Impaired myocardial perfusion and perfusion reserve associated with increased coronary resistance in persistent idiopathic atrial fibrillation

Abstract

In AF, MBF at baseline, at hyperaemia, and at CPT is reduced, whereas CVR under hyperaemic conditions is increased. Following electrical cardioversion, these findings are partly reversible and therefore most likely secondary to the arrhythmia.

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation

“…Our study supports previous findings of impaired stress MBF in male patients with persistent AF determined using positron emission tomography6 and extends the investigation to female patients and those with paroxysmal AF who were in SR at the time of imaging. Stress MBF was lower in all AF patients, irrespective of the rhythm during the preablation CMR.…”

“…Stress MBF was lower in all AF patients, irrespective of the rhythm during the preablation CMR. This difference also persisted after ablation, even in the subgroup of patients with no evidence of recurrent AF on prolonged ambulatory monitoring, suggesting that the previously reported improvement in this parameter in a very small number of patients following cardioversion6 may have been due to the play of chance. These novel findings imply that the reduction in stress MBF in patients with paroxysmal or persistent AF is not a direct effect of the arrhythmia itself but may reflect an underlying coronary endothelial dysfunction 11…”

“…Baseline MBF is closely related to baseline RPP15; thus, baseline MBF was corrected for baseline RPP using the formula baseline MBF corrected =baseline MBF/(baseline RPP/10 000), to account for differences in cardiac work, as previously described 6. In accordance with previous studies, adenosine‐stress–induced MBF was not corrected because this parameter is grossly independent of RPP 16.…”

“…Power calculations were based on prior data reporting a baseline MBF of 0.95±0.19 mL/(min·mL) in AF patients and 1.14±0.22 mL/(min·mL) in matched controls, and a MBF during adenosine stress of 2.07±0.80 mL/(min·mL) in AF patients and 3.33±0.78 mL/(min·mL) in matched controls 6. We calculated that inclusion of at least 48 patients and 24 controls (2:1 allocation ratio) would give >90% power to detect a difference of ≥15% in baseline MBF and ≥20% in stress MBF, respectively, between patients and controls (2‐sided α=0.05).…”

“…Clinicians are also familiar with patients with AF presenting with chest pain and evidence of cardiac ischemia or necrosis, such as “rate‐related” ST depression or troponin release, in the absence of significant epicardial coronary artery disease 4, 5. Despite these intriguing observations, few studies have systematically investigated myocardial perfusion in patients with AF 6, 7…”