Edwin C. Brockenbrough

Transseptal Left Heart Catheterization A Review of 450 Studies and Description of an Improved Technic

Experiences with 450 transseptal left heart catheterizations are reviewed. There were no mortalities in this series, and the only significant complication was accidental puncture of the aorta in three patients. The equipment and technic employed in the current method, by which a radiopaque catheter of large caliber is introduced into the left ventricle, are described in detail. The advantages of this modification are outlined.

Left Atrial and Left Ventricular Pressures in Subjects without Cardiovascular Disease Observations in Eighteen Patients Studied by Transseptal Left Heart Catheterization

Transseptal left heart catheterizations were carried out in 18 patients without apparent evidence of organic cardiovascular disease. These studies have permitted delineation of the pressures that exist in the left side of the heart in normal subjects studied in a basal physiologic state.

Studies on digitalis. V. Comparison of the effects of ouabain on left ventricular dynamics in valvular aortic stenosis and hypertrophic subaortic stenosis.

The acute hemodynamic effects of 0.50 to 0.75 mg. ouabain were studied in six patients with valvular aortic stenosis and in four patients with idiopathic hypertrophic subaortic stenosis. Left atrial and left ventricular pressures were determined by means of transseptal left heart catheterization and cardiac output was measured by the indicator-dilution technic. In the patients with valvular aortic stenosis, ouabain either improved left ventricular function or had no discernible effect on it, but in no patient was left ventricular function depressed. Left ventricular end-diastolic pressure fell slightly or remained unchanged, while cardiac output rose in two of four patients. In the patients with hypertrophic subaortic stenosis, the left ventricular end-diastolic pressure and mean left atrial pressure rose significantly following ouabain administration; cardiac output either fell or remained unchanged and the systolic pressure gradient between the left ventricle and the brachial artery rose. These actions of ouabain in hypertrophic subaortic stenosis are considered to result from a sustained increase in left ventricular contractile force that increased the obstruction produced by the muscular outflow tract.

Transseptal Left Heart Catheterization

Development in the 1950s of the transseptal technique for left heart catheterization is described. Initial studies in animals and human cadavers were followed up by left atrial puncture with measurements of left atrial and left ventricular (LV) pressure (the latter using a small plastic catheter) in patients with cardiac disease. Many such procedures were performed safely without complications. Subsequent modification of the original technique for percutaneous catheter insertion allowed placement of a larger taper-tipped catheter in the LV chamber for selective LV angiography. Early clinical research studies at the National Heart Institute were performed using the transseptal method; these included investigation of the effects of increasing afterload on the normal and failing left ventricle by means of a graded angiotensin infusion to induce a progressive increase in aortic pressure. A marked decrease in the stroke volume occurred with increased afterload in the failing heart. This finding later led to the concept of afterload mismatch with limited pre-load reserve. Another early transseptal catheterization study in which measurements of LV pressure were made at different locations within the left ventricle as well as in the left atrium confirmed the presence of cavity obliteration in some patients and true obstruction in the LV outflow tract in many others. In addition, left ventriculography showed that obstruction was caused by abnormal anterior position during systole of the anterior mitral valve leaflet. With growing acceptance of retrograde catheterization of the left ventricle, the use of the transseptal technique for diagnostic purposes declined. However, in recent years, substantial renewed application of the transseptal method has occurred for special diagnostic and therapeutic purposes, including balloon valvuloplasties and electrophysiologic ablation procedures within the left heart.

PERCUTANEOUS PUNCTURE OF THE LEFT VENTRICLE

Left heart catheterization has become an increasingly important method for the pre-operative assessment of patients with congenital or acquired heart disease, and in recent years a variety of techniques have been introduced for gaining access to the left atrium and left ventricle (Morrow et al., 1960). When the usual clinical examinations indicate the need for such study the physician must select the method of left heart catheterization that will provide the information, in a particular patient, with a minimum of risk and discomfort. One of the techniques most commonly employed for access to the left ventricle is anterior percutaneous puncture. Although this method has been widely used since it was described and popularized by Brock and co-workers in 1956, relatively little information is available concerning experiences with this technique (Fleming et al., 1958; and Raynaud et al., 1959). At the National Heart Institute left ventricular puncture has been employed in the course of 226 haemodynamic studies. The present report constitutes a description of the techniques and a summary of the experience with the procedure in this clinic.

Selective left heart angiocardiography by the transseptal route

Abstract A technic for performing selective left atrial and left ventricular angiocardiography by means of percutaneous transseptal left heart catheterization is described and the results of such studies performed in sixty patients are presented. The clinical applications of this technic in the study of patients with various forms of obstruction to left ventricular outflow, various types of mitral valve lesions, defects of the ventricular septum and anomalies of the aortic arch are discussed in detail.

Partial persistent atrioventricular canal simulating pure mitral regurgitation

Abstract Patients with persistent partial atrioventricular canal and only small interatrial communications may present the clinical features of pure mitral regurgitation. Two such individuals, who on clinical examination were mistakenly considered to have rheumatic mitral regurgitation, are described. The roentgenographic findings supported this diagnosis, and the electrocardiograms did not exhibit the vector loop characteristic of an endocardial cushion defect. Cardiac catheterization made possible the correct diagnosis, however, and at operation each patient was found to have a cleft anterior mitral leaflet and an unusually small interatrial defect of the ostium primum type. Problems which relate to the diagnosis and surgical management of this unusual variant of persistent A-V canal are discussed.

Use of Krypton85 for the Measurement of Cardiac Output by the Single-Injection Indicator-Dilution Technique

When krypton85 in saline solution is injected into the left side of the heart and sampled from a systemic artery, or is injected into a peripheral vein and sampled from the pulmonary artery, only the primary time-concentration curve is obtained. Recirculation is eliminated by the diffusion of this indicator into the extravascular space and its loss from the pulmonary capillary bed. Determination of the radioactivity in a single blood sample, withdrawn at a constant rate throughout the period during which the Kr85 passes across. the sampling site, permits calculation of the average concentration of Kr85 during the inscription of the primary curve. The validity of this technique was tested in a circulatory model against actual flow determined by timed collection. One standard deviation of the differences in 27 trials equaled 5.1 per cent. In 26 comparisons of cardiac output determined simultaneously in dogs by a rotameter and the Kr85 technique, one standard deviation of the differences equaled 8.4 per cent. In 19 comparisons of cardiac output in patients, determined by dye-dilution and Kr85 techniques, one standard deviation of the differences equaled 11 per cent. The Kr85 technique is simpler technically and requires less blood, instrumentation, and calculation than the standard dye techniques.