BACKGROUND: The vast majority of @entity7129 (IST) had included predominantly young females with ages ranging between 15 and 46 years. In contrast, the present study presents the findings in four elderly females (aged 61-71 years) with long-standing symptoms of palpitations, more than 15 years, in whom IST was diagnosed in their 6th or 7th decade. METHODS: Clinical and laboratory examinations including electrocardiograms, echocardiograms, and heart rate variability studies were retrospectively reviewed in four of the nine elderly female @entity1 with long-standing cardiac symptoms. Indices of heart rate variability were compared to four age-matched asymptomatic elderly females with no structural @entity299 . RESULTS: The resting electrocardiograms were normal but one had voltage criteria for @entity4346 . All traditional time- and frequency-domain indices were significantly decreased in the symptomatic elderly females as compared to the controls. Echocardiograms showed normal ejection fraction, and in three @entity1 evidence of @entity67 and mild @entity4346 . Blood pressures were elevated, with systolic blood pressure ranging from 170 to 190 and diastolic blood pressure ranging from 94 to 106. @entity148 were diagnosed in all @entity1 . CONCLUSIONS: This study demonstrates that IST can be present in a wide spectrum of @entity1 populations, including elderly populations. It seems that some cases of IST can become chronic if not treated adequately. Apparently, earlier identification and treatment could have improved the quality of life of the @entity1 . Traditional HRV indices may not be valuable to support either a sympathetic or parasympathetic mechanism. Therefore, further studies should consider the potential usefulness of the nonlinear method such as, for example, approximate entropy and detrended fluctuation analysis.

XXXX in elderly females.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity148 :: ('MESH:D001008', 'Disease') :: ['Anxiety disorders'] @entity4346 :: ('MESH:D017379', 'Disease') :: ['left ventricular hypertrophy'] @entity299 :: ('MESH:D006331', 'Disease') :: ['heart disease'] @entity67 :: ('MESH:D018754', 'Disease') :: ['diastolic dysfunction'] @entity7129 :: ('MESH:D013616', 'Disease') :: ['reports of inappropriate sinus tachycardia']
@entity7129 :: (MESH:D013616,Disease) :: ['Chronic inappropriate sinus tachycardia']
