New perspectives on heart-brain interactions: Is it time to classify cardio-neurological syndromes?

The interplay between heart and brain is bi-directional, complex and profound. Each system influences the other in health as well as in disease, when dysfunction in one organ has broad and as yet incompletely understood reverberations on the other. Although terms such as “heart-brain axis,” “brain-heart axis,” and “brain-heart syndrome” have previously been used to describe the complex interaction between the heart and the brain, a unified and systematic conceptual framework for coherently classifying these various clinical conditions is currently lacking. In the clinic, the two organs are often treated separately rather than contextually, whereas a “common language” between cardiologists and neurologists would be desirable. A similar scenario with obligate multidisciplinary implications is represented by the cardiorenal syndromes, for which a pathophysiology-based classification comprising five subtypes was proposed in 2004 and is now widely accepted [1]. Such classification has been rapidly adopted by the medical community and has greatly helped standardize management approaches as well as lay out the avenues for research. In a similar manner, it seems reasonable to propose a broad concept of Cardio-Neurological Syndromes (CardioNS) as an umbrella term encompassing five different clinical scenarios, based on the primum movens, directionality of damage (heart to brain, vice versa or concomitant) and mode of onset (acute vs chronic). The term CardioNS is intended to integrate pre-existing concepts within a broader, pathophysiological grounded classification system, fostering more effective and shared communication among the various specialties involved in the management of these complex conditions