Division of Cardiovascular Medicine (D.M.A., K.C.S., G.S.D., M.Y., M.N., F.M., F.B.), University of Michigan, Ann Arbor.
Department of Radiology (S.P.), University of Michigan, Ann Arbor.
Circ Arrhythm Electrophysiol. 2019 May;12(5):e007023. doi: 10.1161/CIRCEP.118.007023.
Postinfarction ventricular tachycardia (VT) generally involves myocardial fibers surrounded by scar. Calcification of scar tissue has been described, but the relationship between calcifications within endocardial scar and VTs is unclear. The purpose of this study was to assess the prevalence of myocardial calcifications as detected by cardiac computed tomography (CT) and the benefit for mapping and ablation focusing on nontolerated VTs.
Fifty-six consecutive postinfarction patients had a cardiac CT performed before a VT ablation procedure. Another 56 consecutive patients with prior infarction without VT who had cardiac CTs served as a control group.
Myocardial calcifications were identified in 39 of 56 patients (70%) in the postinfarction group with VT, compared with 6 of 56 patients (11%) in the control group without VT. Calcifications were associated with VT when compared with a control group. A calcification volume of 0.538 cm distinguished patients with calcification-associated VT from patients without calcification-associated VTs (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.88). Myocardial calcifications corresponded to areas of electrical nonexcitability and formed a border for reentry circuits for 49 VTs (33% of all VTs for which target sites were identified) in 24 of 39 patients (62%) with myocardial calcifications. A nonconfluent calcification pattern was associated with VT target sites independent of calcification volume ( P=0.01).
Myocardial calcifications detected by cardiac CT in patients with prior infarction are associated with VT. The calcifications correspond to areas of unexcitability and represent a fixed boundary of reentry circuits that can be visualized by CT. Calcifications correspond to effective ablation sites in >1/3 of patients with postinfarction VT.
心肌梗死后室性心动过速（VT）通常涉及受瘢痕组织环绕的心肌纤维。已有瘢痕组织钙化的描述，但心内膜瘢痕内钙化与 VT 之间的关系尚不清楚。本研究旨在评估心脏计算机断层扫描（CT）检测到的心肌钙化的发生率，并评估其在针对无法耐受的 VT 的标测和消融中的益处。
56 例心肌梗死后 VT 患者在 VT 消融术前进行心脏 CT 检查。另外 56 例有心肌梗死但无 VT 的连续患者作为无 VT 的对照组，他们也进行了心脏 CT 检查。
在有 VT 的心肌梗死后组的 56 例患者中，有 39 例（70%）发现心肌钙化，而在无 VT 的对照组的 56 例患者中，有 6 例（11%）发现心肌钙化。与对照组相比，钙化与 VT 相关。钙化体积为 0.538cm 可区分伴有钙化相关 VT 的患者和不伴有钙化相关 VT 的患者（曲线下面积，0.87；敏感性，0.87；特异性，0.88）。心肌钙化与 39 例患者中的 24 例（62%）中的 49 个 VT（所有确定靶点的 VT 的 33%）的电无兴奋性区域相对应，并形成折返环的边界。在存在心肌钙化的患者中，非连续钙化模式与 VT 靶点独立相关，与钙化体积无关（P=0.01）。
在有心肌梗死病史的患者中，心脏 CT 检测到的心肌钙化与 VT 相关。钙化与无兴奋性区域相对应，并代表折返环的固定边界，可通过 CT 可视化。在 >1/3 的心肌梗死后 VT 患者中，钙化与有效的消融部位相对应。
