Do patients with myocarditis (inflammation of the heart muscle) exhibit signs and symptoms of heart failure and cardiogenic shock?

From the Guidelines

Yes, patients with myocarditis can exhibit signs and symptoms of heart failure and cardiogenic shock. Myocarditis is inflammation of the heart muscle that can impair cardiac function, leading to decreased contractility and reduced cardiac output. In severe cases, this can progress to heart failure, characterized by symptoms such as shortness of breath, fatigue, peripheral edema, and decreased exercise tolerance. When myocarditis severely compromises cardiac function, cardiogenic shock may develop, presenting with hypotension, poor peripheral perfusion, altered mental status, decreased urine output, and metabolic acidosis. The inflammatory process in myocarditis damages cardiomyocytes, disrupting normal electrical conduction and contractile function. This pathophysiological process explains why patients with acute myocarditis may rapidly deteriorate, requiring prompt medical intervention including inotropic support, mechanical circulatory assistance, and in some cases, consideration for heart transplantation. The severity of these manifestations varies widely, with some patients experiencing mild symptoms while others develop life-threatening complications.

According to the 2022 ACC Expert Consensus Decision Pathway on Cardiovascular Sequelae of COVID-19 in Adults 1, patients with definite myocarditis that is either mild or moderate in severity should be hospitalized, ideally at an advanced heart failure center. Those with a fulminant course, such as cardiogenic shock, sustained ventricular arrhythmias, and/or advanced atrioventricular block, should be managed similarly to other forms of cardiogenic shock at centers with expertise in advanced heart failure, mechanical circulatory support, and other advanced therapies.

Key considerations in the management of myocarditis include:

• Hospitalization at an advanced heart failure center for patients with mild or moderate severity myocarditis
• Management of cardiogenic shock and fulminant myocarditis at centers with expertise in advanced heart failure and mechanical circulatory support
• Use of guideline-directed medical therapy for heart failure, including beta-blockers and aldosterone system inhibitors
• Avoidance of strenuous physical activity for 3-6 months
• Follow-up surveillance testing, including ECG, echocardiogram, ambulatory rhythm monitor, and CMR, to gauge recovery of cardiac function and inflammation, guide heart failure management, and assess prognosis.

The 2022 ACC Expert Consensus Decision Pathway on Cardiovascular Sequelae of COVID-19 in Adults 1 provides the most recent and highest quality guidance on the management of myocarditis, and its recommendations should be prioritized in clinical practice.

From the Research

Signs and Symptoms of Heart Failure and Cardiogenic Shock in Myocarditis Patients

• Cardiogenic shock is a primary cardiac disorder that results in both clinical and biochemical evidence of tissue hypoperfusion and can lead to multi-organ failure and death depending on its severity 2.
• The primary causes of cardiogenic shock are myocardial infarction-related CS and acute decompensated heart failure-related CS, which can be associated with myocarditis 3.
• Myocarditis can lead to inadequate cardiac contractility or cardiac power, resulting in cardiogenic shock, which is characterized by a decrease in myocardial contractility and presents a high mortality rate 4.
• Patients with cardiogenic shock, including those with myocarditis, may exhibit signs and symptoms of heart failure, such as tissue hypoperfusion, and may require treatment with inotropes and vasopressors to improve hemodynamics 5, 6.
• The use of inotropes and vasopressors in cardiogenic shock, including in patients with myocarditis, is controversial, and the evidence on their effectiveness in reducing mortality is limited and inconsistent 5, 4, 6.

Treatment of Cardiogenic Shock in Myocarditis Patients

• Inotropes, such as levosimendan, milrinone, and dobutamine, and vasopressors, such as adrenaline, noradrenaline, and vasopressin, are commonly used to treat cardiogenic shock in patients with myocarditis 5, 6.
• The choice of inotrope or vasopressor depends on the patient's hemodynamic profile and the underlying cause of cardiogenic shock 4.
• Mechanical circulatory support, such as intra-aortic balloon pump and percutaneous MCS, may also be used to treat cardiogenic shock in patients with myocarditis, although the evidence on their effectiveness is limited 5.