QT interval dispersion analysis in patients undergoing left partial ventriculectomy (Batista operation).
BACKGROUND
QT interval dispersion (QTd) has been valued as a marker of increased vulnerability for cardiac arrhythmias. QTd was analyzed in patients undergoing the left partial ventriculectomy (LPV) or Batista operation, a palliative surgery for patients in the line for heart transplantation, which is associated with complex arrhythmia and death from sustained ventricular tachyarrhythmia (SVT).


METHODS
Pre- and postoperative R-R, QT, QTc, JT (QT - QRS), and aT (apex to end of T wave) intervals were obtained by 87-lead body surface mapping from 24 patients (18 male), mean age 46.4 +/- 9.15 years. Dispersions of QT, QTc, JT, and aT intervals were calculated, and the total number of arrhythmic events were assessed, aiming to verify a possible risk predictor for the occurrence of SVTs. Subgroups of patients who survived and who died after LPV were also compared, aiming to obtain a QTd cutoff value that could be used prognostically.


RESULTS
No difference between pre- and postoperative mean values were found, but a very significant difference was seen when comparing QTd and QTcD values for surviving and dead patients: QTd, cutoff value was 95 ms, while QTcD value was 114 ms.


CONCLUSIONS
There were no significant differences between pre- and postoperative variables or the number of arrhythmic events, but there were significant differences between both pre- and postoperative QTd and QTcD data from surviving and dead patients; this enabled the determination of cutoff values that we believe may be useful for the prognosis of the LPV outcome.
Pastore
Carlos Alberto
CA
Heart Institute (InCor) of the University of São Paulo Medical School, São Paulo, Brazil. ecg_pastore@incor.usp.br
Arcêncio
Sandra Regina
SR
Tobias
Nancy M M O
NM
Kaiser
Elisabeth
E
Filho
Martino Martinelli
MM
Moreira
Luis Felipe P
LF
Stolf
Noedir A
NA
Bocchi
Edimar
E
Ramires
José Antonio Franchini
JA
D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping; D015716:Electrocardiography, Ambulatory; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D018709:Statistics, Nonparametric; D017180:Tachycardia, Ventricular / Q000601:surgery*