Rabbits were rendered hypertensive by suprarenal coarctation of the abdominal aorta. Seven days later, endothelium-dependent and endothelium-independent vascular relaxations were examined in vascular rings taken from hypertensive (thoracic aorta, carotid artery) and normotensive (abdominal aorta) regions. Relaxation of phenylephrine-contracted rings in response to endothelium-dependent agonists (acetylcholine, A23187) was impaired, compared ...

We developed a hydraulic occluder that could be adjusted percutaneously through a subcutaneous reservoir. Because of the potentially high pressures that may occur in preparing patients with transposition of the great vessels for an atrial switch procedure, the band on that hydrauler was modified to withstand arterial pressure and was ...

The incidence and possible causes of paradoxical hypertension were evaluated in eight children who underwent balloon dilatation and seven children who underwent surgical repair of coarctation of the aorta. Both procedures resulted in a significant reduction in the coarctation gradient. Both systolic and diastolic blood pressures increased in the surgical ...

We analyzed histologic, ultrastructural, and functional characteristics of rabbit aortic conduits regenerated over absorbable polydioxanone prostheses. Twenty-eight polydioxanone-elicited prosthesis/tissue complexes harvested two weeks to 12 months following implantation were analyzed grossly; photographed; sectioned for light, scanning, and transmission electron microscopy; and studied for compliance, bursting strength, and prostacyclin and thromboxane ...

This study evaluates the long-term efficacy of reconstructive surgery for renovascular hypertension caused by arteriosclerosis, which was performed on 112 patients from 1959 to 1983. Despite medical therapy, all patients had persistent hypertension, with a mean preoperative blood pressure of 188/113 mm Hg. Their median age was 49 years, and ...

A girl with Rett's syndrome and renovascular hypertension because of a stenosis in the right renal artery is described. The girl was operated on twice because of the stenosis. Her blood pressure normalized after the second operation in which the artery was reconstructed. High blood pressure causes neurological symptoms which ...

Repair of coarctation of the aorta may not prevent the subsequent development of elevated systemic blood pressure at rest or with exercise. The correlates of late postoperative resting systolic blood pressure and maximal exercise systolic blood pressure levels were investigated in a retrospective study of 42 patients who had graded ...

We have studied mechanical factors that could determine how stenosis protects against distal atherosclerosis in cynomolgus monkeys fed an atherogenic diet. Critical aortic stenosis was produced by coarctation of the thoracic aorta. After 3 months, coarcted monkeys had a mean aortic pressure gradient of 25 +/- 1 mm Hg and ...

A new specific antagonist of bradykinin was used to examine the contribution of bradykinin to the depressor effect of different antihypertensive drugs in two-kidney renovascular rats. First we tested the inhibitory capacity of this peptide for exogenously injected bradykinin (75-200 ng). An inhibition of the vasodepressor action of bradykinin by ...

Pressure of brain retraction was measured with a strain gauge spatula in 31 cases of 21 tumours and 10 aneurysms. They were operated on via different approaches: subfrontal (10 cases), interhemispheric (5), subtemporal (7) and suboccipital (9). The patients' age ranged from 11 to 74 years (average 50). The recorded ...

To evaluate cardiovascular status in human renovascular hypertension, quantitative echocardiographic findings were compared in 42 patients with arteriographically documented renovascular hypertension and 46 age- and sex-matched patients with essential hypertension. Left ventricular (LV) fractional shortening, a measure of systolic performance at rest, was subnormal (less than 26%) in 8 of ...

The mechanical properties of the radially enlarged proximal segment of the aorta of diving marine mammals was studied on 15 excised aortas of harbor seals and five aortas of Weddell seals. This was done by recording static pressure-volume relationships for the whole thoracic aorta, the aortic bulb, and the descending ...

Ischemic spinal cord injury after cross-clamping of the descending aorta can occur independently of aortic disease. In a previous study we had shown a precipitous uniform fall of spinal surface oxygen tension downstream to the clamping site irrespective of level. In the present paper, the hemodynamic changes in the spinal ...

We investigated endothelium-dependent relaxation in rat aortae, using three models of experimental hypertension: deoxycorticosterone and salt; one-kidney, one clip renovascular hypertension; and coarctation. Isolated aortae were contracted with phenylephrine, and relaxation was subsequently induced with acetylcholine or calcium ionophore A23187. Blood vessels denuded of endothelium did not relax in response ...

Blood pressures and heart rates were recorded from two groups of turkeys in two trials. In trial one 20 turkeys, 36 weeks of age and in trial two 24 turkeys, 14 weeks of age, were used. Immediately after blood pressures and heart rates had been determined, the turkeys were killed ...

Arterial blood pressures were measured simultaneously in the thoracic and abdominal aortas in the same conscious rats. Intravenous administration of sodium nitroprusside caused a greater fall in systolic blood pressure in the abdominal aorta than in the thoracic aorta, whereas intravenous administration of methoxamine caused a greater rise in systolic ...

Percutaneous transluminal balloon angioplasty was performed in five children with coarctation restenosis. After angioplasty the pressure gradient had decreased considerably in four patients. In all patients aortography showed an increase in the diameter of the lumen at the site of the restenosis. All patients were normotensive the day after angioplasty. ...

The availability of a chronically implanted electrolytic strain gauge has permitted us to monitor, for the first time in freely moving rats, sequential changes of both resting caliber and mechanical properties of the aorta during onset and maintenance of sustained hypertension. Normotensive rats were subjected to subdiaphragmatic aortic constriction under ...

In coarctation, bipedal exercise induces a pressure triad: exaggerated systolic arm hypertension, unchanging leg pressure, and markedly increased systolic gradient. Constancy of leg pressure derives from the lower body sharing the poststenotic compartment with the kidneys. Exercise-induced poststenotic hypotension stimulates the juxtaglomerular apparatus (JGA) to raise renal pressure to pre-exercise ...

Technical aspects of percutaneous transluminal angioplasty in renovascular hypertension include knowledge about the pathophysiology of dilation, certain radiological and physiological markers, criteria for patient selection, and, finally, the catheter technique. Important factors for a successful procedure are overdilation and adequate pressure and time of balloon inflation. Radiological markers are inflation ...

Transluminal balloon aortoplasty was successfully performed 7 times in 5 children between 3 and 14 months of age who had had the subclavian flap operation for coarctation of the aorta in the neonatal period. In two the balloon aortoplasty was performed twice. All recoarctations presented with upper limp hypertension and ...

Because of structural differences between a synthetic graft and the natural artery, a graft would be expected to alter the haemodynamics of the vessel which is bypassed. To examine this, a segment of the lower descending thoracic aorta in six calves was removed and replaced with a Dacron graft. The ...

In the present retrospective study, the effect of various therapeutic procedures (surgery, percutaneous transluminal dilatation and antihypertensive drugs) was analyzed in 202 patients with renovascular hypertension. The results show that each of the three methods effectively lowers blood pressure. However, marked differences were observed in pretreatment clinical and laboratory data ...

Hypertension was induced in young male pigs by subcutaneous implantation of deoxycorticosterone acetate in a Silastic rubber carrier. Hemodynamic variables were periodically monitored. Six to eight weeks after implantation, the animals were necropsied and aortas were dissected. Glycosaminoglycans (GAG) were isolated from aortas from hypertensive pigs and from normotensive controls. ...

The possible damaging effect on the kidneys of antihypertensive therapy in aortic coarctation was evaluated experimentally in eighteen canine puppies. Aortic coarctation was carried out in 13 puppies at the age of two months while sham-surgery was carried out on five control puppies. Six coarctated dogs were treated with hydrochlorothiazide, ...

Experimental hypertensive choroidopathy was studied in 29 eyes from 15 monkeys in which accelerated renovascular systemic hypertension developed after a modified Goldblatt procedure. We followed up the animals from five days to 21 months to examine clinically and histopathologically the spectrum of the pathologic process. The pathologic features of hypertensive ...

Compared with other available treatment modalities that rely on active pressure over the excised region, this method of therapy works by confinement of the soft tissue to the internal dimensions of the stent. It minimizes the possibility of creating excessive force that could cause an unfavorable response such as inflammation ...

Eighty-four balloon dilatations of dialysis-access fistulas have been performed over a five year period. Fifty-two were done with polyethylene balloons and the last 32 with high-pressure Olbert balloons. Initial success was significantly greater with the high-pressure balloons, but long-term patency rates were similar. Use of high-pressure balloons and long inflation ...

Five children with renovascular hypertension were treated with percutaneous transluminal angioplasty, and followed for 12 to 32 months. Blood pressure fell to normal in four patients and improved in one. Angiographic and endocrinological improvements were associated with a fall in blood pressure and no complications were observed. Angioplasty is considered ...

Regional blood flows were measured with radioactive microspheres in 35 conscious dogs at various times (between 1 h and 28 days) after creation of a stenosis of the descending thoracic aorta. Mean arterial pressure increased moderately proximal to the stenosis. Distally, arterial pressure decreased below control values immediately after stenosis, ...

Unlike most adults with compensated pressure overload of the left ventricle, children with moderate to severe aortic stenosis exhibit pronounced left ventricular muscle hypertrophy, enhanced ejection performance and diminished wall stress. To determine whether these findings are present in other forms of left ventricular pressure overload in children, left ventricular ...

To determine whether altered vascular reactivity could contribute to hypertension after repair of coarctation, the change in forearm and calf vascular resistances to small intra-arterial infusions of norepinephrine were measured in six patients who had undergone surgical correction of coarctation of the aorta but still had upper extremity hypertension and ...

A 17 year old female with aortitis syndrome was reported. The blood pressure of upper extremities was 204/88 mmHg which was higher than that of lower extremities (88/mmHg). Chest X ray showed marked rib notchings at the lower border of the right 7th and 8th rib and left 8th ribs. ...

The hypothesis is presented that paraplegia after coarctation of the aorta is principally due to hypotension of sufficient severity and duration. In a group of 103 patients who underwent surgery during a 10-year period, the distal aortic pressure was maintained above 60 mm Hg while the aorta was cross-clamped or ...

Segments of 35 thoracic and 16 abdominal human aortas, including nine pairs, aged 30-78 yr at autopsy, were perfused with 37 degrees C Tyrode's solution at in situ length. Diameter changes due to 20 mmHg pressure steps between 20 and 180 mmHg were measured to 1 micron accuracy at an ...

In a one-day-old male newborn with severe heart failure, the skin of the upper right thorax was pink, whereas the remaining areas were cyanotic. No peripheral pulses were palpable and the blood pressure could not be measured. On cardiac catheterization, systolic and diastolic pressures were elevated in the left ventricle ...

By means of a chronically implanted electrolytic transducer, changes in the aortic calibre were studied in conscious rats during the onset of acute hypertension produced by subdiaphragmatic aortic constriction. The rise of pressure to its maximum (153 +/- 5 versus 101 +/- 4 mmHg during the control period) was immediate ...

Aortic coarctation was created experimentally in dogs and regional blood flows were measured at various times thereafter with radioactive microspheres in the conscious state. Mean arterial pressure increased moderately proximal to the stenosis, whereas distally it was reduced below control immediately, returning progressively toward control over 28 days. Blood flows ...

We describe two infants with severe hypertension associated with idiopathic arterial calcification of infancy. In both children, blood pressure control was refractory to aggressive antihypertensive therapy. There was radiologic and laboratory evidence of renovascular disease requiring the use of specific renin antagonists and later nephrectomy, resulting in moderate improvement of ...

During aortic blood flow obstructions and angiotensin infusion blood may be accumulated in the heart and the lungs because of retention or redistribution of blood from compliant regions. We measured the cardiopulmonary blood volume (CPBV) when left ventricular systolic pressure was raised by about 50 mmHg by angiotensin infusion and ...

Utilizing a model of ventricular aneurysm of varying size and wall thickness produced on a layered thin-walled elastic sac (original ventricle), the static pressure-volume relationships of the ventricle-aneurysm system were determined. Progressive increase in the size of an aneurysm lowered the intracavitary pressure obtained in the system. Decreasing the wall ...

In order to register pressure changes within the cauda equina, a highly sensitive pressure measuring catheter was inserted through a hole in the dural sac. Its tip was placed among the nerve roots of the cauda equina at levels L2, L3, and L4 in seven freshly removed human specimens. The ...

Although clinical reports have suggested that antihypertensive therapy can control blood pressure in patients with renovascular hypertension, adequate randomized studies comparing medical versus surgical management are lacking. It is well recognized that progressive deterioration in renal function can occur despite good blood pressure control. Recent experience suggests that higher-risk patients ...

Much of the controversy about operative intervention for renovascular hypertension stems from reports that show a low rate of blood pressure benefit, a high technical failure rate of revascularization, or a high operative risk. Current results in centers having a large operative experience with the management of renovascular hypertension, however, ...

Our previous studies, in vivo and in vitro, have shown reduced inotropic responsiveness to isoproterenol of hypertrophied hearts in renovascular hypertensive rats. In the present study, we have investigated, in the same model, the effects of treatment either by nephrectomy or captopril on the inotropic responsiveness to isoproterenol and on ...

The rabbit aorta distends considerably during glutaraldehyde infusion at 100 mm Hg, the distension at the beginning being both fastest and greatest. Over a 2-h period the degree of distension approached a maximum value which was clearly above the in vivo distension. Intimal folds were largely flattened, especially in experiments ...

Segments of 45 human thoracic and 20 abdominal aortas, including 13 pairs, aged 30-88 yr at autopsy, were perfused with 37 degrees C Tyrode's solution at in-situ length. Diameter changes due to 20 mmHg pressure steps, between 20 and 180 mmHg, were measured to 1 micron accuracy with balanced transducers. ...

In order to measure the flow-dynamical effect of arteriosclerotic changes of the vessel wall we determined volume elasticity E' and modulus of elasticity of 53 human aortae in a static p-V-test as other authors did, too. The p-V-curves are normalized to the aortic basic volume Vo, so that we could ...

Percutaneous transluminal angioplasty (PTA) was used successfully to treat coarctation restenosis in seven patients. The patients were 10 months to 17 years old at the time of the angioplasty, and the initial coarctation repair had been performed 10 months to 16 1/2 years previously. PTA reduced the systolic pressure gradient ...

In a 3 day old infant with coarctation of the aorta a loud Doppler signal synchronous with expiration was present for some hours in the femoral vessels, with only barely audible signals synchronous with cardiac systole. It is suggested that in the presence of severe aortic constriction and temporary ductal ...