Profound Bradycardia After Addition of Diltiazem to a Beta Blocker

The document reports two cases where the addition of diltiazem to a beta blocker (ß blocker) resulted in profound bradycardia with serious hemodynamic effects. In the first case, a 68-year-old woman on sotalol for supraventricular tachycardia experienced unconsciousness and a pulse rate of 15 beats/minute after diltiazem was added to her treatment. She required temporary transvenous ventricular pacing but recovered with no further incidents when treated with sotalol alone. The second case involved a 77-year-old woman with stable angina on pindolol who experienced coldness, dizziness, and a pulse rate of 26 beats/minute after taking diltiazem. Her condition improved without further complications when continuing pindolol alone. The authors suggest that the combination of diltiazem with a ß blocker can cause serious bradycardia and recommend avoiding diltiazem in patients taking ß blockers, preferring nifedipine or nicardipine instead.