Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients.
We investigated the effects of muscle functional electrical stimulation on muscle sympathetic nerve activity and muscle blood flow, and, in addition, exercise tolerance in hospitalised patients for stabilisation of heart failure.



Thirty patients hospitalised for treatment of decompensated heart failure, class IV New York Heart Association and ejection fraction ≤ 30% were consecutively randomly assigned into two groups: functional electrical stimulation (n = 15; 54 ± 2 years) and control (n = 15; 49 ± 2 years). Muscle sympathetic nerve activity was directly recorded via microneurography and blood flow by venous occlusion plethysmography. Heart rate and blood pressure were evaluated on a beat-to-beat basis (Finometer), exercise tolerance by 6-minute walk test, quadriceps muscle strength by a dynamometer and quality of life by Minnesota questionnaire. Functional electrical stimulation consisted of stimulating the lower limbs at 10 Hz frequency, 150 ms pulse width and 70 mA intensity for 60 minutes/day for 8-10 consecutive days. The control group underwent electrical stimulation at an intensity of < 20 mA.



Baseline characteristics were similar between groups, except age that was higher and C-reactive protein and forearm blood flow that were smaller in the functional electrical stimulation group. Functional electrical stimulation significantly decreased muscle sympathetic nerve activity and increased muscle blood flow and muscle strength. No changes were found in the control group. Walking distance and quality of life increased in both groups. However, these changes were greater in the functional electrical stimulation group.



Functional electrical stimulation improves muscle sympathetic nerve activity and vasoconstriction and increases exercise tolerance, muscle strength and quality of life in hospitalised heart failure patients. These findings suggest that functional electrical stimulation may be useful to hospitalised patients with decompensated chronic heart failure.
Heart Institute (InCor), University of São Paulo Medical School, Brazil.
Raphaela V
RV
Groehs
Heart Institute (InCor), University of São Paulo Medical School, Brazil.
Ligia M
LM
Antunes-Correa
Heart Institute (InCor), University of São Paulo Medical School, Brazil.
Thais S
TS
Nobre
Heart Institute (InCor), University of São Paulo Medical School, Brazil.
Maria-Janieire Nn
MJ
Alves
School of Physical Education and Sport, University of São Paulo, Brazil.
Maria Urbana Pb
MU
Rondon
Heart Institute (InCor), University of São Paulo Medical School, Brazil.
Antônio Carlos Pereira
AC
Barreto
Heart Institute (InCor), University of São Paulo Medical School, Brazil School of Physical Education and Sport, University of São Paulo, Brazil cndnegrao@incor.usp.br.
Carlos E
CE
Negrão
D000293:Adolescent; D000328:Adult; D000368:Aged; D004558:Electric Stimulation / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005542:Forearm / Q000098:blood supply; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010991:Plethysmography; D011788:Quality of Life; D012039:Regional Blood Flow / Q000502:physiology; D013564:Sympathetic Nervous System / Q000502:physiology*; D055815:Young Adult
Heart failure; electrical stimulation; exercise tolerance; sympathetic nerve activity; vasoconstriction