Atrial placement of Aveir-VR leadless pacemaker in a patient with complex cardiac anatomy.

Leadless pacemakers have provided new treatment modalities that can be especially useful in patients with complex cardiac anatomy and contraindications toward other pacemaker approaches. The Aveir™ single-chamber (VR) leadless pacemaker (LP) (Abbott Laboratories, Chicago, IL) is a recently approved device that can be placed in the right ventricle for patients with bradycardia. In this case, we present a novel use for the device through placement in the atrium to control atrial flutter in a patient with a hypoplastic right ventricle.

Ir(III) Half-Sandwich Photosensitizers with a π-Expansive Ligand for Efficient Anticancer Photodynamic Therapy.

One approach to reduce the side effects of chemotherapy in cancer treatment is photodynamic therapy (PDT), which allows spatiotemporal control of the cytotoxicity. We have used the strategy of coordinating π-expansive ligands to increase the excited state lifetimes of Ir(III) half-sandwich complexes in order to facilitate the generation of 1O2. We have obtained derivatives of formulas [Cp*Ir(C∧N)Cl] and [Cp*Ir(C∧N)L]BF4 with different degrees of π-expansion in the C∧N ligands. Complexes with the more π-expansive ligand are very effective photosensitizers with phototoxic indexes PI > 2000. Furthermore, PI values of 63 were achieved with red light. Time-dependent density functional theory (TD-DFT) calculations nicely explain the effect of the π-expansion. The complexes produce reactive oxygen species (ROS) at the cellular level, causing mitochondrial membrane depolarization, cleavage of DNA, nicotinamide adenine dinucleotide (NADH) oxidation, as well as lysosomal damage. Consequently, cell death by apoptosis and secondary necrosis is activated. Thus, we describe the first class of half-sandwich iridium cyclometalated complexes active in PDT.