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Biomedical subjects

W L Henry

Publications and source records attributed to W L Henry.

At least 145 records · Page 8Linked to original sources
PubMed1975

Electrocardiographic evidence of left ventricular hypertrophy in otherwise normal children. Clarification by echocardiography.

Eleven apparently normal children whose electrocardiograms demonstrated greatly increased precordial QRS voltages suggestive of left ventricular hypertrophy were studied by echocardiography to determine whether this finding represented an early manifestation of cardiac disease. Echocardiographic measurements of the thickness of the ventricular septum and of the left ventricular posterobasal wall were normal in all 11 subjects when compared with normal values for age. Also within normal limits were left ventricular, left atrial and aortic root internal diameters, left ventricular mass and the motion and structure of the anterior and posterior mitral valve leaflets. We conclude: (1) These children probably have normal hearts; (2) increased precordial QRS voltage in children and adolescents, in the absence of other abnormalities, is an unreliable indicator of left ventricular hypertrophy; and (3) echocardiography is a powerful diagnostic test in determining the significance of abnormal electrocardiograms suggestive of left venticular hypertrophy.

Adolescent↗
PubMed1975

Mechanism of left ventricular outlfow obstruction in patients with obstructive asymmetric septal hypertrophy (idiopathic hypertrophic subaortic stenosis).

Left ventricular outflow obstruction in patients with idiopathic hypertrophic subaortic stenosis or obstructive asymmetric septal hypertrophy is due to abnormal forward motion during systole of the anterior mitral leaflet. To determine why some patients with this disease hav left ventricular outflow obstruction whereas others do not, we studied a large number of patiens with assymetric septal hypertrophy using both one- and two-dimensional echocardiography. In 100 patients with asymmetric septal hypertrophy and 22 normal subjects, mitral valve position at the onset of systole was quantitated by measuring the distance from the ventricular septum to the mitral valve and the distance from the mitral valve to the posterior left ventricular wall. None of the normal subjects and only 3 (6 percent) of 51 patients with nonobstructive asymmetric septal hypertrophy had a septal-mitral valve distance of less than 20 mm compared with 23 (66 percent) of 35 patients with obstructive asymmetric septal hypertrophy. Moreover, the mitral valve at the onset of systole was actually positioned forward in the left ventricular activity. Two-dimensional studies in 11 patients with obstructive asymmetric septal hypertrophy revealed that contraction of the malaligned papillary muscles did not cause the abnormal forward mitral valve motion. We propose that the left ventricular outflow obstruction in patients with obstructive asymmetric septal hypertrophy occurs as a result of two factors: (1) narrowing of the left ventricular outflow tract at the onset of systole, and (2) hydrodynamic forces generated by contraction on the left ventricle.

Aortic Stenosis, Subvalvular↗
PubMed1975

Design and function of a mechanical assembly for recording echocardiograms during upright exercise.

It has proved difficult to record satisfactorily echocardiograms during patient motion. This report describes the design and preliminary results obtained with an echo harness with which the transducer can be held stationary or moved rapidly and predictably by remote control. With this apparatus, recordings can be made during tilting, drug intervention, and during bicycle and treadmill exercise.

Amplifiers, Electronic↗
PubMed1975

Measurement of mitral orifice area in patients with mitral valve disease by real-time, two-dimensional echocardiography.

A quantitative assessment of mitral valve orifice area can be achieved in patients with pure mitral stenosis by cardiac catheterization. In the presence of mitral regurgitation, however, accurate measurement often is impossible because total diastolic flow through the mitral valve frequently is unknow. Using a recently developed real-time, two-dimensional echocardiography system, we are able to obtain cross-sectional images of the mitral valve by scanning the heart perpendicular to its long axis at the level of the tip of the mitral leaflets. Twenty consecutive patients undergoing operation for mitral valve disease were studied during the week prior to operation. In 18 of 20 (90%) the mitral orifice was imaged successfully in early diastole by two-dimensional echocardiography so that mitral valve orifice area could be measured directly in square centimeters. In 14 patients (ten with associated mitral regurgitation), mitral orifice area was measured both by echocardiography and directly at time of operation. In 12 of 14 (86%) patients, mitral orifice area by two-dimensional echocardiography was within 0.3 square centimeters of that measured at operation (correlation coefficient for all 14 patients equals 0.92). We conclude that two-dimensional echocardiography is extremely useful in the evaluation of patients with mitral valve disease because it provides a noninvasive method for directly measuring the mitral valve orifice area that is accurate even in the presence of mitral regurgitation.

Calcinosis↗
PubMed1975

Operative treatment in hypertrophic subaortic stenosis. Techniques, and the results of pre and postoperative assessments in 83 patients.

The results of operative treatment in 83 patients with idiopathic hypertrophic subaortic stenosis (IHSS) are described. Most patients with the disease are asymptomatic, or derive satisfactory symptomatic improvement from nonoperative therapy: administration of propranolol, exerice limitation, control of arrhythmia, etc. Operation is required, however, in 10-15% of patients, those who remain severely symptomatic after nonoperative treatment or who become refractory to it. Operation relieves symptoms in IHSS by relieving obstruction to left ventricular outflow, and for a patient to be considered an operative candidate severe obstruction must be documented at left heart catheterization either under resting conditions or after provocative interventions. All 83 patients were severely incapacitated--58 in Class III and 24 in Class IV. Seventy had obstruction at rest (average gradient 96 mm Hg), and 13 had only provocable obstruction. At operation the hypertrophic interventricular septum was exposed via an aortotomy, and a vertical bar of muscle was resected between parallel myotomy incisions. There were six operative deaths (7%); no patient has died since 1970. Seven patients have died late after operation, five of them from causes unrelated to their heart disease or the operation. All surviving patients describe symptomatic improvement. Fifty-two patients with obstruction at rest preoperatively (average gradient 95 mm Hg) have been studied postoperatively: no resting gradient was evident in 47, while in the remaining five the gradient was less than 25 mm Hg. Recurrence of obstruction has never been observed at late catheterization (21 pts) or late echocardiographic examination (37 pts). Obstruction could not be provoked postoperatively in ten of the 11 patients who had large gradients only with the Valsalva maneuver or isoproterenol administration preoperatively. Obstructed and provocable obstructed patients had similar symptomatic improvement after operation. A variety of rhythm and conduction abnormalities were observed both pre and postoperatively, and these are described in detail. The results of operation in these 83 patients with IHSS demonstrate that gratifying symptomatic and hemodynamic improvement uniformly follows left ventriculomyotomy and myectomy. Relief of obstruction and amelioration of symptoms have proved to be long-lasting during postoperative observation periods extending to 14 years. Continued application of the operative procedure in properly selected patients appears to be indicated.

Adolescent↗
PubMed1975

Identification of congenital malformations of the great arteries in infants by real-time two-dimensional echocardiography.

Real-time, two dimensional echocardiography was used to identify great artery relations in 23 infants and small children, including 16 patients with angiography documented transposition of the great arteries, tetralogy of Fallot, or pulmonary aresia. Using this technique, the heart was scanned perpendicular to its long axis at the origin of the great arteries. Great arteries cross-sectioned perpendicular to their long axes appear as circles; when sectioned longitudinally these arteries appeared as elongated sausage-shaped structures. I- patients with normally related great arteries, a curcular structure (aorta) always was positioned posterior to an elongated, sausage-shaped structure (distal right ventricular outflow tract and proximal main pulmonary artery). In transposition of the great arteries, two adjacent circular structures were observed; the anterior circle (aorta) was located to the right, left or directly anterior to the posterior circle (pulmonary artery). In pulmonary atresia or hypoplasis, a large posterior circle (aorta) was associated with an anteriorly positioned structure that was either short and small (atretic right ventricular outflow tract) or elongated with an area of severe narrowing (hypoplastic right ventricular outflow tract). Thus, real-time two-dimensional echocardiography provides a rapid, noninvasive means of accurately identifying congenital malformations of the great arteries in infants and small children and may be a useful adjunct to cardiac catheterization in the diagnosis of cyanotic congenital heart disease.

Child, Preschool↗
PubMed1975

Congenital heart malformations associated with disproportionate ventricular septal thickening.

Asymmetric septal hypertrophy, or ASH, is a genetically determined myocardial disorder that is transmitted as an autosomal dominant trait. ASH is characterized by a disproportionately thickened ventricular septum that contains numerous hypertrophied, bizarrely-shaped and disorganized cardiac muscle cells. Disproportionate hypertrophy of the ventricular septum has also been observed in association with certain congenital cardiac malformations. To determine whether such congenital cardiac malformations are part of the disease spectrum of genetically determined ASH, cardiac pathologic observations were made in eight patients with disproportionate septal thickening (ventricular septal to posterobasal left ventricular free wall thickness ratios of 1.5 to 2.5) and the following three categories of associated lesions: 1) parachute deformity of the mitral valve (occurring either as an isolated lesion or with ventricular septal defect, coarctation of the aorta, supravalvular ring of the left atrium, or double outlet right ventricle); 2) complete interruption of the aortic arch; and 3) ventricular septal defect. The arrangement of cardiac muscle cells in the disproportionately thickened ventricular septum was normal in six of the eight patients; in the other two patients (one with parachute deformity of the mitral valve and one with ventricular septal defect) numerous bundles of hypertrophied cardiac muscle cells were interlaced in a disorganized fashion among more normally arranged bundles of cells. First degree relatives of six of the eight patients were studied by echocardiography and found to have normal ventricular wall thicknesses and septal-free wall ratios. It is concluded that disproportionate ventricular septal thickening may occur in patients with a variety of congenital heart malformations, but that such a finding is not necessarily a manifestation of the disease spectrum of genetically determined ASH.

Adult↗
PubMed1975

Comparative left ventricular dimensions in trained athletes.

Little is known about the structure of athletes' hearts of anatomic variations associated with training. Echocardiograms of 56 active athletes were obtained. Mean left ventricular end-diastolic volume and mass were increased in athletes involved in isotonic exercise, such as swimming (181 ml, 308 g) and running (160 ml, 302 g), compared with controls (101 ml, 211 g); wall thickness was normal (less than or equal to 12 mm). Athletes involved in isometric exercise, such as werstling and shot putting, had normal mean left ventricular end-diastolic volumes (110 ml, 122 ml), but increased wall thickness (13 to 14 mm) and mass (330 g, 348 g). Thus, athletes participating in isotonic exercise had increased left ventricular mass with cardiac changes similar to those in chronic volume overloads. Athletes participating in isometric exercise had increased left ventricular mass with cardiac changes similar to those in chronic pressure loads, recognizing greater left ventricular mass and volume in well-trained athletes aids in interpreting values deviating from "normal" limits.

Adolescent↗