Key result
Patients with Short QT syndrome had a significantly higher diurnal average TPE/QT ratio than healthy controls (0.28 vs 0.21; P=0.01), indicating increased transmural dispersion of repolarization.
Case-Control (n=12)
Absolute Event Rate: 0.28% vs 0.21%
p-value: p=0.01
Patients with Short QT Syndrome exhibit an increased TPE/QT ratio compared to healthy controls, indicating increased transmural dispersion of repolarization that may contribute to arrhythmogenesis.
May support TPE/QT ratio for arrhythmia risk assessment in Short QT syndrome; leaves open its incremental value over existing markers.
BACKGROUND: Short QT syndrome (SQTS) carries an increased risk for sudden cardiac death. However, only a short QT interval does not express the risk of ventricular arrhythmias. Thus, additional evaluation of the repolarization abnormality in SQTS patients is essential. In experimental models of SQTS, increased transmural dispersion of repolarization (TDR) and its electrocardiographic counterpart T-wave peak to T-wave end interval (TPE) appeared critical for induction of polymorphic ventricular tachycardia (PMVT). In a clinical study with acquired long QT syndrome patients, TPE/QT ratio > 0.28 indicated arrhythmia risk. We hypothesized that the TPE/QT ratio would be greater in SQTS patients than in control subjects. METHODS AND RESULTS: We compared the behavior of the electrocardiographic TDR in three seriously symptomatic SQTS patients of unknown genotype presenting baseline QTc values < 320 ms and in nine healthy age-matched control subjects. We determined QT and TPE intervals as well as TPE/QT ratio from 24-hour ECG recordings using a computer-assisted program. Diurnal average of TPE/QT ratio was 0.28 +/- 0.03 in SQTS patients and 0.21 +/- 0.02 in control subjects (P = 0.01). SQTS patients had also lesser capacity to change TPE intervals from steady-state conditions to abrupt maximal values than control subjects. CONCLUSION: SQTS patients have increased and autonomically uncontrolled electrocardiographic TDR. According to experimental SQTS models, the present results may in part explain increased vulnerability of SQTS patients to ventricular arrhythmias.
No takes yet. Share an insight, caveat, or question.
Anttonen et al. (2008) conducted a case-control in Inherited Short QT Syndrome (n=12). 24-hour ECG recording (TPE/QT ratio assessment) vs. Healthy age-matched control subjects was evaluated on Diurnal average of TPE/QT ratio (p=0.01). Patients with Short QT syndrome had a significantly higher diurnal average TPE/QT ratio than healthy controls (0.28 vs 0.21; P=0.01), indicating increased transmural dispersion of repolarization.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: