Normal Sinus Rhythm

If the rhythm is Normal Sinus Rhythm, it should have all of the following features:
  • Normal rate (60 – 100 bpm in adults, i.e. 3-5 large squares between R waves)
  • Normal regularity
  • Normal P waves
  • Normal PR intervals (i.e. 3-5 small squares long)
  • Narrow QRS complexes (i.e. less than 2.5 mm wide)
  • No extra waves (a single P wave before each QRS complex and a single QRS complex after each P wave)
It is important to know that not all abnormal features on the ECG are rhythm problems. For example, is possible for a patient to have very abnormal ST segments or T waves and still be in Normal Sinus Rhythm. This is because the ST segments and T waves represent repolarisation and not depolarisation.
Normal sinus rhythm is a normal rhythm that originates from the sinus (SA) node. If there are no other abnormalities, the ECG will have a normal P, PR and QRS complex, and the rate will be normal (60-100 bpm).

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ECG Library (116)

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In the ECGquest archives, this ECG has been tagged with: - Chest pain Dyspnoea 12-Lead Inverted T waves Normal Sinus Rhythm Premature atrial complex Acute right heart strain Pulmonary embolism Dr Smith's ECG Blog CC BY-NC
An elderly woman transferred to you for chest pain, shortness of breath, and positive troponin – does she need the cath lab now?

This ECG is from an elderly woman who presented with sudden onset shortness of breath after months of inactivity due to a back injury.

This ECG shows sinus tachycardia with large inverted T waves, consistent with right heart strain. The cause was a very large PE.

In the ECGquest archives, this ECG has been tagged with: - Chest pain 12-Lead PR segment depression Widespread ST elevation Normal Sinus Rhythm Pericarditis ECG of the Week CC-BY-NC-SA
ECG of the Week – 24th December 2018 – Interpretation

This ECG is from a man in his 30s who presented with 2 days of positional left sided chest pain.

This ECG shows normal sinus rhythm with widespread ST elevation and PR depression. The diagnosis was pericarditis.

In the ECGquest archives, this ECG has been tagged with: - Chest pain 12-Lead Movement artefact Normal Sinus Rhythm ECG of the Week CC-BY-NC-SA
ECG of the Week – 10th December 2018 – Interpretation

This ECG is from a man in his 80s who presented with chest pain. He had a history of Parkinson's disease.

This ECG shows significant baseline artefact due to a Parkinsonian tremor.

In the ECGquest archives, this ECG has been tagged with: - Chest pain 12-Lead Paediatric Inverted T waves Normal Axis Tall QRS Normal Sinus Rhythm Normal ECG Guru CC-BY-NC-SA
Instructors’ Collection ECG: Normal ECG in Seven-year-old Girl

This ECG is from a young girl with mild chest pain.

This ECG shows normal sinus rhythm with inverted T waves in V1 and a tall QRS complex. This was a normal paediatric ECG.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Inverted T waves J wave Tall QRS Normal Sinus Rhythm Normal Dr Smith's ECG Blog CC BY-NC
Two cases of ST Elevation with Terminal T-wave Inversion – do either, neither, or both need reperfusion?

This ECG is from a teenage male who presented with chest tightness and shortness of breath for 6 hours on a background of asthma.

This ECG shows sinus rhythm with tall QRS and associated repolarisation changes, benign T wave inversion in V3-V6 with J-waves and ST-elevation.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Anterior ST elevation Inverted T waves Normal Sinus Rhythm Old anterior MI Dr Smith's ECG Blog CC BY-NC
Two cases of ST Elevation with Terminal T-wave Inversion – do either, neither, or both need reperfusion?

This ECG is from a man of unknown age who had cardiac stents placed 2 months ago.

This ECG shows sinus rhythm with QS-waves and ST elevation in V1-V3, with some terminal T-wave inversion. Serial troponins and angiography was normal.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Nonspecific baseline artefact Anterior ST depression Inferior ST depression Inverted T waves R in V1 Regular Right Axis Deviation Tall P waves Normal Sinus Rhythm Right atrial enlargement ECG Interpretation CC-BY-NC-SA
ECG Blog #156 (LVH – RVH – LAA – RAA – Strain – Ischemia)
In the ECGquest archives, this ECG has been tagged with: - 12-Lead Normal Axis Normal T waves Normal Sinus Rhythm Dr Smith's ECG Blog CC BY-NC
A Tale of 2 Occlusions in the Same Patient: one with Expert ECG interpretation, the Other Without – baseline ECG

This ECG is from a man in his 40s who presented with chest discomfort and diaphoresis since waking a few hours earlier, on a background of prior infarction with PCI years ago, active smoking, high cholesterol and hypertension. This was the baseline ECG from 2 years prior.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead High V1/V2 misplacement Serial 12-lead Normal Axis Normal P waves Normal T waves Normal Sinus Rhythm Normal Dr Smith's ECG Blog CC BY-NC
A pathognomonic ECG you should recognize instantly. Baseline ECG

This ECG is from a patient of unknown age who presented with generalised weakness and malaise. This was the baseline ECG from a previous presentation.

In the ECGquest archives, this ECG has been tagged with: - Seizure 12-Lead R in aVR Wide QRS Normal Sinus Rhythm Sodium channel blocker toxicity Dr Smith's ECG Blog CC BY-NC
Bupropion Overdose Followed by Cardiac Arrest and, Later, ST Elevation. Is it STEMI? 8 hours later.

This ECG is from a young woman who presented with status epilepticus seizures and an apparent overdose of bupropion, with possible cocaine ingestion. She was intubated and given propofol and benzodiazepines, which terminated the seizures. This was the repeat ECG 8 hours after presentation, just before she arrested.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Serial 12-lead Normal Sinus Rhythm Toxicology / Overdose Dr Smith's ECG Blog CC BY-NC
Bupropion Overdose Followed by Cardiac Arrest and, Later, ST Elevation. Is it STEMI? Repeat ECG on day 4

This ECG is from a young woman who presented with status epilepticus seizures and an apparent overdose of bupropion, with possible cocaine ingestion. She was intubated and given propofol and benzodiazepines, which terminated the seizures, and then a PEA arrest was terminated with epinephrine and bicarbonate. This was the repeat ECG on day 4.

In the ECGquest archives, this ECG has been tagged with: - 12-Lead Delta wave Wide QRS Normal Sinus Rhythm Wolff Parkinson White syndrome ECG Interpretation CC-BY-NC-SA
ECG Blog #153 (LVH – RVH – WPW – RBBB)

This ECG is from a man in his 30s who had a routine pre-employment medical.

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