Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan. Electronic address: https://twitter.com/Muratahiroshige.
Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
JACC Clin Electrophysiol. 2024 Jan;10(1):43-55. doi: 10.1016/j.jacep.2023.08.033. Epub 2023 Oct 18.
Ventricular tachycardia (VT) associated with primary cardiac tumors (PCTs) originating from the ventricles is rare, but lethal, in young patients.
This study aimed to clarify the mechanisms underlying primary cardiac tumor-related ventricular tachycardia (PCT-VT) and establish a therapeutic strategy for this form of VT.
Among 67 patients who underwent surgery for VT at our institute between 1981 and 2020, 4 patients aged 1 to 34 years, including 3 males, showed PCT-VT (fibroma, 2; lipoma, 1; and hamartoma, 1), which was investigated using a combination of intraoperative electroanatomical mapping and histopathological studies.
All 4 patients developed electrical storms of sustained VTs refractory to multiple drugs and repetitive endocardial ablations. The VT mechanism was re-entry, and intraoperative electroanatomical mapping showed a centrifugal activation pattern originating from the border between the tumor and healthy myocardium, where fractionated potentials were detected during sinus rhythm. Histopathological studies of serial sections of specimens acquired from these areas revealed tumor infiltration into the surrounding myocardium with cell disorganization, exhibiting myocardial disarray. Several myocardia entrapped in the tumor edges contributed to the development and sustainment of re-entrant VT activation. In the 2 patients in whom complete resection was unfeasible, encircling cryoablation to entirely isolate the unresectable tumor was effective in suppressing VT occurrence.
The mechanism underlying PCT-VT involves re-entry localized at the tumor edges. Myocardial disarray associated with tumor infiltration is a substrate for this form of VT. Cryoablation along the border between the tumor and myocardium is a promising therapeutic option for unresectable PCT-VT.
原发性心脏肿瘤（PCT）起源于心室的室性心动过速（VT）在年轻患者中较为罕见，但却有致命风险。
本研究旨在阐明原发性心脏肿瘤相关室性心动过速（PCT-VT）的发病机制，并为这种形式的 VT 建立治疗策略。
在我院 1981 年至 2020 年间因 VT 接受手术的 67 例患者中，有 4 例年龄在 1 至 34 岁的患者（男性 3 例）表现为 PCT-VT（纤维瘤 2 例、脂肪瘤 1 例、错构瘤 1 例），通过术中电解剖图和组织病理学研究相结合的方法进行研究。
所有 4 例患者均发生了持续性 VT 的电风暴，对多种药物和重复心内膜消融均无反应。VT 机制为折返，术中电解剖图显示起源于肿瘤和健康心肌交界处的离心激活模式，在窦性节律时检测到碎裂电位。来自这些区域的连续切片标本的组织病理学研究显示，肿瘤浸润到周围心肌，细胞排列紊乱，表现为心肌排列紊乱。几个被肿瘤边缘困住的心肌有助于折返性 VT 激活的发生和维持。在 2 例无法完全切除肿瘤的患者中，完全隔离无法切除肿瘤的环绕冷冻消融术有效抑制了 VT 的发生。
PCT-VT 的发病机制涉及局部折返，肿瘤浸润相关的心肌排列紊乱是这种 VT 的一种基质。沿肿瘤和心肌交界进行冷冻消融是一种有前途的治疗无法切除的 PCT-VT 的方法。
