Management of Stress Cardiomyopathy with Ventricular Tachycardia
Immediate synchronized cardioversion with appropriate sedation is the first-line treatment for patients with stress cardiomyopathy presenting with hemodynamically unstable ventricular tachycardia. 1, 2
Initial Assessment and Classification
- Assess hemodynamic stability by evaluating blood pressure, mental status, and signs of hypoperfusion in patients with stress cardiomyopathy and VT 2
- Obtain a 12-lead ECG for all hemodynamically stable patients with sustained VT to determine if the VT is monomorphic (consistent QRS morphology) or polymorphic (changing QRS morphology) 1, 2
- Any wide-QRS tachycardia should be presumed to be VT if the diagnosis is unclear 1, 3
- Stress cardiomyopathy can induce arrhythmias and cardiogenic shock, with arrhythmias seen in up to 40% of patients 4
Management Algorithm Based on Hemodynamic Status
For Hemodynamically Unstable Patients:
- Perform immediate synchronized direct-current cardioversion with appropriate sedation 1, 2
- Start with 100-200 J for synchronized cardioversion of monomorphic VT 2
- For polymorphic VT, use unsynchronized defibrillation at 200 J, treating it similar to VF 2
- Have resuscitation equipment readily available 2
For Hemodynamically Stable Patients:
- For monomorphic VT, intravenous procainamide is recommended as first-line pharmacological treatment (20-30 mg/min up to 10 mg/kg) 1, 2, 3
- Intravenous amiodarone is reasonable for patients with heart failure or when VT is refractory to cardioversion 1, 2, 5
- For polymorphic VT, intravenous beta-blockers are useful, especially if ischemia is suspected 1, 2, 3
- Intravenous amiodarone loading is useful in the absence of QT prolongation for polymorphic VT 1, 2
Special Considerations for Stress Cardiomyopathy
- Avoid catecholamines if possible, as catecholamine toxicity is implicated in 45% of stress cardiomyopathy cases 4
- If vasopressors are absolutely necessary for hemodynamic support, consider mechanical circulatory support such as intra-aortic balloon pump (used in 20% of stress cardiomyopathy patients with shock) 4
- Consider calcium channel blockers if coronary spasm is suspected as a trigger for VT in stress cardiomyopathy 6
- Monitor for potential complications including systemic thromboembolism and cardiogenic shock 7
Post-Conversion Management
- After initial stabilization, evaluate for underlying causes of stress cardiomyopathy 2
- Amiodarone plus beta-blocker therapy significantly reduces the risk of recurrent VT/VF compared with beta-blocker treatment alone 1
- For intravenous amiodarone, the recommended starting dose is about 1000 mg over the first 24 hours, followed by a maintenance infusion of 0.5 mg/min 5
- Urgent cardiology consultation is recommended, particularly since stress cardiomyopathy was previously thought to be benign but is now recognized to have serious complications 7, 8
Long-term Management Considerations
- Consider ICD evaluation for patients with stress cardiomyopathy and VT who are at high risk for recurrence 2, 6
- Urgent catheter ablation may be considered in patients presenting with incessant VT or electrical storm 1
- Beta-blockers should be continued long-term in patients with stress cardiomyopathy and history of VT 1, 7
Common Pitfalls and Caveats
- Misdiagnosis of wide-complex tachycardias is common; when in doubt, treat as VT 2, 3
- Calcium channel blockers such as verapamil and diltiazem should not be used to terminate wide-QRS-complex tachycardia of unknown origin, especially in patients with myocardial dysfunction 1
- Intravenous amiodarone concentrations greater than 3 mg/mL have been associated with a high incidence of peripheral vein phlebitis; use concentrations of 2.5 mg/mL or less for infusions longer than 1 hour 5
- Stress cardiomyopathy can cause ventricular arrhythmias even after apparent recovery of left ventricular function 6