Table 1.
Creatine transport deficiency subject ECG and Echocardiographic summary findings
| QTc<470msec | QTc≥470msec | P-value | |
|---|---|---|---|
| # of subjects | 11 | 7 | NS |
| Age (years) | 8.0±4.4 | 6.5±2.8 | NS |
| Wt (kg) | 22.6±9.9 | 17.3±7.7 | NS |
| BSA | 0.85±.27 | 0.72±.21 | NS |
| Electrocardiogram findings | |||
| Heart rate (bpm) | 97.5±23.3 | 95.9±12.5 | NS |
| Rhythm | All NSR | All NSR | NS |
| P axis (degrees) | 42.3±19.1 | 38.3±25.0 | NS |
| QRS axis (degrees) | 76.0±19.9 | 56.0±37.4 | NS |
| T axis (degrees) | 38.6±21.0 | 16.4±15.7 | P=0.047 |
| PR interval (msec) | 121.7±17.2 | 129.1±14.4 | NS |
| QRS interval (msec) | 79.6±6.3 | 79.7±9.4 | NS |
| QT interval (msec) | 357.8±38.3 | 405.3±43.4 | P=0.047 |
| QTc interval (msec) | 448.3±15.9 | 510.3±29.0 | P<0.0001 |
| T wave abnormality | 3/11 | 6/7 | P=0.049 |
| Echocardiographic findings | |||
| EF(%) | 64.2±2.1 | 65.7±3.5 | NS |
| FS(%) | 37.8±2.4 | 39.7±5.0 | NS |
| LVIDd(mm) | 33.9±5.2 | 34.7±4.1 | NS |
| LVIDd z-score | −0.93±1.0 | 0.22±0.74 | P=0.0059 |
| LViDs(mm) | 20.0±6.7 | 21.1±3.2 | NS |
| LViDs z-score | −0.86±.75 | −0.32±1.27 | NS |
| IVS (mm) | 5.6±0.9 | 5.1±0.7 | NS |
| IVS z-score | −1.2±0.5 | −1.3±0.6 | NS |
| LVPWDd(mm) | 5.7±0.8 | 5.0±0.6 | P=0.0183 |
| LVPWDd z-score | −0.85±.49 | −1.30±.35 | NS(.11) |
| LV mass (g) | 47.0±17.5 | 42.8±14.9 | NS |
| LV mass z-score | −1.5±0.9 | −0.95±.76 | NS(.065) |
| LV mass indexed | 54.2±10.1 | 57.6±9.5 | NS |
| LV mass index z-score | −1.7±0.9 | −1.2±0.7 | P=0.0417 |
| Pro-BNP (pg/mL) (# of pts with samples) | 147±98.0(5) | 270±102(3) | NS |
Abbreviations: AV, atrioventricular; BSA, body surface area; EF, Ejection fraction; FS, Fractional shortening; ECG, electrocardiogram; HR, heart rate; bpm, beats per minute; LVIDd, left ventricular dimension in diastole (2-dimenstional); LVIDd z-score, LVIDd normalized to individual subject’s BSA; LVIDs, left ventricular dimension in systole (2-dimenstional)); LVIDs z-score, LVIDs normalized to individual subject’s BSA LVPWDd, left ventricular posterior wall dimension (thickness) in diastole; LVPWDd z-score, LVPWDd normalized to individual subject’s BSA; LV, left ventricular; mm, millimeters, measurement units; NSR, normal sinus rhythm; QTc, corrected QT interval (using Bazett’s formula, where QTc=QT/√RR); NS, not significant; pts, subjects; pro-BNP, pro-brain natriuretic peptide; pg/mL, picogram per milliliter; All above statistics were performed using non-parametric T-test(Mann-Whitney).