Background: The subendocardial viability ratio (SEVR) when computed from the aortic pressure is related to degree of subendocardial myocardial perfusion. In heart failure (HF) cardiac function has increased dependency on myocardial oxygen consumption. Oxygen demand can be estimated from the arterial pressure wave by the systolic tension time index (STI) and oxygen supply from the diastolic time index (DTI). SEVR is computed as the ratio DTI/STI. The severity of HF is also related to plasma levels of B-type natriuretic peptide (BNP). The noninvasive measurement of central aortic pressure from the peripheral (radial/brachial) pressure pulse is based on a generally stable relationship between central and peripheral waveforms. Aim: To assess the relationship between plasma BNP and SEVR when determined from the radial pressure wave in HF patients, based on the intrinsic relationship between SEVR determined from the peripheral and central aortic pressure waveform. Methods: Patients (n=17, 7 females) aged 45–82 years (mean 67.5±10.5SD) years) who were diagnosed with HF according to the New York Heart Association (NYHA) classification (II [n=7]; III [n=7]; IV [n=3]) underwent non-invasive measurement of radial pulse waveform (tonometry), sphygmomanometric blood pressure (BP), left ventricular ejection fraction (LVEF, echocardiography) and plasma BNP concentration (chemiluminescence, Architect ci16200, Integrated System). SEVR (average of at least 10 consecutive pulses) was computed from STI and DTI using ejection duration (ED) determined from the beginning of the pulse to the dicrotic notch of the radial tonometric pulse. Results: There was an increase in both plasma BNP concentration and SEVR and a decrease in LVEF with NYHA class severity of HF. For the whole cohort there was a significant correlation between SEVR and BNP (pg/mL) (SEVR = –0.0002 BNP ±1.64; r=0.7; P<0.05) for a BNP range of 347–4293 pg/mL. Increasing tertiles of BNP were associated with significant decrease in SEVR (P<0.05) but not heart rate, age, systolic BP or ED. Separate measurements of non-invasive aortic pressure from the peripheral pulse pulse (SphygmoCor, AtCor Medical) confirmed a high correlation (r >0.9) between SEVR from the radial pulse and SEVR from the corresponding derived central aortic pressure. Conclusions: SEVR computed from the radial pulse has an inverse relationship with plasma BNP in HF. Further studies will aim to assess whether the addition of SEVR as a screening parameter will improve the HF discriminating power of BNP measurement.
|Number of pages||2|
|Publication status||Published - 2015|
|Event||Annual Scientific Meeting of the High Blood Pressure Research Council of Australia (36th : 2014) - Adelaide, Australia|
Duration: 26 Nov 2014 → 28 Nov 2014