[Antagonistic function of the heart muscle : Part II: Clinical implications]

Area of Science:

• Cardiovascular Physiology
• Cardiac Pathophysiology

Background:

• Hypertrophic heart disease is characterized by predominant myostructural afterload from endoepicardial networks, exacerbating myocardial hypertrophy.
• The intrinsic antagonism within the heart muscle is disrupted, leading to increased connective tissue (stromatogenic afterload) and regional cardiac dysfunction.

Purpose of the Study:

• To explore the mechanisms underlying myocardial hypertrophy and identify potential therapeutic targets.
• To evaluate the efficacy of negative inotropic medication and mechanical circulatory support in managing hypertrophic heart conditions.
• To propose novel diagnostic approaches for assessing myocardial stiffness and local motion patterns.

Main Methods:

• Analysis of myostructural and stromatogenic afterload in hypertrophic hearts.
• Assessment of the susceptibility of the myocardial network to negative inotropic agents.
• Evaluation of volume reduction surgery and external mechanical circulatory support parameters.
• Consideration of takotsubo cardiomyopathy as a model for intrinsic antagonism dysfunction.

Main Results:

• The oblique transmural myocardial network shows selective susceptibility to low-dose negative inotropic medication, suggesting a potential to attenuate hypertrophy.
• Volume reduction surgery is effective in reducing wall stress, provided the myocardium is not severely fibrotic.
• External mechanical circulatory support is most effective when maintaining the heart in a resting state with minimal motion.

Conclusions:

• Targeting the auxotonic, contracting myocardial network with negative inotropic medication may slow hypertrophic progression.
• Optimizing mechanical circulatory support for resting heart function is crucial for efficacy.
• Clinical diagnostics for heart disease require advancements focusing on local motion patterns and myocardial stiffness as markers of antagonistic intensity.