When will you suspect reno vascular hypertension ?
Posted Sep 01 2010 10:52am
The much fancied criteria “suspect secondary HT” if the onset of hypertension is before 30 years later than 55 years ,may be useful .But a caution about this criteria : It does not mean you should not hesitate to diagnose renal HT between 30 -55 years. The real onset may be < 30years , but the patient may report to the physician late in his /her 40 or 50s !
Diastolic blood pressure > 120
Sudden acceleration blood pressure
Blood pressure which is resistant to control with three or 4 drugs ,that shall typically include a diuretic.
An episode of left ventricular failure (Often referred to as called flash pulmonary edema)
Presence of Hypertensive retinopathy
Para umbilical bruit
HT associated with significant CAD
Marked LVH in echocardiography
Finally , most importantly , worsening of renal function with ACE inhibitor is a strong clue the kidney is under perfused and the renal circulation is dependent on elevated angiotenisn 2 (Which ,if blocked worsens the GFR ).This implies every physician should take a baseline serum creatinine and urea before starting them on ACEI.(Which is rarely followed , as far as my country is concerned !)
Is there any simple way to differentiate reno vascular from renal parenchymal HT ?
It is very difficult to differentiate between these two clinically. It makes things more difficult , as combination of both occurs. Prolonged renal ischemia can result in parenchymal damage as well.
The simplest way is to do a rapid ultrasound imaging to assess kidney size and texture (Loss of cortical-medullary differentiation indicating early renal contraction phase ).Of course , our nephrology colleagues are always there to help you out .
* It need to be remembered the functional renal HT -Renal tubular acidosis, Adrenal HT (Conn’s /chromo-pheocytomas has to be ruled out , as these entities also occur in the same age group ).The combination of hypokalemia and mild alkalosis is a good clue to rule out many of these defects.
* The CT scan image used in the above illustration courtesy