title: Clinical characteristics of ST-segment elevation in lead V6 in patients with Q-wave acute inferior wall myocardial infarction.
abstract: BACKGROUND
  Precordial ST-segment depression in acute inferior infarction is well recognized, but few studies have evaluated ST-segment elevation in lateral precordial leads. The present study examined the clinical significance of ST-segment elevation in lead V6 in patients with acute Q-wave inferior myocardial infarction.
  
  
  METHODS
  We studied the initial electrocardiography of 125 consecutive patients with acute Q-wave inferior myocardial infarction admitted to hospital within 12 h of the onset of chest pain. They were classified into two groups: group 1 = 34 patients with ST-segment elevation in lead V6; group 2 = 91 patients with no ST-segment elevation in lead V6.
  
  
  RESULTS
  Among the seven clinical variables examined, the number of left ventricular asynergic segments (P < 0.001) and pulmonary capillary wedge pressure (P = 0.001) were related to ST-segment elevation in lead V6. The incidences of major arrhythmias (50% compared with 31%, P = 0.04), pericardial effusion (32% compared with 9%, P = 0.003), and pericardial rub (15% compared with 2%, P = 0.02) during the patients' stay in hospital were greater in group 1 than in group 2. Among the patients in group 1, the right coronary artery was the culprit artery in 22 of 24 patients (92%) with ST segment depression in lead I, whereas the circumflex artery was the culprit artery in nine of 10 patients (90%) with isoelectric or ST-segment elevation in lead I.
  
  
  CONCLUSIONS
  The presence of ST-segment elevation in lead V6 in patients with acute Q-wave inferior myocardial infarction was associated with larger infarct size, and greater incidences of major arrhythmias and pericardial involvement during the patient's stay in hospital.
authors.affiliation: Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuka
authors.forename: T
authors.initials: T
authors.lastname: Sugiura
authors.forename: K
authors.initials: K
authors.lastname: Hatada
authors.forename: Y
authors.initials: Y
authors.lastname: Abe
authors.forename: N
authors.initials: N
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Iwasaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D010343:Patient Admission; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology