Background Patients with heart failure who receive an implantable cardioverter–defibrillator (ICD) for primary prevention (i.e., prevention of a first life-threatening arrhythmic event) may later receive therapeutic shocks from the ICD. Information about longterm prognosis after ICD therapy in such patients is limited. Methods Of 829 patients with heart failure who were randomly assigned to ICD therapy, we implanted the ICD in 811. ICD shocks that followed the onset of ventricular tachycardia or ventricular fibrillation were considered to be appropriate. All other ICD shocks were considered to be inappropriate. Results Over a median follow-up period of 45.5 months, 269 patients (33.2%) received at least one ICD shock, with 128 patients receiving only appropriate shocks, 87 receiving only inappropriate shocks, and 54 receiving both types of shock. In a Cox proportional-hazards model adjusted for baseline prognostic factors, an appropriate ICD shock, as compared with no appropriate shock, was associated with a significant increase in the subsequent risk of death from all causes (hazard ratio, 5.68; 95% confidence interval [CI], 3.97 to 8.12; P<0.001). An inappropriate ICD shock, as compared with no inappropriate shock, was also associated with a significant increase in the risk of death (hazard ratio, 1.98; 95% CI, 1.29 to 3.05; P = 0.002). For patients who survived longer than 24 hours after an appropriate ICD shock, the risk of death remained elevated (hazard ratio, 2.99; 95% CI, 2.04 to 4.37; P<0.001). The most common cause of death among patients who received any ICD shock was progressive heart failure. Conclusions Among patients with heart failure in whom an ICD is implanted for primary prevention, those who receive shocks for any arrhythmia have a substantially higher risk of death than similar patients who do not receive such shocks.

https://www.nejm.org/doi/pdf/10.1056/NEJMoa071098

Prognostic importance of defibrillator shocks in patients with heart failure.

https://anestesiar.org/WP/uploads/2011/01/7-neonatos-ERC-2010.pdf

European Resuscitation Council Guidelines for Resuscitation 2010 Section 1. Executive summary.

https://nrr.org/wp-content/uploads/0000/10/07_ERC_Guidelines_2005_Section7.pdf

European Resuscitation Council guidelines for resuscitation 2005. Section 7. Cardiac arrest in special circumstances.

/pdf/european-resuscitation-council-erc-guidelines-for-1vuo3ljag0.pdf

European Resuscitation Council (ERC) Guidelines for Resuscitation 2005

Background— Current versions of automated external defibrillators (AEDs) require frequent stopping of chest compression for rhythm analyses and capacity charging. The present study was undertaken to evaluate the effects of these interruptions during the operation of AEDs. Methods and Results— Ventricular fibrillation was electrically induced in 20 male domestic swine weighing between 37.5 and 43 kg that were untreated for 7 minutes before CPR was started. Defibrillation was attempted with up to 3 sequential 150-J biphasic shocks, but each was preceded by 3-, 10-, 15-, or 20-second interruptions of chest compression. The interruptions corresponded to those that were mandated by commercially marketed AEDs for rhythm analyses and capacitor charge. The sequence of up to 3 electrical shocks and delays were repeated at 1-minute intervals until the animals were successfully resuscitated or for a total of 15 minutes. Spontaneous circulation was restored in each of 5 animals in which precordial compression was del...

Adverse outcomes of interrupted precordial compression during automated defibrillation

The effects of biphasic and conventional monophasic defibrillation on postresuscitation myocardial function

We investigated the effects of hyper- and hypoventilation on gastric ( Pg CO 2 ) and sublingual (P sl CO 2 ) tissue P CO 2 before, during, and after reversal of hemorrhagic shock. Pg CO 2 was measu...

https://www.physiology.org/doi/pdf/10.1152/jappl.1999.87.3.933

Effects of hyper- and hypoventilation on gastric and sublingual P CO 2

Defibrillation with low-energy biphasic waveform reduces the severity of post-resuscitation myocardial dysfunction after prolonged cardiac arrest

Cardiogenic shock remains a leading cause of early cardiac death. The mortality rate of cardiogenic shock as a complication of acute myocardial infarction (AMI) exceeds 80%. Large multicenter studies disclose an incidence of 5 to 15% of all instances of AMI admitted to the hospital [1, 2, 3, 4, 5]. Cardiogenic shock is in evidence at the time of hospital admission in only minority of patients. Approximately 90% of patients develop shock during the in hospital stay [5].

Andreja Marn Pernat

Papers

The effects of biphasic and conventional monophasic defibrillation on postresuscitation myocardial function

Effects of hyper- and hypoventilation on gastric and sublingual P CO 2

Defibrillation with low-energy biphasic waveform reduces the severity of post-resuscitation myocardial dysfunction after prolonged cardiac arrest

Management of Shock Complicating Acute Myocardial Infarction