Neurovascular Coupling Impairment in Heart Failure with Reduction Ejection Fraction

Area of Science:

• Cardiovascular Physiology
• Neuroscience
• Cerebrovascular Regulation

Background:

• Reduced ejection fraction in heart failure impacts brain hemodynamics.
• Mechanisms of cerebrovascular regulation in heart failure are not fully understood.

Purpose of the Study:

• To investigate cerebrovascular regulation in patients with heart failure with reduced ejection fraction (HFrEF) and recovered ejection fraction (HFrecEF).
• To compare neurovascular coupling (NVC) and cerebral autoregulation between HFrEF, HFrecEF, and healthy controls.

Main Methods:

• Transcranial Doppler (TCD) was used to monitor cerebral blood flow velocity (CBFV).
• Blood pressure and spontaneous oscillations were analyzed.
• NVC was assessed using visual stimulation.
• Cerebral autoregulation was evaluated via transfer function analysis.

Main Results:

• NVC was significantly impaired in HFrEF patients, showing reduced CBFV augmentation and slower response during stimulation.
• Arterial oscillatory properties were reduced in HFrEF.
• Cerebral autoregulation was preserved in both HFrEF and HFrecEF groups compared to controls.
• The neurovascular unit is dysfunctional in chronic heart failure.

Conclusions:

• Patients with HFrEF exhibit severe dysfunction in their neurovascular unit.
• Dynamic testing with TCD may be beneficial for assessing these patients.
• Future studies should investigate TCD's role in predicting cognitive impairment in heart failure.