Renin-angiotensin system in an infant with malignant renovascular hypertension

The clinical and electromyographic signs of the misdirection syndrome after oculomotor palsy are described. Besides the previously described findings we found an increase of intraocular pressure dependent on the direction of gaze. In three young patients (16-26 years), we were able to demonstrate an aberrant reinnervation of the ciliary muscle, which was responsible for an increasing myopia in adduction. These observations supplement the previous concept of the misdirection syndrome.     

Management of the patient with renovascular hypertension

Renal artery stenosis, either fibromuscular or atheromatous, is probably the most common cause of secondary hypertension in man. Both of these diseases are active, ongoing processes that may be ameliorated but not cured by medical or surgical treatment. The clinical history and examination of the patient with hypertension may help differentiate renovascular hypertension from essential hypertension. The presence of a systolic-diastolic or continuous bruit is often an indicator of severe renal artery stenosis. Systemic hypertension is the physiologic consequence of significant renal artery stenosis. Knowledge of the basic concepts of the renin-angiotensin-aldosterone system, as has evolved from experimental models of renovascular hypertension, forms the basis for understanding the process of evaluation and treatment of such patients. The treatment of choice for the patient with severe hypertension and a functionally significant renovascular lesion is surgical--both in terms of successful treatment of hypertension and improved long-term prognosis. Diligent periodic reevaluation of these patients as well as those with less severe hypertension who are receiving medical treatment enables the physician to select the proper management that offers optimal control of patient blood pressure and avoids target-organ damage to the kidneys, central nervous system, or cardiovascular system.     

Captopril renal scintigraphy in renovascular hypertension

Renovascular disease is a common cause of secondary hypertension. Renal artery stenosis is present in up to one third of patients with clinical markers suggestive of renovascular hypertension, such as hypertension refractory to medical management, severe hypertension in a young patient and worsening of renal function after the use of an angiotensin-converting enzyme inhibitor. Early discovery of renal artery stenosis may allow amelioration or cure of the hypertension and halt progressive loss of renal function. Although renal arteriography remains the gold-standard aid to diagnosis and to planning surgical intervention, it is an invasive procedure that may cause deterioration of renal function. In the presence of renal artery stenosis, glomerular filtration is maintained by angiotensin. Administration of captopril in renal scintigraphy removes this compensatory mechanism and causes a temporary impairment of renal function in the affected kidney. Nuclear tracers can visualize this impairment, thus allowing assessment of the physiologic significance of a renal artery stenosis. The test can be done as a outpatient procedure.     

Detection of renovascular hypertension with angiotensin II blockade

Experiments with synthetic substance P incubated in whole blood show that apart from a moderate loss of activity immediately on exposure of the peptide to whole blood, it is inactivated slowly in this tissue, approximately 25% of control activity remaining after 30 min incubation. Incubation with plasma did not result in the degradation of substance P. The attenuation of substance P activity in blood may be due to enzymatic destruction within erythrocytes.     

Surgical treatment of renovascular hypertension

Two hundred sixty-four patients exhibiting renal artery occlusive disease underwent operation for renovascular hypertension between 1961 and 1977. Included were 27 pediatric patients. Fibrodysplastic disease affected 132 adults. Atherosclerotic lesions affected 51 patients with and 54 patients without clinically overt extrarenal arteriosclerotic cardiovascular disease. Ischemic kidney renin hypersecretion (renal: systemic index greater than 0.48), associated with suppressed contralateral kidney renin secretion (renal: systemic index approaching 0.0) predicted curability most reliably. Three hundred forty-eight operations were performed, of which 297 were primary and 51 were secondary procedures. Nephrectomy was initial therapy in 15 cases. Three operative deaths occurred among 51 patients manifesting overt extrarenal arteriosclerotic disease. No operative mortality was encountered among the other 213 patients. Surgical benefits were afforded 96% of pediatric patients and adults with fibrodysplastic disease, 91% of patients with focal renal arteriosclerosis, and 73% of those exhibiting overt extrarenal arteriosclerosis.     

Intraoperative discovery of neuroblastoma in an infant with pulmonary atresia

There have been 28 previously reported cases of neuroblastoma associated with congenital heart disease. Because many of these have been defects of the conotruncal region, it has been proposed that abnormal neural crest cell migration or maturation may be a factor that links these normally disparate pathologic conditions. Most neuroblastomas in these cases have been detected at autopsy or by radiologic studies conducted in the evaluation of the cardiac anomalies. Recently, we discovered an occult posterior mediastinal neuroblastoma in a patient undergoing a unifocalization procedure for tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals. The tumor was resected, and the patient has demonstrated no evidence of residual or metastatic neuroblastoma.     

Detecting and treating arteriosclerotic renovascular hypertension

Renovascular hypertension is the most prevalent form of surgically remediable hypertension. With appropriate selection of operative candidates, a high rate of cure or improvement may be anticipated. Favorable results justify revascularization in hypertensive patients with focal arteriosclerotic renal artery disease. The absence of advanced arteriosclerosis provides the most valid basis for predicting long-term survival following revascularization. Patients with clinically demonstrable diffuse arteriosclerotic disease are preferably treated medically; we consider them candidates for surgery only if drug therapy cannot control blood pressure. Renal revascularization does not appear to alter the inexorable progression of concomitant generalized arteriosclerosis. Revascularization rather than nephrectomy is the primary surgical therapy for renal artery stenosis in properly selected patients.     

Screening for renovascular hypertension in a population with relatively low prevalence

OBJECTIVE: To evaluate the accuracy and cost-efficacy of the diagnostic procedure and treatment for renovascular hypertension. SETTING AND PATIENTS: A total of 519 patients referred to the university clinic for hypertension were screened for renovascular hypertension with 405 captopril challenge tests (CCT) and 450 captopril renographies (CRG). INTERVENTIONS: Abdominal angiography was performed on 84 patients for positive screening. Fifteen patients underwent angiography for a sole suspicious clinical presentation. The angiography revealed 17 renal artery stenoses and five occlusions in 20 patients. Fifteen technically successful angioplasties and three nephrectomies were performed. RESULTS: In the patients who underwent angiography, CCT had a specificity of 39% and a sensitivity of 67% for renovascular hypertension. CRG had a sensitivity of 100% and a specificity of 68%. In the whole study population, the estimated specificity of CCT was 88% and that of CRG 95%. Invasive treatment reduced systolic/diastolic blood pressure from 157/99 to 140/87 mmHg and the number of antihypertensive drugs used from 2.6 to 1.4 in 16 patients (mean age 49 years). Angiotensin converting enzyme (ACE) inhibition was effective in four elderly patients. Cost-efficacy analysis Screening with CRG and invasive treatment cost US$15400 per successful invasive treatment Equally effective pharmacological treatment would have cost US$10400. Limiting the screening with CRG to the 173 patients with no obvious renal parenchymal disease and with hypertension at a younger age (< or =30 years) or unresponsive to two antihypertensive drugs (diastolic blood pressure > 90 mmHg) would have yielded a prevalence of 12% and missed only one elderly patient who responded to ACE inhibition. The limited screening, along with invasive treatment, would have cost US$7300 per patient CONCLUSIONS: CRG is superior to CCT for screening of renovascular hypertension. Screening with CRG is cost-effective when limited to patients with no obvious renal parenchymal disease and with hypertension that does not respond to two antihypertensive drugs or is detected in patients no older than 30 years.     

Increased plasma endothelin concentration in atherosclerotic renovascular hypertension

The aim was to investigate circulating levels of immunoreactive endothelin (ir-ET) in atherosclerotic renovascular hypertension (RVH), and to assess the role of the kidneys in its overall plasma concentration. We studied 16 hypertensive patients with renal artery stenosis evidenced by angiography and admitted to hospital for the diagnostic evaluation of RVH by renal vein plasma renin activity (PRA) determinations. The right femoral vein was catheterized to simultaneously measure PRA and ir-ET in both renal veins and inferior vena cava below the origin of the renal veins. RVH was present in 9 patients as indicated by diagnostic PRA renal vein ratios and the remaining 7 patients were considered to have essential hypertension (EH). Patients with RVH showed a marked increase in systemic plasma ir-ET concentration (10.3 +/- 0.9 pg/ml). Despite a significant increase of PRA in the vein of the ischemic (IK) versus the contralateral (CK) kidney in patients with RVH, no significant differences in ir-ET concentration were observed between both kidneys. These results indicate that patients with RVH have increased circulating levels of ir-ET. However, the higher systemic plasma ir-ET do not arise from the renal circulation, since plasma ir-ET is significantly higher in systemic circulation than in renal veins.     

A patient with aortic dissection and abdominal aortic aneurysm with fistula

Aneurysm of the abdominal aorta is not uncommon in later life. The frequency of aneurysm rupture varies with aneurysm diameter. In rare cases, the aneurysm may rupture intra-abdominally into surrounding structures and give rise to a fistula. When blood vessels are involved, the commonest form is aortocaval fistula, the presenting symptoms being those of severe right-ventricular heart failure. Although thoracic aorta dissection may be made manifest in acute intense chest pain, it is asymptomatic in up to 50 per cent of cases. The article consists in a case report of asymptomatic thoracic aorta dissection occurring concomitantly with a ruptured abdominal aneurysm the symptoms of which were severe right ventricular heart failure due to an aortocaval fistula causing increased pressure, and severe bilateral oedema of the legs. If the rare complication of an aortocaval fistula could be detected earlier, it might be possible to prevent progression to refractory cardiac failure. The possibility of a fistula should be borne in mind if haematuria is present in a case of abdominal aneurysm or a pulsatile abdominal mass is present in conjunction with a murmur.     

The investigation of renovascular hypertension in children: the accuracy of radio-isotopes in detecting renovascular disease

Renovascular disease is an important cause of hypertension in children because it is potentially treatable by surgical or angioplasty techniques. The aim of this study was to assess the accuracy of radio-isotopes (DMSA, DTPA and MAG3) combined with the angiotensin converting enzyme inhibitor, captopril, in detecting children with renovascular hypertension. We retrospectively reviewed the ultrasound and pre- and post-captopril radionuclide studies (either DMSA and/or DPTA and/or MAG3) of children with sustained hypertension investigated at our institution. Renal angiography was used as the 'reference technique'. Thirty-nine children, over a period of 10 years, were evaluated: 17 (44%) children had renovascular disease that involved the proximal three divisions of the renal arteries, some of which were amenable to treatment. The overall sensitivity, specificity, positive predictive value and negative predictive value for detecting such renovascular disease, as assessed by changes between pre- and post-captopril radio-isotope studies, were disappointing at 59%, 68%, 59% and 68%, respectively. When considering only abnormalities in post-captopril studies, these indices were 82%, 41%, 52% and 75%, respectively. Three children with potentially treatable renovascular disease were not identified on the captopril studies. We conclude that renal angiography should remain the 'reference technique' in identifying children suspected of renovascular hypertension.     

Ruptured abdominal aortic aneurysm

In the years 1990-1994, 43 patients with ruptured abdominal aortic aneurysms (RAAA) were operated on at the Department of Vascular Surgery of the Na Homolce Hospital in Prague. Men outnumbered women, average patient age was 70 years. The mean delay between onset of symptoms and hospital admission counted 27 hrs. Prior to transportation, one half to two thirds of patients went through at least two types of confirmative evaluation (CAT, ultrasound, angiography) and/or were referred via two or more hospital departments. In two thirds of patients profound shock with oligoanuria and hypotension were found. Anuria/hypotension proved to occur in a significantly lower rate in later survivors compared to later dead (11.8% vs. 23.5%: p < 0.05). Persistent hypotension during surgery together with eventual resuscitation as well as free blood found within the abdominal cavity showed up as further ominous factors. Renal failure was the leading postoperative complication (51.2%) with 27.9% of patients requiring hemodialysis after repair. Sepsis (25.6%), pneumonia (20.9%) and hemorrhage (13.9%) followed. Twenty-six patients were lost (60.5%) either within the first hours and days after surgery because of irreversible hemorrhagic shock or between the second and fourth week due to the sequels of organ failure and sepsis. In our cohort, regardless of age, sex, concomitant disease or the type of surgery, the patient's status on admission determined his/her further destiny. Urgent transfer to a specialized center going hand in hand with prompt and effective reanimation steps are the patient's only hope for survival.     

Cardioprotective effect of enalapril in renovascular and angiotensin II hypertension

The influence of chronic treatment with enalapril or losartan (10 or 30 mg/kg/24h, respectively) on cardiac mass was evaluated in one-kidney, one clip (1K-1C) hypertensive rats submitted to sodium restriction 3 weeks after clipping and in rats infused for 10 days with angiotensin II (ANGII: 200 ng/kg/min). In 1K-1C hypertension, cardiac mass and arterial pressure were reduced to a similar extent by enalapril and losartan. In ANGII hypertension, enalapril and losartan blunted the increase in cardiac mass whereas losartan but not enalapril prevented the development of hypertension. The cardioprotective effect of enalapril was attenuated by concomitant blockade of bradykinin receptors (Hoe140: 300 micrograms/kg/24h) in both models. The beneficial influence of enalapril on cardiac mass appears to be independent of its effect on blood pressure and ANGII generation and seems partly mediated by endogenous bradykinin in these high ANGII models of hypertension.     

Hypogastric arterial aneurysms associated with abdominal aortic aneurysms

The purpose of this study was to compare the physiological responses of professional and elite road cyclists during an incremental cycle ergometer test. Twenty-five elite cyclists (EC; 23+/-1 yr) and 25 professional cyclists (PC; 25+/-2yr) performed a ramp protocol (increases of 25 W x min(-1)) during which the following parameters were measured: oxygen consumption (VO2), pulmonary ventilation (VE), ventilatory equivalents for oxygen and carbon dioxide (VE x VO2(-1) and VE x VCO2(-1), respectively), respiratory exchange ratio (RER), ventilatory thresholds 1 and 2 (VT1 and VT2, respectively), blood lactate, and electromyographic activity (EMG) of the vastus lateralis. Significant differences existed between the two groups mainly at submaximal intensities, since both VT1 and VT2 occurred at a higher exercise intensity (p<0.001) in PC than in EC (VT2: 80.4+/-6.6 vs 87.0+/- 5.9% VO2max in EC and PC, respectively). Lactate levels showed a similar response in both groups at low-to-moderate intensities (< 300 W), and thereafter blood lactate was significantly higher in EC. Finally, the "electromyographic threshold" (EMGT) occurred at a significantly higher intensity (p < 0.05) in PC when compared to EC (64.7+/-14.2 vs 56.0+/-14.9% VO2max, respectively). It was concluded that, in comparison with EC, PC exhibit some remarkable physiological characteristics such as a high VT2, an important reliance on fat metabolism even at high power outputs, and several neuromuscular adaptations.     

Psychological morbidity associated with abdominal aortic aneurysm screening

The case of a 46 years old man presenting a chronic history of right upper lobe pneumonia is reported. The clinical presentation associated with nodular pulmonary computed tomographic scan lesions, highly suggested a malignant bronchopulmonary process. A lobectomy was performed. Histological analysis revealed an inflammatory pseudotumor. This inflammatory process may be a particular end stage disease of pulmonary infectious disease.