Fractional flow reserve (FFR) is considered the standard for assessment of the physiological significance of coronary artery stenosis. Intracoronary papaverine (PAP) is the most potent vasodilator used for the achievement of maximal hyperemia. However, its use can provoke ventricular tachycardia (VT) due to excessive QT prolongation. We evaluated the clinical efficacy and safety of the administration of PAP after nicorandil (NIC), a potassium channel opener that prevents VT, for optimal FFR measurement.

A total of 127 patients with 178 stenoses were enrolled. The FFR values were measured using NIC (NIC-FFR) and PAP (PAP-FFR). We administered PAP following NIC (NIC-PAP). Changes in the FFR and electrogram parameters (baseline versus NIC versus PAP) were assessed and the incidence of arrhythmias after PAP was evaluated. In addition, we analyzed another 41 patients with 51 stenoses by assessing the FFR using PAP before NIC (PAP-NIC). After propensity score matching, the electrogram parameters between 2 groups were compared.

The mean PAP-FFR was significantly lower than the mean NIC-FFR (0.82 ± 0.11 versus 0.81 ± 0.11, P < 0.05). The mean baseline-QTc, NIC-QTc, and PAP-QTc values were 425 ± 37 ms^1/2, 424 ± 41 ms^1/2, and 483 ± 54 ms^1/2, respectively. VT occurred in only 1 patient (0.6%). Although PAP induced QTc prolongation (P < 0.05), the PAP-QTc duration was significantly shorter in NIC-PAP compared to PAP-NIC (P < 0.05).

The administration of PAP with NIC may induce sufficient hyperemia and prevent fatal arrhythmia through reductions in the PAP-induced QTc prolongation during FFR measurement.

血流储备分数 (FFR) 被认为是评估冠状动脉狭窄生理意义的标准。冠脉内罂粟碱 (PAP) 是用于实现最大充血的最有效的血管扩张剂。然而，由于过度的 QT 延长，它的使用会引起室性心动过速 (VT)。我们评估了在尼可地尔 (NIC)（一种防止 VT 的钾通道开放剂）后施用 PAP 的临床疗效和安全性，以实现最佳 FFR 测量。

共招募了 127 名有 178 处狭窄的患者。FFR 值使用 NIC (NIC-FFR) 和 PAP (PAP-FFR) 测量。我们在 NIC (NIC-PAP) 之后实施了 PAP。评估 FFR 和电图参数（基线、NIC 与 PAP）的变化，并评估 PAP 后心律失常的发生率。此外，我们通过在 NIC 之前使用 PAP (PAP-NIC) 评估 FFR，分析了另外 41 名有 51 处狭窄的患者。倾向评分匹配后，比较两组间的电图参数。

平均 PAP-FFR 显着低于平均 NIC-FFR (0.82 ± 0.11 vs 0.81 ± 0.11, P < 0.05)。平均基线 QTc、NIC-QTc 和 PAP-QTc 值分别为 425 ± 37 ms ^1/2、424 ± 41 ms ^1/2和 483 ± 54 ms ^1/2。VT 仅发生在 1 名患者（0.6%）中。尽管 PAP 诱导 QTc 延长（P < 0.05），但与 PAP-NIC 相比，NIC-PAP 的 PAP-QTc 持续时间显着缩短（P < 0.05）。

通过在 FFR 测量期间减少 PAP 诱导的 QTc 延长，PAP 与 NIC 的管理可能会引起足够的充血并预防致命的心律失常。