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Biomedical subjects

G G Hartnell

Publications and source records attributed to G G Hartnell.

At least 37 records · Page 2Linked to original sources
PubMed1990

Aortic valvoplasty: comparison of the techniques and results of transeptal and retrograde methods.

Balloon aortic valvoplasty is used in some patients with aortic valve stenosis who are unsuitable for aortic valve replacement. Complications associated with the retrograde approach can be avoided using an antegrade approach which has been less widely described. Experience of these two methods is reported and aspects of the differences in technique are emphasized. Aortic valvoplasty was attempted in 21 patients with severe aortic valve stenosis (mean gradient 65 mmHg). A significant reduction in gradient was achieved in 20 (mean reduction 59% transeptal group [four patients], 50% retrograde group [16 patients]) with symptomatic improvement in 18 patients which was maintained at follow-up (mean interval of 5.2 months, range 1-17 months) in 8/15 patients. There were only two significant, resolvable early complications and increases in aortic regurgitation were not seen. There were six late deaths but three patients improved sufficiently to undergo successful aortic valve replacement. Aortic valvoplasty provides good palliation of symptoms. In patients who are unsuitable for the retrograde approach the antegrade, transeptal approach is a satisfactory and effective alternative.

Aged↗
PubMed1990

Chest radiographs after permanent pacing. Are they really necessary?

The chest radiographs of 600 consecutive patients undergoing insertion of a permanent cardiac pacemaker were reviewed to determine the incidence and nature of abnormalities present. Abnormalities were detected on the chest radiographs of 131 patients (21.8%). Unsatisfactory electrode tip position and other features related to the electrode wire were commonest (14.4%). Complications related to the lungs and pleura were present in 5.5%, and those related to the generator and pouch least frequent (1.9%). Complications occurred more frequently following installation of a replacement system (48.3%) compared to new systems (17.2%). Important complications not initially detected included pneumothorax (8/15) and poor electrode loop (26/27). Chest radiographs following permanent cardiac pacing frequently demonstrate significant abnormalities whose detection is improved by awareness of their incidence and nature.

Diagnostic Tests, Routine↗
PubMed1989

Arteriogram scoring systems and Pulse Generated Run-off in the assessment of patients with critical ischaemia for femorodistal bypass.

Conventional arteriography is the investigation of choice in patients with critical ischaemia to select the site for the distal anastomosis of a femorodistal bypass. Several arteriographic scoring systems have been devised in an attempt to quantify the run-off. More recently Pulse Generated Run-off and intraoperative peripheral resistance measurements have been proposed as better predictors of early graft patency. Eighty-eight consecutive femorodistal bypass grafts were studied using Pulse Generated Run-off (PGR), conventional and intra-arterial digital subtraction arteriography (DSA) and peripheral resistance measurement. Three widely used arteriographic scoring systems were used to grade the arteriographic run-off. There were significant correlations between the scoring systems and the measured peripheral resistance, although PGR correlated better with peripheral resistance than arteriography (rs = -0.59, P less than 0.001). Intra-arterial DSA improved the correlation between the arteriogram scoring systems and the measured peripheral resistance in the distal popliteal artery, but not in single calf vessels. In contrast, PGR correlated much better with peripheral resistance in single calf vessels (rs = -0.82, P less than 0.001). We recommend that selection for femorodistal reconstruction be based on a combination of intra-arterial DSA and PGR. PGR will identify patent distal calf vessels not seen on arteriography and determine their continuity with the pedal arch, two features which are essential prerequisites for successful femorodistal bypass.

Adult↗
PubMed1989

Ventricular fibrillation in coronary angiography: what is the role of contrast medium?

A retrospective review of patients with coronary angiography was undertaken to establish the incidence of ventricular fibrillation and other serious arrhythmias and to identify possible causative factors, in particular whether the use of non-ionic contrast medium increased the risk of a serious arrhythmia. Out of 3660 patients reviewed there were 10 cases of ventricular fibrillation. In all cases, there were identifiable technical factors thought to have accounted for the arrhythmia. There were no cases of ventricular fibrillation complicating a technically satisfactory injection of ionic or non-ionic contrast medium. There was no significant difference in the incidence of serious arrhythmias between patients given ionic and those given non-ionic contrast medium.

Angiocardiography↗
PubMed1989

Coil embolization in the treatment of pulmonary arteriovenous malformations.

Twenty-eight pulmonary arteriovenous malformations in six patients were treated with coil embolization. The technique of embolization and the precautions taken to avoid complications are described. All patients had good relief of their symptoms and an improvement in arterial oxygenation. The observed complications were minor and our technique has now been modified to avoid these.

Adult↗
PubMed1988

Digital subtraction dynamic cavernosography.

Digital subtraction angiography (DSA) was used in the investigation, by dynamic cavernosography, of 35 men with acquired erectile impotence. The benefits of using DSA included shorter examination times, lower contrast medium dosage and better definition of abnormal veins. In particular deep crural veins are more clearly seen than in conventional studies and these may be of more importance than was previously thought.

Adult↗
PubMed1988

Radiological investigation of impotence.

Recent advances in the understanding of the causes of impotence have led to the recognition of various treatable physical causes. Some of these causes are related to vascular abnormalities which have necessitated the development of new imaging techniques. These now allow more precise diagnosis and the development of more appropriate surgical and radiological treatment.

Angiography↗
PubMed1988

Management of pulmonary arteriovenous malformations.

Patients with pulmonary arteriovenous malformations (PAVMs) are at risk from a number of serious complications. The development of transcatheter embolization techniques now allows these patients to be effectively treated without the need for major open chest surgery.

Arteriovenous Malformations↗
PubMed1987

Doppler ultrasound in the diagnosis of intestinal ischemia.

Conventional ultrasound is unreliable in detecting narrowing of the visceral arteries. Two cases are reported in which duplex Doppler ultrasound correctly identified severe narrowing of the celiac artery. Doppler ultrasound promises to be more accurate than conventional ultrasound in the diagnosis of visceral ischemia and may help to identify those patients who may require angiography.

Aged↗
PubMed1987

Non-invasive measurement of renal blood flow with 99mTc DTPA: comparison with radiolabelled microspheres.

This technique for non-invasive measurement of renal blood flow is based on the principle of fractionation of cardiac output, and applicable with any recirculating gamma activity tracer. It effectively determines the count rate that would be recorded over the kidney if the tracer behaved like radiolabelled microspheres and was completely trapped in the kidney on first pass. After correction for kidney depth, the estimated first pass activity plateau, expressed as a fraction of the injected dose, is equal to the kidney's fraction of cardiac output. The principle of the technique was validated by comparison with renal blood flow based on radiolabelled microspheres. Nine separate comparisons were made in two anaesthetised dogs. A known dose of 99mTc radiolabelled microspheres (particle size 23-45 microns) was injected into the left ventricle and the count rate over each kidney recorded. A known dose of 99mTc diethylenetriaminepenta acetic acid (DTPA) was then given as an intravenous bolus and the data recorded dynamically with a gamma camera online to a computer. After subtraction of the stable signal arising from the preceding radiolabelled microspheres, the theoretical first pass activity plateau from the DTPA that would have been recorded if the DTPA, after reaching the systemic circulation, had behaved like radiolabelled microspheres and become completely trapped in the renal vascular bed, was estimated. Using doses based on syringe counts before and after injection the ratio of renal blood flow values given by the two techniques (DTPA:RLMS) was 1.14 (SD 0.22) for the left kidney and 1.1(0.17) for the right. Using doses based on whole body counts, corresponding ratios were 1.05(0.11) and 1.02(0.13).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗