Exercise-induced myocardial T1 increase and right ventricular dysfunction in recreational cyclists: a CMR study

Area of Science:

• Cardiology
• Sports Medicine
• Biomarkers

Background:

• Strenuous exercise can elevate cardiac troponin I (cTnI), but exercise-induced myocardial edema is not well understood.
• Cardiac magnetic resonance (CMR) native T1/T2 mapping can detect increases in myocardial water content.

Purpose of the Study:

• To evaluate acute myocardial changes in recreational cyclists after strenuous exercise using biomarkers, echocardiography, and CMR.
• To assess exercise-induced changes in myocardial T1 and T2 relaxation times.

Main Methods:

• Nineteen male recreational cyclists completed a 175 km cycling race.
• Cardiac magnetic resonance (CMR) and echocardiography were performed pre- and post-exercise.
• Blood samples were collected to measure cardiac biomarkers like cTnI.

Main Results:

• Post-exercise, significant increases in cTnI and T1 relaxation times were observed (p < 0.001).
• Right ventricular (RV) dysfunction and reduced RV strain were noted post-race (p < 0.05).
• Increased T1 relaxation time correlated with cTnI release, RV dysfunction, and time spent in high heart rate zones.

Conclusions:

• Strenuous exercise in recreational cyclists leads to early post-race cTnI increase, elevated T1 relaxation times, and RV dysfunction.
• These exercise-induced cardiac changes are interdependent.
• The long-term clinical significance of these findings requires further investigation.