Ms. Ulgen et al., Relation between QT dispersion and ventricular arrhythmias in uncomplicated isolated mitral valve prolapse, JPN CIRC J, 63(12), 1999, pp. 929-933
Citations number
39
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Complications of mitral valve prolapse (MVP), among which serious ventricul
ar arrhythmia and sudden death are of major importance, affect many individ
uals due to the high incidence of MVP itself in the community despite the a
ctual low incidence of these complications. The present study investigated
the incidence and distribution of ventricular arrhythmias according to thei
r severity and relationship with the QT interval and dispersion of repolari
zation in uncomplicated isolated MVP (IMVP) cases. Fifty-eight uncomplicate
d IMVP patients, 33 patients with accompanying tricuspid valve prolapse (TV
P), to compare its relationship with ventricular arrhythmia, and 60 age- an
d sex-matched control subjects were enrolled in the study. Individuals with
accompanying cardiac or systemic disease, or who were on drug therapy that
could potentially affect QT characteristics, were excluded. The incidence
of ventricular arrhythmia was 48% in the IMVP group and 64% in the TVP grou
p; the difference was statistically insignificant. In addition, the differe
nces of the QT and Q peak T values were insignificant, whereas QT dispersio
n (QTd) and Q peak T dispersion (QpeakTd) values were significantly higher
in the patient group (60+/-14, 54+/-14 ms, respectively) compared with the
control group (42+/-10, 38+/-10 ms, respectively, p<0.001). Complex ventric
ular arrhythmias (Lown Grade greater than or equal to III) in the IMVP grou
p had a significant relationship with QTd and QpeakTd (p<0.001), but not wi
th QT or QpeakT. As a result of the study, it is concluded that TVP accompa
nying MVP does not increase the incidence of ventricular arrhythmia, that v
entricular arrhythmia is related to QT dispersion rather than QT interval i
n IMVP, that the QT dispersion is a fairly good marker for identifying the
high-risk group for serious ventricular arrhythmia and sudden death, and th
at QpeakT dispersion measurement is an additional indicator that could be a
n alternative when QT is difficult to determine in conditions such as high
heart rate or the presence of U wave.