■綜説
左室拡張機能と心房細動
丸山 光紀
日本医科大学武蔵小杉病院循環器内科
The Role of Left Ventricular Diastolic Function in Development and Progression of Atrial Fibrillation
Mitsunori Maruyama
Department of Cardiovascular Medicine, Nippon Medical School Musashi Kosugi Hospital, Kanagawa, Japan
Atrial fibrillation (AF) is the most common cardiac arrhythmia that is associated with increased morbidity and mortality. AF and heart failure (HF) frequently coexist and confer an adverse prognosis. It is known that incident AF is strongly associated with HF with preserved ejection fraction, indicating that left ventricular (LV) diastolic function plays an important role in the genesis of AF. Two types of LV diastolic dysfunction (i.e., abnormal relaxation during early-diastole, and increased stiffness during mid- to late-diastole) differently affect LV diastolic pressure and might result in different clinical outcomes. Previous studies showed that abnormal relaxation and left atrial (LA) volume were associated with incident AF. We measured diastolic wall strain (DWS), a noninvasive direct measure of LV stiffness by M-mode echocardiography, and studied the role of LV stiffness in the genesis of paroxysmal AF. We found that a low DWS (<0.38) (i.e., increased LV stiffness) was the strongest indicator of AF (odds ratio: 6.22 in a multivariate model). Furthermore, we studied the role of LV stiffness in the progression of paroxysmal AF to persistent AF by measuring DWS, since AF progression is related to worse morbidity and mortality, and poorer outcomes of radiofrequency catheter ablation (RFCA). During a mean follow-up of 35 months, AF progression occurred in 60 of 172 (35%) patients treated with medications only (medication group), and 3 of 134 (2%) who underwent RFCA (RFCA group). In the medication group, patients with a low DWS (<0.38) had a higher incidence of AF progression than those without, while the AF progression rate was low irrespective of the DWS in the RFCA group. In a multivariate analysis, the DWS and LA volume index were independent predictors of AF progression in the medication group (hazard ratio, 1.13 per 0.01 decrease for DWS; 1.04 per 1 mL/m2 increase for LA volume index). The DWS would be useful to stratify patients at risk of AF progression who could benefit from an earlier RFCA intervention.
日医大医会誌 2021; 17(1), 8-14
Key words
atrial fibrillation, left ventricular diastolic function, diastolic wall strain, catheter ablation
Correspondence to
Mitsunori Maruyama, Department of Cardiovascular Medicine, Nippon Medical School Musashi Kosugi Hospital, 1-396 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-8533, Japan
E-mail：maru@nms.ac.jp
受付：2020年12月31日 受理：2021年1月27日 |
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