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PubMed1998

Minoxidil accelerates heart failure development in rats with ascending aortic constriction.

To test the ability of the heart to express characteristic geometric features of concentric and eccentric hypertrophy concurrently, constriction of the ascending aorta was performed in 4-week-old rats. Simultaneously, these rats were treated with an arteriolar dilator minoxidil. An examination 6 weeks after induction of the hemodynamic overload revealed no signs of congestion in systemic or pulmonary circulation in rats with aortic constriction or minoxidil-treated sham-operated rats. The magnitude of hemodynamic overload caused by aortic constriction or minoxidil treatment could be considered as equivalent, because the same enlargement of left ventricular pressure-volume area was necessary to compensate for either pressure or volume overload. Myocardial contractility decreased in rats with aortic constriction, and the compensation was achieved wholly by the marked concentric hypertrophy. Volume overload in minoxidil-treated rats was compensated partially by the eccentric hypertrophy and partially by the increased myocardial contractility. In contrast, increased lung weight and pleural effusion were found in all minoxidil-treated rats with aortic constriction. Unfavorable changes in left ventricular mass and geometry, relatively high chamber stiffness, and depressed ventricular and myocardial function were responsible for the massive pulmonary congestion.

Animals↗
PubMed1982

Decrease in myocardial oxygen extraction with aortic constriction in the dog.

In the open-chest dog constriction of the descending thoracic aorta, which raises central aortic pressure by 30-80 mmHg, increases cardiac oxygen usage (MVO2) and coronary blood flow (CBF) but reduces heart rate and myocardial oxygen extraction [(A-V)O2]. Pacing tachycardia superimposed on aortic constriction further increases MVO2 and CBF but does not alter (A-V)O2. Atropine or vagotomy abolishes the effect of aortic constriction on (A-V)O2, whereas vagal stimulation in the presence of alpha- and beta-adrenergic blockade reduces (A-V)O2. L-propranolol and phenoxybenzamine fail to modify the effect of aortic constriction on (A-V)O2. These results indicate that aortic constriction reduces (A-V)O2 by eliciting parasympathetically-mediated coronary vasodilation.

Animals↗
PubMed2006

Endoscopic release of limb constriction rings in utero.

Amniotic band syndrome is a sporadic condition that may result in constriction bands, amputation and multiple craniofacial, visceral and body wall defects. It occurs in 1/1,200 to 1/15,000 live births. Most cases present with multiple congenital anomalies that are incompatible with life. A small group of fetuses shows isolated limb constrictions that may cause severe limb dysfunction or limb amputation if left untreated. Successful in utero surgical lyses of constriction rings have been reported. We report a case of constriction amniotic bands involving both legs and compromising blood flow to the distal extremity. The constriction ring was successfully released by a minimally invasive endoscopic surgical technique avoiding severe limb dysfunction or foot amputation.

Amniotic Band Syndrome↗
PubMed1995

Evidence of constriction of optic nerve axons at the lamina cribrosa in the normotensive eye in humans and other mammals.

The ultrastructure of optic nerve axons was examined in several mammals (human, cat, rat, sheep, ox, pig, guinea pig, rabbit). Human material was obtained from normotensive, glaucoma-free eyes and from eyes with a history of glaucoma and raised intra-ocular pressure (IOP). We describe accumulations of organelles (principally mitochondria) in optic nerve axons where they traverse the lamina cribrosa. Accumulations were most prominent in unmyelinated lengths of axons close to lamellae of the lamina cribrosa. Comparable accumulations were not apparent in axons in the retina or optic nerve, suggesting that axoplasmic flow is constricted at the lamina cribrosa. Accumulations were observed both centrally and peripherally to the lamellae, suggesting that flow is constricted in both ortho- and anterograde directions. Accumulations of organelles were more marked in unmyelinated axons than in adjacent, myelinated axons. In the rabbit, in which most axons are myelinated as they traverse the optic nerve head, organelle accumulations were observed only in a sparse population of unmyelinated axons. In human eyes with a history of raised IOP and glaucoma, the accumulations were abnormally large and frequent and in many axons showed dense-body and fibrillar changes not seen in normotensive eyes. It is suggested that chronic, partial constriction of axoplasmic flow is present at the lamina cribrosa of normotensive eyes in a wide range of mammals, including humans, that the constriction results from the pressure gradient across the lamina cribrosa and that the constriction may be a factor in the many cases of primary glaucoma in which IOP is not raised.

Adult↗
PubMed1987

Detection and quantitation of constriction of the fetal ductus arteriosus by Doppler echocardiography.

Pulmonary hypertension may occur in the fetus in the presence of constriction of the ductus arteriosus. The feasibility of detection and quantitation of fetal ductal constriction by Doppler echocardiography was assessed in an animal preparation in which ductal constriction was created in the fetal lamb with a variable ligature causing varying degrees of fetal pulmonary hypertension (fetal pulmonary arterial systolic pressure 57 to 97 mm Hg and ductal gradient 9 to 42 mm Hg). Comparison of blinded, continuous-wave peak Doppler velocity (V) measurements of the ductal gradient with the modified Bernoulli assumption (gradient = 4V2) compared well with direct catheter measurements of instantaneous peak systolic gradient (r = .99, catheter = 0.95 X Doppler + 0.6), peak-to-peak gradient (r = .97), and mid-diastolic gradient (r = .85). Ductal constriction was characterized by an increase in the peak systolic and diastolic velocities. The normal human fetal ductus arteriosus blood flow velocity pattern was assessed by pulsed Doppler techniques in 25 normal human fetuses after 20 weeks gestation. The peak systolic flow velocity in the ductus arteriosus measured by image-directed pulsed Doppler echocardiography ranged from 50 to 141 cm/sec (mean 80 cm/sec) and increased with gestational age (r = .50). Diastolic velocity in the ductus arteriosus was consistently directed toward the descending aorta and ranged from 6 to 30 cm/sec. The ductal systolic velocities were the highest blood flow velocities in the fetal cardiovascular system. Application of these techniques to fetuses whose mothers were receiving indomethacin for treatment of premature labor at 30 to 31 weeks gestation confirmed this method to be sensitive for detection of fetal ductal constriction, which developed in three fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Effects of graded coronary constriction on regional oxygen and carbon dioxide tensions in outer and inner layers of the canine myocardium.

This study was undertaken to investigate the effects of graded coronary constriction on regional gas tensions of the myocardium. In 12 open chest dogs, tissue carbon dioxide (PtCO2) and oxygen (PtO2) tensions were measured simultaneously in outer and inner layers of the myocardium using a mass spectrometer. In normal condition, higher PtO2 and lower PtCO2 were observed in outer layer than in inner layer. With application of coronary constriction, increase in PtCO2 and decrease in PtO2 were observed in both layers of the myocardium, but the response to the ischemic stimuli by applying coronary constriction in inner layer was different from that in outer layer. Severe coronary constriction, more than 90% in its diameter, was necessary to produce significant changes in both gas tensions in both layers of the myocardium. Decrease in PtO2 was found in the condition of less severe coronary constriction and to be greater in inner layer than in outer layer of the myocardium. In terms of the changes in PtCO2, inner layer was also more susceptible to the ischemic stimuli than outer layer. The greater and earlier elevation of PtCO2 in inner layer than in outer layer is regarded as one of the possible mechanisms of the reduction of myocardial contraction in the early stage of myocardial ischemia.

Animals↗
PubMed1987

Constrictive pericarditis associated with patch electrodes of the automatic implantable cardioverter-defibrillator.

A case of constrictive pericarditis intimately involving patch electrodes of the automatic implantable cardioverter-defibrillator is described. Typical clinical and hemodynamic findings for constrictive pericarditis were noted 15 months after lead installation. Additionally, chest x-ray examination revealed a severe crumpling deformity of the patch electrodes. Thoracotomy was performed and revealed marked fibrous reaction surrounding both surfaces of each patch electrode. Histologic examination revealed fibrous tissue with multinucleated giant cells, consistent with a foreign body reaction. The patient had complete resolution of signs and symptoms of constrictive pericarditis after removal of the patch electrodes and pericardial stripping. Constrictive pericarditis from implanted patch electrodes appears to be an uncommon complication of the automatic implantable cardioverter-defibrillator and should be considered in patients with one or more patch electrodes and other signs of constrictive pericarditis.

Aged↗
PubMed1997

Porphyria cutanea tarda with constrictive pericarditis in a family.

Two cases of familial porphyria cutanea tarda (PCT) with constrictive pericarditis are described. A 50-year-old woman and her 48-year-old younger brother were admitted because of right ventricular heart failure. Constrictive pericarditis was diagnosed by RV pressure waveform and echocardiogram. The patients were diagnosed as PCT based on clinical symptoms, histologic findings and elevated urinary excretion levels of uroporphyrin. Even to this day, over 40% of the etiology of constrictive pericarditis remains unknown. There is a possibility of overlooking porphyria cutanea tarda in constrictive pericarditis patients. This report describes the first documented cases of familial PCT with constrictive pericarditis.

Coproporphyrins↗
PubMed1999

Constrictive pericarditis in patients with tuberculous pericarditis.

Constrictive pericarditis is a complication of tuberculous pericarditis that necessitates surgical intervention. In this study, we sought to identify echocardiographic features that could predict the development of constrictive pericarditis from acute or subacute pericarditis. From January 1988 through May 1998, all patients with a discharge diagnosis of tuberculous pericarditis were enrolled in the study, and their clinical features, laboratory findings, sonographic images, treatments, and outcomes were analyzed. Tuberculous pericarditis was demonstrated on the basis of positive Mycobacterium tuberculosis cultures from pericardial fluid or tissue in 11 patients; pericardial biopsy specimens demonstrating caseating granulomas in seven; and bacteriologic or histologic evidence of active extra-pericardial tuberculosis in conjunction with major pericardial effusion in four. Seventeen patients had effusive tuberculous pericarditis and five had constrictive tuberculous pericarditis as the initial diagnosis. The echocardiographic findings of effusive pericarditis were classified as shaggy-type effusion (n = 8) and non-shaggy-type effusion (9). Shaggy effusion was defined as the presence of multiple fibrin strands or a mass-like exudate coating the pericardium and bridging the pericardial effusion. Non-shaggy effusion was characterized by an anechoic pericardial space with or without a thickened pericardium, but no shaggy exudative coating. The mean duration between the onset of symptoms and diagnosis was longer in patients with shaggy-type effusion (39.6 +/- 8.7 vs 21.0 +/- 13.9 days, p < 0.05). Prednisolone (20-30 mg/d) was used in addition to antituberculous chemotherapy in 11 of the 17 patients with effusive pericarditis. Two of 11 patients (18%) who received steroid therapy, and five of the six patients (83%) who did not, developed constrictive pericarditis in the following year. Therefore, we concluded that adjuvant therapy with steroids significantly decreased the risk of constrictive pericarditis in patients with non-shaggy, but not shaggy, effusion.

Adult↗
PubMed2000

Constrictive pericarditis. Early experience in 12 patients in light of modern cardiology.

The last several decades have witnessed major advances in the understanding and management of constrictive pericarditis. The aim of the present study was to compare the diagnosis, treatment and outcome of constrictive pericarditis of 40 years ago to today. The study population consisted of 12 patients with a diagnosis of constrictive pericarditis who presented at the Institute of Cardiology of Beilinson Hospital, from 1961 to 1970. Their main physical findings, electrocardiographic and chest X-ray changes, and hemodynamic study results are discussed in relation to the surgical outcome of patients with constrictive pericarditis today. New noninvasive imaging modalities, such as M mode, two-dimensional and Doppler echocardiography, computed tomography and magnetic resonance imaging are presented, and their advantages and disadvantages in the diagnosis of constrictive pericarditis and its differentiation from restrictive cardiomyopathy are explained.

Adolescent↗
PubMed2001

Effect of chronic and progressive aortic constriction on renal function and structure in rats.

The purpose of this study was to evaluate the functional and structural renal damage observed in aortic-constricted hypertensive rats and to identify their possible relationship with transforming growth factor beta (TGF-beta) expression. Progressive renovascular hypertension was induced by progressive aortic constriction between the two renal arteries. Three months after constriction, the glomerular filtration rate (GFR), effective renal blood flow (ERBF), perfusion pressure (PP), urinary protein excretion (UPE) and urinary electrolyte excretion (U(Na)V and U(K)V) in the kidney above (right kidney, RK) and below the ligature (left kidney, LK) were measured. The cross-sectional corpuscular, capillary tuft and mesangial matrix area and tubulo-interstitial fibrosis were measured in tissue sections stained with Syrius Red using a computer-assisted image analysis system. TGF-beta was detected by immunohistochemistry. The functional parameters were similar in the two kidneys of aortic-constricted hypertensive rats (GFR-RK, 1.33+/-0.08 vs. LK, 1.18+/-0.08 mL/min; ERBF-RK, 9.23+/-1.32 vs. LK, 8.18+/-0.91 mL/min; RVR-RK, 28.3+/-3.9 vs. LK, 21.7+/-3.2 mmHg x min/mL). The RK was subject to a higher PP than the LK (176+/-7 vs. 128+/-5 mmHg, P < 0.05). UPE, U(Na)V, and U(K)V were greater in the RK than in the LK (UPE-RK, 512+/-61 vs. LK, 361+/-38 microg/30 min, P < 0.05; U(Na)V-RK, 0.056+/-0.012 vs. LK, 0.022+/-0.006 mEq/30 min, P < 0.05; UKV-RK, 0.042+/-0.006 vs. LK, 0.029+/-0.003 mEq/30 min, P < 0.05). Morphometric analysis revealed that the RK capillary tuft area and mesangial matrix area were higher than those in the LK. The LK had a higher degree of interstitial fibrosis than the RK. No significant differences in TGF-beta immunostaining were observed between the RK and the LK. In conclusion, the RK (subjected to hypertension) of aortic-constricted hypertensive animals developed glomerular fibrosis, only in the outer glomeruli whereas the LK developed mild interstitial fibrosis. Neither glomerular nor interstitial fibrosis seem to be responsible for the proteinuria observed in both kidneys.

Animals↗
PubMed1992

[Acute posterior interosseous nerve paralysis with constrictions possibly due to twists in the nerve trunk].

This report is concerning a case of acute spontaneous paralysis of the posterior interosseous nerve (P.I.O.N.), possibly caused by twists in the nerve trunk, in a 23-year-old woman. The subject felt a tingling pain over the lateral epicondyle of the right forearm when grasping and lifting a basin, and noticed that the fingers of the right hand could not be extended three days later. The fingers of the left hand also experienced paralysis 3 months after the first injury when she pronated and extended left forearm. Neurological examination revealed bilateral P.I.O.N. paralysis. When, after a period of time, the bilateral P.I.O.N. paralysis had not improved, surgical exploration of both P.I.O.N. was performed. It revealed that the right P.I.O.N. underwent a severe constriction at 2 cm proximal to the superficial portion of the supinator muscle, and that the proximal portion of the right nerve was swollen. The constricted portion of the right nerve was resected 5 mm in length, and nerve suturing was performed. The left P.I.O.N. was also constricted at the same location, and was found to be a sausage-like neurinoma with two constrictions. In the histological examination of the right resected P.I.O.N., edema of the interstitial tissue and a great number of regenerating cluster formations, including swollen axons, were observed proximal to the constriction. Distal to this, severe Wallerian degeneration was found. These histological findings were the same as those of chronic compression neuropathy. The authors reviewed and analysed reports on 20 other cases of P.I.O.N. paralysis that had compressions at 2 cm proximal to the superficial portion of the supinator muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1991

[Vena caval flow patterns in patients with constrictive pericarditis: analysis by catheter-tip Doppler flowmetry].

Changes in superior and inferior vena caval flow patterns were analyzed in 5 patients with constrictive pericarditis and were compared with those of 10 normal control subjects. Caval flows were measured using catheter-tip Doppler flowmeters. The normal controls showed biphasic M-shaped flow patterns; the peaks of the first forward flow (S wave) and of the second forward flow (D wave) appeared coincident with mid-systole and mid-diastole, respectively. Reverse flows fell during the atrial contraction period (A wave) and late systole (V wave). In the normal controls, the ratios of the S wave to the D wave (S/D ratio) and the A wave to the S wave (A/S ratio) were 2.15 +/- 0.41 and 0.18 +/- 0.10, respectively, and there was a disproportionate respiratory variation in the S and D waves in the normal controls. In constrictive pericarditis, superior and inferior vena caval flow velocities were lower than those in the normal controls. The S/D and A/S ratios were 1.46 +/- 0.27 (p < 0.05 vs control) and 0.66 +/- 0.15 (p < 0.01 vs control), respectively, with the A wave increasing in proportion to the severity of constrictive pericarditis. In addition, there was only a minimal respiratory variation in constrictive pericarditis. In conclusion, recognition of the patterns of the superior and inferior vena caval flow velocities may be useful for diagnosing constrictive pericarditis.

Adult↗
PubMed1989

[Significance of disturbances of cardiac filling in constrictive pericarditis].

Using pulsed Doppler echocardiography, blood filling patterns of the right atrium and left and right ventricles in constrictive pericarditis were studied to evaluate the physiological role of the pericardium in the hemodynamics of this disease. Thirteen cases were examined including five cases with atrial fibrillation. The control subjects consisted of 16 healthy persons and six cases of lone atrial fibrillation. 1. Peak velocity of the atrial filling wave during ventricular systole was reduced, and the filling time was shortened, suggesting reduced compliance and restricted motion of the atrial wall, because of the thickening and adhesions of the pericardium. Duration of the atrial filling wave during ventricular diastole was also shortened, reflecting disturbance of the early diastolic filling of the right ventricle. 2. In healthy subjects, duration of the rapid filling wave was longer in the right ventricle than in the left ventricle, probably due to the greater compliance of the right ventricular wall as compared to that of the left ventricular wall. In constrictive pericarditis, the rapid filling time of the right ventricle is shortened, so that the difference in this time between the right and left ventricles is minimized, which may be related to a thinner right ventricular wall. Duration of the rapid filling wave of the right ventricle correlated with right ventricular end-diastolic pressure, indicating that the duration of the right ventricular rapid filling wave is proportional to the severity of constrictive pericarditis. In conclusion, constriction of the pericardium definitely influences the hemodynamics of the right side of the heart more than it does the left side in constrictive pericarditis. This difference appears to result from the difference in thickness of the myocardial layers of both ventricles.

Adult↗
PubMed1987

Endogenous atrial natriuretic factor in dogs with caval constriction.

Chronic constriction of the thoracic inferior vena cava results in decreased filling pressure and cardiac output, in augmented secretion rates of renin and aldosterone, and in marked sodium retention with ascites and edema formation. The goal of the present study was to determine temporal changes in the plasma concentration of immunoreactive atrial natriuretic factor (iANF) in response to chronic constriction of the thoracic inferior vena cava in the conscious dog. Following constriction of the thoracic inferior vena cava, all dogs retained sodium avidly for at least 10 days, and both plasma renin activity and plasma aldosterone concentration increased markedly (p less than 0.05). Additionally, the baseline plasma iANF of 70 +/- 5 pg/ml decreased significantly to 24 +/- 7, 26 +/- 10, and 34 +/- 11 pg/ml (p less than 0.05) on days 2, 6, and 10 following thoracic inferior vena cava constriction. Thus, chronic sodium retention in this model is associated with prolonged endocrine adjustments in the circulating levels of renin-aldosterone and iANF. We suggest that chronic decreases in the secretion of atrial natriuretic factor might contribute to the inability of the dog with constriction of the thoracic inferior vena cava to excrete sodium normally.

Animals↗
PubMed1985

[Constrictive pericarditis as a late complication of heart operations].

Constrictive pericarditis is a rare complication of previous cardiac surgery, the rate of incidence being approximately 0.1 to 0.3%. Until now about 60 cases have been documented. With increasing frequency of surgical procedures, especially bypass operations, cardiac surgery plays a major role in the etiology of pericardial constriction. In our own series of 12 consecutive pericardiectomies previous cardiac surgery was in 4 cases responsible for the constriction. These cases are presented in detail. A correct diagnosis is difficult and - as in our own cases - often not noticed for a long period of time because the symptoms are obliterated by the primary heart disease and the previous operation. In our own patients the diagnosis was eventually established by echocardiography and then confirmed by right sided heart catheterization. Due to the late diagnosis the results of pericardiectomy - considered the method of choice - were only poor. Two patients, both in a very bad overall condition, died soon after surgery. The remaining 2 patients recovered satisfactorily. Regarding the pathogenesis, hematomas seem to play a leading role in the development of subsequent pericardial fibrosis. Typically the patients present symptoms of a prolonged pericarditis soon after the original surgical intervention. The time between cardiac surgery and the development of constrictive features varies between weeks and years. The postoperative course of patients with excessive postoperative bleeding or larger pericardial effusions should be watched carefully, keeping the possibility of later pericardial constriction in mind.

Aortic Valve↗
PubMed1985

Surgical treatment of constrictive pericarditis: analysis of outcome and diagnostic error.

The records of 81 patients with a diagnosis of constrictive pericarditis who underwent surgical treatment were examined to assess the effectiveness of diagnosis and therapy. A false-positive diagnosis occurred in 10 patients (12%); seven had restrictive cardiomyopathy. Of 51 variables examined, only a low right ventricular end-diastolic pressure (RVEDP) significantly and independently predicted diagnostic error. Seventy-one patients with constrictive pericarditis underwent pericardiectomy. Mean follow-up was 4.7 years (maximum 12), and only two patients were untraceable. The study population was notable: 42 patients had visceral as well as parietal pericardial involvement; 32 had idiopathic disease and 25 had pericarditis related to radiation therapy. Results were favorable in 83% of the population. There were seven in-hospital deaths (10%). Actuarial survival estimates were 74% and 64% at 5 and 10 years, respectively. Compared with a normal population, the survival rate of patients with postradiation constrictive pericarditis was significantly inferior, whereas the survival rate of the remaining patients was not significantly different. Patients with constrictive pericarditis and restrictive cardiomyopathy did no better than those with restrictive cardiomyopathy alone. Additionally, patients in NYHA functional class IV had a significantly worse prognosis. Multivariate analysis of 38 preoperative variables identified high RVEDP as a significant independent predictor of in-hospital death, and renal dysfunction and diuretic use were significant independent predictors of overall poor outcome. Differentiation between the diagnosis of constrictive pericarditis and restrictive cardiomyopathy remains a problem. Radiation therapy, pericarditis with restrictive cardiomyopathy, high RVEDP, NYHA class IV status, renal dysfunction, and diuretic use adversely influenced outcome in patients undergoing pericardiectomy.

Actuarial Analysis↗
PubMed1981

Carotid artery constriction in acute hypertension.

The effects of carotid artery constriction on cerebrovascular ultrastructure and permeability in acute hypertension have been assessed. The right common carotid artery of 26 male Wistar-Kyoto normotensive rats was constricted with a silver wire clip. Forty-eight hours later these animals received an angiotensin amide injection (1 microgram/kg body weight) or infusion for 3--4 hours (0.5 or 1.7 microgram/min/kg body weight) or were subjected to subdiaphragmatic aortic constriction. All animals were injected with horseradish peroxidase (HRP) (20 mg/100 g body weight) and sacrificed after 5--15 minutes. Parietal cortex from both hemispheres was processed for light and electron-microscopic examination. The arterial vessels of the right hemisphere from animals given injections of or infused with angiotensin II exhibited increased permeability to HRP, as manifested by the presence of reaction product in interendothelial cell clefts, in subendothelial space, in endothelial and smooth muscle cell pinocytotic vesicles, and along smooth muscle cell basal laminas. In contrast, no alterations in the permeability of ipsilateral vessels were seen in rats with aortic constriction. Cerebral cortical arterial vessels from the left hemisphere in all groups of animals exhibited segmental dilatation and constriction and abnormal permeability to HRP. The results suggest that angiotensin administration can produce increased permeability of cerebral cortical vessels in the absence of elevated blood pressure.

Acute Disease↗