title: Abnormal spatial QRS-T angle, a marker of ventricular repolarisation, predicts serious ventricular arrhythmia in systemic sclerosis.
abstract: OBJECTIVE
  Cardiac involvement may be under-diagnosed in asymptomatic patients with systemic sclerosis (SSc). Standard electrocardiography-derived spatial QRS-T angle (spQRS-Ta) is an established marker of ventricular repolarisation heterogeneity, and a strong independent predictor of cardiac morbidity and mortality, including sudden death, in the general population. We examined whether spQRS-Ta is abnormal in asymptomatic SSc patients and assessed its predictive value for possibly concurrent, serious ventricular arrhythmia.
  
  
  METHODS
  SpQRS-Ta and 24-hour Holter recordings were obtained from 69 SSc patients (aged 51±13 years, 63 women) without clinically evident cardiac involvement and having left ventricular ejection fraction at least 50% by echocardiography. 'Healthy' subjects matched 1:1 with patients for age, gender and body mass index served as controls.
  
  
  RESULTS
  SpQRS-Ta was wider in SSc (median value 15.6°, interquartile range 10.6-24.3°) than controls (10.5°, 7.3-13.5°, p=0.0001) and not associated with skin fibrosis extent or specific clinical manifestations and autoantibodies. Twenty-four-hour Holter recordings revealed couplets of ventricular beats in six (Lown class IVa) and non-sustained ventricular tachycardia in five patients (Lown class IVb); spQRS-Ta was wider in those eleven patients with serious ventricular arrhythmia than the remaining patients (24.9°, 14.9-31.3° vs. 14.4°, 9.6-22.3°; p=0.02). A spQRS-Ta>19.3° demonstrated 80% sensitivity and 68% specificity (area under the curve 0.81, p=0.02) to predict the presence of non-sustained ventricular tachycardia in Holter monitoring.
  
  
  CONCLUSIONS
  Ventricular repolarisation heterogeneity, as reflected by wider spQRS-Ta, is common in SSc. Increased spQRS-Ta could serve as a simple screening test for further investigation to identify patients at risk or prone to develop life-threatening ventricular arrhythmia.
authors.affiliation: First Department of Propaedeutic and Internal Medicine, Athens University Medical School, Greece. gialaf@yahoo.com
authors.forename: E
authors.initials: E
authors.lastname: Gialafos
authors.forename: P
authors.initials: P
authors.lastname: Konstantopoulou
authors.forename: C
authors.initials: C
authors.lastname: Voulgari
authors.forename: I
authors.initials: I
authors.lastname: Giavri
authors.forename: S
authors.initials: S
authors.lastname: Panopoulos
authors.forename: G
authors.initials: G
authors.lastname: Vaiopoulos
authors.forename: M
authors.initials: M
authors.lastname: Mavrikakis
authors.forename: I
authors.initials: I
authors.lastname: Moyssakis
authors.forename: P P
authors.initials: PP
authors.lastname: Sfikakis
mesh_terms: D000328:Adult; D000368:Aged; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012595:Scleroderma, Systemic / Q000401:mortality*; D013318:Stroke Volume / Q000502:physiology; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000401:mortality* / Q000503:physiopathology