Bidirectional tachycardia


Bidirectional tachycardia is an unusual tachyarrhythmia characterized by beat-to-beat alternation of the morphology and the axis of the QRS complexes seen in some of the electrocardiogram (EKG) leads. The usual ventricular rate in bidirectional tachycardia ranges from 140 to 180 bpm and can be regular or irregular


Diagnosis is initially clinical, supported by chest x-ray, echocardiography, and levels of plasma natriuretic peptides. Treatment includes diuretics, ACE inhibitors, angiotensin II receptor blockers, β-blockers, aldosterone antagonists, specialized implantable pacemakers, and correction of the underlying disorder.