Atrial arrhythmias and heart failure: A “modern view” of an old paradox

Background Heart failure (HF) and atrial arrhythmias (AAs) are two clinical conditions that characterize the daily clinical practice of cardiologists. In this perspective review, we analyze the shared etiopathogenetic pathways of atrial arrhythmias, which are the most common cause of atrial arrhythmias‐induced cardiomyopathy (AACM) and HF. Hypothesis The aim is to explore the pathophysiology of these two conditions considering them as a “unicum”, allowing the definition of a cardiovascular continuum where it is possible to predict the factors and to identify the patient phenotype most at risk to develop HF due to atrial arrhythmias. Methods Potentially eligible articles, identified from the Electronic database (PubMed), and related references were used for a literature search that was conducted between January 2022 and January 2023. Search strategies were designed to identify articles that reported atrial arrhythmias in association with heart failure and vice versa. For the search we used the following keywords: atrial arrhythmias, atrial fibrillation, heart failure, arrhythmia‐induced cardiomyopathy, tachycardiomyopathy. We identified 620 articles through the electronic database search. Out of the 620 total articles we removed 320 duplicates, thus selecting 300 eligible articles. About 150 titles/s were excluded for the following reasons: no original available data, no mention of atrial arrhythmias and heart failure crosstalk, very low quality analysis or evidence. We excluded also non‐English articles. When multiple articles were published on the same topic, the articles with the most complete set of data were considered. We preferentially included all papers that could provide the best evidence in the field. As a result, the present review article is based on a final number of 104 references. Results While the pathophysiology of AACM and Heart Failure with reduced ejection fraction (HFrEF) has been studied in detail over the years, the causal link between atrial arrhythmias and heart failure with Preserved Ejection Fraction (HFpEF) has been often subject of interest. HFpEF is strictly related to AAs, which has always been considered significant risk factor. In this review we described the pathophysiological links between atrial fibrillation and heart failure. Furthermore, we illustrated and discussed the preclinical and clinical predicting factors of AF and HFpEF, and the corresponding targets of the available therapeutic agents. Finally, we outlined th