The rostral ventrolateral medulla (RVLM) regulates sympathetic nervous system activity and is involved in hypertension. The RVLM receives inhibitory input and sends projections to sympathetic neurons, increasing cardiac output and peripheral resistance. Increased sympathetic activity from stress, anxiety or pain can lead to hypertension via RVLM signaling. Other causes of hypertension include reduced kidney perfusion from conditions like vasculitis or renal artery stenosis, as well as obstructive sleep apnea, hypercalcemia, burns, and certain medications.

1. PATHOPHYSIOLOGY OF HYPERTENSION IN
PEDIATRICS
(PART – 2)
RISHIKA THAKUR
ROLL NO. 1866

2. NEUROLOGICAL
AND HUMORAL
CONTROL OF
BLOOD
PRESSURE

3. NEUROLOGICA
L AND
HUMORAL
CONTROL OF
BLOOD
PRESSURE
◦ The rostral ventrolateral medulla (RVLM), also known as
the pressor area of the medulla, is a brain region that is
responsible for basal and reflex control
of sympathetic activity associated with cardiovascular
function.
◦ Abnormally elevated sympathetic activity in the RVLM is
associated with various cardiovascular diseases, such as heart
failure and hypertension. The RVLM is notably involved .
◦ It receives inhibitory GABAergic input from the caudal
ventrolateral medulla (CVLM). The RVLM is a primary
regulator of the sympathetic nervous system ; it sends
catecholaminergic projections to sympathetic
preganglionic neurons in the intermediolateral nucleus of
the spinal cord via reticulospinal tract.

4. NEUROLOGICAL CAUSES
OF HYPERTENSION
◦ Increased sympathetic activity ( due to stress, anxiety and pain)
◦ Dysautonomia
◦ Increased intracranial pressure.

5. ◦ Due to increased sympathetic activity caused by stress, anxiety or
pain , RVLM sends catecholaminergic projections to the sympathetic
preganglionic neurons in the intermediolateral nucleus of the spinal
cord via reticulospinal tract.
◦ Spinal cord sends sympathetic signals to heart and blood vessels
thereby leading to increased cardiac output and total peripheral
resistance. Thus further leading to increased blood pressure.

6. CARDIOVASCULAR CAUSES
OF HYPERTENSION
◦ Coarctation of aorta
◦ Vasculitis
◦ Renal artery embolism
◦ Renal vein thrombosis
◦ Renal artery stenosis
◦ Moyamoya disease

7. Coarctation of
aorta
◦ It is a birth defect in which a
part of the aorta is narrower
than usual.
◦ The narrowing of aorta
usually happens near the
patent ductus arteriosus .In
some babies with coarctation
, it is thought that some
tissue from the wall of ductus
arteriosus blends into the
tissue of the aorta. When the
tissue tightens and allows the
ductus arteriosus to close
normally after birth, this extra
tissue may also tighten and
narrow the aorta.

8. Vasculitis
◦ Vasculitis involves
inflammation of blood
vessels.
◦ The inflammation can cause
the walls of the blood vessels
to thicken, which reduces the
width of the passageway
through the vessel. If the
blood flow is restricted, it can
result in organ and tissue
damage.
◦ If renal arteries are affected, it
results in hypertension as
decreased kidney perfusion
lead to activation of RAAS
system.

9. Other causes
◦ Obstructive sleep apnea - Sudden drops in blood oxygen levels that
occur during sleep apnea increase blood pressure and strain the
cardiovascular system.
◦ Hypercalcemia – Acute hypercalcemic hypertension is caused by an
increase in vascular resistance mediated via the direct effect of
calcium on vascular smooth muscle as well as the indirect effect of
calcium induced hypercatecholaminemia.
◦ Burns – Excessive production of catecholamines, increased renin-
angiotensinogen stimulation, expansion of volume and
hypercalcemia have been considered in the pathogenesis.

10. Medications
leading to
hypertension
Corticosteroids
Tacrolimus
Cyclosporine
Erythropoietin
Amphetamines
Oral contraceptives
Anabolic steroids
Vitamin D intoxication
Cocaine
Alcohol
Lead
Mercury toxicity