Title:The Fundamental Basis of Palpitations: A Neurocardiology Approach
Volume: 18
Issue: 3
Author(s): Joshua W. Kandiah, Daniel M. Blumberger and Simon W. Rabkin*
Affiliation:
- Faculty of Medicine, Department of Medicine Division of Cardiology University of British
Columbia, Vancouver, British Columbia, Canada
Keywords:
palpitations, introception, brain, treatment, automic nervous system, neurotransmitters.
Abstract:
Background and Objective: Palpitations are a common symptom that may indicate cardiac
arrhythmias, be a somatic complaint in anxiety disorders, and can be present in patients without
either condition. The objective of this review was to explore the pathways and fundamental
mechanisms through which individuals appreciate palpitations.
Observations: Cardiac afferents provide beat-to-beat sensory information on the heart to the spinal
cord, brain stem, and higher brain centers. Cardioception, a subset of interoception (‘the physiological
sense of the condition of the body’), refers to sensing of the heartbeat. High cardioception is present
in persons with lower body mass index, lower percentages of body fat, and anxiety disorders.
Low cardioception (lower interoceptive awareness) is associated with psychiatric disorders, such as
depression, personality disorders, and schizophrenia. CNS sites associated with heartbeat detection
have been identified by functional magnetic resonance imaging studies and heartbeat-evoked electroencephalogram
potentials. The right insula, cingulate gyrus, somatomotor and somatosensory
cortices nucleus accumbens, left subthalamic nucleus, and left ventral capsule/striatum are implicated
in both palpitations and heartbeat detection. Involvement of the brain as a primary modulator of
palpitations rests on the data that various areas of the brain are activated in association with cardioception,
the ability of focal brain stimulation to induce palpitations, the ability of central alpha receptor
agonists and antagonists to modulate palpitations, and suppression of palpitations by transcranial
repetitive magnetic stimulation (rTMS).
Conclusions: Palpitations should be viewed as a pathway extending from the heart to the brain. Palpitations
are, in part, a reflection of an individual’s cardioception awareness, which is modulated
by body size, percentage of body fat, and psychological or psychiatric conditions. Palpitations can
originate in the brain and involve central neurotransmitters. Treatment of palpitations unrelated to
cardiac arrhythmias or anxiety disorders should consider the use of central alpha-2 agonists and
possibly rTMS.
