Related Research Articles
Hypertension, also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide.
Neuroleptic malignant syndrome (NMS) is a rare but life-threatening reaction that can occur in response to neuroleptic or antipsychotic medication. Symptoms include high fever, confusion, rigid muscles, variable blood pressure, sweating, and fast heart rate. Complications may include rhabdomyolysis, high blood potassium, kidney failure, or seizures.
A catecholamine is a monoamine neurotransmitter, an organic compound that has a catechol and a side-chain amine.
Pheochromocytoma is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as pheochromocytes. When a tumor composed of the same cells as a pheochromocytoma develops outside the adrenal gland, it is referred to as a paraganglioma. These neuroendocrine tumors typically release massive amounts of catecholamines, metanephrines, or methoxytyramine, which result in the most common symptoms, including hypertension, tachycardia, and diaphoresis (sweating). Rarely, some tumors may secrete little to no catecholamines, making diagnosis difficult. While tumors of the head and neck are parasympathetic, their sympathetic counterparts are predominantly located in the abdomen and pelvis, particularly concentrated at the organ of Zuckerkandl.
Tranylcypromine, sold under the brand name Parnate among others, is a monoamine oxidase inhibitor (MAOI). More specifically, tranylcypromine acts as nonselective and irreversible inhibitor of the enzyme monoamine oxidase (MAO). It is used as an antidepressant and anxiolytic agent in the clinical treatment of mood and anxiety disorders, respectively.
Alpha-methyl-p-tyrosine (AMPT) is a tyrosine hydroxylase enzyme inhibitor and is therefore a drug involved in inhibiting the catecholamine biosynthetic pathway. AMPT inhibits tyrosine hydroxylase whose enzymatic activity is normally regulated through the phosphorylation of different serine residues in regulatory domain sites. Catecholamine biosynthesis starts with dietary tyrosine, which is hydroxylated by tyrosine hydroxylase and it is hypothesized that AMPT competes with tyrosine at the tyrosine-binding site, causing inhibition of tyrosine hydroxylase.
Secondary hypertension is a type of hypertension which by definition is caused by an identifiable underlying primary cause. It is much less common than the other type, called essential hypertension, affecting only 5-10% of hypertensive patients. It has many different causes including endocrine diseases, kidney diseases, and tumors. It also can be a side effect of many medications.
Retroperitoneal fibrosis or Ormond's disease is a disease featuring the proliferation of fibrous tissue in the retroperitoneum, the compartment of the body containing the kidneys, aorta, renal tract, and various other structures. It may present with lower back pain, kidney failure, hypertension, deep vein thrombosis, and other obstructive symptoms. It is named after John Kelso Ormond, who rediscovered the condition in 1948.
Fenoldopam mesylate (Corlopam) is a drug and synthetic benzazepine derivative which acts as a selective D1 receptor partial agonist. Fenoldopam is used as an antihypertensive agent. It was approved by the Food and Drug Administration (FDA) in September 1997.
Hypertensive encephalopathy (HE) is general brain dysfunction due to significantly high blood pressure. Symptoms may include headache, vomiting, trouble with balance, and confusion. Onset is generally sudden. Complications can include seizures, posterior reversible encephalopathy syndrome, and bleeding in the back of the eye.
Metirosine is an antihypertensive drug. It inhibits the enzyme tyrosine hydroxylase and, therefore, catecholamine synthesis, which, as a consequence, depletes the levels of the catecholamines dopamine, adrenaline and noradrenaline in the body.
An adrenergic storm is a sudden and dramatic increase in serum levels of the catecholamines adrenaline and noradrenaline, with a less significant increase in dopamine transmission. It is a life-threatening condition because of extreme tachycardia and hypertension, and is especially dire for those with prior heart problems. If treatment is prompt, prognosis is good; typically large amounts of diazepam or other benzodiazepines are administered alongside beta blockers. Beta blockers are contraindicated in some patients, so other anti-hypertensive medication such as clonidine may be used. Antipsychotics are also used to treat the most severe psychiatric reactions such as psychosis, paranoia or terror, after their use was formerly discouraged because of their potential to prolong the QT interval; however, more recent research performed since 2019 has revealed that this and other severe side effects are rare and their occurrence does not warrant banning antipsychotics from the treatment of adrenergic crises for which they can be extremely useful.
Pathophysiology is a study which explains the function of the body as it relates to diseases and conditions. The pathophysiology of hypertension is an area which attempts to explain mechanistically the causes of hypertension, which is a chronic disease characterized by elevation of blood pressure. Hypertension can be classified by cause as either essential or secondary. About 90–95% of hypertension is essential hypertension. Some authorities define essential hypertension as that which has no known explanation, while others define its cause as being due to overconsumption of sodium and underconsumption of potassium. Secondary hypertension indicates that the hypertension is a result of a specific underlying condition with a well-known mechanism, such as chronic kidney disease, narrowing of the aorta or kidney arteries, or endocrine disorders such as excess aldosterone, cortisol, or catecholamines. Persistent hypertension is a major risk factor for hypertensive heart disease, coronary artery disease, stroke, aortic aneurysm, peripheral artery disease, and chronic kidney disease.
Complications of hypertension are clinical outcomes that result from persistent elevation of blood pressure. Hypertension is a risk factor for all clinical manifestations of atherosclerosis since it is a risk factor for atherosclerosis itself. It is an independent predisposing factor for heart failure, coronary artery disease, stroke, kidney disease, and peripheral arterial disease. It is the most important risk factor for cardiovascular morbidity and mortality, in industrialized countries.
Mepiprazole is an anxiolytic drug of the phenylpiperazine group with additional antidepressant properties that is marketed in Spain. It acts as a 5-HT2A and α1-adrenergic receptor antagonist and inhibits the reuptake and induces the release of serotonin, dopamine, and norepinephrine to varying extents, and has been described as a serotonin antagonist and reuptake inhibitor (SARI). Controlled clinical trials of mepiprazole in patients with irritable bowel syndrome (IBS) were also carried out and suggested some benefits of the drug in relieving symptoms of IBS in some patients. Similarly to other phenylpiperazines like trazodone, nefazodone, and etoperidone, mepiprazole produces mCPP as an active metabolite.
Orthostatic hypertension is a medical condition consisting of a sudden and abrupt increase in blood pressure (BP) when a person stands up. Orthostatic hypertension is diagnosed by a rise in systolic BP of 20 mmHg or more when standing. Orthostatic diastolic hypertension is a condition in which the diastolic BP raises to 98 mmHg or over in response to standing, but this definition currently lacks clear medical consensus, so is subject to change. Orthostatic hypertension involving the systolic BP is known as systolic orthostatic hypertension.
Renal cortical necrosis (RCN) is a rare cause of acute kidney failure. The condition is "usually caused by significantly diminished arterial perfusion of the kidneys due to spasms of the feeding arteries, microvascular injury, or disseminated intravascular coagulation" and is the pathological progression of acute tubular necrosis. It is frequently associated with obstetric catastrophes such as abruptio placentae and septic shock, and is three times more common in developing nations versus industrialized nations.
The sympathoadrenal system is a physiological connection between the sympathetic nervous system and the adrenal medulla and is crucial in an organism's physiological response to outside stimuli. When the body receives sensory information, the sympathetic nervous system sends a signal to preganglionic nerve fibers, which activate the adrenal medulla through acetylcholine. Once activated, norepinephrine and epinephrine are released directly into the blood by postganglionic nerve fibers where they act as the bodily mechanism for "fight-or-flight" responses. Because of this, the sympathoadrenal system plays a large role in maintaining glucose levels, sodium levels, blood pressure, and various other metabolic pathways that couple with bodily responses to the environment. During numerous diseased states, such as hypoglycemia or even stress, the body's metabolic processes are skewed. The sympathoadrenal system works to return the body to homeostasis through the activation or inactivation of the adrenal gland. However, more severe disorders of the sympathoadrenal system such as Pheochromocytoma can affect the body's ability to maintain a homeostatic state. In these cases, curative agents such as adrenergic agonists and antagonists are used to modify epinephrine and norepinephrine levels released by the adrenal medulla.
Paroxysmal sympathetic hyperactivity (PSH) is a syndrome that causes episodes of increased activity of the sympathetic nervous system. Hyperactivity of the sympathetic nervous system can manifest as increased heart rate, increased respiration, increased blood pressure, diaphoresis, and hyperthermia. Previously, this syndrome has been identified as general dysautonomia but now is considered a specific form of it. It has also been referred to as paroxysmal sympathetic instability with dystonia, or PAID, and sympathetic storm. Recently, however, studies have adopted the name paroxysmal sympathetic hyperactivity to ensure specificity. PSH is observed more in younger patients than older ones. It is also seen more commonly in men than women. There is no known reason why this is the case, although it is suspected that pathophysiological links exist. In patients surviving traumatic brain injury, the occurrence of these episodes is one in every three. PSH can also be associated with severe anoxia, subarachnoid and intracerebral hemorrhage, and hydrocephalus.
Labile hypertension occurs when there are unexpected changes in blood pressure. The term can be used to describe when people have blood pressure measurements that abruptly fluctuates from being abnormally high, approximately 140/90mm Hg or over and returns to its normal range.
References
- ↑ Kuchel O (1985). "Pseudopheochromocytoma". Hypertension. 7 (1): 151–8. doi: 10.1161/01.hyp.7.1.151 . PMID 3980057.
- ↑
- Kuchel O, Buu NT, Larochelle P, Hamet P, Genest J (1986). "Episodic dopamine discharge in paroxysmal hypertension. Page's syndrome revisited". Archives of Internal Medicine. 146 (7): 1315–20. doi:10.1001/archinte.1986.00360190079011. PMID 3718127.
- ↑
- Seck SM, Ka EF, Niang A, Diouf B (2009). "Pseudopheochromocytoma: An uncommon cause of malignant hypertension". Indian Journal of Nephrology. 19 (3): 122–4. doi:10.4103/0971-4065.57111. PMC 2859479 . PMID 20436734.
