Author + information
- Kristina H. Haugaa,
- Johan Bos,
- Evan Borkenhagen,
- Robert F. Tarrell,
- Bruce W. Morlan,
- Pedro J. Caraballo and
- Michael Ackerman
QT prolongation is a risk marker of sudden cardiac death and all-cause mortality. Left ventricular hypertrophy (LVH) on a 12-lead ECG is associated with poor outcome also. Patients satisfying ECG voltage criteria for LVH frequently show concomitant QT prolongation. We explored the impact of QT prolongation on all-cause mortality in patients co-presenting LVH voltage and prolonged QT on ECG.
We evaluated 86,107 ECGs in 52,579 unique patients performed at Mayo Clinic, MN. Of these, 3364 (6%) had an ECG with QTc > 460 ms. Every ECG with QTc > 460 ms was read manually and evaluated for presence of LVH criteria by Sokolow Lyon, Cornell voltage, and product.
Concomitant LVH voltage was present in 233 (7%) of ECGs with QTc > 460 ms. Cornell product and QTc correlated weakly (R2=0.04, p=0.003). During follow up of 209 ± 180 days, mortality was 32/233 (14%). Independent of age and hypertension, QTc predicted mortality (HR 1.16 per 10 ms increase, 95% CI 1.01-1.35, p=0.04) while none of the LVH voltage markers did. Patients with voltage criteria LVH and QTc ≥ 500 ms had highest mortality (log rank < 0.001, Figure).
QTc was an independent predictor of mortality in patients with concomitant LVH voltage and prolonged QTc on ECG while LVH voltage was not. Mortality was highest in those with QTc > 500 ms. QT prolongation in ECGs with concomitant LVH should not be regarded as a harmless byproduct of LVH, but should be used as a non-invasive marker of increased mortality risk similar to patients without LVH.
Moderated Poster Contributions
Poster Sessions, Expo North
Saturday, March 09, 2013, 10:00 a.m.-10:45 a.m.
Session Title: Prevention: Sudden Cardiac Death Prevention
Abstract Category: 24. Prevention: Clinical
Presentation Number: 1101M-11
- 2013 American College of Cardiology Foundation