Predictors of sudden cardiac death in never previously treated patients with essential hypertension: long-term follow-up.

Increased QT dispersion has been associated with ventricular arrhythmia and sudden death in a variety of cardiac disorders. Left ventricular hypertrophy (LVH) has also been associated with increased incidence of sudden cardiac death in patients with essential hypertension. Furthermore, patients with essential hypertension, particularly those with LVH, are more likely to develop ventricular arrhythmias than are the normal population. The relationship between LVH, QT dispersion, complex ventricular arrhythmia and sudden cardiac death in previously untreated patients over long-term follow-up in hypertension has not been reported before and is the purpose of this study. Fifty-nine adult subjects with essential hypertension, who had never been previously on antihypertensive treatment were followed up for a total of 119.2 +/- 26.2 months. QTc (corrected QT), blood pressure, electrocardiograms, and 24-h Holter ECG recordings were performed in all patients at the time of entry to the study. Ventricular arrhythmias were classified using a modified Lown's scoring system. During the follow-up period death occurred in 12 cases (20%) of which only six (10%) deaths were sudden. The findings of this study indicate that LVH and complex ventricular arrhythmias (Lown's score > or =3) are the only significant predictors of sudden death. Although patients who died suddenly had higher systolic and diastolic blood pressures and greater QTc dispersion compared to surviving patients, this difference was statistically not significant. Similarly, when those who died suddenly were compared to those non-cardiac deaths, LVH and complex ventricular arrhythmias were the only significant predictors of sudden death. In spite of increased QTc dispersion in hypertensive patients, this finding was not associated with increased risk of sudden death and only LVH and high grade ventricular arrhythmias identified hypertensive patients at risk of sudden cardiac death over a 10-year follow-up period.