The use of echocardiographic colour kinetic wall motion to differentiate broad complex tachycardia

Discrimination between supraventricular tachycardia (SVT) with aberrant conduction from ventricular tachycardia (VT) is vital for the safe and effective management of both conditions. Electrocardiographic algorithms for the differentiation of broad complex tachycardia are complex and difficult to implement in the acute setting, with misdiagnosis occurring in up to 40% of acute presentations. This case study shows the potential for echocardiographic colour kinesis (eck) to support electrocardiographic differentiation. A 74-year old man in sinus rhythm with left bundle branch block (lbbb), a history of myocardial infarction and recurrent sustained VT underwent eck analysis of wall motion propagation during a programmed electrical ventricular stimulation study. Sequential 40 ms time frames of echocardiographic colour coded endocardial wall motion velocity were recorded on video during both induced VT of lbbb configuration and near isochronic atrially paced tachycardia in lbbb. During VT there was initial eck propagation of ventricular septal wall motion from the apex to the atria secondary to electrical depolarisation. During atrially paced tachycardia initial eck motion developed in the interatrial septum and atrial wall followed by propagation in the ventricular endocardial septal wall motion from the atria toward the ventricular apex. This eck technique potentially could be used to support the electrocardiographic diagnosis of a broad complex tachycardia.