Interventricular conduction disorders after orthotopic heart transplantation: risk factors and clinical relevance.

BACKGROUND: Causes and significance of interventricular conduction disorders (IVCDs) after orthotopic heart transplantation (OHT) are still unknown. METHODS: We retrospectively researched the presence of IVCDs in 240 patients who underwent bicaval OHT in three time periods: at day 1, after 1 year, and after 3 years from OHT. To evaluate the impact of the surgical technique, a control population treated with biatrial anastomosis was used. RESULTS: The most common IVCD was right bundle branch block (RBBB). Its presence at day 1 correlated with transpulmonary gradient before OHT. Its presence after 1 year and its development correlated with a 1-month acute rejection score≥2 (p = .050 and p = .006). The incidence of RBBB was higher in the biatrial control population (40.7% vs 23.8%, p < .001). CONCLUSIONS: RBBB is the most common IVCD. Its presence can be explained by a susceptibility of the right branch to heart positioning, pressure overload, and acute rejection. IVCDs do not affect prognosis.

Atrial fibrillation after orthotopic heart transplantatation: Pathophysiology and clinical impact.

BACKGROUND: Atrial fibrillation (AF) is a well-established post-cardiac surgery complication. Orthotopic heart transplantation (OHT) represents a peculiar condition where surgical thoracic veins isolation and autonomic denervation occur. This study aims at investigating AF incidence in OHT in order to define its risk factors and to evaluate its prognostic impact. METHODS: 278 patients affected by OHT were recruited in our Cardiac Surgery Unit and retrospectively analyzed, using clinical, surgical and instrumental data. RESULTS: The patients cohort showed 45 post-operative (16.5%) and 20 late AF cases (7.2%). Only paroxysmal AF episodes were observed. Elderly donors and acute rejection resulted as risk factors in patients with post-operative AF episodes, who presented higher all-cause mortality at 11 years post-OHT (p < 0.001, Kaplan Meier analysis). The majority of late AF episodes occurred during hospitalization, due to renal failure or infections and more frequently in male patients; no significant correlation was observed with acute or chronic rejection or other characteristics. CONCLUSION: Pulmonary vein isolation and vagal denervation lead to low AF incidence in OHT recipients. Acute rejection and graft status are the main risk factors for post-operative AF episodes, while other systemic conditions act as late AF triggers. The occurrence of AF episodes is associated with poor outcome and AF should be considered as a marker of clinical frailty.