Q: I recently had an electrocardiogram as part of a routine physical exam. The report said I had a bundle branch block. What does that mean? Will I need a pacemaker? A: Bundle branch blocks are ...

Atrial fibrillation with an uncontrolled ventricular response Intermittent right bundle branch block - rate dependent This ECG shows atrial fibrillation with an uncontrolled ventricular rate. There ...

Yogesh N. Reddy, MBBS: Hi. This is Yogesh Reddy, cardiology fellow at Mayo Clinic. Today we will be discussing the very common clinical scenario of a left bundle branch block (LBBB) on ...

QRS duration of > 120 milliseconds rsR' "bunny ear" pattern in precordial leads Slurred S waves in leads I, V5, and V6. Remember that T wave inversions and ST segment depression is normal in leads V1 ...

DEAR DR. DONOHUE You were asked about a right bundle branch block and you said "Electric current still makes its way to the right ventricle. This doesn't mean you are on the verge of dying." A few ...

DEAR DOCTOR K: I recently had an ECG that showed that I have a "left bundle branch block." What does this mean? DEAR READER: When your heart beats, it does so in response to electrical signals. Your ...

Dear Dr. Roach: I am a 63-year-old male who, during a routine EKG, showed a left bundle branch block. Can you tell me anything about this diagnosis, what it means, any treatment, future concerns, etc.

Dr. Keith Roach writes a medical question-and-answer column weekdays. Dear Dr. Roach: My 35-year-old son recently complained of some chest pain. He went to his doctor, and it was determined that he ...