Corrected QT dispersion improves diagnostic performance of exercise testing in diagnosing coronary artery disease

To determine the best combination of parameters that would improve the diagnostic performance of exercise testing, coronary angiography plus exercise testing were done on 112 patients with angina pectoris and normal electrocardiogram. The univariate predictors of coronary artery disease included: age >/= 40 years, male sex, hypertension, smoking, development of exertional chest pain, decrease in systolic blood pressure [BP] >/= 10 mmHg or systolic BP 3 min post-exercise > 90% of peak, heart rate drop < 12 beats/min 1 min post-exercise, exercise-induced ST-segment depression >/= 1mm. Multivariate logistic regression analysis showed that using either ST depression >/= 1mm or peak exercise QTDc > 70 ms significantly improved sensitivity and negative predictive value of the test without a significant decrease in specificity

Pattern and possible contributing factors to dialysis-associated arrhythmia in young patients

We studied dialysis-associated arrhythmia in 48 uraemic patients < 35 years on chronic haemodialysis [HD] [> 3 months]. Holter findings showed only minor arrhythmia; atrial in 42% of patients and ventricular in 38%. ST-segment depression > 1 mm was observed in 58% of patients; 80% had arrhythmia, and 36% experienced anginal pain. HD caused a significant increase in QTc, QTdc and Ca[2+] level, while K[+] level was significantly decreased. Patients who experienced arrhythmia during HD had higher left ventricular mass and left ventricular mass index, lower post-dialysis K+ level, higher QTc and QTdc both before and after HD. They were more frequently hypertensive. ST-segment depression was significantly related to ventricular arrhythmia