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Renovascular Hypertension. Staci Smith DO. Case Presentation. CC: dizziness
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Renovascular Hypertension Staci Smith DO
Case Presentation • CC: dizziness • HPI:62 yo WM presented to GVH w/ complaints of SOB and dizziness for the past three days. Dizziness occurs w/standing up. No LOC, numbness, or tingling. Positive for history of CVA with right sided upper extremity weakness. Pt’s wife has noticed that bp has been fluctuating.
PMHx: HTN x 20yrs CKD 4-5 CVA PVD AAA CAD L Subclavian stenosis DMT2 (IR) L DVT PSHx: GFF Heart cath CABG x 4v IVC filter Cervical diskectomy EGD / colonoscopy Case Presentation
Aggrenox 200/25 mg two b.i.d Allopurinol 100 mg b.i.d Carvedilol 12.5 mg b.i.d Clonidine 0.2 mg t.i.d Ferrous sulfate 325 mg daily Finasteride 5 mg daily hs Flomax 0.4 mg daily hs Furosemide 80 mg daily Glyburide 5 mg b.i.d Hydralazine 25 mg two tablets t.i.d Isosorbide 60 mg daily Levemir at bedtime Nexium 40 mg daily Plavix 75 mg daily Simvastatin 20 mg q.h.s Medications
Secondary Causes of HTN • Renal Artery Stenosis • Obstructive Sleep Apnea / Obesity • Pheochromocytoma • Thyroid Disease • Cushing’s Syndrome • Hyperaldosteronism • Primary hyperparathyroidism • Congenital Adrenal Hyperplasia • Birth Control • Drugs of Abuse • Caffeine and Diet
Clues to Secondary Causes of Hypertension • Severe or refractory hypertension • Acute rise in blood pressure over a previously stable value • Proven age of onset before puberty • Age less than 30 years • non-obese, non-black patients with a confirmed negative family history of hypertension
When to Suspect Renal Artery Stenosis • Hypertension before the age of 30 years • negative family history and no other risk factors • Onset of severe or stage II hypertension after age 55 yo • Refractory or resistant hypertension • three agents including a diuretic • Acute rise in blood pressure over a previously stable baseline in patients
When to Suspect Renal Artery Stenosis • Unexpected rise in Cr after starting ACE/ ARB • Atrophic kidney size • Flash pulmonary edema or unexplained heart failure • An abdominal bruit that lateralizes to one side
Causes of Renal Artery Stenosis • Atherosclerosis • Fibromuscular dysplasia • Cholesterol embolic disease • Acute arterial thrombosis or embolism • Aortic dissection • Renal arterial trauma or aneurysm • Arteriovenous malformation of the renal artery • Vasculitides
Pathophysiology • clinical consequence of renin-angiotensin-aldosterone activation • occlusion of the renal artery causes ischemia • renin release elevates bp • increased renin levels help in the conversion of angiotensin I to angiotensin II • causing severe vasoconstriction and aldosterone release • presence of a functioning contralateral kidney • determines ultimate cascade of events
Pathophysiology • Two kidneys are out of sync: • ischemic stenotic kidney produces excessive renin and retains sodium • the comparatively normal kidney continues to excrete sodium and water to maintain normal volume levels • End result is systemic hypertension that is renin and angiotensin mediated
Screening and Diagnostic Testing • Gold standard-renal angiography • Magnetic resonance angiography • Computed tomographic angiography • Duplex Doppler ultrasonography
Screening and Diagnostic Testing • MR Angiography: • increasingly used as the first-line screening test • gadolinium during MR imaging • nephrogenic systemic fibrosis • estimated glomerular filtration rate less than 30 mL/min, avoid gadolinium
MRA of Aorta and Renal Arteries • Gadolinium enhanced MRA • Bilateral RAS
Fibromuscular Dysplasia • Beads on a string • Females > Males
If GFR less than 30 • risk of radiocontrast nephropathy • Bicarbonate infusion • Mucomyst • IVF • either spiral CT or arteriography can be performed • preferably digital subtraction arteriography with iodinated contrast
Clinical Significance • arteriographic finding of greater than a 75 percent stenosis • in one or both renal arteries • or a 50 percent stenosis with poststenotic dilatation