The goal of the trial is to study the effects of lavender essential oil on sleep quality, anxiety, and fatigue in patients with chronic heart failure. The main questions it may answer are

1. effects of lavender essential oil on sleep quality
2. effects of lavender essential oil on anxiety
3. effects of lavender essential oil on fatigue

Patients will be randomly divided into experimental and control groups, the control group will inhale essential coconut oil, and the experimental group will inhale lavender essential oil for four weeks. At baseline, on the 7th day, and 28th day, the sleep quality, anxiety, and fatigue will be evaluated.

Heart failure (HF)， a severe manifestation or advanced stage of various cardiac diseases, may seriously affect patients' quality of life because repeated hospitalizations lead to changes in work and living environment, changes in roles, economic burdens, sexual dysfunction, limitations of social life, and worries about maintaining life. Patients are often accompanied by mental problems such as anxiety, depression, fatigue, and sleep disorders, so their quality of life is low.

Currently, the treatment of CHF is mainly to improve physical symptoms and control complications. However, insufficient attention is drawn to mental and psychological problems such as anxiety, sleep disorders, and fatigue associated with CHF patients.

Patients with anxiety and sleep disturbances are generally treated with antipsychotic and sedative-hypnotic drugs. Although effective, this method also creates dependencies and tolerability with the long-term application. So in recent years, complementary and alternative medicine is a novel adjunctive therapy, including aromatherapy, and traditional medicine, which can improve the patient's health and maintain a calm inner peace.

The commonly used lavender essential oil (Lavandula angustifolia) is the least toxic and allergenic of all aromatic oils. The main components of lavender are linalool and linalool acetate, which act as sedative, anti-nociceptive, and antispasmodic by reducing sympathetic nerve activity and stimulating the parasympathetic nervous system activity. Aromatherapy using lavender essential oil has been widely used in patients with cancer, postpartum depression, pregnant women, blood purification, acute coronary syndrome, myocardial infarction, and quasi-coronary angiography. Studies have shown that aromatherapy using lavender essential oil can relieve anxiety and depression, reduce fatigue, and improve sleep quality, and it has not been found to cause associated adverse events and complications. It showed good safety, while the use of lavender essential oil in patients with CHF has been less studied.

This study intends to use aromatherapy for CHF patients to observe the effects of lavender essential oil inhalation on sleep quality, anxiety, and fatigue in CHF patients, in order to provide a new care method for CHF patients with all-round mental and physical self-management and improve the long-term quality of life of CHF patients.

Inclusion Criteria:

• Met the diagnostic criteria of heart failure:cardiac function grade ⅱ-ⅲ, disease duration ≥6 months.
• Blood pressure ≥90/60mmH, heart rate ≥60 times/min.
• No malignant arrhythmia, no need for oxygen or mechanical ventilation.
• Pittsburgh sleep quality (PSQI) score > 5, State-trait anxiety scale (STAI) score 21-59.
• No nasal diseases, normal sense of smell.
• Normal hearing and language expression, able to communicate, volunteer to participate in this study.

Exclusion Criteria:

• Pregnant women.
• Suffering from physical pain diseases or combined with tumors and other serious diseases of the system
• A history of mental illness, the use of psychiatric or sedative hypnotic drugs within 1 month.
• Allergic constitution, allergic to lavender essential oil or coconut oil, suffering from allergic rhinitis, eczema, asthma and other respiratory diseases.
• Declined to participate in this study.