[Emotional stress and extracardiac regulation]

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Stress Physiology

Background:

• Emotional stress significantly impacts cardiovascular function.
• The autonomic nervous system, comprising sympathetic and parasympathetic branches, plays a crucial role in regulating heart activity.
• Understanding the differential effects of these branches during stress is vital for cardiovascular health.

Purpose of the Study:

• To investigate the distinct effects of sympathetic and parasympathetic nervous system dominance on cardiac electric stability and rhythm during emotional stress.
• To determine the influence of these autonomic pathways on the development of arterial hypertension and myocardial structural changes.
• To elucidate the protective mechanisms of vagal nerve activity in the context of emotional stress.

Main Methods:

• Chronic experiments were conducted on rabbits and rats.
• Sympathetic and parasympathetic influences on the heart were modulated during induced emotional stress.
• Cardiac electric stability, heart rhythm, arterial blood pressure, and myocardial structure were monitored.

Main Results:

• Sympathetic nervous system activation during emotional stress reduced cardiac electric stability, induced arrhythmias, and led to arterial hypertension.
• Parasympathetic nervous system activation enhanced cardiac electric stability, inhibited catecholamine increase, and prevented myocardial structural damage.
• Arterial hypertension was notably absent under prevailing parasympathetic influence.

Conclusions:

• The sympathetic nervous system's influence during emotional stress is detrimental to cardiac electric stability and promotes hypertension.
• The parasympathetic nervous system, particularly via the vagal nerves, exerts protective, adaptational, and trophic effects on the heart during emotional stress.
• Vagal nerve activity appears to be a key defensive mechanism against the adverse cardiovascular consequences of emotional stress.