American journal of hypertension
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Comparative Study Clinical Trial
Is a series of blood pressure measurements by the general practitioner or the patient a reliable alternative to ambulatory blood pressure measurement? A study in general practice with reference to short-term and long-term between-visit variability.
We studied the reproducibility of a series of blood pressure measurements by general practitioner (GP) and patient in comparison with that of ambulatory blood pressure measurement (ABPM), with reference to short-term and long-term between-visit variability using a prospective, comparative diagnostic study. The study group was 88 potentially hypertensive primary care patients (initial systolic blood pressure [SBP] between 160 and 200 mm Hg or with diastolic blood pressure [DBP] between 95 and 115 mm Hg). ABPMs were measured on 2 separate days (at a 6 month interval). ⋯ No statistically significant differences were found between the SDDs of the studied measurement procedures (SBP and DBP). In our study the reproducibility of ambulatory blood pressure measurement was not found to be better than that of a series of four duplicate measurements by GP or patient. Long-term (6 months interval) between-visit variability was larger than the short-term (1 week interval) between-visit variability.
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Doppler echocardiographic measurement of time-velocity integral of blood flow across the aortic annulus ("stroke distance") or of stroke volume (SV) have been proposed as noninvasive measures of cardiac pump performance that could elucidate the hemodynamics of hypertension. To evaluate the performance of these measures of hemodynamic volume load in a population with a wide range of body build and other characteristics, we obtained technically adequate imaging and Doppler echocardiograms in 1,935 of 2,212 (87%) American Indian Strong Heart Study participants, without mitral regurgitation or segmental left ventricular (LV) dysfunction, in Arizona, Oklahoma, and South/North Dakota. The subjects ranged widely in age (48 to 81 years) and body mass index (17.0 to 62.6 kg/m2); 65% were women; 1,161 were normotensive and 774 were hypertensive. ⋯ Stroke distance was inversely related to annular area (r = -0.29) and in subjects stratified by aortic annular diameter 1.6 to 1.9, 2.0 to 2.1, and 2.3 to 2.9 cm, mean LV SV increased from 67 to 74 to 80 mL, but average stroke distance fell from 22.8 to 21.6 to 20.1 cm. Stroke distance also failed to identify gender differences in LV SV but did identify that due to obesity. Thus Doppler SV closely parallels independently measured LV SV but slightly underestimates SV in both normotensive and hypertensive adults, whereas aortic stroke distance yields misleading comparisons between genders or individuals of different body sizes.