Question

Widen QRS and tall-tented T waves are observed in

• A. \( \text{Hyponatremia} \)
• B. \( \text{Hyperkalemia} \)
• C. \( \text{Hyperglycemia} \)
• D. \( \text{Hyperphosphatemia} \)

Hint:

Recognizing ECG changes associated with electrolyte imbalances is critical in emergency medicine. Hyperkalemia is particularly dangerous due to its potential to cause life-threatening arrhythmias. The "tall-tented T waves" are often the earliest and most specific ECG sign, followed by progressive QRS widening as potassium levels rise. This progression highlights the need for prompt recognition and treatment.

Answer 1

The Correct Option is B

To solve this question about ECG findings, let's analyze the characteristic changes mentioned and match them with the correct electrolyte imbalance.

1. Understanding the ECG Abnormalities

The question describes two key ECG changes:

• Widened QRS complex: Indicates slowed ventricular depolarization
• Tall, tented T waves: Characteristic of certain electrolyte disturbances

2. Analysis of Each Option

a) Hyponatremia:

• Low sodium levels
• ECG changes are non-specific or minimal
• Does not typically cause these findings

b) Hyperkalemia:

• High potassium levels
• Classically causes:
  • Tall, peaked (tented) T waves (earliest sign)
  • QRS widening (in more severe cases)
  • PR prolongation
• Matches both described abnormalities

c) Hyperglycemia:

• High blood sugar
• May cause electrolyte shifts but not these specific ECG changes
• Associated with other complications (e.g., arrhythmias from DKA)

d) Hyperphosphatemia:

• High phosphate levels
• Primarily affects calcium metabolism
• No characteristic ECG pattern

3. Pathophysiology of Hyperkalemia Effects

The ECG changes occur because:

• Elevated extracellular K⁺ affects cardiac membrane potentials
• Initial hyperpolarization causes tall T waves
• Severe hyperkalemia slows conduction, widening QRS
• Can progress to sine wave pattern and cardiac arrest

4. Clinical Correlation

These findings are particularly important in:

• Renal failure patients
• Rhabdomyolysis
• Medication errors (e.g., K⁺ overdose)
• Adrenal insufficiency

5. Why Other Options Are Incorrect

- Hyponatremia: Causes neurological symptoms, not these ECG changes
- Hyperglycemia: Affects metabolism but not depolarization patterns
- Hyperphosphatemia: Indirect effects but no characteristic ECG signature

6. Emergency Implications

Recognizing these signs is crucial because:

• Indicates potentially life-threatening hyperkalemia
• Requires immediate treatment (calcium, insulin/glucose, etc.)
• Progression can lead to fatal arrhythmias

7. Final Answer

Widened QRS and tall-tented T waves are characteristic ECG findings observed in Hyperkalemia.