Meyers, Michael

Abstract Background Optimal management of checkpoint inhibitor-induced complete heart block is unknown. Previous reports showed relatively high incidence of pacing failure due to the co-existing myocarditis. Case summary A 71-year-old male with a prior history of stage IV metastatic squamous cell lung cancer presents was admitted for dyspnoea and hypotension 10 days after checkpoint inhibitor treatment using pembrolizumab. He was found to have myocarditis, third-degree AV block, severe left ventricular systolic dysfunction with EF 35%, and required pressure support. A dual chamber pacemaker using left bundle branch area pacing (LBBAP) was urgently placed that immediately improved his haemodynamics. Both the cathode and anode were able to capture the ventricle at different pacing outputs. The patient was taken off all intravenous pressors and successfully transferred to a larger centre for further management of the myocarditis with no further arrhythmia or hypotension. Discussion In conclusion, because of the unique ability to capture a large amount of myocardium from both the tip and ring electrodes as well as the ability to deliver cardiac resynchronization therapy, LBBAP may be the preferred pacing strategy in patients who develop complete heart block due to checkpoint inhibitor-induced myocarditis.

Abstract Background Physiologic pacing through left bundle branch area pacing (LBBAP) has recently been shown to be a very promising alternative for cardiac resynchronization therapy (CRT) and to avoid pacing induced cardiomyopathy. However, it is not clear whether the position of LABBP lead may affect the clinical outcomes. Case Report We here report a case of likely LBBAP induced worsening heart failure and cardiomyopathy reversed by re‐positioning of the pacing lead towards a more annular position. A 70‐year‐old male with a previous history of non‐ischemic dilated cardiomyopathy (ejection fraction 40%) who developed intermittent complete heart block and required permanent ventricular pacing. LBBAP was performed with the lead positioned to a position relatively far away from the tricuspid annulus (3.7 cm), due to difficulty in fixating the lead deep into the septum at a more annular position. One month post procedure, the patient's heart failure symptoms worsened, and his EF decreased to 31% despite good heart failure management. He underwent CRT upgrade with successful revision of the originally implanted LBBAP lead to a more annular position, using a deflectable delivery sheath. This resulted in further narrowing of the paced QRS duration from 135 to 106 ms. Two months post procedure, his heart failure symptoms improved by one functional class, and EF improved to 41% by echocardiogram. Conclusions LBBAP may be harmful when the lead is placed too far away from the annulus and may cause paced induced cardiomyopathy.