Balldin U I, Tong A, Marshall J A, Regna M
Flight Stress Protection Division, Air Force Research Laboratory, Brooks AFB, TX 78253-5104, USA.
Aviat Space Environ Med. 1999 Mar;70(3 Pt 1):209-12.
High +Gz is known to provoke cardiac dysrhythmias. Pressure breathing during G (PBG) and extended coverage anti-G suits (ECGS) are used to enhance +Gz-endurance and reduce fatigue during high +Gz flying. It is not known whether PBG in combination with ECGS increases the risk for premature ventricular contractions (PVC).
PBG in combination with ECGS increases the risk of PVCs during high +Gz-loads.
Retrospective data were obtained from 14 subjects exposed to three different simulated aerial combat sorties each, in the centrifuge with a standard anti-G suit ensemble or with PBG in combination with ECGS. Each sortie consisted of a gradual onset G-exposure (GOR) and three simulated aerial combat maneuvers (SACM) containing four cycles of a +4.5 to +7 GzSACM; four cycles of +4 to +9 Gz tactical aerial combat maneuver (TACM) with several rapid transitions from +4 or +5 Gz to +8 or +9 Gz; and four cycles of +5 to +9 Gz SACM (5-9 SACM) with four cycles. ECG was recorded during the +Gz exposures to reveal any cardiac dysrhythmias.
No PVCs occurred during the GORs. During 4.5-7 SACMs, TACMs, and 5-9 SACMs there were 83, 50, and 24 PVCs with standard equipment, respectively, and 63, 54, and 39 PVCs with PBG and ECGS, respectively. There was no statistically significant difference between the equipment in any of the different types of +Gz exposures. No episodes of supraventricular tachycardia or relative bradycardia were found with either equipment.
已知高 +Gz 会引发心律失常。G 力作用下的加压呼吸（PBG）和扩展覆盖抗荷服（ECGS）用于提高高 +Gz 飞行期间的耐力并减轻疲劳。尚不清楚 PBG 与 ECGS 联合使用是否会增加室性早搏（PVC）的风险。
PBG 与 ECGS 联合使用会增加高 +Gz 负荷期间发生 PVC 的风险。
回顾性数据来自 14 名受试者，他们每人在离心机中分别穿着标准抗荷服套装或 PBG 与 ECGS 联合使用的装备，进行三种不同的模拟空战任务。每个任务包括逐渐增加 G 力暴露（GOR）以及三个模拟空战机动动作（SACM），其中包含四个 +4.5 至 +7 Gz 的 SACM 周期；四个 +4 至 +9 Gz 的战术空战机动动作（TACM）周期，包括从 +4 或 +5 Gz 到 +8 或 +9 Gz 的几次快速转换；以及四个 +5 至 +9 Gz 的 SACM（5 - 9 SACM）周期。在 +Gz 暴露期间记录心电图以发现任何心律失常。
在 GOR 期间未发生 PVC。在 4.5 - 7 SACM、TACM 和 5 - 9 SACM 期间，使用标准装备时分别有 83 次、50 次和 24 次 PVC，使用 PBG 和 ECGS 时分别有 63 次、54 次和 39 次 PVC。在任何不同类型的 +Gz 暴露中，两种装备之间均无统计学显著差异。两种装备均未发现室上性心动过速或相对性心动过缓发作。
