Monitoring Spike Potential and Abrupt Impedance Rise with Concomitant Temperature/Contact Force Change for Timely Detection of the Occurrence of “Silent” or “Nonaudible” Steam Pop

Figure 5

(a) In the prospective RFCA procedures, simultaneously recorded spike potential and abrupt rise in impedance with concomitant temperature and CF drop could timely detect the occurrence of “silent” SP. The time from the initiation of RFCA to the occurrence of “nonaudible” SP was 17.4 s. The sudden impedance rise after 17.4 s of RFCA coincided with a SP. After the “nonaudible” SP, an abrupt impedance rise of 10.7 Ω, temperature drop of 2.4°C, and CF drop of 18.1 g were recorded. The RFCA was terminated approximately 3.5 s later. (b) A spike potential with a consequent PAC was recorded immediately during the occurrence of SP. (c) The location of the SP is at the posterior-superior wall of the RSPV. This patient subsequently developed pericardial tamponade and underwent drainage. The patient received a dual-chamber pacemaker for sick sinus syndrome 2 years ago. AP: atrial pacing.

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