Pheochromocytoma: a paradigm for catecholamine-mediated hypertension

Transient or permanent hypertension may result from the inappropriate activation of the sympathetic nervous system and/or from chronically elevated levels of circulating catecholamines (epinephrine or norepinephrine). Recent data implicate this high sympathetic tone as a contributing factor to the genesis of essential hypertension in a significant proportion of individuals, and show that it is frequently associated with insulin resistance and cardiovascular comorbidity. Among the several causes of catecholamine-mediated hypertension, pheochromocytoma, although rare, holds a special place and represents a challenging experience for the clinician. Diagnosis and therapy of this remarkable disease will be reviewed here in details, with a special emphasis on recent findings such as the high diagnostic sensitivity of plasma fractionated metanephrines, the better understanding of genetic diseases predisposing to chromaffin tumor development, and the modern management of pheochromocytoma, including the medical preparation before surgery. Other causes of catecholamine excess will be reviewed more briefly.

[Treating a hypertensive emergency]

A hypertensive crisis is characterized by a massive blood pressure increase of sudden onset, with systolic pressures in excess of 220 mmHg or diastolic pressures of more than 120 mmHg usually being found in patients with underlying hypertensive disease. Of decisive importance for the severity of the patient's presenting state, however, is not the absolute level of the blood pressure, but rather the extent of the acute blood pressure increase. Of decisive importance for the therapeutic approach to the acute case is whether the hypertensive crisis is accompanied by organic manifestations (hypertensive emergency) or is unaccompanied by this life-threatening clinical presentation (hypertensive urgency). The former patients must always be hospitalized, and the preferential treatment is parenteral medication, which is associated with a more rapid and calculable onset of action than can be achieved via the oral or sublingual route.

[Malignant hypertension. Case series of 42 patients]

One could expect that malignant hypertension would belong to the history. Unfortunately, this complication has not been eradicated even though many physicians have already forgot it. The hypertension care units are still confronted to it, and even the arrival of the renin-angiotensin system blockers have changed the prognosis of those patients, an adequate management on emergency remains mandatory in order to avoid in particular the evolution to renal failure. By reporting a series of 42 patients included in a period of 7 years, we aimed to remind the presentation of this severe pattern of hypertension and the basics of its management.

Hypertensive urgencies and emergencies

Severely elevated blood pressure (BP) is commonly encountered in acute care settings. Initial evaluation of patients with severe hypertension should focus on determining the presence and extent of acute target organ damage. Hypertensive emergencies are life-threatening conditions that require immediate reduction of BP in an intensive care unit. Hypertensive urgencies-and severe uncontrolled hypertension also require prompt attention with gradual lowering of BP. There are a number of drugs available for the treatment of these disorders. Careful reduction in BP with special attention to cerebral circulation is key to managing these patients.

Présentation d’un cas atypique de rétinopathie hypertensive maligne chez une fillette

Stage IV hypertensive retinopathies in children have been described, but their incidence appears to be rare. Most etiologies are nephropathies. The authors present a clinical case of malignant high blood pressure in a young girl whose ophthalmological tests detected an unusual nephropathy, the Ask-Upmark kidney, illustrating the importance of determining high blood pressure chronicity and using Kirkendall's classification. Systematic fluorescein angiography and NMR on atypical subjects prevents the diagnosis of Leber neuroretinis, the main differential diagnosis. Early treatment of high blood pressure can avoid complications such as macular exudes.

Malignant hypertensive retinopathy-clinical and fundus manifestations in patients with new onset or acute exacerbation of chronic hypertension

BACKGROUND

We attempted to review the clinical and fundus findings in patients with malignant hypertension (MHT).

METHODS

Charts and fundus photographs of patients with malignant hypertensive retinopathy from 1995 to 2000 were retrospectively reviewed. Data of patients were included when their color fundus photographs revealed findings suggestive of malignant hypertension (MHT). There had to have been at least 1 high blood pressure reading recorded in the chart during the period when the symptoms occurred. Data were excluded from patients with diseases such as diabetes mellitus, blood dyscrasia, and autoimmune and infectious diseases which can mimic the fundus findings of MHT.

RESULTS

Fourteen patients were included in our study. Patients were divided into 2 groups according to whether or not they had a history of hypertension. Group 1 included 6 patients with no hypertension history, while group 2 included 8 patients with a known hypertension history. In group 1, MHT was diagnosed by an ophthalmologist in 4 patients, and the other 2 patients were referred from the Gynecology and Nephrology Departments. Between the 2 groups, there were no significant differences in age, or systolic and diastolic blood pressures. There were more complications such as renal failure and stroke in group 2 patients.

CONCLUSION

Funduscopy has decisive significance in the diagnosis and monitoring of MHT. In order to accurately diagnose and achieve early control of this critical condition, a detailed fundus examination and blood pressure monitoring are mandatory.

Reversible brain lesions in childhood hypertension

Posterior leukoencephalopathy syndrome is characterized by an acute, usually reversible, encephalopathy with transient occipital lobe abnormalities detected on MRI that occur mostly in association with acute hypertension. The clinical presentation includes seizures, headache, altered mental status and blindness. Disturbed autoregulation of cerebral blood flow and endothelial injury are central to the pathogenesis of this disorder. Prompt control of hypertension results in rapid and complete neurological recovery. In this report we discuss the cases of two children with acute onset hypertension of different aetiologies that presented with the characteristic features of posterior leukoencephalopathy syndrome.

CONCLUSION

Early recognition of this readily treatable condition may obviate the need for extensive and invasive investigations. Despite the alarming lesions on the MRI, prompt control of hypertension carries a uniformly favourable prognosis.

Malignant hypertension as a presenting symptom of Takayasu arteritis

We present an unusual case of malignant hypertension in a 20-year-old white woman. One week before hospitalization, she experienced occasional abdominal pain and claudication of both legs; otherwise, she had no remarkable medical history, including no history of high blood pressure. The origin of the patient's hypertension was renovascular, and the vascular injury was due to vasculitis of the large arteries. The combination of a difference in blood pressure between the patient's arms, angiographic findings, elevated erythrocyte sedimentation rate, and lack of markers for specific vasculitis led to the diagnosis of Takayasu arteritis. Surgical intervention was successful.

Acute intermittent porphyria: an unusual cause of malignant hypertension

Hypertension is a rare complication of acute intermittent porphyria (AIP) and is related to the sympathetic over-activity seen in this condition. We report a patient with AIP with malignant hypertension that recurred with a subsequent episode. Mechanisms of hypertension and renal damage are discussed.

Malignant hypertension presenting as hemolysis, thrombocytopenia, and renal failure

This case review describes a patient presenting to the emergency department with malignant hypertension, a medical emergency occurring in up to 1% of the hypertensive population. The features of malignant hypertension resemble those of other diseases. For example, the association between red-cell fragmentation and malignant hypertension is thought to be due to endothelial injury and fibrinoid necrosis, which promote hemolysis, platelet destruction, and varying degrees of renal failure, resulting in a clinical picture similar to that of thrombotic thrombocytopenic purpura. Resolving the hemolysis and improving the renal function can only be achieved through rapid and effective control of the blood pressure. Without treatment, the survival rate for malignant hypertension is 10% to 35%. With appropriate treatment, the 5-year survival rate is 75%.

Continuing follow-up of malignant hypertension

The history of accelerated (malignant) hypertension is reviewed, and unsolved problems related to the disease are illustrated, including its relationship to malignant nephrosclerosis, as well as terminology, current frequency and treatment. Over the past 25 years, out of a series of 131 patients, 53 were classified as suffering from essential malignant hypertension, the only suitable model on which the effects of pharmacological treatment on the disease can correctly be evaluated. In 2000, there were 24 survivors in our series and the maximum follow-up was 290 months. Multiple daily B.P. self-measurements allowed us to establish that pharmacological treatment was only able to approximate, to a varying degree, the conventional threshold of 140/90. Yet, despite this incomplete control over blood pressure levels, renal function was maintained in those patients whose initial creatininemia levels had not been higher than 2 mg/L. The renal protection effect of treatment was preserved even in patients who relapsed intoaccelerated disease phase one or more times over the study period.

Acute bilateral optic disk edema with a macular star figure in a 12-year-old girl

A 12-year-old girl developed headaches and bilateral optic disk edema due to malignant hypertension. Optic disk edema in most of these cases is probably on the spectrum of ischemic optic neuropathy rather than increased intracranial pressure.