General responses to selected questions from Joel Braunstein, MD, of Johns Hopkins University and Joseph Toscano, MD.
Question:
Dear Doctor, I have been diagnosed with a condition called "Paroxysmal Atrial Fibrillation". My questions are as follows: is stress in the workplace causing the attacks (I have had 2 attacks approx 1 year apart when under a lot of pressure). How is the best way to prevent such attacks ? What actually happens to my heart, when an attack happens?
Answer:
Typically, our hearts contract in a coordinated, synchronous fashion. For coordinated contractions to occur, the electric circuitry inside the heart must function properly. This means that electrical stimuli should begin in the sinus node, travel through the atria, the atrioventricular node, and then through the ventricles. We call this natural electrical activity in the heart "normal sinus rhythm".
Given the complexity of the heart's electrical system, it is not surprising that many times, this system can go awry. Sometimes the effects of such a rhythm disturbance are life-threatening as in the case of sudden cardiac death. Other times, the disturbance is non-life threatening, but still a common cause of discomfort and hospitalizations.
Atrial fibrillation is the most commonly diagnosed abnormal heart rhythm. During atrial fibrillation, cells within the atria become a source of abnormal electrical activity and generate abnormal electrical signals, causing the atria to contract uncontrollably fast (sometimes upwards of 300+ beats per minute) and out of synchrony with the rest of the heart; this interferes with the heart's overall pumping abilities. Also, because the atria lose the ability to contract in a coordinated fashion, blood may pool within the atria and predispose to clot formation.
In and of itself, atrial fibrillation is not usually life-threatening, though, left untreated, it is an important cause of heart failure, strokes, and heart attacks. Atrial fibrillation is clearly associated with older age (an estimated 5% of individuals over the age of 65 years have atrial fibrillation) and cardiovascular conditions such as heart failure, hypertension, past heart attack, and valvular disease. Other causes such as overactive thyroid function, alcohol abuse ("holiday heart syndrome"), stress, and excessive caffeine consumption can occasionally preempt the occurrence of atrial fibrillation. "Lone atrial fibrillation" may also occur in otherwise totally healthy, young individuals, without any identifiable causes.
