The prognostic value of J-wave pattern for recurrence of ventricular tachycardia after catheter ablation in patients with myocardial infarction.

BACKGROUND: J-waves and fragmented QRS (fQRS) on surface ECGs have been associated with the occurrence of ventricular tachyarrhythmias. Whether these non-invasive parameters can also predict ventricular tachycardia (VT) recurrence after radiofrequency catheter ablation (RFCA) is unknown. Of interest, patients with a wide QRS-complex have been excluded from clinical studies on J-waves, although a J-wave like pattern has been described for wide QRS. METHODS: We retrospectively included 168 patients (67 ± 10 years; 146 men) who underwent RFCA of post-infarct VT. J-wave pattern were defined as J-point elevation ≥ 0.1 mV in at least two leads irrespective of QRS width. fQRS was defined as various RSR` pattern in patients with narrow QRS and more than two R wave in those with wide QRS. The primary endpoint was VT recurrence after RFCA up to 24 months. RESULTS: J-wave pattern and fQRS were present in 27 and 28 patients, respectively. Overlap of J-wave pattern and fQRS was observed in nine. During a median follow-up of 20 (interquartile range 9-24) months, 46 (27%) patients had VT recurrence. Kaplan-Meier curves revealed that both J-wave pattern and fQRS were associated with VT recurrence. Multivariate Cox regression analysis demonstrated that the presence of J-wave pattern (hazard ratio [HR] 2.84; 95% confidence interval [CI] 1.45-5.58; P = .002) and greater number of induced VT (HR 1.29; 95% CI 1.15-1.45; P < .001) were the independent predictors of VT recurrence. CONCLUSIONS: A J-wave pattern-but not fQRS-is independently associated with an increased risk of post-infarct VT recurrence after RFCA irrespective of QRS width. This simple non-invasive parameter may identify patients who require additional treatment.

Making a Lecture Stick: the Effect of Spaced Instruction on Knowledge Retention in Medical Education.

INTRODUCTION: Poor knowledge retention is a persistent problem among medical students. This challenging issue may be addressed by optimizing frequently used instructional designs, such as lectures. Guided by neuroscientific literature, we designed a spaced learning lecture in which the educator repeats the to-be-learned information using short temporal intervals. We investigated if this modified instructional design could enhance students' retention. MATERIALS AND METHODS: Second-year medical students (n = 148) were randomly allocated to either the spaced lecture or the traditional lecture. The spaced lecture consisted of three 15-min instructional periods, separated by 5-min intervals. A short summary of the preceding information was provided after each interval. The traditional lecture encompassed the same information including the summary in the massed format, thus without the intervals. All students performed a baseline knowledge test 2 weeks prior to the lectures and students' knowledge retention was assessed 8 days after the lectures. RESULTS: The average score on the retention test (α = 0.74) was not significantly different between the spaced lecture group (33.8% ± 13.6%) and the traditional lecture group (31.8% ± 12.9%) after controlling for students' baseline-test performance (F(1,104) = 0.566, p = 0.458). Students' narrative comments showed that the spaced lecture format was well-received and subjectively benefitted their attention-span and cognitive engagement. DISCUSSION AND CONCLUSION: We were unable to show increased knowledge retention after the spaced lecture compared with the traditional lecture. Based on these findings, we provide recommendations for further research. Ultimately, we aim for optimized spaced learning designs to facilitate learning in the medical curriculum and to help educate health professionals with a solid knowledge base.