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Biomedical subjects

C Wren

Publications and source records attributed to C Wren.

85 records · Page 5Linked to original sources
PubMed1987

Balloon dilatation of unoperated aortic coarctation: immediate results and one year follow up.

Fifteen patients aged 1-19 years (mean 10.9) with previously unoperated aortic coarctation underwent percutaneous balloon angioplasty between January 1985 and February 1986. Nine (60%) were hypertensive at presentation. Under general anaesthetic the systolic coarctation gradient was 24-50 mm Hg (mean 29) and the coarctation diameter was 4-9 mm (mean 5.5). Meditech balloon catheters 8-18 mm in diameter were inflated 1-4 times at 410-760 kPa. After dilatation the systolic coarctation gradient decreased to 0-20 mm Hg (mean 6) and the coarctation diameter increased to 7-20 mm (mean 12). One patient developed a fusiform aneurysm of the aorta at the coarctation site immediately after the procedure. At reinvestigation 6-16 months (mean 12.5) after dilatation 14 of the 15 patients were normotensive. In 13 patients the residual coarctation gradient was 0-10 mm Hg (mean 3). Two patients had recoarctation with residual gradients of 20 and 24 mm Hg and underwent successful repeat dilatation. One patient had developed a small discrete aneurysm at the coarctation site. Balloon angioplasty is thus a safe and effective method of relieving unoperated aortic coarctation. The frequency of aortic aneurysm and recoarctation is small and probably related to balloon size. This early experience is encouraging, but long term results and further experience are required before this approach is used to treat coarctation generally.

Adolescent↗
PubMed1987

Percutaneous balloon dilatation of aortic valve stenosis in neonates and infants.

Percutaneous balloon dilatation of severe aortic valve stenosis was attempted in thirteen patients (seven neonates and six infants). In two the valve could not be crossed and both died during subsequent operation. Two patients died during manipulation of the balloon catheter. No significant benefit was obtained in another patient who later died during operation. Balloon dilatation was successful in the remaining eight patients, reducing the aortic valve pressure gradient from a mean of 63 mmHg (95% confidence interval 38 to 88 mmHg) to a mean of 23 mmHg (95% confidence interval 7 to 39 mmHg). Two of these patients subsequently died from heart failure related to other cardiac lesions. The six survivors have done well. At follow up the maximum Doppler velocities in the ascending aorta ranged from 1.9 to 4.0 m/s after 2-23 months, but despite this evidence of an increasing valve gradient there has been lasting clinical improvement.

Aortic Valve Stenosis↗
PubMed1985

Role of echocardiography in differential diagnosis of broad complex tachycardia.

It is not always easy to distinguish between supraventricular tachycardia with aberration and ventricular tachycardia by electrocardiographic analysis alone. M mode echocardiography can often help by providing direct or indirect evidence of the relation between atrial and ventricular contraction. Sixteen consecutive patients with spontaneous sustained broad QRS complex tachycardia with heart rates of 120-225 beats/minute were examined. Echocardiographic evidence of 1:1 conduction was seen in three cases and 2:1 atrioventricular conduction in one (all four had supraventricular tachycardia, confirmed by intracardiac electrocardiography in three). Evidence of retrograde block was seen in 12 (all had ventricular tachycardia, with electrophysiological confirmation in 10). Satisfactory views of the mitral valve were obtained in all patients. Patients with ventricular tachycardia had a variable mitral valve opening time (range 42-110%) compared with those who had supraventricular tachycardia (9-15%). Aortic root and left atrial views gave direct evidence of atrial contraction in three cases, and subcostal right atrial wall views were diagnostic in four of five cases. Seven patients with ventricular tachycardia had been wrongly diagnosed elsewhere as having supraventricular tachycardia. This study confirms that echocardiography is a simple and rapid aid to accurate diagnosis in patients with broad QRS complex tachycardia.

Adolescent↗
PubMed1982

Sinus node function in first three weeks after cardiac transplantation.

Donor sinus node function was studied in 10 patients from day 4 to day 24 after cardiac transplantation. Cycle length, atrial arrhythmias, corrected sinus node recovery time, and estimated sinoatrial conduction time were recorded daily. Five patients had at least two sets of results suggesting sinus node dysfunction (group A) while five patients had no such abnormalities (group B). The prognosis in group A was poor, with four of the five patients dying within four months of the operation; one unexpected death from arrhythmias was recorded by ambulatory electrocardiographic monitoring. All five patients in group B survived for at least eight months. In nine patients sinus node function varied from day to day, with corrected sinus node recovery time reaching a peak at 11 to 18 days after operation. The longest corrected sinus node recovery time was 11 160 ms. Neither the differences between the patients, nor the day to day variation, could be explained solely by the degree of rejection as assessed by biopsy or by the ischaemia time of the heart during procurement. Sinus node dysfunction soon after transplantation is associated with a poorer prognosis and might be the terminal event in some cases.

Adult↗
PubMedDate not supplied

Validation of the Takeda 2421 ambulatory blood pressure monitor in children.

The purpose of this study was to assess the accuracy of an ambulatory monitor (Takeda 2421; A&D company) which measures blood pressure using oscillometric and Korotkoff methods, in children. Blood pressure was measured simultaneously by the device and two observers in 529 children aged 7-15 years. The Korotkoff method received BHS grade A for sitting and standing readings in all age groups except for age 13-15 years (grade C). The diastolic readings (phase V) received grade B for sitting and C when standing. The oscillometric method received grade C or worse for systolic and diastolic blood pressure in both sitting and standing positions except for systolic readings in those aged 13-15 years (grade B). During the ambulatory phase 30% of the Korotkoff readings and 4% of the oscillometric readings gave an error code. The Takeda 2421 ambulatory monitor achieved generally satisfactory grades using the Korotkoff system but the oscillometric readings were generally unacceptable. Ambulatory devices should be specifically validated in children before being accepted into clinical paediatric practice.

Adolescent↗