Lithium cardiac conduction

Lithium + antiarrhythmic drugs —> potentiation of the cardiac conduction effects of the antiarrhythmic drugs. 

A very uncommon adverse effect involves sinus node dysfunction (extreme bradycardia, sinus arrest, sinoatrial block), which can be associated with syncopal episodes, perhaps due to hypothyroidism (119,120). In such cases, lithium must either be withdrawn or continued in the presence of a pacemaker. At therapeutic concentrations, other cardiac conduction disturbances have been reported, sometimes in conjunction with hypercalcemia (121), but are uncommon. 

Lithium can also be associated with changes in cardiac conduction [42" ]. 

Lithium iodide is the electrolyte in a number of specialist batteries, especially in implanted cardiac pacemakers. In this battery the anode is made of lithium metal. A conducting polymer of iodine and poly-2-vinyl pyridine (P2VP) is employed as cathode because iodine itself is not a good enough electronic conductor (Fig. 2.3a). The cell is fabricated by placing the Li anode in contact with the polyvinyl pyridine-iodine polymer. The lithium, being a reactive metal, immediately combines with the iodine in the polymer to form a thin layer of lithium iodide, Lil, which acts as the electrolyte ... 

Lithium causes disturbances in electrical conduction (i.e., flattening of T-wave). The shift in potassium distribution caused by the drug also causes supersensitivity to potassium, and may lead to cardiac arrest. 

Polymer electrolyte batteries have been used in implanted cardiac pacemakers since 1972. The system used is lithium/iodine-polyvinylpyridine. Although the conductivity of the Li ions in Li2l is poor, the current requirements are very small, and the major consideration is the storage of a high energy density of nearly 1 Whcm . ... 

---