Physical recklessness in adolescence. Trait or byproduct of depressive/suicidal states?

The authors assessed adolescents (264 psychiatric inpatients and 742 high school students) with a new instrument (the Sommerfeldt-Clark Adolescent Recklessness Scale) to test whether adolescents show individual differences on a dimension ranging from physical caution to physical recklessness. The three dimensions that emerged reflect an interest in weapons and military dangers, which we have tentatively labeled "foolhardiness"; the combination of dangerous driving and substance abuse; and involvement with smoking, drug use, and "bad company." The personality traits of "venturesomeness" and "impulsiveness" were significantly correlated with all three recklessness factors. The first two factors showed no significant relationship with patient status, diagnosis of mood disorder, or history of suicidal behavior; the third factor was associated with inpatient status and a history of suicide attempts.

Efficacy of coronary bypass grafting in exercise-induced ventricular tachycardia.

The effects of coronary bypass grafting on ventricular tachycardia induced by treadmill stress testing (TST) were analyzed in nine patients by repeating the test an average of 5 months after operation. Preoperatively, eight patients experienced pain and all had ischemic ST-segment depression during exercise. Six patients had a single episode and two patients had multiple episodes of ventricular tachycardia; in one patient ventricular tachycardia degenerated into ventricular flutter necessitating direct-current cardioversion. Postoperatively, time of exercise and double product were significantly higher during TST. Electrocardiographic ischemic changes were present in only two patients and ventricular tachycardia was not observed. All patients are alive and average of 24 months after the operation, and eight of them are asymptomatic. In conclusion, among patients with coronary artery disease who have exercise-induced ventricular arrhythmias, myocardial revascularization is associated with improvement of exercise capacity and suppression of arrhythmias.

Clinical significance and characteristics of exercise-induced ventricular tachycardia.

Forty-seven patients (0.08%) from a total of 5,730 consecutive patients undergoing treadmill stress tests developed one or more episodes of ventricular tachycardia. Forty patients had heart disease, coronary artery disease being the leading cause. Rest ECG was normal in 12 patients and showed long QTc (greater than 440 msec) in 16 patients. Ventricular tachycardia was brief and self-terminating, requiring D/C cardioversion in only one patient. "Exertional hypotension" preceded ventricular tachycardia in 16 of 34 patients. There was poor correlation (r = 0.16) between the rate of ventricular tachycardia (VT) and the underlying heart rate. Only four episodes of VT were initiated by R on T premature ventricular beats. In summary, exercise-induced ventricular tachycardia 1) is a rare complication of treadmill stress test and occurs in patients with heart disease; 2) is frequently preceded by "exertional hypotension," and 3) is not related to the R on T phenomenon. The high incidence of prolonged QT may indicate a role for the automatic nervous system in its pathogenesis.