A 58-year-old woman with fatigue, weight gain, and cold intolerance presents with an ECG showing sinus bradycardia (HR 48 bpm), low-voltage QRS complexes (<5 mm in limb leads), and diffusely flattened T waves. Serum TSH is 45 mIU/L and free T4 is 0.3 ng/dL. The ECG pattern marked **B** in the diagram is characteristic of overt hypothyroidism. Which of the following BEST explains the mechanism underlying the low-voltage QRS complexes seen in this patient?
Ready to test yourself?
Test your Medicine knowledge with AI-powered MCQs and detailed explanations — no signup required to try.
Sign up free and practice all 1 Hypothyroidism ECG MCQs with AI-powered explanations tailored to your performance.
Create Free Account