Among patients with a history of idiopathic ventricular fibrillation, there is an increased prevalence of early repolarization.

Increased QT dispersion is related to susceptibility to reentrant ventricular tachyarrhythmias, independent of degree of left ventricular dysfunction or clinical characteristics of the patient, suggesting that the simple, noninvasive measurement of this interval from a standard 12-lead ECG makes a significant contribution to identifying patients at risk for life-threatening arrhythmias after a previous myocardial infarction.

Background-Trigger mechanisms for the onset of paroxysmal atrial fibrillation (AF) in patients without structural heart disease are not well established. New analysis methods of heart rate (HR) variability based on nonlinear system theory may reveal features and abnormalities in R-R interval behavior that are not detectable by traditional analysis methods. The purpose of this study was to reveal possible alterations in the dynamics of R-R intervals before the spontaneous onset of paroxysmal AF. Methods and Results-Traditional time and frequency domain HR variability indices, along with the short-term scaling exponent ␣ 1 and approximate entropy (ApEn), were analyzed in 20-minute intervals before 92 episodes of spontaneous, paroxysmal AF in 22 patients without structural heart disease. Traditional HR variability measures showed no significant changes before the onset of AF. A progressive decrease occurred both in ApEn (1.09Ϯ0.26 120 to 100 minutes before AF; 0.88Ϯ0.24 20 to 0 minutes before AF; PϽ0.001) and in ␣ 1 (1.01Ϯ0.28 120 to 100 minutes before AF, 0.89Ϯ0.28 20 to 0 minutes before AF; PϽ0.05) before the AF episodes. Both ApEn (0.89Ϯ0.27 versus 1.02Ϯ0.30; PϽ0.05) and ␣ 1 (0.91Ϯ0.28 versus 1.27Ϯ0.21; PϽ0.001) were also lower before the onset of AF compared with values obtained from matched healthy control subjects. Conclusions-A decrease in the complexity of R-R intervals and altered fractal properties in short-term R-R interval dynamics precede the spontaneous onset of AF in patients with no structural heart disease. Further studies are needed to determine the physiological correlates of these new, nonlinear HR variability measures. (Circulation. 1999;100:2079-2084.)

Multiple recurrences of VF occurred in 27% of patients with early repolarization abnormality and may be life threatening. Isoproterenol in acute cases and quinidine in chronic cases are effective AADs.

Cardiac conduction defect and atrial arrhythmias in a large Finnish family appear to result from the SCN5A D1275N mutation. Although no sudden cardiac death was recorded in the family, at least three affected members had encountered brain infarction at the age of 30 or younger.

Continuous epidural bupivacaine/fentanyl analgesic regimen, started preoperatively, reduces the amount of myocardial ischaemia in elderly patients with hip fracture.

In the selected group of patients studied, a decrease in overall HRV was associated with altered nonlinear heart rate dynamics after CABG surgery. Current results suggest that a more random short-term heart rate behavior may be associated with a complicated clinical course. Analysis of fractal-like dynamics of heart rate may provide new perspectives in detecting abnormal cardiovascular function after CABG.

Our findings indicate that current programmed stimulation protocols do not enhance risk stratification in ER syndrome.