Atrial and ventricular arrhythmias commonly arise in the setting of
cardiogenic shock and often result in hemodynamic deterioration. Causative factors include
myocardial ischemia, volume overload, and metabolic disturbances. Correcting these factors plays an important role in managing arrhythmias in this setting. Ventricular arrhythmias are more ominous compared to atrial arrhythmias but both require prompt intervention with electrical
shock and
anti-arrhythmic drug suppression. Coronary reperfusion is key to improving survival, including reducing the risk of
sudden cardiac arrest, in acute
myocardial infarction. Case series have also demonstrated the value of intra-aortic balloon pump counter-pulsation in suppressing ventricular arrhythmias in
cardiogenic shock. The mechanism of
arrhythmia suppression may be due to improved coronary perfusion and afterload reduction. Percutaneous
ventricular assist device placement may be effective in this setting; however, data addressing this specific endpoint are lacking.
Anti-arrhythmic drug options for ventricular and atrial
arrhythmia suppression, in the setting of
cardiogenic shock, are relatively limited. Common class I agents are excluded due to the inherent abnormal cardiac structure and function in the setting of
cardiogenic shock. Class III
drug options include
dofetilide and
amiodarone. The other Class III agents,
sotalol and
dronedarone, are excluded due to associated mortality observed in the SWORD and ANDROMEDA trials, respectively.
Dofetilide is renally excreted and causes QT interval prolongation. Care should be taken to avoid excessive
drug accumulation due to poor kidney perfusion and function.
Dofetilide is approved for use for atrial arrhythmias and has not been studied for ventricular
arrhythmia suppression. The
DIAMOND-CHF trial established its safety in the setting of
heart failure.
Amiodarone is very effective in suppressing both atrial and ventricular arrhythmias. It is often the
drug of choice in
heart failure. Its
off-label use for atrial arrhythmias is very common. Care should be taken with intravenous
amiodarone to avoid
hypotension.