Treatment of severe left ventricular dysfunction with calcium chloride in patients receiving verapamil

The use of calcium salts in the prevention and management of verapamil-induced hypotension

OBJECTIVE

To review the available literature on the use of intravenous calcium salts for the prevention of hypotension associated with intravenous verapamil.

METHODS

A MEDLINE search (1966-June 1999) identified pertinent articles; references from these articles were identified to serve as additional resources.

DISCUSSION

Verapamil is effective in inhibiting atrioventricular nodal conduction, thereby controlling ventricular rate in patients with atrial fibrillation/flutter and terminating paroxysmal supraventricular tachycardia. However, hypotension may be caused by the negative inotropic and vasodilating effects of verapamil. In vitro and animal data suggest that calcium pretreatment may minimize the effects of verapamil on cardiac output and blood pressure. Case reports suggest that intravenous calcium may be useful for both prevention and reversal of the hemodynamic effects of verapamil. A number of small clinical trials have been performed, suggesting that calcium administered prior to intravenous verapamil results in a decreased incidence of hypotension. The most common adverse effect of intravenous calcium is flushing.

CONCLUSIONS

Calcium pretreatment prior to intravenous calcium-channel blocker administration should be considered in patients in whom further reductions in blood pressure may precipitate hypoperfusion or worsen underlying cardiovascular status. A dose of calcium gluconate 1 g (ionized calcium 90 mg) administered over three minutes is recommended for preventing or lessening the hypotensive effect of verapamil without affecting the antiarrhythmic effects of verapamil.

Development of ventricular fibrillation after intravenous calcium chloride administration in a patient with supraventricular tachycardia

The i.v. administration of calcium before or shortly after treatment of supraventricular tachycardia with verapamil has been suggested to counteract a hypotensive response to verapamil. We discuss the case of a patient who presented to the emergency department with an accelerated wide-complex tachycardia and minimal symptoms. Immediately after i.v. administration, of 1 g calcium chloride as pretreatment for verapamil administration, ventricular fibrillation developed. Emergency physicians should be aware of potential dangers after the administration of i.v. calcium preparations when trying to prevent known hypotensive side effects of i.v. verapamil administration.