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

Table 3

RFCA parameters prior to and after the occurrence of audible steam pop during pulmonary vein isolation (power: 35–40 W).

	Audible steam pop group (N = 15)
Real-time temperature prior to audible steam pop (°C)	37.1 ± 1.7
Abrupt temperature change after audible steam pop
Temperature rise (°C, n)	2.3 ± 1.0, 8
Temperature drop (°C, n)	2.3 ± 1.3, 5
Temperature without discernible change (n)	2
Real-time impedance prior to audible steam pop (Ω)	110.9 ± 9.7
Abrupt impedance change after audible steam pop
Impedance rise (Ω, n)	11.8 ± 9.2, 14
Impedance drop (Ω, n)	0, 0
Impedance without discernible change (n)	1
Real-time CF prior to audible steam pop (g)	13.6 ± 4.2
Abrupt CF change after audible steam pop
CF rise (g, n)	6.7 ± 1.0, 3
CF drop (g, n)	8.4 ± 5.5, 9
CF without discernible change (n)	3
Spike potential recorded during audible steam pop (%)	10 (66.7%)
Pericardial tamponade occurred after audible steam pop (%)	2 (13.3%)

Values are given as mean ± SD. Spike potential was defined as a high-frequency and amplitude potential recorded during the audible steam pop. Nonnormally distributed data. Data in the parentheses indicate RF parameters, percentage, and case numbers. RF = radiofrequency; CF = contact force.