tailieunhanh - Ebook Graphics-sequenced interpretation of ECG: Part 2

(BQ) Part 2 book "Graphics-sequenced interpretation of ECG" presents the following contents: QRS complex, ST segment (normal ST segment, abnormal ST segment, ECG practice strips), T wave (Normal T wave, useful methods for analyzing T wave, ECG practice strips), other common abnormal ECGs. | Chapter 4 QRS Complex Rui Zeng Xiaohan Zhang Tianyuan Xiong Guojun Zhou and Rongzheng Yue Normal QRS Complex Features of Normal QRS Complex QRS complex is a group of waves of comparatively deep amplitude and shows the electrical changes during left and right ventricular depolarization. The morphological features of normal QRS complex can be summarized into the main wave s direction and the morphology of Q q wave. 1. The main wave is positive in leads I II and V4 to V6 while the main wave is negative in leads aVR and V1. 2. From lead V1 to V6 R wave grows taller S wave grows lower and R S ratio becomes larger. 3. In leads V1 and V2 there should be no Q q wave QS pattern can be present . In leads aVR aVL and III there can be Q or q wave. In leads I II aVF and V4 to V6 Q wave should not be present q wave is probably present . Features of Normal QRS Complex Voltage 1. In at least one limb lead the sum of Q R and S voltages sum of the absolute values is greater than or equal to mV. R. Zeng 13 Department of Cardiology West China Hospital West China School of Medicine Sichuan University Chengdu Sichuan Province e-mail zengrui_0524@ X. Zhang T Xiong G. Zhou West China School of Medicine Sichuan University Chengdu Sichuan Province R. Yue Department of Nephrology West China Hospital West China School of Medicine Sichuan University Chengdu Sichuan Province Springer Science Business Media Singapore Pte Ltd. 69 and People s Medical Publishing House 2016 R. Zeng Graphics-sequenced interpretation ofECG DOI 978-981-287-955-4_4 70 R. Zeng et al. 2. In at least one chest lead the sum of QRS voltages is greater than or equal to mV. 3. RV5 mV RaVL mV RaVF mV RI mV and RV5 SV1 mV. 4. RV1 mV RV1 SV5 mV and RaVR mV. If you think what is mentioned above is lengthy or hard to memorize don t worry and just keep reading and you will find some simple drawing that can help you understand and .