Heart arrest verapamil

Verapamil s cardiotoxic effects are dose-related and usually avoidable. A common error has been to administer intravenous verapamil to a patient with ventricular tachycardia misdiagnosed as supraventricular tachycardia. In this setting, hypotension and ventricular fibrillation can occur. Verapamil s negative inotropic effects may limit its clinical usefulness in diseased hearts (see Chapter 12 Vasodilators the Treatment of Angina Pectoris). Verapamil can lead to atrioventricular block when used in large doses or in patients with atrio-ventricular nodal disease. This block can be treated with atropine and -receptor stimulants. In patients with sinus node disease, verapamil can precipitate sinus arrest. 

Patients with impaired function of the sinus node or impaired atrioventricular conduction can develop sinus bradycardia, sinus arrest, heart block, hypotension and shock, and even asystole, with verapamil (139) or diltiazem. These drugs should not be given to patients with aberrant conduction pathways associated with broad-complex tachydysrhythmias, and they can cause severe conduction disturbances in hypertrophic cardiomyopathy. 

Other case reports and studies describe heart failure, dyspnoea, - sinus arrest, heart block, "" hypotension, " and bradycar-(jj 4,5,8,io,ii,i4-i8 jjj patients taking verapamil with alprenolol, atenolol, metoprolol, " propranolof " or pindolol. In two further cases, bradycardia occurred in patients taking verapamil and using timolol eye drops. Another case has been reported, but this was complicated by the presence of flecainide , (p.844). A number of reports noted that patients experiencing this interaction had reasonable left ventricular function. Heart block and hypotension or cardiogenic shock has also been reported after verapamil was given with atenolol or propranolol in overdose. 

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