Postural test: patient
remains 10 min in resting supine position (45˚ angle). Blood pressure, heart
rate are measured after 2, 5 and 10 minutes. Then the patient is asked to
stand unaided for 5 minutes. The same parameters are measured. A decrease of
SBP > 20 mmHg or DBP > 10 mmHg within 3 min of standing
and delayed orthostatic hypotension as a sustained BP fall occurring
beyond 3 minutes of standing are considered as sympathetic adrenergic failure.
Valsalva maneuver: The
patient is asked to blow through a mouthpiece attached to a manometer
monitoring a pressure of 40 mmHg for 15 minutes, during ECG monitoring. The
Valsalva ratio (longest R-R after/shortest R-R during) is then determined.
grip sphyngomanometer cuff inflated to 20 mmHg with dominant hand at one third
of maximal volimetric contraction force for 2 minutes. Blood pressure is
measured at rest and at end of 2 minutes.
cold pressor test: hand is immersed up to wrist in ice cold (4˚ C) for 2
minutes. Blood pressure and heart rate is measured before and after test.
Mental arithmetic test:
serial subtractions for 2 minutes. Blood pressure and heart rate is measured
before and after test.
Deep breathing test: six
deep breaths in one minute while in supine position. The difference in heart
rate is measured between maximal and minimum heart rate is calculated in an
individual respiratory cycle and expressed as the mean of the difference in
six successive cycles.
Measures of plasma
catecholamines. Antecubital venous blood is drawn through an indwelling
catheter, after at least 15 min of supine rest and after 5 min of standing.
Plasma noradrenaline, adrenaline and dopamine is assayed.
Response of growth hormone after
administration of clonidine. Increased in healthy individuals, PD and PAF.