Hemodynamic Response to Rapid Saline Infusion Compared with Exercise in Healthy Participants Aged 20-80 Years.

BACKGROUND AND OBJECTIVE: Rapid saline infusion and exercise has been proposed as methods to unmask cardiovascular disease. However, the normal hemodynamic response to rapid saline infusion has not been compared to exercise nor is it known whether the responses are age-dependent.We assessed the hemodynamic response to rapid saline infusion in healthy participants over a wide age-range and compared it to exercise in the same participants. METHODS AND RESULTS: Fifty healthy participants (young <40 years, n = 16, middle-aged 40-59 years, n = 15, elderly 60-80 years, n = 19) underwent right heart catheterization at rest, during semisupine ergometer exercise at three exercise levels (25%, 50%, and 75% of peak VO2) and after rapid saline infusion (10 ml/kg at a rate of 150 ml/min). Rapid saline infusion significantly increased pulmonary capillary wedge pressure (PCWP) similarly across all age groups (∆PCWP 6 ±â€¯2; 7 ±â€¯2; 6 ±â€¯4 mmHg for the young, middle-aged and elderly respectively) with no correlation between age and ∆PCWP (r = 0.05; p = 0.74). However, there was a negative correlation between age and ∆stroke volume (SV) as elderly participants had a lower increase in SV following rapid saline infusion (r = 0.44; p = 0.002). On the contrary, exercise-induced significantly larger and age-dependent increases in PCWP (r = 0.58; p < 0.0001). Exercise also caused a larger increase in SV compared with rapid fluid loading (p = 0.0003) CONCLUSION: Unlike exercise, rapid saline infusion caused an age-independent increase in PCWP in healthy adults. Suggesting that age-related impairments beyond passive stiffness have a greater impact on exercise-induced increase in PCWP. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT01974557.

Cardiac procholecystokinin expression during haemodynamic changes in the mammalian heart.

Cardiac myocytes express the cholecystokinin gene (CCK) at propeptide level. We recently reported that cardiac CCK expression is acutely regulated by isoprenaline in a porcine model. The regulation of CCK expression after myocardial infarction, in exercise, and in severe heart failure is, however, unknown. Cardiac tissue was obtained from healthy new-born and adolescent farm pigs. Myocardial infarction was induced by coronary artery occlusion in adult minipigs. Healthy male subjects performed a 3-hour exercise test, and patients with severe heart failure referred for right heart catheterization were included. Extracts of porcine cardiac tissue and human plasma were analysed with specific proCCK radioimmunoassays. Cardiac proCCK expression shifted from the right atrium in new-born piglets to include the left atrium in adolescent pigs. Regional proCCK expression in the adolescent pig heart was mainly confined to the atria without different expression in sinus node tissue. In adult minipigs with myocardial infarction, no changes in overall left ventricular function or proCCK expression were observed after 8 weeks. In healthy adults, proCCK in circulation increased markedly during exercise in parallel with pro-B-type natriuretic peptide. Finally, patients with severe heart failure displayed markedly increased proCCK - but not CCK - concentrations in plasma. Taken together, our data shows that regional proCCK expression reflects haemodynamic changes in the mammalian heart. The data supports the notion that cardiac CCK expression resembles that of cardiac natriuretic peptides in atria. The ventricular content of proCCK, however, differs from natriuretic peptides and suggests a distinct secretory pathway in ventricular cardiomyocytes.

Hyponatraemia at hospital admission is a predictor of overall mortality.

BACKGROUND: Hyponatraemia is a prognostic marker of increased mortality and morbidity in selected groups of hospitalised patients. The aim of the present study was to examine the prevalence and prognostic significance of hyponatraemia at hospital admission in an unselected population with a broad spectrum of medical and surgical diagnoses. METHODS: Consecutive patients >40 years of age admitted to a general district hospital in Greater Copenhagen between 1 April 1998 and 31 March 1999. Median follow-up time was 5.16 years (range 0-4372 days). Plasma sodium measurements were available in 2960 patients, and hyponatraemia defined as P-Na(+) <137 mmol/L at hospital admission was present in 1105 (37.3 %) patients. RESULTS: One-year mortality was higher for hyponatraemic patients than for normonatraemic patients: 27.5% versus 17.7%. Moreover, hyponatraemia was an independent predictor of short and long-term all-cause mortality after 1 year and after the entire observation period respectively: hazard ratio (HR) 1.6 (95 % confidence interval (CI) 1.4-1.9, P < 0.0001) and HR 1.4 (95 % CI 1.3-1.6, P < 0.0001). Patients with hyponatraemia had longer hospitalisations than patients with normonatraemia: 7.6 (±0.38) days vs 5.6 (±0.21) days, P < 0.001. There was no interaction between hyponatraemia at admission and any admission diagnoses (P > 0.05 for all interaction analyses). CONCLUSION: Hyponatraemia is associated with increased all-cause mortality and longer admission length independently of diagnosis and clinical variables.