Cardiac Phenotypes and Endophenotypes in Schizophrenia : A systematic Review

Area of Science:

• Cardiology
• Psychiatry
• Genetics

Background:

• Schizophrenia is a multisystemic disorder with frequent cardiac anomalies.
• Cardiac issues include autonomic, electrophysiological, and structural heart abnormalities.
• The distinction between cardiac phenotypes and endophenotypes in schizophrenia is unclear.

Purpose of the Study:

• To review clinical, neurobiological, and genetic evidence of cardiac alterations in schizophrenia.
• To evaluate the potential of these cardiac anomalies as endophenotypes for schizophrenia.

Main Methods:

• Systematic review of existing literature.
• Synthesis of clinical, neurobiological, and genetic data.
• Assessment of cardiac anomalies against endophenotype criteria.

Main Results:

• Autonomic dysfunction, characterized by reduced heart rate variability (HRV) and parasympathetic impairment, is the most consistent cardiac phenotype.
• Impaired HRV meets the criteria for an endophenotype in schizophrenia.
• Electrophysiological and structural anomalies show genetic links but lack sufficient evidence to be endophenotypes.

Conclusions:

• Autonomic dysfunction, specifically HRV impairment, is the sole cardiac anomaly fulfilling endophenotype criteria in schizophrenia.
• Observational nature of most studies limits conclusion robustness.
• Future heritability and multi-omic studies are essential to understand the pathogenomic link between schizophrenia and heart disease.