Objectives: To construct gestational age-adjusted reference ranges for the right fetal modified myocardial performance index (RMPI) in an Australian population and to assess the influence of valve click caliper position on constituent time intervals and the RMPI. Methods: A prospective cross-sectional study of RMPI from 235 normal fetuses at 17-38 weeks of gestation was performed. Two Doppler waveforms were obtained: tricuspid and pulmonary valves for ‘a' and ‘b' readings, respectively. The ultrasound machine settings were: Doppler sweep velocity 15 cm/s, angle of insonation <15°, minimal gain, and wall motion filter 300 Hz. The ‘a' and ‘b' intervals were measured at three different caliper positions in each fetus: at the beginning of the original valve clicks (‘original'), at the beginning of the reflected tricuspid and pulmonary closure clicks (‘reflected') and at the peak of valve clicks (‘peak'). RMPI was calculated as (a - b)/b. The three readings were obtained and averaged per examination, with intraobserver repeatability assessed by intraclass correlation coefficient (ICC) and 95% CI. Results: For ‘original', ‘reflected' and ‘peak' RMPI, mean ± SD, ICC (95% CI) were: 0.53 ± 0.10, 0.86 (0.83-0.89); 0.48 ± 0.10, 0.84 (0.81-0.87) and 0.48 ± 0.10, 0.89 (0.87-0.91), respectively. The RMPI increased by approximately 15% as gestation increased and decreased slightly with increasing heart rate. Conclusion: This is the first publication of reference ranges for RMPI based on caliper position. All methods showed good ICC, including the ‘peak' method which we have previously proposed for routine use based on its repeatability and ease of identification when measuring the myocardial performance index.
Suboptimal management of hypertension is often a result of poor patient compliance in the form of missed doses of their antihypertensive medication. This multicentre, randomised, double-blind, parallel-group trial was designed to compare the persistence of the antihypertensive efficacy of the amlodipine and nifedipine gastrointestinal therapeutic system (GITS) after two 'missed doses', and also to compare the drugs' overall efficacy and safety in Asian patients with mild-tomoderate essential hypertension. Following a 2-week placebo run-in period, 222 patients were randomised to receive either amlodipine (5 mg daily, increased after 6 weeks if necessary to 10 mg daily, n ¼ 109) or nifedipine GITS (30 mg daily, increased after 6 weeks if necessary to 60 mg daily; n ¼ 113) for 12 weeks. A placebo was then substituted for further 2 days with continuous ambulatory blood pressure (BP) monitoring. The increases in the last 9 h of mean ambulatory BP on day 2 after treatment withdrawal were significantly less with amlodipine than with nifedipine GITS: 4.4 7 7.0 vs 11.2 7 11.3 mmHg for systolic BP (Pp0.0001) and 2.4 7 6.3 vs 6.0 7 6.0 mmHg for diastolic BP (Pp0.0002). Significant differences between the two drugs in mean 24-h ambulatory BP levels were already evident on day 1 after withdrawal, even though there were no significant differences on the final day of treatment. No differences in safety parameters were observed, and neither drug caused any serious or severe treatment-related adverse events. In conclusion, amlodipine provides greater protection than nifedipine GITS against loss of BP control following missed doses.
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