title: Safety of a combined strength and endurance training using neuromuscular electrical stimulation of thigh muscles in patients with heart failure and bipolar sensing cardiac pacemakers.
abstract: Neuromuscular electrical stimulation (NMES) is an effective and non-strenuous therapy to enhance the strength and endurance capacity of the skeletal muscles in patients with severe chronic heart failure. NMES in patients with pacemakers is controversial because potential electromagnetic interference may result in pacemaker malfunction. Therefore, such patients are in general excluded from NMES. The aim of this pilot study was to evaluate the safety of a combined NMES protocol to increase strength and endurance capacity of the skeletal muscles in patients with heart failure and implanted pacemakers. Seven patients with chronic heart failure and implanted cardiac pacemakers with bipolar sensing leads received NMES treatment of thigh muscles, using a combined protocol comprising biphasic, symmetric, rectangular constant current impulses at different frequencies (8-50 Hz), pulse width up to 60 s (8 Hz), 4 s (15 Hz), 4 s (30 Hz), and 6 s (50 Hz), and amplitudes up to +/- 100 mA (all frequencies) applied to both knee extensor and flexor muscles via surface electrodes (8 x 13 cm each). Acute electromagnetic interference during a safety procedure (telemetric monitoring) before therapeutic NMES application was not observed in any of the patients. The 7 patients received during 20 therapeutic NMES sessions a total of 23,380 on-phases, comprising 2194.08 x 10(3) biphasic electrical pulses, without adverse events. Heart rate monitoring during stimulation and pacemaker interrogation revealed no abnormalities. NMES treatment of thigh muscles using a combined NMES protocol to enhance strength and endurance capacity appears to be safe in patients with heart failure and implanted pacemakers with bipolar sensing, as far as the described electrode configuration and parameter range is applied.
authors.affiliation: Universitätsklinik für Physikalische Medizin und Rehabilitation, Universität Wien, Vienna, Austria. richard.crevenna@univie.ac.at
authors.forename: Richard
authors.initials: R
authors.lastname: Crevenna
authors.forename: Winfried
authors.initials: W
authors.lastname: Mayr
authors.forename: Mohammad
authors.initials: M
authors.lastname: Keilani
authors.forename: Johannes
authors.initials: J
authors.lastname: Pleiner
authors.forename: Martin
authors.initials: M
authors.lastname: Nuhr
authors.forename: Michael
authors.initials: M
authors.lastname: Quittan
authors.forename: Richard
authors.initials: R
authors.lastname: Pacher
authors.forename: Veronika
authors.initials: V
authors.lastname: Fialka-Moser
authors.forename: Michael
authors.initials: M
authors.lastname: Wolzt
mesh_terms: D000328:Adult; D000368:Aged; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D010138:Pacemaker, Artificial; D010807:Physical Endurance; D010865:Pilot Projects; D012449:Safety; D013848:Thigh