Which beta blocker has intrinsic sympathomimetic activity and should not be used after myocardial infarction?

Pindolol is classified as a beta blocker with intrinsic sympathomimetic activity (ISA), meaning it can partially stimulate beta-adrenergic receptors while simultaneously blocking them. This characteristic can result in a milder effect on heart rate and contractility compared to other beta blockers without ISA.

In the context of myocardial infarction (MI), the primary goal of beta blocker therapy is to reduce heart workload, lower heart rate, and improve outcomes following the event. Beta blockers without intrinsic sympathomimetic activity are preferred in these situations because they provide a stronger blockade against excessive sympathetic stimulation, which can be detrimental following an MI.

Using a beta blocker with ISA, like pindolol, may not adequately protect the heart post-MI and could potentially lead to adverse outcomes due to its unique pharmacological profile. Thus, due to these properties and the potential risks after an MI, pindolol is generally contraindicated in this scenario.