The pediatric ECG

Knowledge of the basics of pediatric ECG interpretation is helpful in differentiating normal from abnormal findings. These basics include familiarity with the age-related normal findings in heart rate, intervals, axis, and waveform morphologies; an understand-ing of cardiac physiologic changes associated with age and maturation, particularly the adaptation from right to left ventricular predominance; and a rudimentary understanding of common pediatric dysrhythmias and findings associated with congenital heart diseases.     

Troubleshooting the ECG

Improper ECG monitoring is dangerous to patient care. Artifact in ECG monitoring can be annoying, costly and produce delays in proper care. Understanding the technical sources of artifact and care in the application of monitoring electrodes can significantly reduce or even eliminate the problem. Critical to the success of ECG monitoring are the technical aspects of proper equipment selection, preventive maintenance, and timely and rapid application to the patient, all to deliver the highest quality patient care. Just as critical is the prehospital clinician's understanding of equipment capabilities and limitations. Take time to read and understand the operator's manual for the ECG monitor/defibrillator in use in your ambulance. The ECG offers invaluable diagnostic information to EMS clinicians. With recent technological advances, today's ECG monitors provide even greater ease and versatility, which results in enhanced patient monitoring. Many factors can affect the quality of the ECG trace and therefore must be controlled in order to gain the most accurate and meaningful reading. Electrode placement and selection, as well as site preparation, are key considerations when applying and monitoring a patient's ECG.     

临床应用型心电图辨识护理人才培养方式探索

目的培养应用型临床心电图辨识护理人才。方法构建以临床应用为目的的实践教学模式,以心电图的基础理论为前提,以急诊心电图教学图集为训练资源,兴趣培养为手段,通过速度强化法完成实训。结果实验组学生在实训前后的读片速度和读片正确率都有了明显的提高,其中读片摸底总成绩为（35．54±9．13）分,训培后总成绩为（83．46±9．42）分,组间比较差异具有统计学意义（t=20．0085,P〈0．01）。结论以心电图的基础理论为前提、急诊心电图教学图集为训练资源、兴趣培养和速度强化为手段的教学方式有助于临床应用型心电图护理人才的培养。     

On the consistency of ECG reports from two different computer-based ECG recorders

Summary. Four consecutive computer-based ECG recordings/interpretations were made on each of 100 patients. Two of the recordings were made with the MAC II recorder (Marquette Electronics Inc., Milwaukee, USA) and two with the Cardisuny IC503FA (Fukuda M-E Kogyo Co. Ltd, Tokyo, Japan). Computer measurements of PQ interval, Q-width in III, R-amplitude in V₅ and QRS axis in the frontal plane were compared between recordings, as also were diagnostic statements pertaining to the presence of atrial fibrillation and myocardial infarction. The MAC II was found to be more consistent than the Cardisuny as regards the measurements. There was a tendency that the MAC II was more specific than the Cardisuny and the Cardisuny more sensitive than the MAC II. The MAC II gave no false positive reports of atrial fibrillation and only one false positive report of myocardial infarction.     

Difference in QT Interval Measurement on Ambulatory ECG Compared with Standard ECG

Measurement of the QT interval on standard ECG has diagnostic importance in the congenital long QT syndrome, in pharmacological therapy of arrhythmias, as well as in ischemic heart disease. It has been suggested that QT prolongation on ambulatory ECG (Holter) may have similar importance. To assess agreement between methods, QT interval measurement on standard ECG was compared to that on Holter. Simultaneously obtained ECG and Holter tracings (25 mm/s) of the same complexes in leads V₁ and V₅ were studied in 14 patients (age range 4–36 years). ECG pairs (n = 100, 49 V₁ and 51 V₅) were compared over a range of QT interval from 300–620 ms, as determined with the use of calipers by two observers blinded to pairing relationship. Correlation between methods was high for both observers (observer 1: r[V₁] = 0.872, r[V₅] = 0.973; observer 2: r[V₁] = 0.972, r[V₅] = 0.988), and interobserver variability was small (> 85% of measurements within 20 ms). As compared to ECG, Holter underestimated QT interval in V₁ mean difference (QT [Holter]—QT [ECG]) observer 1 (-23 ms, P < 0.001), observer 2 (-7 ms, P < 0.05), and overestimated QT in V5, mean difference observer 1 (+ 13 ms, P < 0.001), observer 2 (+13 ms, P < 0.001). However, individual variation between methods was wide, as expressed by the difference between individual measurements (95% confidence interval [V₁]: observer 1 [-99 to +53 ms] observer 2 [-47 to +33 ms]; [V₅]: observer 1 [-33 to +59 ms] observer 2 [-17 to +43 ms]). Furthermore, when using the QTA (interval from onset of Q wave to apex of T wave) similar variability was observed. In the assessment of QT interval, potential sources of error of this magnitude could limit the clinical utility of ambulatory monitoring in detecting prolongation of the QT interval for diagnostic purposes.     

Self-test: ECG examination

Challenge your knowledge about electrocardiograms with this quiz.