Xiaopeng Song1, Bhaswati Roy2, Milena Lai1, Ashish Sahib1, Gregg C Fonarow3, Mary A Woo2, Rajesh Kumar4. 1. Department of Anesthesiology, University of California at Los Angeles, Los Angeles, California 90095. 2. UCLA School of Nursing, University of California at Los Angeles, Los Angeles, California 90095. 3. Division of Cardiology, University of California at Los Angeles, Los Angeles, California 90095. 4. Department of Anesthesiology, University of California at Los Angeles, Los Angeles, California 90095; Department of Radiological Sciences, University of California at Los Angeles, Los Angeles, California 90095; Department of Bioengineering, University of California at Los Angeles, Los Angeles, California 90095; Brain Research Institute, University of California at Los Angeles, Los Angeles, California 90095. Electronic address: rkumar@mednet.ucla.edu.
Abstract
BACKGROUND: Patients with heart failure (HF) show abnormal autonomic activities, which may stem from altered functional connectivity (FC) between different brain sites. METHODS AND RESULTS: We evaluate insular and cerebellar FC with other brain areas, before, during, and after the Valsalva challenge, with functional magnetic resonance imaging in 35 HF and 35 control subjects. Significant insular FC emerged with striatum, thalamus, and anterior cingulate. While left and right cerebellar cortices showed significant FC with each other constituting the cerebellum network, the insula and cerebellum networks showed significant negative FC with each other at baseline, challenge, and recovery phases. The challenge induced increased FC within the insula and the cerebellum networks in both HF and controls. However, patients with HF showed more increased insular network FC, but less enhanced cerebellar FC. During the recovery phase, the negative FC between the insular network and cerebellum enhanced significantly in controls, but not in HF. Lower left ventricle ejection fraction was correlated with lower insula network FC, and impaired negative FC between cerebellum and the insula network in HF. CONCLUSIONS: Increased insular FC in patients with HF might contribute to exaggerated sympathetic tone. While impaired cerebellar FC and diminished negative interactions between cerebellum and insular systems may indicate impaired parasympathetic functions in HF.
BACKGROUND:Patients with heart failure (HF) show abnormal autonomic activities, which may stem from altered functional connectivity (FC) between different brain sites. METHODS AND RESULTS: We evaluate insular and cerebellar FC with other brain areas, before, during, and after the Valsalva challenge, with functional magnetic resonance imaging in 35 HF and 35 control subjects. Significant insular FC emerged with striatum, thalamus, and anterior cingulate. While left and right cerebellar cortices showed significant FC with each other constituting the cerebellum network, the insula and cerebellum networks showed significant negative FC with each other at baseline, challenge, and recovery phases. The challenge induced increased FC within the insula and the cerebellum networks in both HF and controls. However, patients with HF showed more increased insular network FC, but less enhanced cerebellar FC. During the recovery phase, the negative FC between the insular network and cerebellum enhanced significantly in controls, but not in HF. Lower left ventricle ejection fraction was correlated with lower insula network FC, and impaired negative FC between cerebellum and the insula network in HF. CONCLUSIONS: Increased insular FC in patients with HF might contribute to exaggerated sympathetic tone. While impaired cerebellar FC and diminished negative interactions between cerebellum and insular systems may indicate impaired parasympathetic functions in HF.
Authors: Rajesh Kumar; Haidang D Nguyen; Jennifer A Ogren; Paul M Macey; Paul M Thompson; Gregg C Fonarow; Michele A Hamilton; Ronald M Harper; Mary A Woo Journal: Eur J Heart Fail Date: 2011-03-09 Impact factor: 15.534