Reader: Three years ago I began having chest pains during my brisk walks. My family physician advised that my symptoms were typical of angina and referred me to a coronary specialist.

Reader: Twice I have worn a heart monitor for three to four days. Both tests showed a rapid heartbeat and low to regular blood pressure. Two physicians have advised me to take metoprolol 25 mg twice daily.

I am a woman in my early 60s. Since age 12 or so, I could feel my heart pounding and racing. During treatment at a hospital, I set off the heart monitor. I am sending my latest thyroid test results and the Holter monitor test results.

Reader: It has been written that the heart's beat is caused by "electricity" and that energy is made up of electrons. Where does this electrical impulse come from? Where is it generated? Are we receptors? Do we "store" energy like a battery?

Reader: My husband's lead (on the left ventricular side) of his nearly three-month-old pacemaker came out of his heart. It made him vibrate as it was hitting his diaphragm. How could the lead come out after three months?

Reader: I am 52 years old and have episodes of paroxysmal atrial fibrillation. I am taking amiodarone, initially 1,600 mg daily and now 200 mg, along with diltiazem and aspirin. Is amiodarone a safe drug to use long term?

Reader: I am a woman in my upper 60s and for years have had a faster-than-usual pulse, sometimes when I am at rest. Also, I have irregular beats that make me uncomfortable. I have seen a heart specialist who took an EKG but said it was nothing to worry about and that it was a "woman thing." Should I ignore the irregularities or seek another opinion?

Reader: I am 91 years old and take atenolol 50 mg twice dally. My blood pressure is 135/53. The new suggested normal blood pressure is 120/80 or less. Is my top number (systolic) too high and the bottom (diastolic) number too low?