title: Ventricular arrhythmias and left ventricular hypertrophy in hypertrophic cardiomyopathy.
abstract: BACKGROUND
  In hypertrophic cardiomyopathy (HCM), the degree of left ventricular hypertrophy (LVH) could influence the development of ventricular arrhythmias.
  
  
  OBJECTIVE
  In HCM, analyze the association between the occurrence of ventricular arrhythmias determined by Holter electrocardiogram (ECG-Holter) and the degree of LVH determined by maximum wall thickness (MWT) in echocardiography and body mass index (BMI).
  
  
  METHODS
  Fifty-four consecutive patients with HCM underwent 24-hour ECG-Holter and echocardiography for assessment of level of LVH through MWT and BMI. Two levels were established for the occurrence of Ventricular Arrhythmias: I - alone or paired extrasystoles and II - Non- Sustained Ventricular Tachycardia (NSVT).
  
  
  RESULTS
  In 13 patients (24%) with NSVT (level II), there was a higher frequency of MWT of the left ventricle (LV) > 21 mm (n = 10, 77%, 25 ± 4 mm) and LLLV = 144 g/m² (n = 10, 77%, 200 ± 30 g/m²), in comparison with those presenting with extrasystole arrhythmias (level I) (n = 41, 76%), in which these measures were identified in, respectively, 37 % (n= 15, 23 ± 1 mm), p = 0.023, and 39% (n = 16, 192 ± 53 g / m²) of the cases (p = 0.026). The cut-off values mentioned were determined by the ROC curve with a confidence interval of 95%. NSVT was more common in patients with MWTLV > 21 mm and LLLV > 144 g/m² (8 of 13, 62%) than in those with (4 of 13, 31%) or without (1 of 13; 8%) echocardiographic variables above cut-off values (p = 0.04).
  
  
  CONCLUSIONS
  In HCM, occurrence of ventricular arrhythmias by Holter was associated with the degree of LVH assessed by echocardiography through MWT and BMI.
authors.affiliation: Serviço de Cardiologia do Hospital de Clínicas de Porto Alegre1; Faculdade de Medicina - Universidade Federal do Rio Grande do Sul2, Porto Alegre, RS – Brazil. bpmattos@cardiol.br
authors.forename: Beatriz
authors.initials: B
authors.lastname: Piva e Mattos
authors.forename: Marco Antonio Rodrigues
authors.initials: MA
authors.lastname: Torres
authors.forename: Valéria Centeno de
authors.initials: VC
authors.lastname: Freitas
authors.forename: Fernando Luís
authors.initials: FL
authors.lastname: Scolari
authors.forename: Melina Silva de
authors.initials: MS
authors.lastname: Loreto
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000000981:diagnostic imaging; D004452:Echocardiography / Q000379:methods; D015716:Electrocardiography, Ambulatory; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D018709:Statistics, Nonparametric; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000209:etiology*; D014693:Ventricular Fibrillation / Q000000981:diagnostic imaging / Q000209:etiology*