John M. Miller MD FACC


Normal Sinus Rhythm

The normal sinus rhythm is the rate of impulses generated by certain muscle cells as a signal to the upper heart chambers (atria) to contract. The heart contains a cluster of specialized muscle cells that act as the heart’s natural pacemaker. This cluster is called the sinoatrial node, or SA node. The SA node generates…

Paroxysmal Atrial Fibrillation

Paroxysmal atrial fibrillation is a type of atrial fibrillation, an irregular heart rhythm. Paroxysmal means that the atrial fibrillation episodes last 7 days or less. The episodes may go away on their own or they go away after treatment. Typically, over time, episodes of paroxysmal atrial fibrillation come on more…

Desfibrilador cardioversor implantable

Un médico coloca un desfibrilador cardioversor implantable (también llamado ICD, por sus siglas en inglés) en el pecho. El ICD tiene uno o dos cables llamados derivaciones. Estas derivaciones llegan al corazón a través de la vena subclavia (transvenosa). Algunos ICD tienen una derivación que se coloca debajo de la piel…

Heart Rate Problems: Should I Get a Pacemaker?

Topic guides reader through decision to get a pacemaker for heart rate problems. Provides general overview of what pacemakers are and what heart problems can be helped with pacemakers. Lists benefits and possible complications of getting a pacemaker.