Category Archives: atrial fibrillation

Battery-less pacemaker tests out

X-ray image of installed pacemaker showing wir...
X-ray image of installed traditional pacemaker showing wire routing (Photo credit: Wikipedia)

A new pacemaker, designed without battery or wires, is implanted directly into the heart and gets its energy wirelessly from radio frequency radiation transmitted by an external battery pack. It can also control electrical signals to all four chambers of the heart. The prototype, developed by researchers from Rice University and others, was presented at the recent Texas Heart Institute (THI) at the IEEE’s International Microwave Symposium (IMS) in Honolulu. The wireless transmitter can be up to a few centimeters away.

Traditional pacemakers use electrical signals to keep the heart beating steadily, but they are planted in the upper side chest so that doctors can access them easily to replace the onboard batteries with minor surgery. The signals transmit to the heart via wires called leads, which are known sometimes to lead to bleeding or infection.

This new pacemaker can even act as a defibrillator when needed. Worked flawlessly on a pig.

It’s sure got a lot going for it. Only thing we worry about is: Even if the external transmitter is very small, how’s the patient going to keep it always within the required distance without wearing some kind of external pack – something that could be way too easy to damage or lose?

Further work underway. Read more here on the wireless, battery-less pacemaker.

Sex hormones may predict sudden cardiac arrest (not heart attack)

A "street defibrillator". Having a c...
A “street defibrillator”. Having a cardiac arrest in the “heart of Monaco” could be less problematic. (Photo credit: Wikipedia)

There appears to be a relationship between levels of sex hormones in the blood, for both men and women, may be related to occurrence of the nearly-always-fatal sudden cardiac arrest – which is different from myocardial infarction (“heart attack”) in people who have blockages in their arteries. Sudden cardiac arrest has to do with faulty electrical signals in the heart. Think about it. Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times. The heart is a muscle that has to have stimulation to do its work, and that’s where the electrical signals come in. In atrial fibrillation the signals come irregularly and often too fast. But meds can do a good job of controlling this condition and thus lowering the risk of stroke. In sudden cardiac arrest they go out of whack so suddenly and severely that immediate death nearly always occurs. A recent study measured levels of male sex hormone testosterone in men and female sex hormone extradiol in both women and men who died of sudden cardiac arrest versus those who didn’t. The levels were strikingly higher in the deceased. This study promises potential for earlier detection – a much-desired goal that will allow docs to begin devising ways to treat this random-seeming fatal condition.