1.
Secondary
hypertension (defined as hypertension due to an identifiable cause) affects
only 5-10% of hypertensive patients.
2.
The
following are characteristics suggestive of secondary hypertension: early onset
of hypertension (less than 30 year), resistant hypertension (defined as
hypertension despite the use of three antihypertensive drugs including a
diuretic at the optimal dosages), severe hypertension (greater than 180/110 mm
Hg), sudden increase of blood pressure (BP) in a previously stable patient, non-dipping
or reverse dipping during 24-hour ambulatory BP monitoring (ABPM), and presence
of target organ damage.
3.
Before
screening for secondary arterial hypertension, pseudo-hypertension (defined as
cuff diastolic BP at least 15 mm Hg higher than simultaneously measured
intra-arterial BP) and pseudo-resistance (due to inadequate measurement
techniques, as with too small cuff size) need to be excluded.
4.
ABPM
is the best measurement method to assess arterial BP, and allows for exclusion
of white-coat hypertension, assessment of treatment adherence, confirmation of
resistant hypertension, and assessment of dipping status.
5.
The
absence of a night-time drop in BP (“dipping”) of >10% relative to the
daytime value during ABPM is associated with several secondary forms of hypertension.
6.
Obstructive
sleep apnea is one of the most common causes of secondary hypertension.
Nocturnal hypoxemia may impact the renin-angiotensin-aldosterone system and
increase sympathetic nerve activity.
7.
The
authors wrote, “Practicing physicians cannot simply ‘forget’ about renal artery
stenosis despite the fact that randomized trials show little if any benefit of
revascularization.” The authors suggest that urgent revascularization could be
“lifesaving” in those with flash pulmonary edema secondary to bilateral renal
artery stenosis.
8.
There
are insufficient data on the long-term effects of renal denervation on arterial
BP.
9.
Primary aldosteronism may be suggested by
hypokalemia (albeit only in 40% of patients), resistant hypertension, muscle
weakness, constipation, and fatigue. The plasma aldosterone-renin ratio (ARR)
is a screening test for primary aldosteronism. Antihypertensive medication
should be changed to those with minimal effects on ARR (e.g., verapamil,
hydralazine, or doxazosin) prior to laboratory testing.
10.
Even
after identification and treatment of a secondary cause of hypertension, BP may
not return to normal. This is likely secondary to concomitant essential
hypertension and/or vascular remodeling that has occurred over time.
Posted
by: Steven Almany M.D.
No comments:
Post a Comment