CLINICAL CONFERENCE

PEDIATRICS ◽  
1957 ◽  
Vol 19 (6) ◽  
pp. 1139-1147
Author(s):  
Mary Allen Engle

Dr. Engle: When pulmonic stenosis occurs as an isolated congenital malformation of the heart, it usually is due to fusion of the valve cusps into a dome with a small hole in the center. In Figure 1 the pulmonary artery has been laid open so that one can see the three leaflets of the pulmonary valve are completely fused, and that there is only a small, central, pinpoint opening which permits blood to leave the right ventricle and enter the pulmonary circulation. Valvular pulmonic stenosis is much more common than subvalvular or infundibular stenosis, where the obstruction to pulmonary blood flow lies within the substance of the right ventricle. There it may be due to a diaphragm of tissue which obstructs the outflow of the right ventricle, or to an elongated narrow tunnel lined with thickened endocardium, or to a ridge of fibrous or muscular tissue just beneath the pulmonary valve. The changes in the cardiovascular system which result from obstructed pulmonary blood flow are so characteristic that they permit the ready recognition of this condition. Proximal to the constriction, these changes manifest the burden placed on the right ventricle, which enlarges and hypertrophies. On physical examination this is demonstrated by the precordial bulge and tapping impulse just to the left of the sternum, where the rib cage overlies the anterior (right) ventricle. Radiographically, both by fluoroscopy and in roentgenograms in the frontal and both oblique views, right ventricular enlargement is seen. In the electrocardiogram, the precordial leads show a pattern of right ventricular hypertrophy.

1992 ◽  
Vol 2 (4) ◽  
pp. 377-381 ◽  
Author(s):  
Michael L. Rigby ◽  
Micelia Salgado ◽  
Celia Silva

SummaryA retrospective study was undertaken of patients with hypoplastic right ventricles, either with pulmonary atresia and intact ventricular septum or critical pulmonary valvar stenosis, and duct-dependent pulmonary blood flow who were investigated at the Royal Brompton Hospital between January 1976 and December 1990. The diagnosis was made on the basis of at least one diagnostic method (cross-sectional echocardiography, cardiac catheterization and angiography, or autopsy). Of the patients, 56 (82%) were found to have an imperforate pulmonary valve or infundibulum (pulmonary atresia), while 12(18%) had critical pulmonary valvar stenosis. The ratio of the diameters of the tricuspid and mitral valvar orifices was measured angiographically during diastole, and the right ventricle was analyzed according to the presence or overgrowth of the inlet, apical trabecular and outlet components. A correlation was made between the severity of the disease and the outcome. The overall mortality was 53% when those not undergoing any surgery were excluded, and significant differences were found between the group dying and those who survived. The incremental risk factors for death were a ratio between the diameter of the tricuspid and mitral valves of less than 0.6; the presence of fistulous communications with the coronary arteries; and obliteration of the apical trabecular component of the right ventricle. There was no significant difference between the group with pulmonary valvar atresia and the group with critical stenosis of the pulmonary valve.


2021 ◽  
Vol 4 (5) ◽  
pp. 01-04
Author(s):  
Miguel Maluf

We report long-term outcome after one-stage, surgical repair, in a two months-old girl with persistent truncus arteriosus type I, II. The operation was carried out with the remodeling of the right ventricle, using a swine bicuspid pulmonary prosthesis. Twenty-six years later, the patient is in excellent clinical condition, CF I (NYHA), with normal peripheral oxygen saturation. Recent invasive and not invasive imaging show: absence of intracardiac shunt and growing of the right ventricle outlet tract and discrete double lesion of the pulmonary valve. The pulmonary flow directed uniformly for both lungs. In selected cases, the long-term prognosis of patients with persistent truncus arteriosus, undergoing early surgical repair, avoiding the use of valved conduit, makes for an excellent evolution, without new interventions. Endovascular procedures, now well standardized, for the implantation of a pulmonary valve stent, through a catheter, will allow an effective approach, in the presence of late obstructions, in patients who have undergone right ventricular remodeling, without the use of valved conduits.


1981 ◽  
Vol 241 (5) ◽  
pp. H708-H713 ◽  
Author(s):  
C. M. Bonnin ◽  
M. P. Sparrow ◽  
R. R. Taylor

The fractional synthesis rate of collagen (the percent of total ventricular collagen synthesized in one day) was measured in the hearts of normal dogs and those with pulmonary artery stenosis using a continuous 6-h intravenous infusion of [14C]proline. The fractional synthesis rate in normal ventricles was slow, 0.56%/day, and it increased eightfold to 4.8%/day in the hypertrophying right ventricle after 5 days. After 12 and 28 days the synthesis rate was still significantly greater than in the control left ventricle, being 2.6 and 1.3%/day, respectively. However, the synthesis rate of noncollagen protein was significantly greater than normal at 5 days only. The collagen content (expressed as a mass fraction) of the right ventricle decreased over the first 12 days of hypertrophy but by 28 days was restored to the normal right ventricular value of 9.6 mg/g wet wt tissue. The total amount of collagen in the hypertrophied ventricle calculated from the synthesis rates was in accord with that measured chemically. In normal dogs the collage content of the right ventricle was greater than that of the left, and the epicardium contributed substantially to the total collagen in the ventricular walls.


2003 ◽  
Vol 105 (6) ◽  
pp. 647-653 ◽  
Author(s):  
Jean-François JASMIN ◽  
Peter CERNACEK ◽  
Jocelyn DUPUIS

Although activation of the endothelin (ET) system contributes to pulmonary hypertension, modifications of the cardiopulmonary ET system and its responses to chronic ET receptor blockade are not well known. To investigate this, rats were injected with monocrotaline (60 mg/kg intraperitoneal) or saline, followed with treatment with the selective ETA receptor antagonist LU135252 (LU; 50 mg·kg-1·day-1) or with saline. After 3 weeks, haemodynamics, cardiac hypertrophy, ET-1 levels and cardiopulmonary ET-receptor-binding profile were evaluated. Monocrotaline (n=7) elicited marked pulmonary hypertension and right ventricular hypertrophy compared with controls (n=8). Both variables were substantially attenuated by LU therapy (n=8; P<0.05 for both). After monocrotaline, right ventricular ET-1 levels were more significantly increased than in the left ventricle (+198% compared with +127%; P<0.05). ETB receptor density was augmented (3-fold) in the right ventricle, whereas that of ETA receptors was not affected. LU treatment also significantly attenuated these alterations (P<0.05). In the lungs, ET-1 levels were not increased after monocrotaline, whereas the balance of ETB to ETA receptors was altered, with a trend toward a lower percentage of ETB than in the control rats. LU treatment did not affect these variables in the lungs. Therefore monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy are associated with the up-regulation of ET-1 and ETB receptors in the right ventricle. These alterations are attenuated with the reduction of pulmonary hypertension and right ventricular hypertrophy after chronic blockade of the ETA receptors, supporting the role of the ET system in right ventricular hypertrophy.


2021 ◽  
pp. 1-15
Author(s):  
Lars K. Markvardsen ◽  
Lene D. Sønderskov ◽  
Christine Wandall-Frostholm ◽  
Estéfano Pinilla ◽  
Judit Prat-Duran ◽  
...  

<b><i>Introduction:</i></b> Pulmonary hypertension is characterized by vasoconstriction and remodeling of pulmonary arteries, leading to right ventricular hypertrophy and failure. We have previously found upregulation of transglutaminase 2 (TG2) in the right ventricle of chronic hypoxic rats. The hypothesis of the present study was that treatment with the transglutaminase inhibitor, cystamine, would inhibit the development of pulmonary arterial remodeling, pulmonary hypertension, and right ventricular hypertrophy. <b><i>Methods:</i></b> Effect of cystamine on transamidase activity was investigated in tissue homogenates. Wistar rats were exposed to chronic hypoxia and treated with vehicle, cystamine (40 mg/kg/day in mini-osmotic pumps), sildenafil (25 mg/kg/day), or the combination for 2 weeks. <b><i>Results:</i></b> Cystamine concentration-dependently inhibited TG2 transamidase activity in liver and lung homogenates. In contrast to cystamine, sildenafil reduced right ventricular systolic pressure and hypertrophy and decreased pulmonary vascular resistance and muscularization in chronic hypoxic rats. Fibrosis in the lung tissue decreased in chronic hypoxic rats treated with cystamine. TG2 expression was similar in the right ventricle and lung tissue of drug and vehicle-treated hypoxic rats. <b><i>Discussion/Conclusions:</i></b> Cystamine inhibited TG2 transamidase activity, but cystamine failed to prevent pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial muscularization in the chronic hypoxic rat.


2004 ◽  
Vol 286 (3) ◽  
pp. H1185-H1192 ◽  
Author(s):  
Saumya Sharma ◽  
Heinrich Taegtmeyer ◽  
Julia Adrogue ◽  
Peter Razeghi ◽  
Shiraj Sen ◽  
...  

Hypobaric hypoxia induces right ventricular hypertrophy. The relative contribution of pulmonary hypertension, decreased arterial oxygen, and neuroendocrine stimulation to the transcriptional profile of hypoxia-induced right ventricular hypertrophy is unknown. Whereas both ventricles are exposed to hypoxia and neuroendocrine stimulation, only the right ventricle is exposed to increased load. We postulated that right ventricular hypertrophy would reactivate the fetal gene transcriptional profile in response to increased load. We measured the expression of candidate genes in the right ventricle of rats exposed to hypobaric hypoxia (11% O2) and compared the results with the left ventricle. Hypoxia induced right ventricular hypertrophy without fibrosis. In the right ventricle only, atrial natriuretic factor transcript levels progressively increased starting at day 7. Metabolic genes were differentially regulated, suggesting a substrate switch from fatty acids to glucose during early hypoxia and a switch back to fatty acids by day 14. There was also a switch in myosin isogene expression and a downregulation of sarcoplasmic/endoplasmic ATPase 2a during early hypoxia, whereas later, both myosin isoforms and SERCA2a were upregulated. When the right and left ventricle were compared, the transcript levels of all genes, except for myosin isoforms and pyruvate dehydrogenase kinase-4, differed dramatically suggesting that all these genes are regulated by load. Our findings demonstrate that hypoxia-induced right ventricular hypertrophy transiently reactivates the fetal gene program. Furthermore, myosin iso-gene and pyruvate dehydrogenase kinase-4 expression is not affected by load, suggesting that either hypoxia itself or neuroendocrine stimulation is the primary regulator of these genes.


1984 ◽  
Vol 56 (4) ◽  
pp. 966-974 ◽  
Author(s):  
H. V. Thommasen ◽  
B. A. Martin ◽  
B. R. Wiggs ◽  
M. Quiroga ◽  
E. M. Baile ◽  
...  

The effect of pulmonary blood flow on leukocyte uptake and release by the lung was examined in 10 anesthetized spontaneously breathing dogs. Pulmonary arterial and pulmonary venous blood was sampled with catheters placed into the right ventricle and aorta, respectively. Pulmonary blood flow was lowered by inflating a balloon catheter located in the inferior vena cava. In five experiments simultaneous blood samples were drawn from the right ventricle and aorta at 10-s intervals during a control period, a 2- to 3-min period of low flow, and a recovery period. In five additional experiments, less frequent samples were taken over periods of 15–60 min. Total leukocyte concentrations and differential counts were determined for each blood sample. The study shows that large numbers of leukocytes become sequestered within the lung when pulmonary blood flow is low and that an equivalent number of cells are released from the lung after deflation of the balloon catheter. Both the polymorphonuclear leukocytes and the lymphocytes were taken up by the lung when pulmonary blood flow was reduced. We conclude that pulmonary blood flow has a marked effect on the uptake and release of leukocytes by the dog lung.


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