Tachycardias. What must the emergency physician know?

Clinical characteristics and the surface electrocardiogram (ECG) are important diagnostic tools for patients with tachycardias. Tachycardias are characterized by a ventricular heart rate > 100/min and have been divided into those with narrow (QRS width < 0.12 s) or wide QRS complex tachycardias (QRS width a parts per thousand yenaEuro parts per thousand 0.12 s). In broad complex tachycardias, AV dissociation, negative or positive concordant pattern in V-1-V-6, a notch in V-1 and qR complexes in V-6 in tachycardias with left bundle-branch block morphologies are findings indicating ventricular tachycardia (VT). In addition, an R/S relation < 1 in V-6 favors VT when right bundle-branch block tachycardia morphologies are present. By analyzing the surface ECG in the right way with a systematic approach, the specificity and sensitivity of correctly identifying supraventricular tachycardia or VT can be > 95%. Therapeutic options in supraventricular or ventricular tachyarrhythmias are preferentially adenosine, ajmaline, amiodarone, and adrenaline. If antiarrhythmic drugs fail, electric cardioversion using short-acting anesthesia is recommended.