title: [Electrovectorcardiographic manifestations of supraventricular ectopic rhythms (an interpretive hypothesis)].
abstract: When a low right atrial rhythm is present, P waves are negative in the low leads, they are variable in a VR and positive in a VL and LI. The figure eighth PF loop is located in the first quadrant, the PH loop has a counterclockwise rotation, and the PS can rotate in either direction. In the presence of upper left atrial rhythms, P waves are positive in the low leads and negative in a VL and a VR. The PF and PH loops can be found in the third quadrant of both planes with a clockwise rotation. If the rhythm originates in low left atrial regions, negative P waves are recorded in left precordial leads and positive ones in a VR and a VL. The PF loop has counterclockwise rotation or its branches superimposed and is situated in the second quadrant; PH with clockwise rotation is registered in the third quadrant; PS with either counterclockwise or clockwise rotation develops above and slightly ahead of the E point. When a nodal rhythm exists, P waves are negative in the low leads. The P loops show a counterclockwise rotation or a figure eight morphology. In the absence of atrial enlargements, the PF loop can be recorded in the first quadrant and the PH in the first or the fourth quadrant.
authors.affiliation: Departamento de Electrocardiografía y Vectocardiografía, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F.
authors.forename: A
authors.initials: A
authors.lastname: de Micheli
authors.forename: G A
authors.initials: GA
authors.lastname: Medrano
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D004562:Electrocardiography; D006801:Humans; D013617:Tachycardia, Supraventricular / Q000145:classification / Q000503:physiopathology*; D014672:Vectorcardiography
vernacular_title: Manifestaciones electrovectocardiográficas de los ritmos ectópicos supraventriculares. (Una hipótesis interpretativa).