Blood flow requirements of the respiratory muscles (RM) increase markedly during exercise in chronic heart failure (CHF). We reasoned that if the RM could subtract a fraction of the limited cardiac output (QT) from the peripheral muscles, RM unloading would improve locomotor muscle perfusion. Nine patients with CHF (left ventricle ejection fraction = 26 +/- 7%) undertook constant-work rate tests (70-80% peak) receiving proportional assisted ventilation (PAV) or sham ventilation. Relative changes (Delta%) in deoxy-hemoglobyn, oxi-Hb ([O2Hb]), tissue oxygenation index, and total Hb ([HbTOT], an index of local blood volume) in the vastus lateralis were measured by near infrared spectroscopy. In addition, QT was monitored by impedance cardiography and arterial O2 saturation by pulse oximetry (SpO2). There were significant improvements in exercise tolerance (Tlim) with PAV. Blood lactate, leg effort/Tlim and dyspnea/Tlim were lower with PAV compared with sham ventilation (P < 0.05). There were no significant effects of RM unloading on systemic O2 delivery as QT and SpO2 at submaximal exercise and at Tlim did not differ between PAV and sham ventilation (P > 0.05). Unloaded breathing, however, was related to enhanced leg muscle oxygenation and local blood volume compared with sham, i.e., higher Delta[O2Hb]% and Delta[HbTOT]%, respectively (P < 0.05). We conclude that RM unloading had beneficial effects on the oxygenation status and blood volume of the exercising muscles at similar systemic O2 delivery in patients with advanced CHF. These data suggest that blood flow was redistributed from respiratory to locomotor muscles during unloaded breathing.

Background: Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. Loss of pyramidal and anterior horn motor neurons leads to progressive limb weakness, disability, dysarthria, dysphagia and respiratory insufficiency with a progressive fatal course. Objective: To evaluate the epidemiological and clinical characteristics of amyotrophic lateral sclerosis (ALS) in the Republic of Moldova (3,559,497 inhabitants) during a 5-year period (2009)(2010)(2011)(2012)(2013). Materials and methods: To ensure complete case ascertainment, multiple sources of information were used, including neurologists, other medical specialties, neurophysiology laboratories. ALS diagnosis was based on El Escorial criteria. Although all patients with motor neuron disease were enrolled, only probable and definite cases were included in the study. Results: A total of 94 cases was collected. The average annual incidence of ALS was 0.42 per 100,000 inhabitants. On December 31, 2013 the prevalence was 2.64 per 100,000. Mean age at onset was 55.7 years, with no sex difference. The peak incidence was in the age group 51-60 years. The male: female ratio was 2,03:1. The mean duration of the disease at diagnosis was 13.6 months. The clinical spectrum comprised spinal onset, beginning in the upper or lower limbs, or bulbar onset. Conclusion: The clinical features of ALS in Moldova are similar to those of other epidemiological studies in Europe. Incidence and prevalence are lower than in other European countries. This could be explained by under ascertainment of cases due to misdiagnosis and late neurological consultation.