Advanced EKG - 10 Miscellaneous Diagnoses

Summary

In this educational video on mastering EKGs, Eric Strong takes viewers through 10 diverse EKG diagnoses, from commonplace conditions like pericarditis and hyperkalemia to rarer phenomena like ventricular parasystole and TCA overdose. Each diagnosis is paired with an EKG and a clinical history to help viewers identify key patterns, understand their significance, and recognize how these findings relate to patient care. Through a mix of visual analysis and clinical insight, the video offers valuable knowledge for healthcare professionals seeking to improve their EKG interpretation skills.

Takeaways

• 😀 Pericarditis is characterized by widespread ST elevations and PR depression in almost every lead, and its EKG progression includes four stages: initial widespread ST elevations, followed by normalization, T-wave inversions, and final normalization.
• 😀 Hyperkalemia presents with peaked T-waves, which may appear narrow-based, especially in mild to moderate cases. As severity increases, the EKG can show widened QRS complexes, AV blocks, and bundle branch blocks.
• 😀 Electrical alternans and low voltage QRS complexes are key indicators of a large pericardial effusion. The EKG may also show sinus tachycardia and the heart 'rocking' within the effusion.
• 😀 Hypothermia manifests on the EKG with a distinctive Osborne wave (or J wave), along with PR, QRS, and QT prolongation, as well as various bradyarrhythmias.
• 😀 Lead transposition can mimic right axis deviation on an EKG, where wires are switched between the limbs (e.g., right and left arms), leading to an incorrect EKG interpretation.
• 😀 Dextrocardia results in a mirror-image EKG. Precordial leads show reversed R-wave progression, and limb leads appear to be switched. The heart is located on the opposite side of the thorax.
• 😀 Subarachnoid hemorrhage can cause giant symmetric precordial T-wave inversions, which can also be seen in conditions like acute MI, hypertrophic cardiomyopathy, and stress cardiomyopathy.
• 😀 Ventriculophasic sinus arrhythmia occurs when the PP interval (duration between successive P waves) changes between two values and is associated with complete heart block, though it is usually a physiological curiosity.
• 😀 Tricyclic antidepressant (TCA) overdose can result in QRS and QT prolongation, with a prominent R-wave in AVR and S-wave in lead I, a unique EKG finding related to the medication's effects on sodium channels.
• 😀 Ventricular parasystole occurs when a ventricular focus fires at a fixed rate while surrounded by unidirectional block, leading to PVCs that do not reset with normal ventricular depolarization, resulting in a constant PVC-to-PVC interval.

Q & A

What are the four stages of EKG findings in pericarditis?

The four stages of EKG findings in pericarditis are: 1) Widespread ST elevations and PR depression (Stage 1), seen within the first week. 2) Normalization of findings (Stage 2). 3) Widespread T-wave inversions (Stage 3), which may or may not occur. 4) Normalization once again (Stage 4). Additionally, Spodic sign (downsloping TP segments) can also be observed in some cases.

What are the key EKG features of hyperkalemia?

Key EKG features of hyperkalemia include peaked T-waves, which are narrow-based in mild cases. As the condition worsens, the QRS complex widens, and patients can develop sinus bradycardia, AV block, and bundle branch blocks. Severe hyperkalemia may lead to a 'sine wave' rhythm, where the distinction between QRS complexes and T-waves is lost.

What is electrical alternans, and what does it signify in an EKG?

Electrical alternans refers to the alternating amplitude of QRS complexes in an EKG, seen most notably in large pericardial effusion. It occurs because the heart 'rocks' back and forth within the fluid-filled pericardial sac. While it suggests the presence of an effusion, it does not necessarily indicate tamponade.

What does an Osborne wave on an EKG suggest?

An Osborne wave, also known as a J-wave, is a characteristic finding in hypothermia. It typically appears as a positive deflection at the junction of the QRS complex and the ST segment. Other EKG signs of hypothermia include PR, QRS, and QT prolongation, along with bradyarrhythmias like atrial fibrillation with a slow ventricular response.

How can dextrocardia be identified on an EKG?

Dextrocardia is a condition where the heart is located on the opposite side of the thorax. On an EKG, this results in reversed limb lead morphology, and the precordial leads show reversed R-wave progression. The heart's electrical vector is directed to the right, causing the changes observed in the EKG.

What does the combination of giant symmetric precordial T-wave inversions and sudden onset headache suggest?

Giant symmetric precordial T-wave inversions in the setting of a sudden onset headache suggest subarachnoid hemorrhage, though this finding can also be seen in conditions like acute MI, Wellen syndrome, hypertrophic cardiomyopathy, and stress cardiomyopathy.

What is ventriculophasic sinus arrhythmia, and how is it identified on an EKG?

Ventriculophasic sinus arrhythmia is characterized by alternating PP intervals that are influenced by the ventricular depolarization cycle. The shorter PP intervals correspond with QRS complexes, while the longer intervals do not, indicating that the sinus node's activity is modulated by the ventricular depolarization.

What are the EKG features of tricyclic antidepressant (TCA) overdose?

In TCA overdose, the EKG may show sinus tachycardia, QRS prolongation, and QT prolongation. A distinctive feature is the rightward deviation of the terminal 40 milliseconds of the QRS complex, often characterized by a prominent R-wave in AVR and an S-wave in lead I.

What does the presence of a sine wave rhythm on an EKG indicate?

A sine wave rhythm on an EKG, often seen in severe hyperkalemia, indicates a loss of distinction between QRS complexes and T-waves. This can occur when the QRS complex becomes wide and bizarre, and the T-waves are merged into the same deflection, creating a sine-like appearance.

What is the significance of lead reversal on an EKG?

Lead reversal occurs when the electrodes are incorrectly placed, typically on the left and right arms. This can create an EKG that mimics right axis deviation or other abnormalities. To confirm, the leads should be checked and the recording repeated to ensure proper electrode placement.