Efficacy of compression of different capacitance beds in the amelioration of orthostatic hypotension

Abstract

Orthostatic hypotension (OH) is the most disabling and serious manifestation of adrenergic failure, occurring in the autonomic neuropathies, pure autonomic failure (PAF) and multiple system atrophy (MSA). No specific treatment is currently available for most etiologies of OH. A reduction in venous capacity, secondary to some physical counter maneuvers (e.g., squatting or leg crossing), or the use of compressive garments, can ameliorate OH. However, there is little information on the differential efficacy, or the mechanisms of improvement, engendered by compression of specific capacitance beds. We therefore evaluated the efficacy of compression of specific compartments (calves, thighs, low abdomen, calves and thighs, and all compartments combined), using a modified antigravity suit, on the end-points of orthostatic blood pressure, and symptoms of orthostatic intolerance. Fourteen patients (PAF, n = 9; MSA, n = 3; diabetic autonomic neuropathy, n = 2; five males and nine females) with clinical OH were studied. The mean age was 62 years (range 31-78). The mean +/- SEM orthostatic systolic blood pressure when all compartments were compressed was 115.9 +/- 7.4 mmHg, significantly improved (p < 0.001) over the head-up tilt value without compression of 89.6 +/- 7.0 mmHg. The abdomen was the only single compartment whose compression significantly reduced OH (p < 0.005). There was a significant increase of peripheral resistance index (PRI) with compression of abdomen (p < 0.001) or all compartments (p < 0.001); end-diastolic index and cardiac index did not change. We conclude that denervation increases vascular capacity, and that venous compression improves OH by reducing this capacity and increasing PRI. Compression of all compartments is the most efficacious, followed by abdominal compression, whereas leg compression alone was less effective, presumably reflecting the large capacity of the abdomen relative to the legs.

Squatting test: A posture to study and counteract cardiovascular abnormalities associated with autonomic dysfunction

“…A reduction in venous capacity, secondary to some physical counter manoeuvres (e.g., squatting or leg crossing), or the use of compressive garments, can ameliorate orthostatic hypotension. Compression of all compartments is the most efficacious, followed by abdominal compression, whereas leg compression alone was less effective, presumably reflecting the large capacity of the abdomen relative to the legs (Denq et al, 1997). Another study confirms that in patients with neurogenic orthostatic hypotension, abdominal compression (somewhat mimicking that occurring during squatting) increases standing BP to a varying degree by increasing stroke volume (Smit et al, 2004).…”

Compression leggings modestly affect cardiovascular but not cerebrovascular responses to heat and orthostatic stress in young and older adults

“…Furthermore, Denq et al (1997) found that compression (at +40 mmHg) of the lower abdomen, thighs and calves attenuated tilt-induced reductions in BP. Such compression reduces venous pooling by reducing the overall venous cross-sectional area of the lower limb (thereby increasing the linear velocity of venous outflow), reducing venous distension, and by enhancing the emptying of valvular cusps (Agu et al 1999).…”

Effect of harness application and postural changes on cardiovascular parameters of individuals with spinal cord injury

“…15,30,41,43 One of the non-pharmacological alternatives commonly used in individuals with orthostatic hypotension is the application of external counterpressure in order to decrease capacitance of the vasculature beds in legs and abdominal cavity -the major areas of blood pool during standing. 40,41,[44][45][46] Previously, numerous studies evaluated effects of chest and abdominal binders on cardiovascular parameters owing to increased intrathoracic pressure. 47,48 The authors reported that changes in intrathoracic pressure were associated with reciprocal changes in both intrathoracic vascular pressures and blood volume.…”

“…Denq et al 45 reported that compression of the abdomen is by far the most effective site to improve standing arterial pressure in patients with orthostatic hypotension. More recently, Smit et al 41 in a cohort of 23 individuals with orthostatic hypotension of varying etiology also demonstrated that abdominal compression significantly improves upright blood pressure by an increase in stroke volume.…”