title: [Depressed electrical atrial activity in hypertrophic and dilated cardiomyopathies. An electrocardiographic, vectorcardiographic and echocardiographic study].
abstract: OBJECTIVE
  To evaluate the "normal" or low-voltage P wave of the 12-leads conventional electrocardiogram (ECG), in patients with serious electric ventricular disturbances in hypertrophic (HC) and dilated (DC) cardiomyopathies.
  
  
  METHODS
  Twenty cases of cardiomyopathies, 11 HC and 9 DC, ages ranging from 23 to 73 (x = 41) years have been studied. The analysis of the P wave was performed with ECG, amplified ECG at 1 mv = 20 mm and speed-paper at 50 mm/sec (ECG2), and the Frank-system vector-cardiogram (VCG). Voltage, delays and shapes of the P wave were evaluated by ECG2 and amplified VCG with gain at 1 mv = 160 mm. All electrical data were correlated with dimension of the left atrium (LA), dimension of left ventricular diastolic diameter (LVDD), dimension of left ventricular systolic diameter (LVSD), interventricular septal thickness (IST), posterior wall thickness ((PWT) and ejection fraction (EF) of the left ventricle of bidimensional echocardiogram (ECHO).
  
  
  RESULTS
  Changes in morphologies and delays on the the P wave were best observed only on ECG2 and VCG. The mean voltage of P wave on ECG was 0.1 mv and the mean duration of the P loop on VCG was 133.7 msec in HC and 145.2 msec in DC, with mean terminal delay of 49.2 msec and 46.8 msec, respectively, due to slow atrial depolarization.
  
  
  CONCLUSIONS
  In HC and DC with severe electric ventricular changes, the low-voltage and increased duration of P wave, are attributed to intraatrial-block due to structural changes of the atrial myocardium.
authors.affiliation: Hospital Universitário Pedro Ernesto, UERJ, Rio de Janeiro.
authors.forename: P
authors.initials: P
authors.lastname: Ginefra
authors.forename: E C
authors.initials: EC
authors.lastname: Barbosa
authors.forename: F M
authors.initials: FM
authors.lastname: Albanesi Filho
authors.forename: P J
authors.initials: PJ
authors.lastname: da Rocha
authors.forename: P R
authors.initials: PR
authors.lastname: Barbosa
authors.forename: S H
authors.initials: SH
authors.lastname: Boghossian
mesh_terms: D000328:Adult; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging*; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D014672:Vectorcardiography; D016276:Ventricular Function
vernacular_title: Atividade elétrica atrial deprimida nas cardiomiopatias hipertrófica e dilatada. Estudo eletro, veto e ecocardiográfico.