Browsing by Author "Okwose, Nduka C. (57194427179)"

Aims Primary care physicians lack access to an objective cardiac function test. This study for the first time describes a novel cardiac output response to stress (CORS) test developed to improve diagnosis and monitoring of heart failure in primary care and investigates its reproducibility. Methods and results Prospective observational study recruited 32 consecutive primary care patients (age, 63 ± 9 years; female, n = 18). Cardiac output was measured continuously using the bioreactance method in supine and standing positions and during two 3 min stages of a step-exercise protocol (10 and 15 steps per minute) using a 15 cm height bench. The CORS test was performed on two occasions, i.e. Test 1 and Test 2. There was no significant difference between repeated measures of cardiac output and stroke volume at supine standing and Stage 1 and Stage 2 step exercises (all P > 0.3). There was a significant positive relationship between Test 1 and Test 2 cardiac outputs (r = 0.92, P = 0.01 with coefficient of variation of 7.1%). The mean difference in cardiac output (with upper and lower limits of agreement) between Test 1 and Test 2 was 0.1 (-1.9 to 2.1) L/min, combining supine, standing, and step-exercise data. Conclusions The CORS, as a novel test for objective evaluation of cardiac function, demonstrates acceptable reproducibility and can potentially be implemented in primary care. © 2018 The Authors.

Objectives. Heart rate variability (HRV) and haemodynamic response to exercise (i.e. peak cardiac power output) are strong predictors of mortality in heart failure. The present study assessed the relationship between measures of HRV and peak cardiac power output. Design. In a prospective observational study of 33 patients (age 54 ± 16 years) with chronic heart failure with reduced left ventricular ejection fraction (29 ± 11%), measures of the HRV (i.e. R-R interval and standard deviation of normal R-R intervals, SDNN) were recorded in a supine position. All patients underwent maximal graded cardiopulmonary exercise testing with non-invasive (inert gas rebreathing) cardiac output assessment. Cardiac power output, expressed in watts, was calculated as the product of cardiac output and mean arterial blood pressure. Results. The mean RR and SDNN were 837 ± 166 and 96 ± 29 ms, peak exercise cardiac power output 2.28 ± 0.85 watts, cardiac output 10.34 ± 3.14 L/min, mean arterial blood pressure 98 ± 14 mmHg, stroke volume 91.43 ± 40.77 mL/beat, and oxygen consumption 19.0 ± 5.6 mL/kg/min. There was a significant but only moderate relationship between the RR interval and peak exercise cardiac power output (r = 0.43, p =.013), cardiac output (r = 0.35, p =.047), and mean arterial blood pressure (r = 0.45, p =.009). The SDNN correlated with peak cardiac power output (r = 0.42, p =.016), mean arterial blood arterial (r = 0.41, p =.019), and stroke volume (r = 0.35, p =.043). Conclusions. Moderate strength of the relationship between measures of HRV and cardiac response to exercise suggests that cardiac autonomic function is not good indicator of overall function and pumping capability of the heart in chronic heart failure. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2. The clinical presentation of this virus mainly manifests in the respiratory system but may also lead to severe complications in the cardiovascular system. The global burden of COVID-19 has led to an unprecedented need to gain further insight into patient outcomes, management, and clinical practice. This review aims to provide an overview of the current literature on heart failure (HF) hospitalizations, management, and care pathways for supporting patients during and beyond this pandemic. A literature review of five areas of interest was conducted and included: (i) HF hospitalization; (ii) recognizing the needs and supporting HF patients during COVID-19; (iii) supporting rehabilitation services; (iv) transitioning to a telehealth framework; and (v) the need for evidence. Patients with new-onset or existing HF are particularly vulnerable, but a significant reduction in HF hospital admissions has been reported. During these periods of uncertainty, the current care pathways for acute and elective cardiac patients have had to change with the relocation of HF services to protect the vulnerable and reduce transmission of COVID-19. Optimizing community HF services has the potential to reduce the pressures on secondary care during the recovery from this pandemic. Telemedicine and virtual health care are emerging technologies and overcome the risk of in-person exposure. Successful remote delivery of cardiac rehabilitation services has been reported during the pandemic. Delivery of a robust telehealth framework for HF patients will improve communication between clinician and patient. The reduction in HF admissions is a concern for the future and may result in unintended mortality. New-onset and current HF patients must understand their diagnosis and future prognosis and seek help and support using the appropriate platform when needed. Realigning HF services and the use of telemedicine and virtual health care has great potential but needs to be carefully understood to ensure engagement and approval in this population to overcome barriers and challenges. © 2020 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology

Aims: N-terminal prohormone of brain natriuretic peptide (NT-proBNP) plays an important role in diagnosis and management of heart failure. The aim of the present study was to assess haemodynamic response to exercise and to evaluate the relationship between NT-proBNP, cardiac function, and exercise tolerance in chronic heart failure. Methods and results: A single-centre, cross-sectional pilot study recruited 17 patients with chronic heart failure with reduced left ventricular ejection fraction (age 67 ± 7 years) and 20 healthy volunteers (age 65 ± 12 years). The NT-proBNP was measured in the heart failure group. All participants completed maximal graded cardiopulmonary exercise stress testing coupled with gas exchange (using metabolic analyser for determination of exercise tolerance, i.e. peak O 2 consumption) and continuous haemodynamic measurements (i.e. cardiac output and cardiac power output) using non-invasive bioreactance technology. Heart failure patients demonstrated significantly lower peak exercise cardiac function and exercise tolerance than healthy controls, i.e. cardiac power output (5.0 ± 2.0 vs. 3.2 ± 1.2 W, P < 0.01), cardiac output (18.2 ± 6.3 vs. 13.5 ± 4.0 L/min, P < 0.01), heart rate (148 ± 23.7 vs. 111 ± 20.9 beats/min, P < 0.01), and oxygen consumption (24.3 ± 9.5 vs. 16.8 ± 3.8 mL/kg/min, P < 0.01). There was no significant relationship between NT-proBNP and cardiac function at rest, i.e. cardiac power output (r = −0.28, P = 0.28), cardiac output (r = −0.18, P = 0.50), and oxygen consumption (r = −0.18, P = 0.50), or peak exercise, i.e. cardiac power output (r = 0.18, P = 0.49), cardiac output (r = 0.13, P = 0.63), and oxygen consumption (r = −0.05, P = 0.84). Conclusions: Lack of a significant and strong relationship between the NT-proBNP and measures of cardiac function and exercise tolerance may suggest that natriuretic peptides should be considered with caution in interpretation of the severity of cardiac dysfunction and functional capacity in chronic heart failure. © 2019 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.