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Biomedical subjects

R B Pridie

Publications and source records attributed to R B Pridie.

At least 19 recordsLinked to original sources
PubMed1988

Correction of left ventricular asynchrony by coronary artery surgery.

To investigate the effect of coronary artery bypass grafting on the timing of regional left ventricular wall motion, contrast left ventriculograms from 27 patients were digitised frame by frame before and after operation. End diastolic and end systolic volumes, ejection fraction, and peak ejection and filling rates showed no significant change. The commonest preoperative abnormality was delayed onset of inward wall motion during ejection, which was present in 14 patients over 10% (range 5-40%) of the cavity outline, leading to a pattern of "diagonal contours". After operation this pattern had resolved completely in 12 patients and partially in two. Minor abnormalities appeared postoperatively in five but overall the mean (1SD) area affected was reduced by 5 (8)%. The time span between the onset of inward motion in different regions of the cavity also fell significantly after surgery from 190 (50) to 130 (50) ms. Regional hypokinesis (6 cases) and abnormal wall motion during isovolumic contraction (4 cases) or isovolumic relaxation (5 cases) were not consistently affected. Thus successful coronary artery surgery is without consistent effect on overall left ventricular function, overall hypokinesis, or abnormal wall motion during the isovolumic periods. It does, however, strikingly reduce the asynchrony of wall motion during ejection, suggesting that before operation this abnormality may directly reflect impaired coronary blood flow. The results emphasise the potential value of analysing regional wall motion to elucidate functional abnormalities associated with coronary artery disease.

Adult↗
PubMed1985

Angiography and complement activation. Evidence for generation of C3a anaphylatoxin by intravascular contrast agents.

The potent anaphylatoxin C3a was measured in the peripheral blood of eleven patients receiving radiocontrast agents whilst undergoing coronary angiography. In seven patients C3a levels were raised during this procedure and in three of these the anaphylatoxin was increased between four and tenfold. In four patients C3a levels remained within the normal range. In vitro tests of five contrast agents revealed marked heterogeneity in their ability to generate C3a from serum.

Anaphylatoxins↗
PubMed1985

Coronary artery ectasia. Its prevalence and clinical significance in 4993 patients.

To assess the clinical significance of coronary artery ectasia 4993 consecutive coronary arteriograms were reviewed to identify patients with this condition and to allow the assessment of their progress. Coronary ectasia was a relatively uncommon finding (overall incidence 1.4%). It was not related to the development of aortic aneurysms and did not affect the outcome, results of coronary artery surgery, or symptoms.

Coronary Angiography↗
PubMed1983

Visual versus computerised assessment of left ventricular function from cinéangiography.

Visual assessment of left ventricular function from cinéangiography was compared with computerised assessment in 48 randomly selected cinéangiograms. The parameters compared included end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and left ventricular output. There was poor agreement between visual and calculated values for end-diastolic volume, stroke volume and left ventricular output, but good agreement for ejection fraction and moderately good agreement for end-systolic volumes. Absolute values are particularly difficult to assess.

Cardiac Output↗
PubMed1980

The importance of magnification in left ventriculography.

A method of measuring the magnification of ventriculograms is described. The catheter in the ventricle is X-rayed on cine film together with a radio-opaque ruler attached to the table. A second cine run is exposed after shifting the table by an amount which can be determined from the ruler. The magnification is equal to the distance that the catheter moves on the projected angiogram divided by the actual distance moved. Studies to prove the accuracy and reproducibility of the method have been undertaken. In random series of 48 patients, the linear magnification factor varied between 1.04 and 1.46. The cubic magnification as used for calculating ventricular volume ranged from 1.12 to 3.11. The error by ignoring the magnification can therefore be 211% and by taking a mean value, up to 62%.

Angiocardiography↗
PubMed1976

Coronary angiography Review of 1500 consecutive cases.

Fifteen hundred coronary angiograms have been performed by the staff of Harefield Hospital since 1970. Only 2 deaths have occurred in the last 1000 consecutive cases though there were 5 in the first 500 cases. This drop in the mortality is ascribed to careful attention to detail and better training of the operators. It is concluded that the Fudkin's method of coronary angiography in trained hands is a safe method of investigation but that because of the very serious potential dangers it is unjustifiable for new units to start unless there is a fully experienced investigator in charge.

Adolescent↗
PubMed1975

Echocardiography of the intra-aortic balloon.

Echocardiography was performed on 9 patients being treated for cardiogenic shock with an intra-aortic balloon. The value of simultaneous recording of the electrocardiogram, cardiac movements, and arterial pressure, with the echocardiogram of the intra-aortic balloon is discussed. The results indicate that echocardiography provides a method of studying intra-aortic balloon function.

Adult↗
PubMed1975

Non-invasive left ventricular volume determination by two-dimensional echocardiography.

Twenty patients undergoing routine left ventricular single-plane angiography have been investigated by an ultrasonic triggered B-scan technique to provide a two-dimensional cross-sectional image of the left ventricle in end-systole end-diastole. An area-length method has been used to establish the correlation between the angiographic and the echocardiographic assessments of left ventricular chamber volume (r equals 0.88) and ejection fraction (r equals 0.81). Differences between the two techniques are discussed, and it is concluded that in approximately 80 per cent of patients triggered B-scanning may provide a safe, non-invasive, and convenient technique for the determination of volumes and certain functional parameters, especially in patients with dilated hearts and irregular left ventricular shape, where M-scanning is known to be less reliable.

Adult↗