Department of Advanced Biomedical Sciences, Federico II University of Naples, Naples, Italy.
Division of Cardiology, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
Echocardiography. 2024 Oct;41(10):e70003. doi: 10.1111/echo.70003.
Cardiac resynchronization therapy (CRT) is a standard treatment for patients with heart failure and electrical dyssynchrony. Cardiac magnetic resonance (CMR) is the gold standard for assessing left ventricular (LV) function. However, the feasibility of using CMR with active CRT is still uncertain.
To assess the feasibility of a CRT "off-on" protocol during CMR and measure the acute effects of CRT interruption on LV function.
Patients underwent CMR before (pre-CRT) and 6 months after (post-CRT) an MR-conditional CRT defibrillator implantation. The post-CRT scan included two complete sets of cine images, one with inactive (post-CRT) and one with active CRT (post-CRT), maintaining a continuous connection between device and programmer.
Out of 29 enrolled patients, 8 (28%) had complete and analyzable post-CRT data. Unsuccessful procedures were attributed to connection problems between the CRT device and the programmer (n = 10), poor image quality (n = 7), and lack of patient cooperation (n = 4). LV ejection fraction significantly increased between pre-CRT scan (28.1%) and both post-CRT (37.9%; p = 0.046) and post-CRT CMR (35.0%; p = 0.037), with a nonstatistically significant trend toward decreased LV volumes. No adverse events or significant changes in device electrical parameters (including battery level) were detected during the post-CMR scan period.
A CRT "off-on" protocol during CMR studies can be safely executed in patients with an MR-conditional CRT defibrillator. However, technical improvements are needed to facilitate high-quality scans during active CRT. Favorable changes in LV function induced by CRT remodeling were not acutely reversed with the interruption of electrical therapy.
心脏再同步治疗（CRT）是心力衰竭和电不同步患者的标准治疗方法。心脏磁共振（CMR）是评估左心室（LV）功能的金标准。然而，使用带主动 CRT 的 CMR 的可行性仍不确定。
评估在 CMR 期间进行 CRT“开-关”方案的可行性，并测量 CRT 中断对 LV 功能的急性影响。
患者在 MR 条件下 CRT 除颤器植入前（CRT 前）和植入后 6 个月（CRT 后）进行 CMR。CRT 后扫描包括两组完整的电影图像，一组为无活动（CRT 后），一组为有活动 CRT（CRT 后），在设备和程控器之间保持连续连接。
在 29 名入组患者中，有 8 名（28%）患者有完整且可分析的 CRT 后数据。不成功的手术归因于 CRT 设备与程控器之间的连接问题（n=10）、图像质量差（n=7）和患者配合不佳（n=4）。LV 射血分数在 CRT 前扫描（28.1%）和 CRT 后（37.9%；p=0.046）和 CRT 后 CMR（35.0%；p=0.037）之间显著增加，LV 容积呈非统计学显著降低趋势。在 CRT 后 CMR 扫描期间未检测到设备电参数（包括电池电量）的不良事件或显著变化。
在具有 MR 条件的 CRT 除颤器的患者中，可以安全地执行 CMR 研究期间的 CRT“开-关”方案。然而，需要进行技术改进，以在主动 CRT 期间实现高质量扫描。CRT 重塑引起的 LV 功能的有利变化并未因电治疗的中断而急性逆转。
