M Kirtley | PubMed Health

PubMed1991

Mitral valve prolapse.

Mitral Valve Prolapse (MVP) is a common cardiac disorder in our community. It is estimated that 4% to 15% of the general population have the anatomical defect of prolapsed mitral valve leaflets during ventricular systole. Patients with MVP that suffer from chest pain, dyspnea, fatigue, dizziness, syncope, palpitations, cardiac arrhythmias, anxiety, and panic attacks are diagnosed as having Mitral Valve Prolapse Syndrome. There is much controversy in the medical literature as to the causes of MVPS symptomatology. Some scientists believe that autonomic dysfunction, adrenergic, and vagal responsiveness are factors which appropriately explain the symptoms of MVPS. Pharmacological therapy, depending on the severity of the symptoms, is one option for treatment. Education on the etiology of their symptoms, instruction on lifestyle modifications, and reassurance from their physician are appropriate methods for the management of MVPS patients.

Autonomic Nervous System↗

PubMed1988

Incidence of exercise induced hypoxemia in elite endurance athletes at sea level.

Recent evidence suggests that exercise-induced hypoxemia (EIH) may occur in healthy trained endurance athletes. However, at present, no data exist to describe the regularity of EIH in athletes or non-athletes. Therefore, the purpose of the present investigation was to determine the incidence of EIH during exercise in healthy subjects varying in physical fitness. Subjects (N = 68) performed an incremental cycle ergometer test to volitional fatigue with percent arterial oxyhemoglobin saturation (%SaO2) measured min-by-min. For the purpose of data analysis subjects were divided into three groups according to their level of physical training: 1) untrained (N = 16), 2) moderately trained (N = 27), and 3) elite highly trained endurance athletes (N = 25). EIH was defined as a %SaO2 of less than or equal to 91% during exercise. EIH did not occur in any of the untrained subjects or the moderately trained subjects. However, EIH occurred in 52% of the highly trained endurance athletes tested and was highly reproducible (r = 0.95; P less than 0.05). These findings further confirm the existence of EIH in healthy highly trained endurance athletes and suggests a rather high incidence of EIH in this healthy population. Hence, it is important that the clinician or physiologist performing exercise testing in elite endurance athletes recognize that EIH can and does occur in the elite endurance athlete in the absence of lung disease.

Adult↗