Ivabradine in Catecholamine-Induced Tachycardia in a Patient with Paraganglioma

This correspondence reports the case of a 54 year old man with an inoperable metastatic paraganglioma who developed resistant tachycardia and hypertension during treatment with ${}^{177}$Lu Dotatate, despite maximal β-adrenoceptor and calcium channel blockade. The patient's condition worsened, leading to systolic heart failure and acute kidney injury. Administration of ivabradine, an $I_f$