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Audrey Adji

Publications and source records attributed to Audrey Adji.

10 recordsLinked to original sources
PubMed2006

Clinical use of indices determined non-invasively from the radial and carotid pressure waveforms.

OBJECTIVE: To evaluate the clinical use of radial and carotid artery applanation tonometry as an independent supplement to cuff sphygmomanometry. METHODS: In 44 patients, radial and carotid tonometric pressure recordings were taken at short intervals apart by two persons who had prolonged experience with both. Comparisons were made between directly recorded radial and carotid waveforms and between aortic waves synthesized from both, using SphygmoCor. Focus was on waveform features: time intervals between wavefoot and incisura, denoting ejection duration, between wavefoot and first systolic peak or shoulder T1, and augmentation index - the rise in pressure from this point to systolic peak divided by pulse pressure. RESULTS: No patient had discomfort with radial tonometry, whereas many found carotid tonometry uncomfortable. Beat-to-beat variability was lower for the radial than carotid site. The device's operator "quality index" was achieved for 78% of radial waveforms but just 20% of carotid waveforms (P<0.05). Interobserver variability was lower for all indices derived from radial, cf. carotid, waveforms. For the two observers combined, there was no difference between aortic indices determined from carotid and radial sites except for T1 (radial-derived 117+ or -17 ms, cf. carotid-derived 103+ or -17 ms, P<0.05), but this did not influence the value of augmentation index (radial-derived 26+ or -13%, cf. carotid-derived 28+ or -14%, P=NS). CONCLUSION: The present study conforms with most published results, and indicates superiority of radial to carotid tonometry in clinical practice.

Adult↗
PubMed2005

Effect of sildenafil on cardiac performance in patients with heart failure.

Sildenafil is rarely used in patients with heart failure despite a high prevalence of erectile dysfunction, and the theoretic possibility that by increasing nitric oxide availability, it may improve left ventricular (LV) load and performance. This study aimed to determine the peak effects of sildenafil on LV load and performance in patients with heart failure caused by systolic LV dysfunction. Twenty patients with controlled LV failure and ejection fractions <35% received sildenafil 50 mg or a matching placebo when not receiving regular medication for > or =12 hours, in a randomized, placebo-controlled, double-blind, 2-way crossover fashion. Cardiac output was measured by Doppler echocardiography. The aortic pressure waveform was determined using generalized transfer function from radial artery applanation tonometry. Aortic and femoral arterial stiffness was determined as carotid-femoral and femoral-pedal pulse-wave velocity (PWV); wave reflection was measured as an augmentation index (AIx). Cardiac index increased significantly (by 0.37 L/min.m(2), p <0.0001), with the peak effect 60 minutes after sildenafil administration. Compared with the baseline value, total systemic resistance showed a reduction of 479 dynes.s.cm(-5) (p <0.0001). Aortic and lower limb PWV decreased significantly (by 0.89 and 1.14 m/s, respectively, p <0.0001 for both), as did AIx (by 3.6% absolute, p <0.0001); these remained significant after adjustment for mean pressure and heart rate changes. In conclusion, sildenafil improves cardiac performance because of a decrease in LV load, which is caused by decreases in peripheral resistance, in aortic and large artery stiffness, and in wave reflection from peripheral sites. This can explain the increase in cardiac output and in exercise capacity with sildenafil in patients with heart failure.

Aged↗
PubMed2005

An updated clinical primer on large artery mechanics: implications of pulse waveform analysis and arterial tonometry.

PURPOSE OF REVIEW: The use of pulse wave analysis with arterial tonometry has accelerated over the last year. Despite approval from the US Food and Drug Administration in 2001 on the use of generalized transfer function to generate the central (aortic) pressure wave from the radial waveform, this technique is still questioned. This review summarizes major findings on (a) value of arterial tonometry in determining indices of cardiovascular function, (b) use of these indices in outcome and drug studies, (c) relevance to major trials on blood pressure reduction. RECENT FINDINGS: Pulse pressure has emerged as a better predictor of cardiac ischemic events than systolic, diastolic, and mean brachial pressure. Central systolic and pulse pressure and augmentation index have shown an even better relation with cardiovascular events and with outcomes. The claim by specific angiotensin-converting enzyme inhibitor and angiotensin receptor blocker drugs of their benefits "beyond blood pressure lowering" has been challenged on the basis of greater reduction in central and aortic pressure compared with brachial pressure measured by cuff sphygmomanometer, as shown by the pREterax in regression of Arterial Stiffness in a contrOlled double-bliNd study. Augmentation index is higher in hypertension, is inversely related to body height, and can be reduced by exercise. Augmentation index shows a linear relation with age up to 60 years. Regrettably, recent major trials such as the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis, Prevention of Events with Angiotensin Converting Enzyme Inhibition, and Valsartan Antihypertensive Long-term Use Evaluation studies have not included pulse wave analysis to distinguish the relative benefit of different drugs. SUMMARY: Pulse wave analysis will assist in a better understanding of hypertension as well as in establishing the extent of cardiovascular disease and for monitoring therapy.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2005

Benefits from angiotensin-converting enzyme inhibitor 'beyond blood pressure lowering': beyond blood pressure or beyond the brachial artery?

OBJECTIVE: The substantial benefits of ramipril over conventional therapy in high-risk patients are not always associated with clinically significant differences in brachial arterial pressure, and largely remain unexplained. We undertook this acute study to establish the magnitude of and reason for different acute effects of ramipril and atenolol on arterial pressure. METHODS: We enrolled 30 patients, who took 10 mg ramipril, 100 mg atenolol, and placebo at intervals of > or = 7 days, in a randomized, double-blind, placebo-controlled trial. After baseline, measurements were taken at 30-60 min intervals for 5 h, and comprised cuff brachial pressure, radial artery tonometry with generation of central aortic pressure, and pulse wave velocity for aorta, upper limb and lower limb arteries. RESULTS: Both ramipril and atenolol reduced arterial pressure, and the diastolic pressure fall was similar in the aorta and brachial artery, but the systolic pressure fall for ramipril was greater than for atenolol (by 5.2 mmHg, P < 0.0001) in the aorta compared with the brachial artery. The aortic systolic pressure difference with ramipril in comparison with atenolol was accompanied by an absolute difference of 10.7% (P < 0.0001) in the augmentation index, denoting a reduction in peripheral wave reflection by ramipril. The aortic pulse wave velocity fell to a similar degree with ramipril in comparison with atenolol, but fell to a greater degree (1.35 and 0.44 m/s, respectively, P < 0.0001 for both) in muscular arteries of the lower and upper limbs. CONCLUSION: A greater (average, 5.2 mmHg) decrease in aortic systolic pressure caused by ramipril may explain the greater benefit of ramipril over atenolol. The difference is attributable to decreased stiffness of peripheral arteries and a reduction in wave reflection.

Aged↗
PubMed2004

Validation of the transfer function technique for generating central from peripheral upper limb pressure waveform.

Central aortic pressure waveforms can be calculated from the radial artery pressure waveform using a generalized transfer function to correct for pressure wave distortion in the upper limb. Although validated to standards conventionally applied, reservations are still expressed on use of this process, because of the relatively small number of patients from whom appropriate invasive data were obtained. The study described here supplemented such data with noninvasive data obtained from carotid and radial artery tonometry in 439 patients and normal subjects. The carotid-radial artery transfer function was similar to the aortic-radial when allowance was made for wave travel from aorta to carotid artery. The carotid-radial transfer function was identical in male and female individuals, was similar at different arterial pressures and in mature adults. Differences are relatively small, are seen at frequencies where central pressure wave components are small and are similar to those seen with vasodilator agents in invasive studies. Findings provide further support for use of a generalized transfer function to calculate aortic from upper limb pressure and conform with previously established views on vascular impedance.

Adolescent↗
PubMed2004

Determination of central aortic systolic and pulse pressure from the radial artery pressure waveform.

OBJECTIVE: Measurements of central aortic systolic and pulse pressure, either gauged directly or estimated indirectly, have been shown to be superior to brachial pressure in outcome studies. While the radial pressure convolution method has proved to satisfy the criteria for 'substantial equivalence' to measure central pressure non-invasively, this study sought simpler methods to generate central systolic and pulse pressure directly from the radial artery waveform. METHODS: Two sets of data were used, in which radial artery pressure waves were measured by applanation tonometry and ascending aortic pressure was generated by the SphygmoCor process. Different approaches were applied to each dataset: firstly, using the time period from wave foot to systolic peak in central arteries; secondly, through identifying the pressure surge from the reflected wave in the radial artery; and thirdly from extrapolation and calibration of carotid systolic pressure when mean and diastolic pressure considered to be equal with radial values. RESULTS: Both datasets showed good correspondence between the central systolic and pulse pressure obtained with each of the three approaches and respective pressures generated by SphygmoCor process; all were within AAMI SP10 criteria and grade A for BSH criteria. CONCLUSION: All three approaches gave results similar substantially equivalent to those obtained with the SphygmoCor system for aortic, systolic and pulse pressure. Hence, simple inspection of the radial waveform has the potential to improve the estimation of aortic systolic and pulse pressure.

Aorta↗