Association between heart rate variability and haemodynamic response to exercise in chronic heart failure.

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.

Renal outcomes among snake-envenomed patients with acute kidney injury in southern India.

Background: . Acute kidney injury (AKI) is a common complication of snake envenomation. However, the long-term renal outcomes of such patients are not well defined. We aimed to determine the proportion of patients who developed AKI, characterize the presenting syndromes and ascertain the long-term resolution of AKI. Methods: . We did a cohort study with prospective follow- up from two centres in southern India. All admitted patients >15 years of age with snake envenomation and serum creatinine ≥1.5 mg/dl over the past 10 years were identified through their discharge summaries. These patients were prospectively contacted, interviewed telephonically and requested to come for a hospital review. Results: . Of the 866 patients screened, 1 84 developed AKI (21.2%). Among these, 53% had combined renal, haematological and neurological manifestations; 33.6% required admission to the intensive care unit and 38% were dialysed. On follow-up of hospital records the creatinine of 49% of patients had normalized. Of those admitted, 36% were contacted and none had a known renal disease or were on dialysis. Among these, 16 patients came to the hospital for review and only 2 had an elevated creatinine. The total mortality was 1 4. Conclusion: . AKI is an important cause of morbidity with snake envenomation and a proportion will require dialysis. The mortality in our study was low and long-term renal outcomes were relatively good.

Prioritizing symptom management in the treatment of chronic heart failure.

Chronic heart failure (CHF) is a chronic, progressive disease that has detrimental consequences on a patient's quality of life (QoL). In part due to requirements for market access and licensing, the assessment of current and future treatments focuses on reducing mortality and hospitalizations. Few drugs are available principally for their symptomatic effect despite the fact that most patients' symptoms persist or worsen over time and an acceptance that the survival gains of modern therapies are mitigated by poorly controlled symptoms. Additional contributors to the failure to focus on symptoms could be the result of under-reporting of symptoms by patients and carers and a reliance on insensitive symptomatic categories in which patients frequently remain despite additional therapies. Hence, formal symptom assessment tools, such as questionnaires, can be useful prompts to encourage more fidelity and reproducibility in the assessment of symptoms. This scoping review explores for the first time the assessment options and management of common symptoms in CHF with a focus on patient-reported outcome tools. The integration of patient-reported outcomes for symptom assessment into the routine of a CHF clinic could improve the monitoring of disease progression and QoL, especially following changes in treatment or intervention with a targeted symptom approach expected to improve QoL and patient outcomes.

The role of exercise hemodynamics in assessing patients with chronic heart failure and left ventricular assist devices.

Introduction: Chronic heart failure is characterized by reduced exercise capacity. Invasive exercise hemodynamics are not routinely performed unless patients undergo transplant or left ventricular assist devices (LVAD) assessment, though now with readily available noninvasive devices, exercise hemodynamics are easily obtained. Our contention is that this is a valuable opportunity to acquire a more accurate measure of cardiac status in heart failure. Exercise hemodynamic measures such as cardiac power output can be carried out cheaply and effectively. Recent studies have highlighted the added value of exercise hemodynamics in prognostication of heart failure, and their role in assessing myocardial recovery in LVADs. Areas covered: In this review, we explore the literature available on Medline until 2019 focusing on resting and exercise hemodynamics alongside the methods of assessment (invasive and noninvasive) in heart failure with reduced ejection fraction and patients with implanted LVADs. Expert opinion: Hemodynamics measured both at rest and exercise are expected to play a significant role in the work up of transplant and LVAD patients. Furthermore, there is the potential to utilize noninvasive assessment in a complimentary fashion to support patient selection and improve the monitoring of response to treatment across the full cohort of heart failure patients.