Human myocardial ATP content and in vivo contractile function

Area of Science:

• Biochemistry
• Cardiology
• Physiology

Background:

• Cardiac muscle metabolism is crucial for heart function.
• Alterations in energy metabolites are implicated in heart failure.
• Understanding these changes can inform therapeutic strategies.

Purpose of the Study:

• To investigate the relationship between human cardiac muscle metabolite levels and in vivo cardiac function.
• To quantify adenosine triphosphate (ATP), total adenine nucleotides, and nicotinamide adenine dinucleotide (NAD) in myocardial tissue.
• To correlate metabolite levels with measures of systolic and diastolic function.

Main Methods:

• High-performance liquid chromatography (HPLC) was used to quantify ATP, total adenine nucleotides, and NAD.
• Myocardial biopsies were obtained from patients with dilated cardiomyopathy, restrictive cardiomyopathy, normal function, and from donor hearts.
• Tissue samples were also collected during cardiac transplantation surgery.

Main Results:

• ATP, total adenine nucleotides, and NAD levels were similar in healthy donor hearts and individuals with normal cardiac function.
• These metabolites were significantly depressed in patients with dilated or restrictive cardiomyopathy.
• A significant correlation was observed between ATP levels and pulmonary capillary wedge pressure, but not ejection fraction.

Conclusions:

• Reduced levels of myocardial ATP, adenine nucleotides, and pyridine nucleotides are associated with cardiomyopathy.
• These metabolic changes are primarily linked to diastolic dysfunction rather than systolic dysfunction.
• Metabolite profiling may serve as a biomarker for assessing cardiac health and dysfunction.