Hypertension

1. Hypertension • Karolina Narębska • Oddział Kliniczny Pediatrii i Nefrologii • Wojewódzki Szpital Specjalistyczny dla Dzieci i Dorosłych w Toruniu

2. Hypertension - general informations • One of the most common disease in population ~30% of adult people. • In children ~ 1-3% young population and mainly it has secondary character ( secondary hypertension ). • Main causes of hypertension in pediatrics are acquired and congenital renal diseases. The younger hypertensive child is, the bigger likelihood of secondary hypertension is!!!

3. Hypertension- general information continued • - Primary hypertension refers to older children (over 10yrs) and it is strongly connected with obesity and lifestyles risk factors. • It has unknown origin ( genetic and environmental factors ) • There are also known 9 types of monogenic hypertension, like e.g. Liddle’a syndrome, Gordon syndrome, etc.

4. Hypertension - etiopathogenesis • Blood pressure depends on CO and TPR according to the following formula: • RR = CO ( cardiac output) x TPR ( total peripheral resistance ) • CO depends on the left ventricular contractility and volemia. • TPR depends on contraction vessels factors and the main is RAAS ( renine-angiotensine-aldosterone system ).

5. Angiotensinogen RAAS RENINE Angiotensin I Angiotensinase ANGIOTENSIN II Angiotensin receptors Angiotensin III Aldosterone release Symphaticotony Vessels contraction Fluid retension Na+ retention Increase of the fluid volume Increase of the TPR Increase of the blood pressure

6. Hypertension - definition • Hypertension is defined as average systolic and/or diastolic blood pressure greater than the 95th percentile for: • - gender • - age • - hight percentile • measured on at least 3 separate occasions.

7. Normal blood pressure • Normal blood pressure is defined as systolic and/or diastolic blood pressure lower than the 90th percentile for age, gender, height percentile.

8. Prehypertension • Prehypertension is defined as systolic and/or diastolic blood pressure between the 90th and 95th percentile for age, gender and height percentile, • but also • as in adults, children and adolescents whose blood pressure is greater than 120mmHg ( systolic ) and/or 80mmHg ( diastolic ) are also classified as prehypertensive

9. „White-coat” hypertension • White-coat hypertension refers to the patients, whose blood pressure is greater than the 95th percentile in the physicians office, but less than the 90th percentile outside a clinical setting.

10. Stages of hypertension • Stage 1 hypertension • Stage 2 hypertension • Severe hypertension • Hypertensive urgency • Hypertensive emergency

11. Stage 1 hypertension • is defined as blood pressure levels ranging from the 95th to 5mmHg above the 99th percentile. • Asymptomatic patients with stage 1 hypertension may undergo a diagnostic evaluation before initiation of treatment

12. Stage 2 hypertension • is defined as blood pressure levels greater than 5mmHg above the 99th percentile. • Patients with stage2 hypertension should undergo more timely evaluation and initiation of hypotensive therapy. • Symptomatic patients with stage 2 hypertension require immediate pharmacologic treatment and consultation with an expert.

13. Severe hypertension • is defined as blood pressure levels greater than 30mmHg above the 99th percentile for age, gender and hight percentile.

14. Hypertension urgency • Impending organ failure during hypertension, usually with unspecific symptoms like headaches and vomiting.

15. Hypertension emergency • Done or ongoing organ damage during hypertension, most often leading to organ failures, with the symptoms of encephalopathy. • Those hypertension emergency stages require immediate intervention.

16. Hypertension - measurement • The rules of blood pressure ( BP ) measurement: • Child shouldn’t eat or drink for at least 30min before measurement • Child should rest in a sitting position for at least 5 minutes with feet on the floor and arm supported on the heart level • The cuff bladder should cover 80% to 100% of the arm circumference and two thirds of length of the upper arm • Remember: smaller cuff sizes result in an increase of blood pressure and bigger cuff sizes result in a decrease of blood pressure!!! • The cuff should be inflated to a pressure 20 to 30mmHg higher than the patient’s systolic blood pressure and then deflated at 2 to 3mmHg each second • Measurement should be done on the right arm

17. Measurement - continued • Systolic pressure- occurs when the first sound is heard during cuff deflation ( the first Korotkoff sound ) • Diastolic pressure- occurs at the point before disappearance of sounds ( the second Korotkoff sound )

19. Measurement - continued • During the first examination the blood pressure should be measured on four limbs • In babies and infants untill they reach vertical position the blood pressure levels on lower limbs are lower than on upper limbs • In babies while they are sleeping the systolic blood pressure levels are lower by 5-7mmHg. • In a 2-year-old child, who can stand vertically, the blood pressure levels on lower limbs become about 20mmHg greater than on upper limbs; in adolescents about 30-40mmHg greater.

20. Measurement - continued • Next measures should be taken on the abducted right arm laying on the level of the heart. • Every measurement should be repeated 2 or 3 times per an examination. • The difference of measurement between two arms greater than 5mmHg must be notified in patient’s card.

21. When to start to measure blood pressure ( BP)? • In children aged of three or more the BP should be measured at least once a year and during routine examination • In children under the age of three the BP should be measured in the following situations: • When a perinatal history is affected: prematurity, LBW, intensive therapy during perinatal period • Congenital anomalies • Recurrent urinary tract infections, chronic kidney disease • Tumors • When drugs effecting BP are used • Diseases connected with hypertension ( neurofibromatosis, hyperthyroidism )

22. ABPM - ambulatory blood pressure monitoring • ABPM method assesses: • 24-hour blood pressure measurement • variability of 24-hour blood pressure referring to different periods of day and night, during some activities ABPM results have the meaning in diagnosis, prognosis and monitoring of the treatment. The norms of ABPM are published for childrenfrom 120cm height.

23. ABPM - assessment • MSBP - stands for mean ( 24-hour ) systolic blood pressure • MDBP - stands for mean ( 24-hour ) diastolic blood pressure • Loads of BP ( percent of blood pressure levels greater than the 95th percentile ) during the day and night ( norm less than 20% ). • Dipping of BP in the night(norm is minimum 10%) • The lack of night dipping of BP is an extra risk factor of cardiovascular incidents, especially in patients with diabetes.

24. ABPM – indications • Suspicion of the „white coat” hypertension • Organ changes in patients with prehypertension • Paroxysmal hypertension • Resistance to drugs hypertension • Assessment of night blood pressure or suspicion of high blood pressure in the night • Assessment of effectiveness hypotensive treatment in patients with too big reduction of blood pressure • Assessment of indications for hypotensive treatment

25. Hypertension in ABPM • Mean 24-hour systolic and/or diastolic blood pressure greater than the 95th percentile for age, gender and height. ( We use special ABMP percentile charts )

26. MAP – mean arterial pressure • MAP is defined as hypothetic mean blood pressure during one cycle of the heart • MAP= DP+1/3 ( SP-DP ) • Norma: 75-100mmHg • A normal MAP has clinical meaning in supporting organ perfusion ( good blood flowing ). • MAP under 60mmHg results bed perfusion and hypoxia.

27. Causes of secondary hypertension whatever the age • Hypertension in kidney diseases: • renal parenchymal diseases secondary to reflux nephropathy, obstructive uropathy, chronic renal infections ( pyelonephritis! ) • primary and secondary glomerulonephritis, • polycystic kidney diseases, • Wilm’s tumour • chronic kidney diseases 2.Renovascular hypertension – eg. bilateral renal artery stenosis ( often with CoA )

28. Causes of secondary hypertension whatever the age • 3. Endocrine-origin hypertension: • pheochromocytoma • primary hyperaldosteronism ( Conn syndrome ) – hypernatremia with hypokaliemia • Cushing syndrome • Congenital adrenal cortex steroidogenesis abnormalities ( like eg congenital adrenal cortex hypertrophy ) • hyperthyroidism, hypothyroidism • Hyperparathyroidism ( with high calcium serum level, PTH and vitD3 )

29. Causes of secondary hypertension whatever the age • 4. Others: • coarctation of the aorta • Turner syndrome • obstructive sleep apnea ( OSA ) • multiple neuritis • neurofibromatosis ( NF ) • drug-induced hypertension • and many more…

30. Most common causes of hypertension by age • Newborns: • - renal artery or venous thrombosis • - renal artery stenosis • - congenital renal abnormalities (e.g. congenital renal dysplasia ) • - coarctation of the aorta • - bronchopulmonary dysplasia

31. Most common causes of hypertension by age • First year: • - coarctation of the aorta • - renovascular diseases • - renal parenchymal disease • - iatrogenic ( medication, volume overload ) • - tumour

32. Most common causes of hypertension by age • Infancy to 6year: • renal parenchymal diseases secondary to reflux nephropathy, obstructive uropathy, chronic renal infections ( pyelonephritis! ) and nephrotic syndrome,HUS, glomerulonephritis, polycystic kidney disease - renovascular disease ( stenosis of renal artery ) - coarctation of the aorta - endocrine causes ( hyperthyroidism, hypercalcemia, mineralocorticoids excess) - iatrogenic

33. Most common causes of hypertension by age • 6-10yrs: • - renovascular diseases ( stenosis of renal artery ) • - essential/idiopathic/primary hypertension • - renal parenchymal disease • - thyroid diseases • - pheochromocytoma • - neurofibromatosis

34. Most common causes of hypertension by age • Over 10yrs: • - primary hypertension!!! • - renal parenchymal diseases • - and others

35. Diagnostic evaluation • Finding the cause of hypertension ( medical history ) • Assessment of organ changes and risk factors ( medical history and physical examination )

36. Medical history • - family history of hypertension (primary hypertension ) • - lifestyle factors ( diet, sport, salt intake ) • - cardiovascular risk factors ( in patients and in their families like eg. premature atherosclerosis, cardiovascular disease ) • - concomitant diseases that could affect prognosis and guide treatment ( especially diabetes ) • - medications • - renal diseases ( in patients and their families ) • - substance abuse

37. Physical examination • Inspection: - skin: cafe au lait stains ( marks ) – NF - exophthalmia, goiter – hyperthyroidism - bisexual organs, gynekomastia, the lack of secondary sexual features in girls, hirsutism – failure of biosynthesis of adrenal cortex hormones ( eg CAH ) - hypertrophy of the tonsils – disorders of night respiratory

38. Examination - continued • 2. Palpable exam: • big, pulsing fontanel – hydrocephalus • goiter – hyperthyroidism • Abnormal abdominal masses – Wilm’s tumor, hydronephrosis, polycystic kidney disease 3. Auscultation: • Systolic murmur above aorta and between blade bones – coarctation of the aorta • systo-diastolic murmur in abdominal and/or lumbar area – reno-vascular hypertension

39. Examination - continued • 4. Neurological exam: • -Chwostek and Trousseau syndrome, weakened tendinous reflex – hyperaldosteronism( low Ca, K, high Na ) • 5. Pulses examination: • decreased – possibility of intracranial hypertension • increased – hyperthyroidism • normal in the upper limbs and poor or none in the lower limbs – coarctation of the aorta

40. Physical examination • - calculation of BMI ( body mass index ) and WHR ( waist-hip ratio ) • - ophthalmogical examination - fundus of the eye

41. Diagnostic tests • 1. Serum tests: • -creatinine, BUN, ionogram ( sodium, kalium and calcium ) • -lipidogram • -renine serum activity with sodium and aldosterone urine elimination • 2. Urine analysis

42. Lab test - continued • 3. 24-hour urine collection of : • - microalbumines ( to assess glomerulus damage ) • - VMA ( vaniline-mandelic acid ), catecholamines - to exclude pheochromocytoma/neuroblastoma ( an excess release of catecholamines to the blood system ) • 17-KS, 17-OHCS - markers of adrenal cortex ( to assess aderenal cortex abnormality like e.g. Cushing syndrome ), • steroid profile ( to exclude steroidogenesis abnormalities)

43. Lab test continued • cortisol profile ( Cushing syndrome ) • TSH, T3 and T4 ( thyroid abnormalities ) • OGTT in every obese child with BMI over the 85 percentile !!! • drug screen – when substance abuse is suspected

44. Primary hyperaldosteronism ( Conn syndrome ) • is susspected when there is hypertension with: • Hypokaliemia ( <3,5mEg/l ) • Increased kalium urine eliminations is confirmed when: • Aldosteron activity in urine and blood is high • Renine Serum Activity is low.

45. Primary hyperaldosteronism - continued • Primary hyperaldosteronism – Conn syndrome can be caused by: • hypertrophy, • adenoma, • carcinoma of adrenal cortex

46. Primary hyperaldosteronism - continued • Symptoms: • polidypsia, poliuria, weakness of the muscles, cramps ( follow from hypokaliemia) • Hypertension ( retension of sodium ) Diagnosis: - scyntygraphy with scintadren Treatment: • Spironolacton ( blocker of mineralocorticoids receptors ) • Triamteren, Amilorid – diuretics-severs of kalium • Ace-inhibitors; rarely Ca-blockers

47. Hypertension with hyperkaliemia • Very rare diagnosis of e.g. monogenic Gordon’s syndrome or it can occure in polycystic kidney disease.

48. Additional tests • Abdominal US with renal assessment and renal doppler ( the assessment of renal arteries ) This test should be done in every patient before initiation of ACE-inhibitor treatment!!! Bilateral renal artery stenosis is contraindication for ACE inhibitors !!!

49. Additional tests continued • - Renoscyntygraphy ( sometimes with captopril test - when renovascular hypertension is suspected ) • - Miction cystoureterography especially in young children with history of urinary tract infections or kidney scars occurring in renoscyntygraphy. • - Echo with assessment of the left ventricular mass and aortic arch. • - AngioCT, renal arteriography and angioMR of renal arteries are done when the diseases of renal vessels are suspected. • - Scyntygraphy with MIBG ( when pheochromocytoma is suspected ) or with scintadren ( when adrenal cortex tumour is suspected )