Analysis of severe dysrhythmia and conduction abnormalities using cardiac monitor

Abstract

Severe arrhythmias and conduction abnormalities are frequent in the intensive care unit. The attentive analysis of cardiac monitor recordings may allow their rapid diagnosis and consequent treatment. The occurrence of a significant bradycardia, mainly if not well-tolerated by the patient, suggests a severe conduction abnormality. The presence on the monitor of an organized atrial activity, if identifiable, suggests an atrioventricular rather than a sino-atrial block. The occurrence of a tachycardia questions the possibility of severe dysrhythmia when associated with a significant decrease in patient’s blood pressure. Ventricular fibrillation and torsadede-pointes present typical aspects. A regular tachycardia with enlarged QRS complexes suggests a ventricular tachycardia. The distinction between ventricular tachycardia and supraventricular tachycardia with bundle-branch block is often difficult based on monitor analysis without performing an electrocardiogram. Analysis of other available information on the monitor including curves of oxygen saturation and invasive blood pressure is helpful to identify possible artefacts. Supraventricular tachycardia should be considered as dangerous if resulting in circulatory failure. Diagnosis is usually easy in the presence of non-enlarged QRS complexes except if associated with a bundle-branch block.