title: Concealed ventricular quadrigeminy linked to atrial quadrigeminy: a manifestation of modulated parasystole.
abstract: Analysis of a long electrocardiographic recording including many atrial and ventricular extrasystoles shows that when atrial extrasystoles are in a quadrigeminal distribution, the ventricular extrasystoles also manifest a quadrigeminal distribution or reflect a distributional pattern of concealed quadrigeminy. Conversely, when atrial extrasystoles are other than in a quadrigeminal distribution, the ventricular extrasystoles do not occur in a quadrigeminal or concealed quadrigeminal distribution. This pattern is explained on the basis of modulated parasystole. A biphasic phase-response curve explains the observed phenomena on the basis of variations of the parasystolic cycle length due to the modulating effect of supraventricular beats.
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000503:physiopathology*; D005117:Cardiac Complexes, Premature / Q000503:physiopathology*; D004562:Electrocardiography; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology; D006333:Heart Failure / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000503:physiopathology*