Recommendations for pacing.
Explore the source record for details and available documents.
Cardiac Pacing, Artificial↗
Biomedical subjects
J Perrins
Publications and source records attributed to J Perrins.
Tachycardia recognition and diagnosis from changes in right atrial pressure waveform--a feasibility study.
Implantable defibrillators either monitor heart rate or use a probability density function to detect ventricular fibrillation/tachycardia. As a result, they are unable to discriminate sinus tachycardia and atrial arrhythmias from malignant ventricular rhythms. We have assessed high fidelity fiber-optic pressure recordings in the right atrium during cardiac arrhythmias in 23 patients (mean age 44 years, 11 females) undergoing electrophysiological study. The unfiltered pressure signal was amplified and recorded on paper. During sinus rhythm, a constant amplitude deflection occurred during atrial systole (a wave). A characteristic waveform pattern was observed during each of the studied tachyarrhythmias, which included atrial flutter and fibrillation, atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, and ventricular tachycardia with and without ventriculoatrial conduction. The waveform pattern allowed clear visual discrimination of the underlying arrhythmia. Mean atrial pressure was increased during all arrhythmias and did not allow discrimination of the nature of the tachycardia. High fidelity pressure recordings produced characteristic appearances for pattern recognition of each arrhythmia studied. They allowed determination of the temporal relation between electrical and mechanical cardiac events and may have potential in the detection and recognition of cardiac arrhythmias.
Adult↗
Respiratory gas exchange in the assessment of patients with impaired ventricular function.
Respiratory gas exchange on exercise was evaluated as a non-invasive method of assessing patients with heart failure. Twenty four men (age 28-72) with symptomatic chronic stable heart failure (New York Heart Association class II-III) and ten controls aged 36-70 were studied. During treadmill exercise oxygen consumption and carbon dioxide production were measured continuously by analysis of mixed expired gas with a computerised mass spectrometer. The anaerobic threshold was defined as the oxygen consumption at which carbon dioxide production increased disproportionately in relation to oxygen consumption. Oxygen consumption was stable at rest and increased on exercise, reaching a steady state within three minutes of any change in workload. The measurements of maximum oxygen consumption at the end of exercise and of anaerobic threshold were reproducible (retest reliability coefficients 90% and 91% respectively). There were significant differences in maximum oxygen consumption between functional classes. Similarly, there were significant differences in anaerobic threshold between classes, though there was considerable overlap. Measurement of oxygen consumption and anaerobic threshold provides an objective noninvasive assessment of patients with heart failure.
Adult↗