October 2, 2016
Hypertension secondary to Pheochromocytoma
Definition: Pheochromacytomas are neuroendocrine tumors of the adrenal medulla (and occasionally elsewhere) that can result in hypertension secondary to the hypersecretion of the catecholamines epinephrine and/or norepinephrine. This can be continuous or episodic and this release subsequently affects blood pressure by raising it as part of the body’s fight or flight response. According to our textbook (Fox, p. 339), Pheochromocytomas are rare and usually benign tumors treated with alpha and beta adrenergic receptor blockers and adrenalectomy.
Normal Physiology: The adrenal glands lie atop the kidneys producing and excreting hormones. The …show more content…
Their release by the pheochromocytoma travels to adrenergic α1 recepters in the smooth muscle of blood vessel walls causing vasoconstriction. Additionally, they also travel to β1 recepters in the heart causing increased cardiac contractility and increased heart rate. These factors collectively cause spikes in blood pressure. This resultant hypertension has the potential to be life threatening. According to Zuber et al, “there is also evidence suggesting a correlation between biochemical phenotype and characteristics of hypertension. Patients with tumors that produce high concentrations of norepinephrine are likely to incur sustained hypertension, while patients with significantly elevated levels of epinephrine are often seen having paroxysmal and orthostatic hypertension.” (Zuber, Kantorovich MD, & Pacek MD, PHD, 2011)
Symptoms: Patients with hypertension secondary to a pheochromocytoma may present with symptoms including headache, hypertension, palpitations, tachycardia and dizziness. They may also experience diaphoresis, irritability and flushing. Any sustained hypertension has the potential to leads to strokes and myocardial ischemia and their associated symptoms or signs. Orthostatic hypertension may lead to falls and syncopal