75-year-old lady with history of hypothyroidism

Written by Judy Haluka

A 75-year-old lady with a history of hypothyroidism (HT) presents with a period of a brief loss of consciousness after getting up from a chair to answer the phone. She became dizzy and passed out for a few minutes. She denies palpitations, chest pain, or shortness of breath. Her blood pressure (BP) is 138/68 and fell to 118/68 upon standing. The 12-lead electrocardiogram (ECG) is as follows:

Question 1: The ECG shows

• A. Atrial fibrillation
• B. Normal sinus rhythm
• C. Left bundle branch block (LBBB) with first-degree heart block
• D. Ventricular tachycardia

Initial telemetry in the hospital was unremarkable. An event recorder was requested. The transmission is as follows:

Question (2) The above recording shows:

• A. Atrial fibrillation and flutter
• B. Ventricular standstill and torsades de pointes
• C. Supraventricular tachycardia (SVT) and right bundle branch block (RBBB)
• D. Junctional rhythm and aberrant conduction

The patient went into cardiac arrest, and after 6 minutes of cardiopulmonary resuscitation (CPR) and defibrillation, a return of spontaneous circulation was achieved. Blood electrolytes were normal. Below is a post-resuscitation ECG.

Answers and discussion

Question 1 Answer: Left bundle branch block (LBBB) with first-degree heart block

Question 2 Answer: Ventricular standstill and torsades de pointes

Ventricular standstill is an arrhythmia that is potentially fatal and often associated with syncope. Torsades de Pointes is polymorphic ventricular tachycardia that may terminate spontaneously or worsen into ventricular fibrillation.