I have heard about hypertension and hypertensive emergencies, but few people know about subacute hypertension.
What are the causes of subacute hypertension?
Subacute hypertension is an acute and critical condition in which blood pressure is significantly elevated without severe clinical symptoms and progressive target organ damage.
On the basis of primary or secondary hypertension, subacute hypertension can be triggered by many factors, such as stress, abnormal neurological reflexes, and abnormal endocrine hormone levels, which can increase sympathetic tone and the release of vasoactive substances, triggering a rapid rise in blood pressure in the short term.
Once the disease develops, the patient suffers from systemic small artery spasm, which can lead to stress polyuria and reduced circulating blood volume, and reflexively causes the activation of vasoactive substances, resulting in continued vasoconstriction and the production of inflammatory factors, thus forming a vicious circle.
When the elevated blood pressure leads to endothelial damage and fibrinoid necrosis of small arteries, it can trigger ischemia, further release of vasoactive substances and aggravate the damage.
Hypertensive emergencies vs. subacute hypertension
There is only one word difference between hypertensive subacute and hypertensive emergency, but there is a clear difference, and both are collectively called hypertensive crisis.
1. Criteria: The difference is not related to the degree of elevated blood pressure, but is based on the presence or absence of new acute progressive target organ damage in the patient.
2. Symptoms: Hypertensive emergencies mainly include hypertensive encephalopathy, intracranial hemorrhage (cerebral hemorrhage and subarachnoid hemorrhage), cerebral infarction, acute heart failure, acute coronary syndrome, aortic coarctation, renal damage, perioperative severe hypertension, pheochromocytoma crisis, etc.
In contrast, patients with subacute hypertension mainly present with headache, dizziness, irritability, palpitations, as well as nausea, vomiting, blurred vision, etc., without accompanying hypertensive encephalopathy, intracranial hemorrhage, acute heart attack or acute left heart failure, unstable angina pectoris, and aortic coarctation.
3.Treatment: In terms of treatment, hypertensive emergencies usually require continuous intravenous use of antihypertensive drugs, while subacute hypertension usually does not require intravenous antihypertensive drug therapy, but rather the application of oral drugs to lower blood pressure.
Intravenous medications or rapid oral antihypertensive drugs may cause a sudden drop in blood pressure in patients with subacute conditions, which can lead to a decrease in perfusion pressure in major organs and serious neurological complications.
How to deal with subacute hypertension?
For sudden onset subacute hypertension, the initial treatment taken clinically should be a combination of immediate oral antihypertensive drugs with rest and observation, and in principle, blood pressure should be gradually lowered within 24-48 hours with a view to bringing it under control gradually over several days.
Especially for elderly patients with subacute hypertension, it is recommended to add short- and medium-acting oral drugs to stable, moderate and long-acting oral antihypertensive drugs as appropriate and avoid intravenous medication. The blood pressure can be slowly reduced to 160/100 mmHg over 24-48 hours with blood pressure monitoring, with dose adjustment after 2-3 days, after which long-acting agents are applied to control to the final target blood pressure.
Caution is required during treatment. Patients who get adequate rest may be able to bring down their blood pressure, and if it remains high, symptomatic treatment is required. Second, in patients with severe hypertension, the cause needs to be identified and the treatment optimized. It is recommended to actively search for abnormally high, correctable causes or triggers of blood pressure, such as inappropriate medication reduction and discontinuation, after the condition has been stabilized.
On a daily basis, hypertensive patients also need to increase their awareness of hypertensive crisis, adhere to regular medication, correct poor lifestyle habits, and seek early medical attention if their self-measured blood pressure is found to be significantly higher than the usual value to avoid developing into a subacute hypertensive condition that can cause important damage to the body.
References
[1] National Health and Family Planning Commission Rational Drug Use Expert Committee, National Association of Physicians Hypertension Professional Committee. Guide to the rational use of medication for hypertension (2nd edition) [J]. Chinese Journal of Frontiers in Medicine,2017,7(9):75.
[2]Chinese Society of Geriatrics Hypertension Branch,National Center for Clinical Medical Research on Geriatric Diseases China Geriatric Cardiovascular Disease Prevention and Control Alliance. Guidelines for the management of hypertension in the elderly in China 2019[J]. Chinese Journal of Geriatric Multi-Organ Diseases,2019,2(18):91.
[3]Gao RL,De Pei. Chinese medical encyclopedia. Cardiovascular pathology [M]. China Union Medical University Press,2017:222.