Management of pericarditis and myocarditis: could heart-rate-reducing drugs hold a promise?

Rest is usually recommended in acute pericarditis and acute myocarditis. Given that myocarditis often leads to hospitalization, this task seems easy to carry out in hospital practice; however, it could be a real challenge at home in daily life. Heart rate-lowering treatments (mainly beta-blockers) are usually recommended in case of acute myocarditis, especially in case of heart failure or arrhythmias, but level of proof remains weak. Calcium channel inhibitors and digoxin are sometimes proposed, albeit in limited situations. It is possible that rest or even heart rate-lowering treatments could help to manage these patients by preventing heart failure as well as by limiting "mechanical inflammation" and controlling arrhythmias, especially life-threatening ones. Whether heart rate has an effect on inflammation remains unclear. Several questions remain unsolved, such as the duration of such treatments, especially in light of new heart rate-lowering treatments, such as ivabradine. In this review, we discuss rest and heart-rate lowering medications for the treatment of pericarditis and myocarditis. We also highlight some work in experimental models that indicates the beneficial effects of such treatments for these conditions. Finally, we suggest certain experimental avenues, through the use of animal models and clinical studies, which could lead to improved management of these patients.