Medical Student Survival Skills

ECG

Philip Jevon, Jayant Gupta

• Publisher: Wiley-Blackwell
• Year: 2019
• ISBN:
  9781118818169
• Edition: 1
• Topic: Medicine
• Subtopic: Medical Education

Medical students encounter many challenges on their path to success, from managing their time, applying theory to practice, and passing exams. The Medical Student Survival Skills series helps medical students navigate core subjects of the curriculum, providing accessible, short reference guides for OSCE preparation and hospital placements. These guides are the perfect tool for achieving clinical success.

Medical Student Survival Skills: ECG is an indispensable resource for students new to ECG interpretation and cardiac arrhythmia recognition and treatment. Integrating essential clinical knowledge with practical OSCE advice, this portable guide provides concise and user-friendly coverage of all aspects of ECG monitoring, including atrial and ventricular fibrillation, myocardial infarction, and 12 lead ECG interpretation. Easy-to-find information, plentiful illustrations, OSCE checklists and expert discussions of actual ECG trace examples help medical students and junior doctors quickly get up to speed with ECG interpretation skills.

1
Introduction to ECG monitoring

Conduction system of the heart (figure 1.1)

Figure 1.1 Conduction system of the heart.

PQRST complex (figure 1.2)

Figure 1.2 PQRST complex.

• P wave: atrial depolarisation
• PR interval: atrial depolarisation and the impulse delay in the atrioventricular (AV) node prior to ventricular depolarisation
• QRS complex: ventricular depolarisation
• T wave: ventricular repolarisation

Sinus rhythm (figure 1.3)

Figure 1.3 Sinus rhythm.

• Normal rhythm of the heart
• Impulse originates in the sinoatrial (SA) node (i.e. ‘sinus’), regular rate of 60–100 beats per minute (bpm)
• No abnormal conduction delays

Sinus rhythm: Identifying ECG features

• Electrical activity: present
• QRS rate: 60–100 bpm
• QRS rhythm: regular
• QRS width: normal width and morphology
• P waves: present and of constant morphology
• Relationship between P waves and QRS complexes: P waves associated to QRS complexes; PR interval normal and constant

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NB Sinus rhythm can occasionally be seen in a cardiac arrest: pulseless electrical activity (PEA).

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