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Biomedical subjects

C Kourouklis

Publications and source records attributed to C Kourouklis.

7 recordsLinked to original sources

Percutaneous balloon mitral valvuloplasty by retrograde left atrial catheterization.

A new technique was developed for percutaneous mitral valve balloon valvuloplasty, using a retrograde approach to the left atrium via the left ventricle. A newly designed externally steerable guiding catheter is used for the introduction of 1 or 2 guidewires to the left atrium and the balloon catheters are advanced along these guidewires into the mitral orifice. The technique was used successfully in 10 adult patients with rheumatic mitral stenosis. After the procedure there was a significant reduction in mitral valve pressure gradient and an increase in the mitral valve area in all cases. There were no serious complications during or after the procedure. This technique should prove to be a useful nonsurgical treatment for mitral stenosis and could provide an alternative to the transseptal method.

Cardiac Catheterization↗

Distensibility of the ascending aorta: comparison of invasive and non-invasive techniques in healthy men and in men with coronary artery disease.

Distensibility of the ascending aorta, measured non-invasively, was compared with values obtained by invasive techniques in 46 males (30 patients with coronary artery disease and 16 age-matched normal subjects). Aortic diameters were measured at a level 3 cm above the aortic valve using both echocardiographic and angiographic techniques. Aortic distensibility was calculated from the aortic diameters and aortic pressure or brachial artery pressure using the formula: 2 x (change in aortic diameter)/(diastolic aortic diameter) x (change in aortic pressure). Distensibility of the ascending aorta determined non-invasively was closely related to that obtained by direct measurements (r = 0.949, P less than 0.001). Patients with coronary artery disease had similar pressures, but markedly lower distensibility than normal subjects, as shown by both invasive and non-invasive techniques. The results indicate that aortic distensibility in patients with coronary artery disease can be obtained non-invasively with a high degree of accuracy.

Adult↗

Percutaneous transluminal coronary angioplasty using a steerable guiding catheter: a new technique.

A new type of steerable guiding catheter is described for use in percutaneous transluminal coronary angioplasty (PTCA). It is simple to use and externally steerable. The catheter incorporates a steering system by means of which the catheter tip can be made to assume the form of either a right or left Judkins catheter or to be fixed in any intermediate configuration, entirely through external manipulation. We used this new guiding catheter to perform PTCA on 15 patients. Single lesions were found in the left anterior descending branch in seven patients, in the right coronary artery in four, and in the circumflex artery in two, whereas stenosis of a coronary bypass graft was found in two patients. Angioplasty was successful in all cases. There were no complications, during either the procedure or the postoperative hospitalization. The steerable guiding catheter described here may prove useful for PTCA in cases where a conventional catheter cannot be placed accurately or in cases with multi-vessel coronary disease.

Adult↗

Determination of left ventricular residual function by analysis of post-extrasystolic beat in mitral stenosis.

Residual function of the left ventricle was assessed in 25 patients with mitral stenosis and a normal left ventriculogram. The post-extrasystolic beat (R2) in sinus rhythm (nine patients) and the first beat after an early beat (R2) in atrial fibrillation (16 patients) were analysed angiocardiographically. Five subjects with a normal heart (controls) were also studied. The results are expressed as percentage changes in left ventricular contractility from the beat preceding the extra beat (R1) to the beat R2. In the control group the mean changes from R1 to R2 were: end diastolic volume +68.3% (increase), end systolic volume -21.7% (decrease), ejection fraction +36.2%, mean systolic ejection rate +22.1%, and mean velocity of circumferential fibre shortening +31%. A significant increase in proportional systolic shortening of all left ventricular axes was found in R2 compared with R1. In five patients with sinus rhythm and nine with atrial fibrillation the results fell within the normal range. In the remaining patients the beat R2 indicated signs of poor left ventricular function. The mean changes from R1 to R2 in the patients with sinus rhythm and those with atrial fibrillation were respectively: end diastolic volume +47.8% and +36.6%, end systolic volume +20% and +27%, ejection fraction +12.5% and +6.2%, mean systolic ejection rate -23.3% and -30.2%, and mean velocity of circumferential fibre shortening -25.5% and -39.2%. The increase in the left ventricular axial systolic shortening was not significant. Thus analysing a post-extrasystolic beat in sinus rhythm of the beat following an early beat with a long diastole in atrial fibrillation is a valuable method of determining the residual function in patients with mitral stenosis who have a normal left ventriculogram in basic rhythm.

Adolescent↗

Bumetanide in congestive heart failure.

Bumetanide, a new diuretic exerting its major effect on the ascending limb of the loop of Henle, was evaluated in 20 patients with congestive heart failure. Dosage ranged from 1 mg to 3 mg daily depending on the patient's condition. The results after 3 and 8 days' treatment showed that bumetanide caused a significant diuresis, an increased excretion of sodium, potassium and chloride, and a comparable fall in the serum levels of these electrolytes. Changes in electrolyte levels were directly related to the dose of the drug. The resultant hypochloraemia was accompanied by a slight metabolic alkalosis. A comparative crossover study between placebo, bumetanide and frusemide using equipotent doses was performed in 10 patients. Both drugs had a similar effect upon water excretion and the serum and urinary electrolytes.

Bumetanide↗