title: The electrocardiographic characteristics of septal flash in patients with left bundle branch block.
abstract: OBJECTIVE
  In patients with systolic heart failure and left bundle branch block (LBBB), septal flash (SF) movement has been described by echocardiography. We evaluated the prevalence of SF in LBBB and non-LBBB patients and evaluated whether specific electrocardiographic (ECG) characteristics within LBBB are associated with the presence of SF on echocardiography.
  
  
  RESULTS
  One hundred and four patients with probable LBBB on standard 12-lead ECG were selected, 40 patients with non-LBBB served as controls. Left bundle branch block and non-LBBB were defined, according to the most recent guidelines. The presence of SF was assessed by echocardiography. Strict LBBB criteria were met in 93.3% of the patients. Septal flash was present in 45.2% of LBBB patients and was not present in non-LBBB patients. This was more prevalent in patients without anterior ischaemic cardiomyopathy (ICMP) compared with those with anterior ICMP (P = 0.008). The duration of QRS was longer in SF patients compared with that of non-SF patients (P < 0.05). The presence of a mid-QRS notching in more than two consecutive leads was a good predictor for the presence of SF (P = 0.01), and when combined with an absent R-wave in lead V1, the presence of SF is very likely (P = 0.001).
  
  
  CONCLUSIONS
  Our data show that SF is present in 45.2% of LBBB patients, whereas it was absent in patients with non-LBBB. Patients with SF fulfilled more LBBB criteria compared with LBBB patients without SF. Our findings raise the provocative question of whether the presence of SF identifies patients with 'true LBBB' and whether this echocardiographic finding might be considered as a selection parameter in cardiac resynchronization therapy.
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium.
authors: Ben
authors: B
authors: Corteville
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium.
authors: Jan
authors: J
authors: De Pooter
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium.
authors: Tine
authors: T
authors: De Backer
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium.
authors: Milad
authors: M
authors: El Haddad
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium.
authors: Roland
authors: R
authors: Stroobandt
authors: Ghent University Hospital, Heart Center, Department of Cardiology, 8K12 IE, De Pintelaan 185, Ghent 9000, Belgium frank.timmermans@ugent.be.
authors: Frank
authors: F
authors: Timmermans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium / Q000453:epidemiology; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D016022:Case-Control Studies; D016208:Databases, Factual; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D054143:Heart Failure, Systolic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D015588:Observer Variation; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D016277:Ventricular Function, Left; D054088:Ventricular Septum / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Cardiac resynchronization therapy; Dyssynchrony; Echocardiography; Left bundle branch block; Septal flash