A Cameron

Publications and source records attributed to A Cameron.

At least 109 records · Page 6Linked to original sources
PubMed1983

Left main coronary artery stenosis: angiographic determination.

Reliability of angiographic assessment of the left main coronary artery segment was evaluated by review of 106 coronary cineangiograms from the Coronary Artery Surgery Study. The films were interpreted by three groups of angiographers: those at a clinical site, those at a quality control site, and those on a study census panel. Among the readings of these three groups, there was 41% to 59% agreement on the severity of the lesion, with 80% agreement on whether the lesion was greater or less than 50%. The severity of lesion, its location, or presence of ectasia or calcium did not affect the discrepancy rate, whereas segments that were unusually short, diffusely diseased, or obscured by overlapping vessels were especially difficult to interpret.

Arterial Occlusive Diseases↗
PubMed1982

Interobserver variability in interpreting contrast left ventriculograms (CASS).

Randomly selected left ventricular cineangiograms performed by 14 medical centers (clinical sites) participating in a large multicenter study of medical and surgical treatment of coronary artery disease (CASS) were systematically recalled and reread by one of four designated quality control centers. The end diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) calculated by the quality control center were compared with those calculated by the clinical site, and correlation coefficients of 0.71, 0.84, and 0.79, respectively, were obtained. Regional left ventricular (LV) wall motion abnormalities were assessed by dividing the LV wall as viewed in the right anterior oblique (RAO) and left anterior oblique (LAO) views into five segments each and grading the motion of each segment according to six categories of increasing abnormalities from normal to aneurysm. When discrepancies based on "nearest neighbor" differences in naming adjacent segments were eliminated and only marked differences of more than one degree of severity of wall motion abnormality were considered, interobserver differences were 7% and 10% for RAO and LAO segments, respectively. Agreement was less frequent in designating a segment "aneurysmal." When each LV segment was assigned a numerical score based on increasing severity of wall motion abnormality and a total LV score for each ventriculogram computed, the quality control and clinical site readings were in good agreement with a correlation coefficient of 0.83.

Cardiac Volume↗
PubMed1982

Reproducibility of coronary arteriographic reading in the coronary artery surgery study (CASS).

Eight hundred seventy arteriograms from the Coronary Artery Surgery Study (CASS) were independently read by readers at two different clinics to evaluate the reproducibility of the interpretation of coronary arteriograms. Among proximal segments, the interpretation of lesions of the left main coronary artery were the least reproducible, P less than .02. When one angiographer reads a stenosis of 50% or more in the left main coronary artery, it is estimated that a second reader will report no lesion 18.6% of the time. In 94.7% of the films, the number of significantly (greater than or equal to 70% stenosis) diseased vessels was the same for both readers (72.1%) or differed by one vessel (22.6%). The reproducibility of interpretation of films of good or acceptable quality or completeness was better than the reproducibility of readings of arteriograms judged to be of poor quality or incomplete studies. The mean absolute difference between readings of the percent stenosis decreased over the time of the patient enrollment, 1975 to 1978. This may have resulted from major collaborative efforts made during the course of the study to improve the quality of angiography and to standardize the reading of the cine films.

Angiography↗
PubMed1982

[Variability in the interpretation of coronary angiograms by different specialists based on data from the cooperative Coronary Artery Surgery Study].

Randomly selected cine arteriographic films of 30 diseased patients were read twice by each of three experienced observers. The intrareader variability was less than one-half of the interreader variability in reading the stenosis of segments of the coronary anatomy - a statistically significant difference (p less than 0.001). When extent of disease was evaluated by the number of diseased vessels, interreader variability was larger than intrareader variability (p less than 0.01). One reader read considerably less disease than the other two readers. The films were rated as to quality of the arteriographic films and the completeness of the study. In each case there was a greater interreader than intrareader variability (p less than 0.01). The films were rated good, acceptable, or poor. One of the three interpreters consistently gave worse ratings than the other two readers. It was particularly noteworthy that a larger amount of interreader variability was observed in both the left main coronary artery and the proximal left anterior descending artery.

Canada↗
PubMed1979

Asynchronous ventricular relaxation: an angiographic temporal analysis of asynchronous left ventricular relaxation in man.

Segmental "early relaxation" is a common angiographic finding. An attempt was made to elucidate the temporal characteristics of this event. Twenty subjects with and 20 without segmental early relaxation were studied. The left ventricular diastolic relaxation time was precisely determined angiographically, and the findings were as follows: 0.12 +/- 0.04 second (mean +/- standard deviation) in the normal patients, 0.14 +/- 0.03 second in the patients with coronary artery disease but no segmental early relaxation and 0.20 +/- 0.04 second in the patients with segmental early relaxation. These findings indicate that early relaxation is associated with a significantly prolonged ventricular relaxation time. The use of the term asynchronous ventricular relaxation is proposed to denote the disturbed diastolic properties of the ventricle with "early relaxation."

Angiocardiography↗
PubMed1979

Aortocoronary bypass surgery: a 7-year follow-up.

Follow-up of 748 consecutive patients who underwent aortocoronary artery bypass grafts was obtained for 5 to 94 months (average, 59 months). Operative mortality of 2.5% did not vary with number of vessels bypassed. There was a linear 3.5% annual recurrence rate of angina, and average annual late infarction rate of 1.4%. The cumulative survival rates did not differ for the number of grafts performed or for men and women, but did differ for left main coronary stenosis and impaired ejection fractions. The late cumulative survival rates for the entire group approached those of the general U.S. population.

Adult↗