Effects of Docosahexaenoic Acid (DHA) on Heart Rate Variability in Elderly Patients

In western countries, sudden cardiac death (SCD) represents the most common form of cardiovascular death. SCD is often caused by ventricular arrhythmias in patients with a known history of ischemic heart disease but it may also occurs in healthy persons.

In the last years has been extensively studied the protective role of long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) against SCD both in healthy persons and in patients affected by coronary artery disease.

The hypothesis that these evidences could be ascribed to an antiarrhythmic effect of n-3 LCPUFA, has been corroborated by the observation of a direct relationship between the dietary intake of these nutrients and a better cardiac autonomic control.

This pathway, in particular, has been confirmed by the analysis of changes in heart rate variability.

Most studies in this field used n-3 LCPUFA derived from fish oil, composed by a combination of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). At our knowledge there are few studies available evaluating the isolated role of DHA, derived from alternative sources of n-3 LCPUFA, as the microalgae, in the prevention of fatal arrhythmias.

Inclusion criteria

• Age above 65 years

Exclusion criteria

• Treatment with or allergy to polyunsaturated fatty acids
• Diagnosis of arrhythmia or antiarrhythmic therapy
• Anticoagulant therapy (except acetylsalicylic acid)
• Pacemaker
• Bleeding diathesis
• Recent cerebral hemorrhage (less than 6 months)
• Thyroid dysfunction