Integrated Cardiopulmonary Profile as an Additive Signal in Patients Evaluated for Suspected Newly Detected Atrial Fibrillation.

backgroundAtrial fibrillation (AF) is associated with atrial remodelling, hemodynamic stress, and complex cardiopulmonary interactions. While natriuretic peptides and echocardiographic abnormalities are established markers of AF-related substrate, the contribution of spirometry changes, as a landmark of pulmonary impairment, remains less clearly defined. This study evaluated whether AF is associated with an integrated cardiopulmonary profile characterized by altered spirometry, increased NT-proBNP, and conventional echocardiographic markers of left atrial structure and function.

methodsWe performed a retrospective, single-center observational study based on an existing clinical database of adult patients referred for 24 h 12-lead Holter ECG monitoring because of palpitations and/or chest pain. None of the included patients had a previously documented diagnosis of atrial fibrillation before Holter monitoring. Because a single 24 h Holter recording cannot establish spontaneous termination or long-term temporal pattern with certainty, AF documented for the first time during this recording is referred to throughout as "newly detected AF" rather than "paroxysmal AF". During Holter monitoring, no ECG changes suggestive of myocardial ischemia were detected. From 536 records of patients without previously known AF who underwent 24 h 12-lead Holter ECG monitoring for palpitations and/or chest pain, 164 patients were retained for the main comparison, including 48 with newly detected paroxysmal AF and 116 without AF. Demographic, biochemical, spirometric, and echocardiographic variables were analyzed. The main respiratory parameters were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and peak expiratory flow (PEF). NT-proBNP was the primary biomarker, while conventional left atrial structural and functional variables were used for echocardiographic assessment.

resultsNT-proBNP was markedly higher in the AF group (684.5 vs. 62.3 pg/mL,

conclusionsIn this cohort, AF was most strongly associated with NT-proBNP, while the respiratory signal was weaker but directionally consistent with a broader cardiopulmonary phenotype. These findings do not support spirometry or NT-proBNP as stand-alone diagnostic tools for AF. However, when interpreted alongside traditional AF risk factors and symptoms, elevated NT-proBNP with concordant spirometric impairment may represent a hypothesis-generating additive signal supporting longer or repeated rhythm monitoring beyond 24 h in selected patients with suspected AF; this additive value was not formally tested against clinical models alone and requires prospective confirmation.