ERC Young Investigator Competition

In occasione del Simposio ERC Resuscitation 2011 Implementation, tenutosi a Malta lo scorso 14 e 15 Ottobre, il Dr Giuseppe Ristagno è stato insignito del terzo premio nell'ambito di Young Investigator Competition per l'abstract dal titolo "Signifcant decreases in amplitude spectrum area during pre-defbrillation pauses in chest compression in out-of-hospital cardiac arrest patients". Nel complimentarci con il Dr Ristagno per il premio vinto, di seguito riportiamo il testo integrale del suo lavoro.

Dr Giuseppe Ristagno

SIGNIFICANT DECREASES IN AMPLITUDE SPECTRUM AREA DURING PRE-DEFIBRILLATION PAUSES IN CHEST COMPRESSIONS IN OUT-OF-HOSPITAL CARDIAC ARREST PATIENTS

Introduction. Interruptions in chest compression (CC) cause important decreases in coronary perfusion and translate into major compromises in the success of resuscitation efforts and outcomes. Amplitude spectrum area (AMSA), which is calculated by fast Fourier transformation of ventricular fibrillation (VF) waveform, has been recognized as an accurate predictor of successful defibrillation (DF), as well as valid monitor of the effectiveness of chest compression. Accordingly, AMSA is related to heart perfusion and viability during CPR. We therefore hypothesized that pre-DF pauses, causing reduction in heart perfusion, will yield to AMSA decreases overtime.

Methods. ECG data were obtained from patients through an internal registry of ZOLL AED Pro and AED Plus defibrillators from multiple areas in the US. The sampling rate of the ECG data files was 250 Hz. AMSA was calculated every 256 points, representing respectively 1.05 sec ECG windows, throughout a 16 sec pre-DF pause observed before each DF attempt, due to rhythm analyses and defibrillator charge. Changes in AMSA values during the pause were compared at the beginning of CC interruption, and 8 and 16 secs later. Further analyses were performed based on the first and subsequent DF attempts and based on CC depth.

Results. A total of 1261 DF attempts from 579 cardiac arrest patients were included in the analyses. AMSA decreased during the 16 sec pre-DF pauses from 8.7 to 6.2 and 5.5 mV Hz, after 8 and 16 secs respectively (p<0.0001). Considering only the first DF attempt (n=579), AMSA decreased more importantly during pauses, from 12.2 to 7 and 5.8 mV Hz, after 8 and 16 secs respectively (p<0.0001). At the beginning of the pause, AMSA was significantly higher for a CC depth > 1.5 compared to that assessed when CC depth was < 1.5 in (13.7 vs 10.2 mV Hz, p<0.03). Nevertheless, AMSA significantly decreased during the pauses, independently from the CC depth: 7.7 and 5.7 mV Hz, after 8 and 16 secs respectively (p<0.0001), for a depth > 1.5 in; and to 6.2 and 6.1 at 8 and 16 secs respectively (p<0.0001), for a depth < 1.5 in. Decreases were more important when CC depth was greater.

Conclusions. Pre-DF pauses caused significant decreases in AMSA over the 16 sec interval. These decreases in AMSA might be directly related to the reduced myocardial perfusion and ultimately anticipate decreases in DF success.