Atrial fibrillation in ventricular-paced rhythm: under-recognised, underdiagnosed and potentially dangerous.

Background: There is only scant published evidence demonstrating the importance of diagnosing atrial fibrillation (AF) in patients with a ventricularly paced rhythm. This potential pitfall to recognise AF has the implication of devastating outcomes.

Method: A short survey was undertaken in order to gauge the ability of doctors of all grades to recognise AF, and adequate anticoagulation, in the patient with chronic right ventricular pacing (RVp), based on ECG interpretation.

A support vector machine for predicting defibrillation outcomes from waveform metrics.

Background: Algorithms to predict shock success based on VF waveform metrics could significantly enhance resuscitation by optimising the timing of defibrillation.

Objective: To investigate robust methods of predicting defibrillation success in VF cardiac arrest patients, by using a support vector machine (SVM) optimisation approach.

Methods: Frequency-domain (AMSA, dominant frequency and median frequency) and time-domain (slope and RMS amplitude) VF waveform metrics were calculated in a 4.

Detection of cardiac arrest using a simplified frequency analysis of the impedance cardiogram recorded from defibrillator pads.

An algorithm based only on the impedance cardiogram (ICG) recorded through two defibrillation pads, using the strongest frequency component and amplitude, incorporated into a defibrillator could determine circulatory arrest and reduce delays in starting cardiopulmonary resuscitation (CPR). Frequency analysis of the ICG signal is carried out by integer filters on a sample by sample basis. They are simpler, lighter and more versatile when compared to the FFT.

Assessment of the impedance cardiogram recorded by an automated external defibrillator during clinical cardiac arrest.

Objective: To assess the impedance cardiogram recorded by an automated external defibrillator during cardiac arrest to facilitate emergency care by lay persons. Lay persons are poor at emergency pulse checks (sensitivity 84%, specificity 36%); guidelines recommend they should not be performed. The impedance cardiogram (dZ/dt) is used to indicate stroke volume.

The impedance cardiogram recorded through two electrocardiogram/defibrillator pads as a determinant of cardiac arrest during experimental studies.

Objective: Laypersons are poor at emergency pulse checks (sensitivity 84%, specificity 36%). Guidelines indicate that pulse checks should not be performed. The impedance cardiogram (dZ/dt) is used to assess stroke volume.