Heart failure and sleep disorders

Abstract

Awareness of the importance of sleep-related disorders in patients with cardiovascular diseases is growing. In particular, sleep-disordered breathing, short sleep time, and low sleep quality are frequently reported by patients with heart failure (HF). Sleep-disordered breathing, which includes obstructive sleep apnoea (OSA) and central sleep apnoea (CSA), is common in patients with HF and has been suggested to increase the morbidity and mortality in these patients. Both OSA and CSA are associated with increased sympathetic activation, vagal withdrawal, altered haemodynamic loading conditions, and hypoxaemia. Moreover, OSA is strongly associated with arterial hypertension, the most common risk factor for cardiac hypertrophy and failure. Intrathoracic pressure changes are also associated with OSA, contributing to haemodynamic alterations and potentially affecting overexpression of genes involved in ventricular remodelling. HF treatment can decrease the severity of both OSA and CSA. Indeed, furosemide and spironolactone administration, exercise training, cardiac resynchronization therapy, and eventually heart transplantation have shown a positive effect on OSA and CSA in patients with HF. At present, whether CSA should be treated and, if so, which is the optimal therapy is still debated. By contrast, more evidence is available on the beneficial effects of OSA treatment in patients with HF.

Upward Shift and Steepening of the Blood Pressure Response to Exercise in Hypertensive Subjects at High Altitude

“…Aging, presence of hypertension, and environmental conditions may modify such physiological response to physical effort, upward shifting, or even steepening the BP–cardiac output relationship 17, 18, 19, 20. This may hold true also for forms of hypoxia‐related BP rise commonly encountered in clinical practice, such as those observed in case of obstructive sleep apnea episodes, which can be characterized by nocturnal hypertension related to hypoxia and sympathetic activation 21. Indeed, we found that exposure to acute hypobaric hypoxia was responsible for both an upward shift and steepening of the BP response to exercise in our middle‐aged, mildly hypertensive individuals.…”

Sleep Apnea, the Risk of Developing Heart Failure, and Potential Benefits of Continuous Positive Airway Pressure (CPAP) Therapy

“…Third, disrupted sleep increases sympathetic nervous activity, leading to an increase in blood pressure and heart rate, which demands cardiac activity at a time when the heart should be regenerating 2, 19, 20. In addition, several studies have shown that SA is associated with hypertension, coronary artery disease, arrhythmias, obesity, diabetes mellitus, and metabolic disturbances, all known to increase the risk of HF 2, 3, 21, 22. Hence, we applied many of these comorbidities in our regression models, including continuous assessment of their presence.…”

“…Sleep apnea (SA) is associated with increased risk of cardiovascular events, worsening of heart failure (HF), metabolic disturbances, and overall a reduced quality of life 1, 2, 3, 4. One study even found an increased risk of incident HF among men with obstructive sleep apnea (OSA) 5.…”

Heart failure and sleep disordered breathing

“…Inspiratory efforts in OSA against the occluded upper airway are associated with intrathoracic pressure oscillations that result in increased sympathetic activity 4,16) . The hypoxia, hypercapnia, and arousal from sleep that occur at the end of the OSA further increase sympathetic activity.…”