Table 1.
Demographic, clinical and laboratory characteristics of patients with Torsades de pointes.
| Patients, n | 48 |
|---|---|
| Age, median years (interquartile range) | 81(73–85) |
| Females, n | 31/48(65%) |
| Mean QTc, ms(range) | 596.0 ± 80.7(490–910) |
| Electrolyte imbalances, n | 37/47(79%) |
| Hypokaliemia | 28/45(62%) |
| Hypocalcemia | 22/37(59%) |
| Hypomagnesemia | 7/27(26%) |
| Concomitant diseases*, n | 45/48(94%) |
| Cardiac diseases | 40/48(83%) |
| Left ventricular hypertrophy | 19/48(40%) |
| Dilated cardiomyopathy/heart failure | 13/48(27%) |
| II-III degree atrioventricular block | 10/48(21%) |
| Acute coronary syndrome | 9/48(19%) |
| Chronic coronary artery disease | 7/48(15%) |
| Sinus bradycardia | 6/48(13%) |
| Extra-cardiac diseases | 20/48(42%) |
| Diabetes mellitus type II | 13/48(27%) |
| Chronic kidney disease | 8/48(17%) |
| Hypothyroidism | 2/48(4%) |
| Subarachnoid hemorrhage | 1/48(2%) |
| Cirrhosis | 1/48(2%) |
| Anorexia nervosa | 1/48(2%) |
| HIV infection | 1/48(2%) |
| QTc prolonging-medications, n | 34/48(71%) |
| Amiodarone | 14/48(29%) |
| Citalopram | 5/48(10%) |
| Sertraline | 4/48(8%) |
| Fluconazole | 3/48(6%) |
| Trazodone | 3/48(6%) |
| Levofloxacin | 2/48(4%) |
| Clarithromycin | 2/48(4%) |
| Promazine | 2/48(4%) |
| Quetiapine | 2/48(4%) |
| Mean medication number per patient | 1.1 ± 1.0 |
| Anti-Ro/SSA positivity, n | 18/32(56%) |
| Systemic inflammation, n† | 38/48(79%) |
| C-reactive protein, mg/dl(range) | 2.66(0.1–29.65) |
| Definite inflammatory diseases | 22/48(46%) |
| Acute infections | 15/48(31%) |
| Immuno-mediated diseases | 5/48(10%) |
| Others | 2/48(4%) |
| Mean QTc-prolonging risk factor number per patient§ | 5.3 ± 1.5 |
Except where indicated otherwise, data are expressed as mean ± standard deviation or median (range).
Appropriate serum potassium, calcium or magnesium measurements available in 45, 37, and 27 out of 48 patients, respectively; anti-Ro/SSA antibodies tested in 32 out of 48 patients.
*
Diseases recognized to be a risk factor for QTc prolongation (Viskin, 1999; El-Sherif and Turitto, 2003; Drew et al., 2010).
†
Increased C-reactive protein level (>0.5 mg/dl) with or without a definite inflammatory disease.