Pulse Wave Velocity Predicts Response to Renal Denervation in Isolated Systolic Hypertension

Introduction: Arterial compliance is a marker for cardiac burden in atherosclerotic disease, with the pressure Pulse Wave Velocity (PWV) correlated to compliance. Current clinical practice employs pulsed wave Doppler to measure Flow Wave Velocity (FWV) as a surrogate of PWV. We hypothesized that PWV and FWV are not directly related and are affected by left ventricular ejection time (LVET). Furthermore, we proposed that aortic PWV is independent of mean arterial pressure (MAP) in the setting of isolated systolic hypertension. Methods: Using a physiologically accurate electromechanical cardiovascular simulator, two solid state manometer-tipped pressure transducers and two transit time flow sensors were located at the aortic root and at the aortic bifurcation. PWV and FWV were directly measured while individually varying contractility and thus LVET. The experiments were repeated at various systemic vascular resistances (SVR) and vascular compliances. Automated signal processing and data extraction techniques were used to calculate the key parameters. Results: As LVET increased, FWV decreased but PWV increased while MAP remained constant for a fixed SVR and compliance. (Figure 1) This trend held consistent at different SVR’s and compliances. The relationship of PWV and FWV with LVET appeared to be exponential and linear respectively. For a constant MAP, the associated PWV varied by up to 50m/s and FWV by up to 10m/s for a change in LVET of 225ms. Conclusions: In conclusion, our data shows that PWV and FWV appear to be inversely related. Our data also suggest that PWV and FWV are independent of MAP in the setting of isolated systolic hypertension. These findings suggest that FWV measured by pulsed wave Doppler may not be a simple surrogate for true PWV. Future work is needed to elucidate the hemodynamic principals governing the relationship between PWV and FWV.

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Resistant isolated systolic hypertension: prevalence, hemodynamic and clinical features

Arterial’naya Gipertenziya (Arterial Hypertension) ◽

10.18705/1607-419x-2012-18-6-497-504 ◽

2012 ◽

Vol 18 (6) ◽

pp. 497-504

Author(s):

K. V. Protasov ◽

O. V. Fedorishina

Keyword(s):

Arterial Stiffness ◽

Elderly Patients ◽

Pulse Wave Velocity ◽

Clinical Features ◽

Systolic Hypertension ◽

Pulse Wave ◽

Aortic Pulse Wave Velocity ◽

Stiffness Index ◽

Isolated Systolic Hypertension ◽

Arterial Stiffness Index

Objective. To investigate the prevalence, clinical features and markers of resistant isolated systolic hypertension (ISH) in elderly patients. Design and methods. 261 patients with essential arterial hypertension (AH) and mean age of 73,2 ± 7,2 were included into the study. Resistant AH was diagnosed both by the office BP and ABPM criteria. We detected and compared the ABPM parameters, myocardial, vessels and renal damage signs in the resistant ISH group with those of resistant systolic-diastolic hypertension (SDH) and controlled AH groups. Factors reliably associated with resistant ISH development were revealed by logistic regression. Results and conclusion. The resistant ISH was detected by office BP in 11,8 % and by ABPM in 12,2 % of elderly patients. The resistant SDH was diagnosed in 13,6 and 5,4 % respectively. The «white-coat» effect was found in 30,4 %. In patients with resistant ISH the systolic BP variability, Sokolow-Lyon voltage index, left ventricular ejection fraction decrease occurrence and ambulatory arterial stiffness index were greater than in the compared groups. In comparison to controlled AH the aortic pulse wave velocity was higher while ankle-brachial index was lower. We found the markers of resistant ISH to be systolic BP variability, aortic pulse wave velocity and ambulatory arterial stiffness index.

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