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At least 1,315 records · Page 73Linked to original sources
PubMed1985

Doppler evaluation of left ventricular diastolic filling in children with systemic hypertension.

To assess left ventricular (LV) diastolic function in children with systemic hypertension, 11 patients with hypertension (mean blood pressure 99 mm Hg) and 7 normal patients (mean blood pressure 78 mm Hg) underwent M-mode echocardiography and pulsed Doppler examination of the LV inflow. From a digitized trace of the LV endocardium and a simultaneous phonocardiogram, echocardiographic diastolic time intervals, peak rate of increase in LV dimension (dD/dt), and dD/dt normalized for LV end-diastolic dimension (dD/dt/D) were measured. Doppler diastolic time intervals, peak velocities at rapid filling (E velocity) and atrial contraction (A velocity), and the ratio of E and A velocities were measured. The following areas under the Doppler curve and their percent of the total area were determined: first 33% of diastole (0.33 area), first 50% of diastole, triangle under the A velocity (A area), and the triangle under the E velocity (E area). The A velocity (patients with hypertension = 0.68 +/- 0.11 m/s, normal subjects = 0.49 +/- 0.08 m/s), the 0.33 area/total area (patients with hypertension = 0.49 +/- 0.09, normal subjects = 0.58 +/- 0.08), the A area (patients with hypertension = 0.17 +/- 0.05, normal subjects = 0.12 +/- 0.03), and the A area/total area (patients with hypertension = 0.30 +/- 0.11, normal subjects = 0.20 +/- 0.07) were significantly different between groups (p less than 0.05). M-mode and Doppler time intervals, (dD/dt)/D, E velocity, and the remaining Doppler areas were not significantly different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Assessment of left ventricular aneurysm resectability by two-dimensional echocardiography.

Mortality of surgical resection of a left ventricular (LV) aneurysm is largely determined by size and function of nonaneurysmal or residual myocardium. A residual myocardial index was determined using 2-dimensional echocardiography (2-D echo) in 56 consecutive patients scheduled for LV aneurysmectomy, and these results were correlated with surgical outcome. The index was calculated using 3 apical cross sections: the 2- and 4-chamber views and the long-axis view. These views were recorded at mutual angles of 60 degrees. In each view the end-diastolic length of normally moving endocardium of the 2 opposite walls was expressed as a fraction of the end-diastolic LV long axis. The index was assessed by averaging the 6 ratios obtained. In 41 survivors the index ranged from 40 to 71% (mean +/- standard deviation 53 +/- 7.8) and in 15 nonsurvivors from 29 to 67% (mean 38 +/- 8.5, p less than 0.01). With 1 exception, this echocardiographic index sharply separated survivors from nonsurvivors. The lower limit to survive aneurysmectomy was 40%.

Adult↗
PubMed1986

Morphologic characteristics and structure of surface excrescences (Lambl's excrescences) in the normal aortic valve.

The incidence, morphologic characteristics and structure of surface valve excrescences (Lambl's excrescences) were studied by transmission and scanning electron microscopy of the aortic valve of 56 human subjects, age range birth to 91 years, without cardiac disease. Valve excrescences consisting of a core of connective tissue covered by the endocardium were observed in 90% of the subjects; the incidence was significantly lower in patients in the first decade of life. Two types of excrescences, lamellar and filiform, were found. Lamellar excrescences are located along the lower boundary of the lunulas and occurred more often in those younger than 30 years. Filiform excrescences appear most often in the nodulus Arantius and in the free-margin of the cusps. The excrescences of the nodulus are the most numerous. Free-margin excrescences are the least numerous and occur more frequently in persons older than 40 years. The connective tissue core of the filiform excrescences contains abundant collagen fibrils and elastic material arranged in apposed layers with different collagen fibril orientation. A circular zone devoid of identifiable connective tissue is present at the center of the filiform excrescences.

Adult↗
PubMed1989

Clinical and echocardiographic comparison of patients with the carcinoid syndrome with and without carcinoid heart disease.

To correlate clinical and laboratory variables in carcinoid heart disease, clinical data, echocardiograms, 24-hour urinary 5-hydroxyindoleacetic acid levels and liver function tests were evaluated in 30 patients with the carcinoid syndrome. The dominant cardiac lesion of carcinoid heart disease by echocardiography and Doppler was severe tricuspid regurgitation with right ventricular volume overload. A characteristic finding was thickened, retracted tricuspid valve leaflets that were fixed in a partially open position. Carcinoid heart disease was progressive and often fatal. The 17 patients with echocardiographic evidence of carcinoid heart disease had higher peak levels of urinary 5-hydroxyindoleacetic acid (331 +/- 231 vs 58 +/- 78 mg, p less than 0.001) and more severe hepatic dysfunction than the 13 patients without carcinoid heart disease. Although duration of symptoms of the carcinoid syndrome before echocardiography was similar for patients with and without carcinoid heart disease (5.4 +/- 6.4 vs 6.2 +/- 5.9 years, respectively, p greater than 0.1), survival after echocardiography was shorter for those with carcinoid heart disease (1.9 +/- 1.4 vs 3.8 +/- 2.9 years, p = 0.05). The findings support the concept that long-term exposure of the endocardium to serotonin in the right side of the heart leads to the development of heart lesions; in addition, progressive hepatic dysfunction may allow more serotonin to bypass liver enzymes and reach the right side of the heart.

Adult↗
PubMed1989

Surgical management of tachyarrhythmias.

In this study of surgical procedures for various tachyarrhythmias, Wolff-Parkinson-White syndrome comprised most of the cases. An endocardial approach was used to ablate accessory pathways. Additional use of cryocoagulation after surgical incision of the atrium, previously routinely performed, is at present only done occasionally for septal accessory pathways. Ventricular tachycardia (VT) was the next most frequent condition. The surgical procedures for ischemic and nonischemic VTs are completely different, although both are based on the principle of complete electrophysiologic mapping. For ischemic VT, surgery consists of resection of the left ventricular aneurysm and excision or cryocoagulation of the endocardium, or both. For nonischemic VT, either excision of the entire thickness of the myocardium (2.0 X 2.5 cm on average) at the earliest excitation site of the right ventricle and cryocoagulation of the area of delayed potential or only incision and cyrocoagulation of the left ventricle were performed to avoid reduction of the left ventricular cavity. Ectopic atrial tachycardia was cured by excision of the earliest excitation site without use of a heart-lung machine, when the focus was located in the atrial free wall. Other successful treatments were of reentrant atrial tachycardia by cryocoagulation, atrial flutter by cryocoagulation of impulse pathways at the coronary sinus and around the atrioventricular node, and a new surgery for atrial fibrillation and flutter, which retained sinus rhythm. Johnson's procedure was used for surgical ablation of atrioventricular nodal reentrant tachycardia.

Adolescent↗
PubMed1994

Quantification of left ventricular function with an automated border detection system and comparison with radionuclide ventriculography.

Quantification of 2-dimensional echocardiograms with a recently developed automated border detection (ABD) system provides on-line estimation of left ventricular (LV) function. Previous studies showed that short-axis cavity area measurements with the ABD system approximate manually traced cavity areas obtained with conventional 2-dimensional echocardiography. Further clinical validation needs a comparison of LV function between the ABD system and established methods. Fractional area change and ejection fraction measured by the ABD system were compared with ejection fraction measured by radionuclide ventriculography. Echocardiographic measurements were obtained from LV short-axis views at the level of the papillary muscles. Calculation of ejection fraction by the ABD system was based on an algorithm using a modified ellipsoid model. Forty-six patients underwent echocardiography on the same day as radionuclide ventriculography. Patients were included in the study if > or = 75% of the endocardium was visualized with conventional 2-dimensional echocardiography. Twenty-seven of 46 patients (59%) had a technically adequate, conventional echocardiogram. Fractional area change with the ABD system was highly correlated with ejection fraction from radionuclide ventriculography (r = 0.92; SEE 8.4%). Ejection fraction determined by the ABD system and radionuclide ventriculography also showed a strong linear relation in the 23 patients without severe wall motion abnormality (r = 0.90; SEE 9.5%). It is concluded that LV function measurements by the ABD system and radionuclide ventriculography have a strong linear relation.

Adolescent↗
PubMed1976

Metastatic infection secondary to genitourinary tract sepsis.

Metastatic infections arising from sepsis in the genitourinary tract are reviewed in 175 cases, including five in which we treated the patients. The skeleton was the most common site of metastasis (59 per cent). The endocardium was next most frequently involved (28 per cent). Gram-negative organisms were implicated in less than two-thirds of the cases (59 per cent). Impaired host defense mechanisms were noted in 25 per cent of the patients experiencing metastatic infections. The lower urinary tract was the source of metastasis in 75 per cent of the patients, particularly after urologic manipulation in men. Women were more likely to experience metastatic infection from the upper urinary tract. Anatomic and pathologic considerations explaining these sex differences are presented.

Aged↗
PubMed1978

Dynamic left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve in the absence of asymmetric septal hypertrophy.

Systolic anterior motion of the anterior mitral valve leaflet and asymmetric septal hypertrophy are the principal components of the dynamic subaortic stenosis in hypertrophic obstructive cardiomyopathy. Mitral valve systolic anterior motion without septal hypertrophy or left ventricular outflow tract obstruction has been described, but asymmetric septal hypertrophy is supposedly a consistent feature of dynamic subaortic stenosis. We describe two patients with syncope, chest pain and the typical systolic murmur of hypertrophic subaortic stenosis whose echocardiograms showed mitral valve systolic anterior motion but not asymmetric septal hypertrophy. Normal septal thickness on echo was confirmed by intravenous indocyanine green to identify the right septal endocardium. At catheterization, left ventricular outflow tract gradients were provoked, and neither patient had interventricular septal hypertrophy on biventricular cineangiography. These findings in two cases suggest that mitral valve systolic anterior motion can be the only definable anatomic abnormality associated with symptomatic dynamic left ventricular outflow tract obstruction and that asymmetric septal hypertrophy is not a necessary component of this condition.

Adult↗
PubMed1985

The carcinoid syndrome: comparison of 21 necropsy subjects with carcinoid heart disease to 15 necropsy subjects without carcinoid heart disease.

Carcinoid heart disease is a morphologically specific type of cardiac disorder that involves the mural and valvular endocardium on the right side of the heart. Twenty-one subjects (57 percent) (Group I) with carcinoid heart disease and 15 subjects (43 percent) (Group II) without carcinoid heart disease were studied at necropsy. The two groups were similar in mean age (54 years versus 55 years), duration of clinical illness (4.7 years versus 6.3 years), body weight (50 kg versus 52 kg), systemic blood pressure (117/77 mm Hg versus 128/77 mm Hg), blood hematocrit levels (37 percent versus 36 percent), total serum protein levels (6.0 g/dl), and serum albumin levels (2.2 g/dl versus 2.6 g/dl). The two groups were different in the frequency of the presence of precordial murmurs consistent with tricuspid regurgitation and/or pulmonic stenosis (95 percent versus 13 percent), cardiomegaly by chest radiography (38 percent versus 0), low voltage on electrocardiography (47 percent versus 0), and location of the primary site of the carcinoid tumor. Total electrocardiographic 12-lead QRS voltage was similar in each group (105 mm versus 132 mm) (10 mm = 1 mV). Of Group I subjects, 43 percent died of cardiac causes; none of the Group II subjects died of cardiac causes. Of the 21 subjects with carcinoid heart disease, seven had left-sided cardiac involvement, but in none was it of functional significance. Thus, although carcinoid heart disease frequently is the cause of death in patients with the carcinoid syndrome, the development of carcinoid heart disease is not related to the duration of symptoms of the carcinoid syndrome.

Adult↗
PubMed1990

Computerized potential distribution mapping: a new intraoperative mapping technique for ventricular tachycardia surgery.

This study evaluated potential distribution mapping as a method for localizing the site of origin of ventricular tachycardia (VT). In contrast to conventional activation time maps, potential distribution maps require less editing and thus can be more automated and rapidly processed for interpretation of multiple beats of VT. As a series of potential distribution maps during VT is required for detailed analysis, an on-line computerized system was designed to display potential distribution maps sequentially at 1-ms intervals as a color movie. Potential distribution maps and activation time maps were constructed from 182 epicardial and endocardial unipolar electrodes during 12 episodes of reproducible monomorphic VT in 9 dogs four to six days after experimental myocardial infarction (mean cycle length, 162 +/- 21 ms). At the onset of each depolarization during VT, a potential minimum abruptly developed on the surviving epicardium and another on the surviving endocardium of the left ventricle, both immediately adjacent to the subendocardial infarct. These two minima on the initial potential distribution maps corresponded to the sites of earliest epicardial and endocardial activation breakthrough recorded on the activation time maps. These two minima subsequently expanded or moved into the adjacent area and coincided with the spread of activation fronts on the epicardial and endocardial surfaces. Thus, the rapid display of sequential, computerized potential distribution maps of multiple beats of VT provides a dynamic means of identifying the site of origin of VT, and therefore should facilitate intraoperative mapping.

Action Potentials↗
PubMed1991

Optimizing myocardial hypothermia: I. Temperature probe design and clinical inferences.

Myocardial hypothermia is an essential component of myocardial preservation for most cardiac operations. Because of multiple causes of rewarming, it is necessary to monitor temperatures at specific sites (right and left ventricular epicardium and endocardium or cavity). Thus, plastic temperature probes have been designed and fabricated to facilitate temperature monitoring at these sites. Using a bare thermocouple as a standard, in vitro comparison of metallic probes and plastic probes revealed differences of 4.0 degrees +/- 0.9 degrees C and 0.7 degrees +/- 0.6 degrees C, respectively (p less than 0.005). Consequently, metallic probes do not have sufficient accuracy to detect transmural temperature gradients because of "stem effect." Using the plastic probes to evaluate temperature changes in porcine hearts after cardioplegia-induced hypothermia revealed a temperature rise of 1 degree C/min at all sites if control of systemic and venous return and local myocardial cooling are not provided. The use of temperature monitoring at multiple sites permits identification and prevention of various causes of myocardial rewarming and is facilitated by the use of plastic probes described herein which contain dual thermocouples.

Animals↗
PubMed1992

Left ventricular diverticulum with hypertrophy of the left ventricular apex.

A surgical case of diverticulum in the left ventricular apex is presented. A two-dimensional echocardiogram and magnetic resonance image showed a calcified tumor buried in the marked hypertrophied apex of the left ventricle. Enucleation of the oval and hard tumor (4 x 2.5 x 2.5 cm) was performed through the apex, and the defect was anastomosed by buttress sutures. Histologic examination demonstrated that the tumor cavity was filled with a thrombus encapsulated by thickened and calcified endocardium that extended to the left ventricular cavity. In this report, the etiology of the diverticulum with a hypertrophied myocardium is discussed.

Cardiomyopathy, Hypertrophic↗
PubMed1993

Primary left atrial myxosarcoma.

A patient in whom rapidly progressive congestive heart failure developed due to the presence of a left atrial myxosarcoma is described. The histologic picture is consistent with the hypothesis that cardiac myxoid tumors are neoplasms derived from undifferentiated cells found in the endocardium. Unfortunately, most cardiac malignancies are detected too late for curative resection, and palliation remains the mainstay of therapy.

Adult↗
PubMed1996

Comparisons of methods of myocardial hypothermia for cardiac transplantation.

BACKGROUND: Myocardial hypothermia of less than 10 degrees C is an essential component of preservation of donor hearts before implantation. Here we report temperature changes and comparison of methods for maintenance of myocardial hypothermia during implantation. METHODS: Twenty patients were prospectively randomized into two equal groups. In one cohort myocardial hypothermia was maintained by the "Stanford method" of continuous lavage of the pericardium and left atrium with refrigerated saline solution. In the other a cooling jacket was used without saline lavage. Temperatures at multiple sites were measured at 30-second intervals from initiation of cardiac suturing until aortic cross-clamp removal. Comparisons were made between groups at each temperature site. RESULTS: The cooling jacket group temperatures were significantly lower at the left ventricular epicardium and endocardium than those of the Stanford method group. CONCLUSIONS: During cardiac implantation maintenance of myocardial hypothermia with a cooling jacket resulted in significantly deeper and more consistent hypothermia of the left ventricle than pericardial and left atrial lavage with refrigerated saline solution. Blood loss from aspirated saline lavage and perfusate dilution by the saline solution were eliminated.

Adult↗
PubMed1988

Tentative identification of arterial baroreceptors associated with arteriovenous anastomoses.

Nerve endings of the trigeminal nerve were examined in the lip, nostril, upper jaw and supraorbital skin of cat by the horseradish peroxidase (HRP) tracing method. Wheatgerm agglutinin-HRP (WGA-HRP) as injected into the spinal trigeminal nucleus was transported transganglionically to nerve endings. The present study deals with presumptive baroreceptive nerve endings found on arteriovenous anastomoses and on some other large arteries. By light microscopy HRP-labeled, complexly arborized nerve endings were found on the walls of arteries located deep in the subcutaneous tissue of the lip and nostril. These arteries were identified in serial sections to be an arterial segment of an arteriovenous anastomosis. By electron microscopy characteristic nerve endings were located in the adventitia and partly extended into the adjacent connective tissue of the arterial wall. These terminals had no connective tissue capsule. Axon terminals were somewhat enlarged (1-2 microns in diameter) and extended through bundles of collagen fibrils. The terminals contained an abundance of mitochondria and some vesicles. Axon terminals were typically covered by thin Schwann cell processes, but parts of the axolemma were sometimes devoid of such Schwann cell coverings, being invested only by basal laminae. Cell bodies of Schwann cells were located apart from axons. These light and electron microscopic features of the endings resembled those of other well-defined baroreceptors reported in the carotid sinus, aortic arch and endocardium, as well as of Ruffini terminals and Golgi tendon organs, suggesting that they would be baroreceptors of arteriovenous anastomosis. In addition HRP-labeled single nerve fibers with varicosities were found in the walls of some large arteries in the facial skin. By electron microscopy, such a HRP-positive nerve fiber contained some mitochondria and vesicles in varicosities and coursed with a bundle of HRP-negative fine fibers in the adventitia of arteries. These HRP-labeled single fibers were considered to be sensory derived from trigeminal nerves.

Animals↗
PubMed1984

Hyaluronidase activity in embryonic chick heart muscle and cushion tissue and cells.

Hyaluronidase activity was compared in embryonic chick cardiac cushion and noncushion segments, as well as in cultures of mesenchyme derived from cardiac cushion endocardium (cushion tissue-enriched cultures) and in cultures of myocardial cells at stages critical to heart valve and septum development. Enzyme levels were higher in both heart tissue regions at periods of active cushion tissue mesenchyme migration than after migration ceases, and higher in the cushion region than in the noncushion region at both periods. Hyaluronidase was measured in cells and medium in both types of cultures, with five times greater activity found in the myocardial cultures. The cardiac hyaluronidase from cells and medium of both culture types had an estimated molecular weight of 41,000 to 44,000 and degraded hyaluronate and, to a lesser degree, chondroitin sulfate, at an acidic pH optimum. Ion-exchange chromatography demonstrated that in both culture types, a proportion of the secreted enzyme was more acidic than that found in the cell layer. These studies indicate the potential for hyaluronate degradation by the major cell types present in the developing heart at early stages and that the enzyme responsible is probably a lysosomal enzyme. Therefore, hyaluronate internalization is a likely requirement for degradation, and thus, the turnover of hyaluronate in developing heart valves is more complex than the extracellular degradative process suggested by histochemical data.

Animals↗
PubMed1991

Angioblast differentiation and morphogenesis of the vascular endothelium in the mouse embryo.

Bandeiraea simplicifolia B4 isolectin (BSLB4) and polyclonal antisera against von Willebrand factor (VWF) were used to study the origin of endothelial cells and their organization into blood vessels in the postimplantation mouse embryo. Examination of BSLB4-stained whole mounted and sectioned embryos revealed intense staining of the endothelium, highlighting large vessels, capillaries, and many individual cells. Dorsal aorta formation was first obvious at E7 when many lectin-positive cells appeared in paraxial and lateral plate mesoderm. As development proceeded to E8, BSLB4-positive cells became organized into craniocaudal lines destined to become the aorta proper. At E9, BSLB4 stained all vessels of the embryo including the dorsal aorta, the intersomitic arteries, and the endocardium. VWF expression was not detected until E8 when BSLB4/VWF double-stained sections revealed the dorsal aortae as the first VWF-positive vessels, while other endothelium visible with BSLB4 remained negative for VWF immunostaining. By E12 many other vessels became VWF-positive, including the aortic arches, the intersomitic arteries, and the cardinal veins. However, many angioblasts and capillaries remained VWF-negative, reflecting the heterogeneous expression of VWF among endothelium that has been reported in adults of other species. The histochemical data reported here support the conclusions of earlier avian studies by showing distinct vascular patterns in the initial formation of vessels from isolated angioblasts (vasculogenesis), followed by the extension and organization of the initial vascular structures (angiogenesis). Moreover, our data suggest that the endothelium arises from distinct VWF-positive sources associated with the dorsal aorta, as well as VWF-negative sources associated with other vessels in the embryo.

Animals↗