Approach to a young hypertensive patient - Investigations and diagnosis Dr.

Approach to a young hypertensive patient- Investigations and

diagnosis

Dr.

Overview Introduction General Approach to the Patient Most Common Causes of Secondary HT by Age

Children and Adolescents (Birth to 18 Years of Age)

Renal parenchymal disease Coarctation of the aorta

Young Adults (19 to 39 Years of Age)

Takayasu’s arteritis in India (Asia) Fibromuscular dysplasia Thyroid dysfunction

Algorithm for initial evaluation of secondary HT Conclusions

Introduction

SBP, systolic blood pressure; DBP, diastolic blood pressure

Classification of Hypertension:

The Seventh Report of the Joint National Committee (JNC VII)

NIH Publication No. 04-5230 August 2004

General Approach to the Patient Confirm that the patient’s blood pressure

(BP) has been accurately measured using Correct positioning with an appropriately sized

cuff

If white coat hypertension suspected Ambulatory BP monitoring can be useful to rule

out

Hypertension. 2003;42(6):1206-1252,Am Fam Physician. 2009;79(10):863-869.

General Approach to the Patient (Contd) Important to review

The patient’s diet and medication use for other potential causes of HT

Excessive consumption of Sodium, Licorice (Hindi: Jethimadh, Mulhathi), or Alcohol is known to increase BP

J Clin Hypertens (Greenwich) 2008;10(7):556-566.HT - hypertension

General Approach to the Patient (Contd) Many drugs affect BP

A trial period off of a potentially offending medication may be all that is needed to reduce BP

Am Fam Physician 2010 Dec 15;82(12):1471-8.

General Approach to the Patient (Contd) If these potential contributors to

hypertension have been excluded and Concern for secondary hypertension

remains, the physician can investigate for potential physiologic causes


Most Common Causes of Secondary Hypertension by Age*


Must remember that these are not absolute categories; There may be overlap of causesbetween age groups

Signs and Symptoms That Suggest Specific Causes of Secondary Hypertension


Signs and Symptoms That Suggest Specific Causes of Secondary Hypertension (Contd)


Children and Adolescents(Birth to 18 Years of Age) Renal parenchymal disease

Coarctation of the aorta


Renal parenchymal disease Most common cause of hypertension in

preadolescent children In this age group, such renal pathology

includes Glomerulonephritis Congenital abnormalities and Reflux nephropathy

Sometimes the resulting hypertension is not apparent until young adulthood, so This etiology should still be considered in the

differential diagnosis outside of childhood


Renal parenchymal disease (Contd)

Initial evaluation for suspected renal parenchymal disease should include Measurement of blood urea nitrogen and

creatinine levels A urinalysis Urine culture and Renal ultrasonography


Coarctation of the aorta The second most common cause of HT in

children, and Two to five times more common in boys

Although coarctation may present acutely in the neonate as congestive heart failure, It is typically diagnosed around five years of

age with the onset of HT or a cardiac murmur Rarely, mild cases of coarctation have

occurred in adults


Coarctation of the aorta (Contd) Discrepancies between bilateral brachial,

or brachial and femoral blood pressures, suggest coarctation

Chest radiography In younger patients, may be nonspecific,

whereas In adults the classic “three” sign or rib

notching may be evident


Coarctation of the aorta (Contd)

Close up of upper thorax in a patient with Coarctation of the Aorta.

Red arrows - rib notching caused by the dilated intercostal arteries

Yellow arrow - the aortic knob,

Blue arrow - the actual coarctation and

Green arrow -the post-stenotic dilation of the descending aorta

Coarctation of the aorta (Contd) Transthoracic echocardiography

Sufficient for diagnosis in children, given their smaller body habitus, and

Useful to concurrently evaluate for left ventricular hypertrophy

Magnetic resonance imaging (MRI) is increasingly common and The preferred imaging method in adults


Young Adults (19 to 39 Years of Age)

Takayasu’s arteritis in India (Asia) Thyroid dysfunction Fibromuscular dysplasia Renal parenchymal disease

Takayasu’s arteritis (TA)

Although TA has a worldwide distribution, it is observed frequently in Asia than in North America

The most common cause of RVH in India China Korea Japan and other countries of South East Asia

Eur J Vasc Endovasc Surg 2007;33, 578-82RVH-Renovascular hypertension

TA: Indian studies TA

In one study from Chandigarh by Sharma et al Takayasu’s arteritis was found as the leading cause of hypertension in hospitalised patients

Involvement: 50% cases bilateral and in 28% unilateral

Indicating that this condition must be kept in mind as one of the important causes, especially in northern India, whenever one is considering RVH

Angiology 1985; 36: 370-8

TA: Indian studies (Contd) Study at PGI Chandigarh

205 patients with hypertension were shown to have a renovascular aetiology over 16 years. Of these,

125 (61 %) Takayasu's arteritis, 58 (28.3 %) fibromuscular dysplasia, 16 (7.8 %) atherosclerosis, five (2.4 %) polyarteritis nodosa and one (0.5 %) renal artery aneurysm

Q J Med. 1992;85:833-43.

TA: Indian studies (Contd) Study at PGI Chandigarh (Contd)

Among patients with TA, males were affected as commonly as females

The mean age of these patients at the time of detection was 26.8 +/- 8.6 years (range 5-52 years) Type I arteritis in nine (7.2 %), Type II in 40 (32 %) and Type III in 76 (60.8 %) patients

The abdominal aorta was involved in 117 (93.3 %) patients TA was associated with ulcerative colitis in two patients and

with renal amyloidosis and focal segmental glomerulosclerosis with a nephrotic syndrome in one patient each

Q J Med. 1992;85:833-43.

TA: Indian studies (Contd) Seth GS Medical College & KEM Hospital,

Parel, Mumbai Medical records of 54 patients with RVH

showed Aortoarteritis 44 (81.5%), Atherosclerotic disease 7 (31.5%) and Fibromuscular dysplasia 3 (5.6%) as etiologies

of RVH

32nd Annual Conference of Indian Society of Nephrology September, 2001

TA (Contd) TA is a chronic vasculitis involving mainly

the aorta and its branches, as well as the pulmonary and coronary arteries

Classical definition of TA is that of Chronic, progressive, inflammatory, occlusive

disease of the aorta and its branches

Eur J Vasc Endovasc Surg 2007;33, 578-82

TA: Aetiology Remains enigmatic Various mechanisms such as post-

infective, autoimmune, ethnic susceptibility and a genetic predisposition have been postulated

Autoimmunity appears to be the most plausible mechanism


TA: Diagnostic criteria Following table mentions

Sensitivity and specificity for the various diagnostic criteria


TA: Diagnostic criteria


Modified diagnosis criteria for TA: Sharma et al

TA: Diagnostic criteria (Contd)


Modified diagnosis criteria for TA: Sharma et al(Contd)

TA: Diagnostic criteria (Contd)


Type I is limited to the aortic arch and its branches

Type II affects the descending thoracic and abdominal aorta

Type III is extensive form involving the arch and the thoracic and abdominal aorta

Type IV is designated to those cases with pulmonary involvement in addition to the features of type I, II, or III

TA: Clinical features TA classically progresses through 3 stages:

An early systemic illness usually associated with constitutional symptoms and fever

A vascular inflammatory phase The inflammation settles down or burns out


TA: Clinical features (Contd)


Fibromuscular dysplasia (FMD) 10% of cases of RVH are due to FMD

Mainly in younger women Bilateral renal artery involvement with

extension into the distal portion of the artery and its branches is common

US Nephrology 2009;5(2):56–59, Proc (Bayl Univ Med Cent) 2010;23(3):246–49

FMD (Contd) Vascular disorder of unknown etiology that

has a predilection for the renal arteries, causing narrowing that leads to decreased renal perfusion

In young adults, particularly women, FMD is one of the most common causes of

secondary hypertension Patients with renal artery stenosis may

have an audible high-pitched holosystolic renal artery bruit


FMD (Contd) Compared with patients without such a

finding, those in whom a renal artery bruit is detected have a relative risk of approximately 5.0 for renal artery stenosis; these patients should all have further testing


FMD (Contd) Although angiography is the diagnostic

standard for detecting renal artery stenosis, it is invasive and should not be used as an

initial diagnostic test MRI with gadolinium contrast media and

computed tomography (CT) angiography are equally accurate in visualizing stenosis


CT angiogram obtained in a 45 y.o. woman presenting with new onset RVHAneurysmal dilation and vascular occlusion beyond a fibromuscular lesion is present in the right kidney associated with loss of perfusion to the entire upper pole of the kidney

FMD (Contd)

Fibromuscular Dysplasia, beforeand after PTRA

Safian & Textor. NEJM 344:6;

FMD (Contd) MRI

Does not use radiation and can determine the physiologic degree of stenosis

Can also be used for patients with poor renal function, particularly when used without gadolinium, although with a slight decrease in sensitivity and specificity

If MRI and CT angiography are contraindicated, renal Doppler can be used;

Doppler Provides useful information regarding blood flow, but Its accuracy is affected by body habitus and operator

skill


FMD (Contd) Captopril-augmented renography has

Poor sensitivity and specificity, which translate into likelihood ratios close to 1.0,

No longer considered a good first-line test


Thyroid dysfunction Thyroid hormone affects cardiac output

and systemic vascular resistance, which in turn affect BP Hypothyroidism can cause an elevation in

diastolic BP, whereas Hyperthyroidism can cause an isolated

elevation of systolic BP, leading to a widened pulse pressure


Thyroid dysfunction Contd) Although hypothyroidism is one of the

more common secondary causes of hypertension in young adults, There is actually an increased incidence of

hypothyroidism with age, peaking in a patient’s 60s

In contrast, hyperthyroidism is significantly associated with elevated BP in 20- to 50-year-olds


Thyroid dysfunction (Contd)

Because thyroid dysfunction occurs across multiple age groups, testing for it should be considered if there are any suggestive symptoms

Thyroid-stimulating hormone is a sensitive marker used for initial diagnosis of either condition


Accuracy of Diagnostic Tests for Causesof Secondary Hypertension


Algorithmic approach to the initial evaluation of patients with suspected secondaryhypertension

CT = computed tomography; MRI = magnetic resonance imaging; TSH =thyroid-stimulating hormone


Conclusions Prevalence and etiology of hypertension varies

with age

Young/early onset hypertension should be approached with evaluation of Symptoms

(e.g., flushing and sweating s/o pheochromocytoma), Examination findings

(e.g., a renal bruit s/o renal artery stenosis), or Laboratory abnormalities

(e.g., hypokalemia s/o aldosteronism)

s/o- suggestive of

Conclusions (Contd)

In young adults, particularly women, renal artery stenosis caused by fibromuscular dysplasia is one of the most common secondary etiologies FMD can be detected by abdominal magnetic resonance

imaging or computed tomography

Takayasu’s arteritis is common cause for hypertension in young adults in Asian countries must keep in mind

Any questions?

Approach to a young hypertensive patient - Investigations and diagnosis Dr.

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